National Park Service

U.S. Department of the Interior

Natural Resource Program Center

Vegetation Classifi cation, Distribution, 

and Mapping Report

Tumacácori National Historical Park

Natural Resource Report NPS/SODN/NRR—2009/148
ON THE COVER

Church and Santa Rita Mountains, Tumacácori National Historical Park. NPS photo by Jeff Axel.
Vegetation Classifi cation, Distribution, 

and Mapping Report

Tumacácori National Historical Park

Natural Resource Report NPS/SODN/NRR—2009/148

Authors

Sam Drake

Steve Buckley

Miguel Villarreal

Offi ce of Arid Lands Studies

University of Arizona

Tucson, Arizona

Sarah Studd

J. Andrew Hubbard

National Park Service

Sonoran Desert Network

Tucson, Arizona

Editing and Design

Alice Wondrak Biel

National Park Service

Sonoran Desert Network

Tucson, Arizona

September 2009

U.S. Department of the Interior

National Park Service

Natural Resource Program Center

Fort Collins, Colorado
ii Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

The National Park Service, Natural Resource Program Center publishes a range of reports 

that address natural resource topics of interest and applicability to a broad audience in the 

National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. 

The Natural Resource Report Series is used to disseminate high-priority, current natural 

resource management information with managerial application. The series targets a general, 

diverse audience, and may contain NPS policy considerations or address sensitive issues of 

management applicability. 

All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifi cally credible, technically accurate, appropriately written for the intended 

audience, and designed and published in a professional manner. This report received formal 

peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data, and whose background and expertise put them on par technically 

and scientifi cally with the authors of the information.

Views, statements, fi ndings, conclusions, recommendations, and data in this report are those 

of the author(s) and do not necessarily refl ect views and policies of the National Park Service, 

U.S. Department of the Interior. Mention of trade names or commercial products does not 

constitute endorsement or recommendation for use by the National Park Service.

This report is available from the web sites of the Sonoran Desert Network 

(http://www.nature.nps.gov/im/units/sodn), NPS Natural Resource Program Center 

(http://www.nature.nps.gov/publications/NRPM), and USGS-NPS Vegetation Characterization Program (http://biology.usgs.gov/npsveg).

Please cite this publication as:

Drake, S., S. Buckley, M. Villarreal, S. Studd, and J. A. Hubbard. 2009. Vegetation classifi cation, 

distribution, and mapping report: Tumacácori National Historical Park. Natural Resource 

Report NPS/SODN/NRR—2009/148. National Park Service, Fort Collins, Colorado.

NPS 311/100300, September 2009
Contents iii

Contents

Figures ..................................................................................................................................... v

Tables ..................................................................................................................................... vii

Acronyms and Abbreviations ................................................................................................ ix

Executive Summary ................................................................................................................ xi

Acknowledgements ............................................................................................................. xiii

Chapter 1: Introduction ............................................................................................ 1

1.1 Background ...............................................................................................................1

1.2 Scope and Products ...................................................................................................1

1.3 The USGS-NPS Vegetation Characterization Program ............................................1

1.4 The National Vegetation Classifi cation Standard ...................................................3

1.5 The National Vegetation Classifi cation ...................................................................4

1.6 Terminology and Naming Conventions ...................................................................4

1.7 Park Environment ......................................................................................................5

Chapter 2: Classifi cation and Mapping of Plant Communities .............................. 9

2.1 Methods .....................................................................................................................9

2.2 Results ......................................................................................................................11

Chapter 3: Accuracy Assessment ............................................................................ 35

3.1 Methods ...................................................................................................................35

3.2 Results ......................................................................................................................35

3.3 Resolution of Discrepancies ....................................................................................36

3.4 Spatial Accuracy Assessment ..................................................................................36

Chapter 4: Discussion .............................................................................................. 41

4.1 Strata and Growth Form .........................................................................................41

4.2 Notable Vegetation Patterns ..................................................................................41

4.3 Implications for Management ................................................................................42

Chapter 5: Literature Cited ..................................................................................... 45

Appendices

Appendix A: Vegetation Formation Key ......................................................................47

Appendix B: Polygon Data Sheets .................................................................................49

Appendix C: Plot Data Sheets ........................................................................................53

Appendix D: Vegetation Type Descriptions ..................................................................57

Appendix E: Species List ...............................................................................................105

Appendix F: Accuracy Assessment Data Sheet ...........................................................115

Appendix G: Root Mean Square Error ........................................................................117

Contents v

Figures

Figure 1.2-1. Location of Tumacácori National Historical Park (including the Calabazas and 

Guevavi units), along the Santa Cruz River in southern Arizona. ....................................... 2

Figure 1.2-2. Tumacácori National Historical Park vegetation mapping project area. ...................... 3

Figure 2.2-1. Vegetation map of the Mission unit of Tumacácori National Historical Park. ........... 14

Figure 2.2-2. Vegetation map of the Calabazas and Guevavi units of Tumacácori National 

Historical Park. ...................................................................................................................... 15

Figure 2.2-3. Populus fremontii - Salix gooddingii Forest. ................................................................ 16

Figure 2.2-4. Prosopis velutina Forest Alliance. .................................................................................. 17

Figure 2.2-5. Celtis laevigata var. reticulata Forest Alliance. ............................................................. 18

Figure 2.2-6. Populus fremontii - Salix gooddingii Woodland. ......................................................... 19

Figure 2.2-7. Prosopis velutina Woodland Alliance. .......................................................................... 20

Figure 2.2-8. Acacia greggii Woodland Alliance. ............................................................................... 21

Figure 2.2-9. Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded Shrubland 

Alliance. ................................................................................................................................. 22

Figure 2.2-10. Prosopis velutina - Acacia greggii Shrubland. ............................................................ 23

Figure 2.2-11. Acacia constricta Shrubland Alliance. ......................................................................... 24

Figure 2.2-12. Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance. ...................... 25

Figure 2.2-13. Populus fremontii / Mixed Annual Wooded Herbaceous Alliance. ........................... 26

Figure 2.2-14. Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance. ............................ 27

Figure 2.2-15. Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance. ...................... 28

Figure 2.2-16. Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] Shrub 

Herbaceous Alliance. ............................................................................................................ 29

Figure 2.2-17. [Amaranthus palmeri - Salsola kali - Chenopodium spp.] Herbaceous Alliance. ..... 30

Figure 2.2-18. Inland Freshwater Strand Beach Sparse Vegetation. ................................................. 31

Figure 2.2-19. Developed Woodland. ................................................................................................. 32

Figure 2.2-20. Cropland and Pasture. .................................................................................................. 33

Contents vii

Tables

Table 1.4. Summary of the National Vegetation Classifi cation Standard hierarchical approach. .... 4

Table 2.2. Summary of vegetation classifi cation and mapping results. ........................................... 13

Table 3.2-1. Accuracy assessment error matrix. .................................................................................. 37

Table 3.2-2. Cases of ambiguity in accuracy-assessment fi eld data. ................................................. 38

Table 3.2-3. Cases of true error or discrepancy between map data and accuracy-assessment 

fi eld data. .............................................................................................................................. 38

Table 3.3. Resolution of discrepancies. ............................................................................................... 39

Table 3.4. Spatial accuracy assessment summary for each of the three units at TUMA. ................ 40

Table E-1. Plant species observed at Tumacácori National Historical Park, organized by family. . 105

Table E-2. Plant species observed at Tumacácori National Historical Park, by scientifi c name. .... 110

Table G-1. RMSE, Mission Unit ........................................................................................................... 117

Table G-3. RMSE, Guevavi Unit .......................................................................................................... 117

Table G-2. RMSE, Calabazas Unit ....................................................................................................... 117

Contents ix

Acronyms and Abbreviations

AA accuracy assessment

ac acres

CEGL Community Element Code–Global

CIR color infrared

cm centimeter

DOQQ digital orthophoto quarter quadrangle

DVD digital compact disk

ERDAS Earth Resources Data Analysis System

ESRI Environmental Systems Research Institute

FGDC Federal Geographic Data Committee

ft foot/Feet

GB gigabytes

GCP ground control point

GIS geographic information system

GPS global positioning system

ha hectares

I&M Inventory and Monitoring Program

ITIS Integrated Taxonomic Information System

km kilometers

m meters

mi miles

.mdb Microsoft Access fi le format

MMU minimum mapping unit

MS Microsoft

NA not applicable

NAD83 North American Datum of 1983

NBII National Biological Information Infrastructure

NED National Elevation Dataset

NHP National Historical Park

NMAS National Map Accuracy Standards

NP national park

NPS National Park Service

NVCS National Vegetation Classifi cation Standard (or System)

NVC National Vegetation Classifi cation

OALS Offi ce of Arid Lands Studies (University of Arizona)

RMSE root mean square error

RRQRR Reversed Randomized Quadrant Recursive Raster

SODN Sonoran Desert Network (National Park Service)

spp species (plural)

.tif tagged image fi le format

TNC The Nature Conservancy

TUMA Tumacácori National Historical Park

UNESCO United Nations Education, Science, and Cultural Organization

USDA U.S. Department of Agriculture

USGS U.S. Geological Survey

UTM Universal Transverse Mercator

.xls Microsoft Excel fi le format

Map class abbreviations

ACACON Acacia constricta

ACAGRE Acacia greggii

AMAPAL Amaranthus palmeri

CELLAE Celtis laevigata var. reticulata

HYMMON Hymenoclea monogyra

POPFRE Populus fremontii

PROVEL Prosopis velutina

PROVEL-ACAGRE Prosopis velutina - Acacia greggii

TAMRAM Tamarix ramosissima

Contents xi

Executive Summary

In 2007–2008, the National Park Service, Sonoran Desert Network Inventory and Monitoring Program, 

in cooperation with the Arizona Remote Sensing Center (University of Arizona, Offi ce of Arid Lands 

Studies), carried out classifi cation and mapping of vegetation at Tumacácori National Historical Park 

(NHP), as part of the national U.S. Geological Survey–National Park Service Vegetation Characterization Program. The primary objective of the program is to produce high-quality, standardized maps and 

associated data sets of vegetation and other land cover occurring within the parks (http://science.nature.nps.gov/im/inventory/veg/index.cfm). In particular, the aim of this project was to create a vegetation map at the National Vegetation Classifi cation alliance level or fi ner, with a minimum mapping unit 

of 0.5 hectares, thematic accuracy of 80% or better per map class, and spatial accuracy meeting U.S. 

National Map Accuracy Standards.

Project scoping, initiated in October 2007, involved the project team and Tumacácori NHP staff . Quickbird satellite imagery, acquired in August 2006, was used for this project, which covered the three subunits of the park plus a 100-m buff er around each one, for a total area of 238 hectares. Image preprocessing and initial interpretation to the vegetation formation level were done at the Arizona Remote Sensing 

Center. The draft formation-level map was produced through limited fi eld reconnaissance and visual 

interpretation of the pan-sharpened imagery and heads-up digitizing in ArcGIS to delineate polygons 

based on vegetation physiognomy.

Vegetation classifi cation and mapping to the alliance level were done simultaneously, through intensive 

fi eld work from November 2007 to April 2008. The fi eld team, including the image interpreters, took the 

formation map as a starting point and verifi ed or modifi ed formation boundaries; split formation polygons into alliance- or fi ner-level, fl oristically based polygons; and characterized each alliance type with 

quantitative (plot- and polygon-based) data on species composition, relative cover, and other factors. 

Because Tumacácori is a small park, a census of the entire park was done in this way. Nineteen vegetation types were identifi ed and mapped.

Thematic accuracy was assessed by the park’s resources manager/archeologist after a thorough briefing on the methods used for classifi cation and mapping, as well as on the map classes. The assessor was 

provided with tools similar to those used by the mappers, including a GPS-linked handheld computer 

loaded with draft map polygon boundaries, and printed map sections with each polygon labeled with 

a simple identifi cation number. The assessor completed a census of every mapped polygon, walking 

through each one to evaluate the lifeform and canopy cover of the dominant species, and choosing the 

best-fi tting map class name for the polygon. Initial accuracy was 90.2%, with four classes below 80%. 

Because of the small area of the park and the small number of polygons, each discrepancy between the 

accuracy assessment data and the map data was investigated and resolved, resulting in 100% thematic 

accuracy. Spatial accuracy was assessed against 2006 digital orthophoto quarter quadrangle imagery, 

using 20 test points for each of the park’s three units. The maximum absolute error measured was less 

than 2 m ground distance, and maximum root mean square error was 1.03 m, well within the limits of 

the National Map Accuracy Standards.

While the main products of this project are the vegetation classifi cation and the vegetation map database, a number of ancillary digital geographic information system and database products were also 

produced that can be used independently or to augment the main products.

Contents xiii

Acknowledgements

This project was a cooperative eff ort between the USGS-NPS Vegetation Characterization Program national offi ce, with support from Karl Brown, Tammy Hamer, and Chris Lea; the National Park Service, 

Sonoran Desert Network; and the University of Arizona, Offi ce of Arid Lands Studies.

Field work was carried out primarily by Steve Buckley and Jon Green. We would like to thank the staff of 

Tumacácori National Historical Park for their support and assistance during this project—particularly 

Jeremy Moss, who was responsible for the accuracy assessment performed on the maps. Data management support and database development were provided by the Sonoran Desert Network data management staff .

The project also benefi ted from the critical review of the report and digital products by: Kathryn Thomas, of the U.S. Geological Survey, and Tomye Folts, of the Southern Plains Network. The project team is 

extremely grateful for the help, advice, and assistance provided by all of these people and their respective institutions.

Chapter 1: Introduction 1

1.1 Background

Vegetation is a primary resource of natural areas, 

and description of vegetation composition, structure, and distribution is fundamental to eff ective 

land management. The term “vegetation” encompasses plants at multiple scales, from the most 

refi ned fl oristic levels (referred to as “plant communities” in this report) to the broadest physiognomic or lifeform levels. This report describes 

the methods and results of a two-year project 

(2007–2008) to classify, describe, and develop a 

vegetation map database for Tumacácori National Historical Park (NHP), located in Santa Cruz 

County, south of Tucson, Arizona.

The National Park Service’s (NPS) Sonoran Desert Network (SODN), part of the servicewide 

Inventory and Monitoring (I&M) Program, organized and coordinated vegetation classifi cation, description, and mapping at Tumacácori 

National Historical Park (TUMA). For TUMA, 

as well as the other network parks, the SODN 

needed baseline vegetation data upon which to 

develop and implement specifi c monitoring programs, and park managers needed baseline data 

and information on park resources for management purposes.

The current eff ort to create a new vegetation map 

for Tumacácori NHP is part of the USGS-NPS 

Vegetation Characterization Program (http://biology.usgs.gov/npsveg/), in cooperation with the 

SODN and the University of Arizona’s Offi ce of 

Arid Lands Studies. The map should meet the 

standards of the USGS-NPS Vegetation Characterization Program, including a minimum mapping unit of 0.5 hectares, 80% thematic accuracy 

per class, and spatial accuracy meeting the U.S. 

National Map Accuracy Standards.

1.2 Scope and Products

The aim of this project was to create a vegetation 

map at the National Vegetation Classifi cation 

(NVC) alliance level or fi ner for a study area of 

238 hectares (588 acres), made up of the three 

disjunct units of Tumacácori NHP: Mission (195 

ha), Calabazas (24 ha) and Guevavi (19 ha), plus a 

100-meter buff er surrounding each unit (Figures 

1.2-1 and 1.2-2). Lands within park boundaries 

comprised 147 ha (363 ac) or 61.5% of the project area.

Products developed for Tumacácori NHP as part 

of this project included:

• A fi nal report, including a vegetation key 

and full vegetation community-type descriptions;

• Digital photos of each vegetation type (four 

per polygon mapped);

• A spatial database containing vegetation 

data, plot data and location, accuracy assessment routes, and satellite imagery; 

• Hard-copy and digital graphics of fi nal map 

coverages; and

• Federal Geographic Data Committee-compliant metadata for all spatial database fi les 

and fi eld data.

1.3 The USGS-NPS Vegetation 

Characterization Program

The USGS-NPS Vegetation Characterization 

Program is a cooperative project between the U.S. 

Geological Survey (USGS) and the NPS to classify, describe, and map vegetation in more than 

270 national park units within the United States.* 

The USGS Center for Biological Informatics administers the program, in cooperation with the 

NPS I&M Program.

The Vegetation Characterization Program supports consistent vegetation classifi cation, mapping, and accuracy-assessment protocols and 

standards across all park-mapping projects. The 

program has established guidance for all vegetation-mapping projects in four documents:

Chapter 1

Introduction

*Language for the sections on the USGS-NPS Vegetation Characterization Program, National Vegetation Classifi cation 

Standard, and Federal Geographic Data Committee is from Thomas et al. (2007), modifi ed from Van Loh et al. (2006).
2 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

• Standardized National Vegetation System 

(TNC and ESRI 1994a)

• Methodology for Assessing the Utility of 

Existing Data for Vegetation Mapping (TNC 

and ESRI 1996)

• Field Methods for Vegetation Mapping 

(TNC and ESRI 1994b)

• Accuracy Assessment Procedures (ESRI et 

al. 1994)

In addition, the program has defi ned national 

standards for all park vegetation classifi cation and 

mapping projects:

• Vegetation classifi cation follows the Federal Geographic Data Committee (FGDC) 

standard for vegetation classifi cation, the 

National Vegetation Classifi cation Standard. 

• Spatial data formatting follows the FGDC 

standards for spatial data transfer.

• Metadata for each spatial dataset uses the 

FGDC metadata standard.

• Spatial data is provided with a horizontal 

positional accuracy that meets National Map 

Accuracy Standards at the 1:24,000 scale; 

each well-defi ned object within the spatial 

database is within 1/50 of an inch display 

scale or 12.2 m (40 ft) of its actual location.

• All plant names used in the classifi cation are 

consistent with the Integrated Taxonomic 

Information System (ITIS).

• Each vegetated map class will meet or exceed 80% accuracy at the 90% confi dence 

level. 

• The minimum mapping unit (MMU) is 0.5 

ha (1.24 ac).

Figure 1.2-1. Location of Tumacácori National Historical Park (including the Calabazas 

and Guevavi units), along the Santa Cruz River in southern Arizona.
Chapter 1: Introduction 3

1.4 The National Vegetation 

Classifi cation Standard

Patterns of vegetation vary continuously over 

landscapes. Classifi cation systems attempt to categorize those patterns by identifying and describing assemblages of plants that repeat in similar 

habitats. The National Vegetation Classifi cation 

Standard (NVCS) provides a classifi cation framework that is the standard for all NPS vegetation 

mapping projects (Comer et al. 2003, TNC and 

ESRI 1994a). In 1997, the FGDC formally adopted the NVCS version 1 (FGDC 1997). During 

the course of this project, version 2 of the NVCS 

(FGDC 2008), also known as the National Vegetation Standard, was approved, but not yet implemented. 

The NVCS is a hierarchical system that allows 

vegetation classifi cation to occur at multiple 

scales. In version 1, used for this project, there 

are seven levels. The upper fi ve are based on the 

physiognomic characteristics of vegetation, and 

the lower two are based on the fl oristic characteristics of the plant community—relative abundance of dominant species. Table 1.4 identifi es 

the seven levels of the NVCS used in this report 

and depicts their placement in the hierarchical 

relationship (Maybury 1999).

The NVCS evolved from vegetation classifi cation primarily conducted over more than two 

decades by The Nature Conservancy (TNC), 

NatureServe, and the Natural Heritage Program 

network (Grossman et al. 1998). It derives in part 

from earlier vegetation classifi cation frameworks 

produced by the United Nations Educational, 

Cultural, and Scientifi c Organization (UNESCO 

1973, Driscoll et al. 1984). Use of this standardized classifi cation system helps ensure data compatibility throughout the National Park Service 

and other agencies.

0 0.25 0.5 1.0

Kilometers

Figure 1.2-2. Tumacácori 

National Historical Park 

vegetation mapping 

project area. Project 

area includes a 100-m 

buffer around each 

unit (area between red 

lines).

Mission unit. Calabazas unit.

Guevavi unit.
4 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

1.5 The National Vegetation 

Classifi cation

The NVCS provides a framework for levels of 

classifi cation but does not provide descriptions 

of all existing vegetation types at all levels. Those 

descriptions comprise the National Vegetation 

Classifi cation (NVC), which is being fi lled out by 

individual vegetation characterization projects, 

such as the present one, and other sources. The 

NVC, which is maintained by NatureServe and 

used by many federal agencies, including the NPS, 

includes the plant communities (associations and 

alliances) defi ned for the United States.

Work on the NVC, conducted primarily by TNC 

through 1999, provided initial defi nitions of some 

plant communities at each level. NatureServe 

inherited that documentation when it branched 

from TNC. NatureServe manages a database 

of NVC plant community entities. Their online 

database, NatureServe Explorer (http://www.

natureserve.org/explorer/), provides public access to regularly updated versions of the NVC 

plant community listings and descriptions. NatureServe’s documentation of alliances and associations is the most accessible listing currently 

available. However, the plant community listings 

within the NVC are not yet complete.

In addition to the NVC, NatureServe has created 

a standardized Ecological Systems Classifi cation 

for describing sites, based on both vegetation and 

the ecological processes that drive it. Ecological 

systems are mid-scale biological communities that 

occur in similar physical environments and are infl uenced by similar dynamic ecological processes, 

such as fi re or fl ooding. They are not conceptually 

a unit within the NVCS but are rather a vegetation 

mapping concept. However, NVC associations 

occur within ecological systems. An association 

may occur in any number of ecological systems, 

limited only by the range of ecological settings in 

which that association occurs. Ecological systems 

are broad-scale, and can embody any number of 

highly specifi c associations that might be found in 

a particular setting.

For more information on the NVC, see the USGSNPS Vegetation Characterization Program standards (http://biology.usgs.gov/npsveg/standards.

html) or Grossman et al. (1998). 

1.6 Terminology and Naming 

Conventions

Alliances and associations are based on both the 

dominant (greatest-canopy-cover) species in the 

upper strata of a stand and on diagnostic species (those consistently found in some land-cover 

types but not others). Associations are the most 

specifi c classifi cation, and are hierarchically subsumed in alliances. Typically, each association is 

included in only one alliance, while each alliance 

may include many associations. 

Alliance names are generally based on the dominant/diagnostic species in the uppermost stratum 

of the vegetation, though up to four species may 

be used, if necessary, to defi ne the type. Associations defi ne distinct plant compositions that 

repeat across the landscape, and are generally 

named using both the dominant species in the 

uppermost stratum of the vegetation and one or 

more dominant species in lower strata (or a diagnostic species in any stratum). 

Table 1.4. Summary of the National Vegetation Classifi cation Standard hierarchical approach.

Level Primary basis for classifi cation Example 

Class Structure of vegetation Forest

Subclass Leaf phenology Deciduous forest

Group Leaf types, corresponding to climate Cold-deciduous forest

Subgroup Relative human impact (natural/semi-natural, or 

cultural)

Natural/Semi-natural cold-deciduous forest

Formation Additional physiognomic and environmental factors, 

including hydrology

Temporarily fl ooded cold-deciduous forest

Alliance Dominant/diagnostic species of the uppermost or 

dominant stratum

Populus fremontii Temporarily Flooded Forest 

Alliance

Association Additional dominant/diagnostic species from any strata Populus fremontii - Salix gooddingii / Baccharis 

salicifolia Forest
Chapter 1: Introduction 5

Naming conventions and syntax for all NVC 

names are as follows:

• A hyphen with a space on either side ( - ) 

separates names of species occurring in the 

same stratum. 

• A slash with a space on either side ( / ) separates names of species occurring in diff erent 

strata. 

• Species that occur in the uppermost stratum 

are listed fi rst, followed successively by those 

in lower strata. 

• Order of species names generally refl ects 

decreasing levels of dominance, constancy, 

or indicator value. 

• Parentheses around a species name indicates 

the species is less consistently found either 

in all associations of an alliance, or in all occurrences of an association. 

• Association names include the dominant 

species of the signifi cant strata, followed by 

the class in which they are classifi ed (e.g., 

Forest, Woodland, or Herbaceous).

• Alliance names also include the class in 

which they are classifi ed (e.g., Forest, Woodland, or Herbaceous), but are followed by 

the word “Alliance” to distinguish them 

from associations.

The species nomenclature for all alliances and associations follows Kartesz (1999). Examples of 

association names from TUMA:

• Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest

• Inland Freshwater Strand Beach Sparse 

Vegetation

Examples of alliance names from TUMA: 

• Prosopis velutina / Mixed Annual Wooded 

Herbaceous Alliance

• Tamarix spp. Semi-natural Temporarily 

Flooded Shrubland Alliance

1.7 Park Environment

1.7.1 Park establishment

Tumacácori National Historical Park was originally designated Tumacácori National Monument on 

September 15, 1908, by proclamation of President 

Theodore Roosevelt. The original, four-hectare 

monument was designated to protect Misión San 

Jose de Tumacácori, a Jesuit-established and Franciscan-constructed mission that was relocated to 

the present site in 1751, although construction of 

the building now protected was not completed 

until the mid-1820s. San Jose de Tumacácori was 

one of a line of Franciscan, although originally Jesuit, missions built in far northern Sonora beginning in 1691, with the arrival of the Jesuit Padre 

Eusebio Kino. Kino fi rst visited the Pimería Alta, 

or the “place of the upper Pimas” as this area of 

southern Arizona was known at the time, and established a mission on the east side of the Santa 

Cruz River. A more favorable site was later selected on the west side of the river for permanent 

construction of the mission church and other facilities. The area was chosen because of its habitation, at the time, by O’odham people, also known 

as the Papago or Pima, along that stretch of the 

river. The word tumacácori is thought to be taken 

from two O’odham words, chu-uma and kakul, 

making reference to Saint Joseph of the fl at, rocky 

place (http://www.nps.gov/tuma). Other sources 

suggest the name means caliche, or pepperbush 

(Lamb and Scott 1993). 

Two other early churches are also part of the 

park’s holdings, Los Santos Ángeles de Guevavi and San Cayetano de Calabazas. Guevavi is 

the southernmost of these units, consisting of 

a 3.9-hectare parcel adjacent to the Santa Cruz 

River 23 km SSE of the main (Mission) unit of Tumacácori NHP. Calabazas comprises an 8.9-hectare parcel situated to the south of the confl uence 

of the Santa Cruz River and Sonoita Creek, a major tributary, 15 km SSE of the main unit. Guevavi 

was the earliest of all these missions, designated 

as a mission after Padre Kino visited the O’odham 

settlement in 1691. The word guevavi is derived 

from the O’odham gi-vavhia, meaning big well or 

big spring (http://www.nps.gov/tuma). The mission church whose ruins this unit protects was not 

built until the early 1750s, and was abandoned by 

1775, because of continuing Apache raids. 

San Cayetano de Calabazas was a mission at the 

site of a relocated O’odham village and, according to records, was founded in 1756, but not 

functional until 1773. It suff ered at the hands of 

Apaches, just as Guevavi did. By 1853, the church 

was functioning as a ranch house for the Governor of Sonora, who ran 6,000 head of cattle in 

the area. Although it went through many other 

incarnations, the site was totally abandoned by 

1878 (http://www.nps.gov/tuma). Both of these 

units were added to the park in 1990, and in 2002, 

Congress authorized the acquisition of an addi-
6 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

tional 125 hectares surrounding the main unit.

Today, Tumacácori National Historical Park comprises the three units for a total area of 145 hectares. All land abutting these park units is private, 

providing a challenge to resource managers.

1.7.2 Environmental history

Tumacácori NHP is located in southern Arizona, 

along the Santa Cruz River valley, which is part 

of the southern Basin and Range physiographic 

province. This physiographic province, which 

encompasses southeastern Arizona and northern 

Sonora, is a “terrain of alternating fault-bounded 

linear mountain ranges and sediment-fi lled basins which began to form in southeastern Arizona 

as the result of dominantly east-northeast/westsouthwest directed crustal extension” (Powell et 

al. 2005). The result is a landscape of many rugged 

mountain ranges: to the west, the Tumacácori and 

Atascosa mountains; to the east, the Santa Rita, 

Patagonia, and San Cayetano mountains. 

The climate of the area is marked by a bimodal 

precipitation regime, with a monsoonal fl ow from 

the Gulf of Mexico in summer, and Pacifi c frontal storms in winter. The area’s hot season occurs 

from April through October; maximum temperatures in July often exceed 40°C. Intense surface 

heating during the day and active radiant cooling 

at night can result in daily temperature ranges of 

17–22° C. Winter temperatures are mild. Prevailing winds tend to follow the Santa Cruz Valley, 

blowing downslope (from the south) during the 

night and early morning, and upslope (from the 

north) during the day (Powell et al. 2005).

The Santa Cruz Valley has a long history of anthropogenically driven ecological change. Prior 

to Spanish colonization, marked by the arrival of 

Kino in 1691, O’odham communities are thought 

to have inhabited these areas for hundreds, if not 

thousands, of years (Spicer 1962). These small, 

subsistence-based agricultural communities were 

semi-nomadic and relied on the existence of permanent surface water for their survival (Robinett 

1990). Although indications are that their impact 

was limited, opinions as to their overall impact 

vary, given the uncertainty surrounding specifi c 

practices, such as fi ring the landscape. With the 

arrival of the Spanish and their livestock, conditions changed drastically. In the 1804 Spanish 

census, 5,000 sheep were reported at Tubac, the 

presidio immediately downstream of the Tumacácori Mission unit. These numbers were replicated 

at Tumacácori, with 4,000 of the mission’s cattle 

being sold in 1821, to pay for the construction of 

the church (http://www.nps.gov/tuma). 

With the 1853 Gadsden Purchase, all land south 

of the Gila River, formerly owned by the Spanish, was transferred to the United States. Following the Gadsden Purchase and the end of the 

Apache wars, Euro-American settlement began 

throughout the region in earnest, further amplifying ecological change. Along the Santa Cruz 

River, changes in land use included the clearing 

of mesquite bosque and cottonwood–willow forests along the river for agricultural purposes. Evidence also indicates that cottonwoods more than 

six meters in diameter were girdled and killed 

in the 1920s, in the mistaken understanding that 

such actions would free up more water for agriculture (Logan 2002). Tumacácori National Monument, as designated in 1908, originally included 

only four hectares. The area around the mission 

began to be converted to more extensive agricultural operations sometime in the 1940s, replacing what appears to have been mesquite bosque 

(as documented in aerial photography dating to 

1936). More agricultural fi elds appear in aerial 

photographs from 1956, and expand further to 

the north in 1959, when they appear to have totally surrounded the mission and run to the edge of 

the riparian zone. From the 1930s onward, there 

has been a general increase in the obligate riparian vegetation in this reach of the river, attributed 

to agricultural abandonment immediately adjacent to the river, periodic fl ooding that helped in 

the germination of cottonwood, specifi cally, and 

later, the existence of effl uent water fl ow since the 

development of the Nogales International Wastewater Treatment Plant (Webb et al. 2007, Powell 

et al. 2005).

Beginning in the late 1970s, the agricultural fi elds 

surrounding Tumacácori began to be abandoned 

(J. Moss, pers. comm.). In aerial photographs 

from 1975, fi elds and historic acequias (irrigation 

canals) are still clearly visible. However, in aerial 

photographs from 1980 and 1983, these fi elds are 

clearly beginning to undergo type conversion to 

sparse shrubland, indicating their abandonment 

sometime previous to these photographs. In aerial photographs taken in 1992, 1996, 2003, and 

2004, the growth of trees and shrubs in these former fi elds is clearly evident. Cattle ranching in the 

area has probably had an uninterrupted history 

since Spanish colonization, and continues today. 

Despite the park’s eff orts to maintain boundary 
Chapter 1: Introduction 7

fencing, trespass cattle are a recurring problem in 

the park. 

Cattle ranching also continues around both the 

Guevavi and Calabazas units. Guevavi was, in 

fact, part of a ranch until 1990, when the rancher 

donated the land to the Archaeological Conservancy. Guevavi had small, subsistence agricultural fi elds during the period of mission occupation, but had none of the extensive fi elds in the 

twentieth century that surrounded the main unit. 

Calabazas was similar in this respect, although 

there are indications that it was used as a farm for 

the mission at Tumacácori during the early 1800s 

(http://www.nps.gov/tuma). Neither Guevavi nor 

Calabazas has the same density of riparian-obligate species as is found at the main unit, although 

the existence of many deceased large cottonwoods is believed to be partly a consequence of 

local groundwater development for Nogales, in 

the case of Guevavi, and Rio Rico, in the case of 

Calabazas (Webb et al. 2007).

1.7.3 Vegetation

The area of Tumacácori National Historical Park 

lies in the Arizona Upland division of the Sonoran 

Desert, as designated by Brown et al. (1979) and 

previously by Shreve and Wiggins (1964). Alternatively, this area is known as part of the Apache 

Highlands Ecoregion developed by The Nature 

Conservancy (Marshall et al. 2004). The vegetation is composed primarily of cottonwood–willow (Populus fremontii–Salix gooddingii) riparian 

forest and woodland along the Santa Cruz River 

channel, and mesquite (Prosopis velutina) forest 

(bosque) and woodland on low terraces fl anking 

the river, with a gradation to savanna, semi-desert 

grassland, and desertscrub on the uplands away 

from the river. Within the dominant forest and 

woodland communities, hackberry (Celtis laevigata var. reticulata), and elderberry (Sambucus 

nigra ssp. caerulea) are common constituents and 

are, in some places, the dominant woody species 

along the upland edges where woodlands give 

way to savannas. Other associated species include 

acacias (Acacia greggii, Acacia constricta), wolfberry (Lycium spp.), greythorn (Ziziphus obtusifolia), and desert broom (Baccharis sarothroides).

Diff erent communities across the three park units 

exhibit diff erent densities and species composition, depending not only on their site characteristics relative to the river, but also on their specifi c 

land-use histories. Although there are signifi cant 

grass communities scattered throughout the 

park, ranging from mixed grama grass communities (Bouteloua spp.) to limited dominance by big 

sacaton (Sporobolus wrightii), there is a notable 

dominance by disturbance-tolerant species, such 

as amaranth (Amaranthus palmeri) and Bermuda grass (Cynodon dactylon). Bermuda grass, in 

particular, defi nes the contemporary strand vegetation community throughout the three units. 

There is also a notably large amount of Russian 

thistle (Salsola kali) throughout the park, possibly 

a lingering consequence of agricultural development around the park units.

Chapter 2: Classification and Mapping of Plant Communities 9

2.1 Methods

In general, we followed the classification and 

mapping methodology elaborated in the USGSNPS Vegetation Characterization Program documentation, including the NVC standards. However, our approach to classification and mapping 

was more integrated than the traditional practice 

of having ecologists collect plot data for classification and photointerpreters delineate polygons 

with particular signatures, then combining the 

two efforts. Instead, we used an integrated team 

of observers who collected plot- and polygonbased data for classification while creating map 

polygons in the field. 

An initial polygon map at the formation level (actually more like the class level) was drafted from 

interpretation of high-spatial-resolution satellite 

imagery and field reconnaissance (see following 

two sections). The field team, including the image 

interpreters, took this formation map as a starting 

point and verified or modified formation boundaries; split formation polygons into alliance or 

finer-level, floristically based polygons; and characterized each alliance type with quantitative data 

on species composition, relative cover, and other 

factors. Because Tumacácori is a small park, we 

were able to census the entire park in this way.

2.1.1 Satellite imagery

The imagery we used was acquired by DigitalGlobe Inc.’s Quickbird satellite on August 27, 

2006, as a new, tasked acquisition for this project. 

Image preprocessing and initial interpretation to 

the formation level were done at the Arizona Remote Sensing Center, University of Arizona. The 

imagery product purchased was the “Ortho-ready 

Standard” bundle of four spectral bands (blue, 

green, red and near-infrared) at 2.4-m spatial resolution, plus the broadband panchromatic data 

at 0.6-m resolution. This imagery is intended to 

be orthorectified by the user and is only coarsely 

geo-registered, with a nominal spatial accuracy of 

23 m CE90—meaning that 90% of features in the 

imagery must be within 23 meters of their true 

location on the ground. More information about 

the general specifications of this imagery can be 

found at www.digitalglobe.com/ or, more specifically, at www.digitalglobe.com/product/standard_imagery.shtml. 

2.1.2 Image processing

The imagery was orthorectified with ERDAS (Leica) software, using a USGS National Elevation 

Dataset digital elevation model, ground control 

points (GCPs) from ca. 2006 digital orthophoto 

quarter quadrangles (DOQQs), and the Quickbird rational polynomial coefficient model. During the rectification process, the coordinates 

of GCP locations collected from the reference 

DOQQs were entered into a table and compared 

to image coordinates for the same GCP locations. 

An optimal set of GCPs was selected and the images were rectified using a polynomial model with 

cubic convolution resampling. The multispectral 

image had a root mean square error (RMSE) of 

1.19 m, calculated from six GCPs. The panchromatic image had an RMSE of 0.65 m, calculated 

from nine GCPs. These errors are in relation to 

the 2006 DOQQ reference, the highest-accuracy 

reference source available.

Following orthorectification, the multispectral imagery was pan-sharpened for visual interpretation, using the resolution merge tool in 

ERDAS Imagine. Principal components and cubic convolution were selected as merge parameters. Pan-sharpening is the process of merging 

the high-resolution, 0.6-m panchromatic image 

with the 2.4-m multispectral image to produce a 

multispectral image with 0.6-m resolution. The 

draft formation-level map was produced through 

visual interpretation of the pan-sharpened imagery and heads-up digitizing in ArcGIS to delineate polygons. Seven formations were identified, 

based on the percentages of tree, shrub, and herbaceous cover present, following the formation 

key we had previously developed (Appendix A). 

These were: Forest, Woodland, Wooded Shrubland, Shrubland, Shrub Herbaceous, Wooded 

Herbaceous, and Herbaceous. 

Chapter 2

Classification and Mapping of 

Plant Communities
10 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Each polygon in the draft formation map was assigned a unique alphanumeric identifier (ID) for 

reference throughout the project. When formation polygons were split, new, daughter polygons 

were given appropriate IDs, but still traceable to 

the parent. We prepared 11 × 17-inch hard-copy 

prints of the tentative formation polygons overlaid on the background imagery, at 1:4000 scale 

with a 100-m UTM grid, for use in the field-based 

vegetation alliance mapping. The field team also 

had the digital formation map and the imagery 

available on handheld and laptop computers, 

with the useful ability to zoom for viewing at multiple scales.

2.1.3 Field-based classification and mapping

Field-based mapping and data collection for classification were conducted from November 1, 

2007, through early April 2008. Working in teams 

of two or three for a multiple-observer, consensus-based approach, the field crew visited each of 

the formation polygons on the draft map of the 

study area. Assisted by the hard-copy prints and 

the spatial data loaded on GPS-linked handheld 

computers (RECONs), the field crew generally 

walked the boundary and much of the interior of 

each polygon to make a careful visual assessment 

of it. They determined whether the image interpreters had labeled it correctly (shrubland vs. 

woodland, for example) and whether its boundary needed any modifications. Then they looked 

at species composition and determined whether 

the polygon was sufficiently homogeneous to 

consider it a single alliance, or if it needed to be 

split into more than one alliance. Boundary modifications and splits were sketched on the hardcopy prints and explained in words on field data 

sheets. 

From this point forward, work focused on the 

alliance-level polygons created. Next, the crews 

collected semi-quantitative data on canopy cover 

of dominant species by stratum, plant heights, associated species present, disturbance, and a range 

of soil/landscape characteristics. A sequence of 

four representative photographs was taken in 

the four cardinal directions from near the center 

of the polygon (at a specific point stored in the 

GPS), and a tentative alliance-type description of 

the polygon was written.

This was all done for each alliance-level polygon. 

In addition, a set of 20 × 50-m plot data was collected for each alliance type (not necessarily each 

polygon). Plot locations had been preselected 

with the spatially balanced RRQRR (Reversed 

Randomized Quadrant-Recursive Raster) algorithm to provide an objective, park-wide sampling 

basis for vegetation classification (Theobald et al. 

2007). Essentially the same information was recorded in the plots as in the whole polygons, with 

the notable addition of measured basal diameters 

of trees present. The plots provided a uniform, 

delimited scale of observation to supplement 

and corroborate the extensive observations of 

whole polygons. To the extent that the plots are 

representative of the polygon or alliance type as 

a whole, collecting plot data can address the difficulty associated with making accurate visual estimates of the canopy cover of several species in 

large polygons. As such, evaluating both polygons 

and plots provides the most robust and useful 

dataset for characterizing alliances.

The RRQRR points were numbered and sampled 

in sequential order to maintain the spatial balance 

and the probabilistic nature of sampling. Each 

point was understood to serve as any corner of a 

plot, giving the field crew some flexibility to avoid 

major changes in vegetation type or distinct, nonrepresentative inclusions. Also, plots were oriented in any direction that most closely corresponded to the formation type in which the RRQRR 

point fell. Plots that crossed different types were 

still sampled but were placed to encompass the 

least amount of variation. If a plot crossed three 

or more community types, it was not sampled; 

rather, it was noted as being dropped and the crew 

moved to the next point. After the plot was established, the bearings of the 20-m and 50-m edges 

from the RRQRR origin point were recorded on 

the data sheet, the polygon in which the point was 

located was noted, and a photograph representative of the plot was taken from the origin point, 

the coordinates of which were marked in a GPS 

file in the RECON unit.

Vegetation-cover data were collected across the 

entire plot, with species ranked by relative dominance and assigned to absolute cover classes. 

Basal diameters of all individual trees of more 

than 2 m tall and larger than 10 cm in diameter 

were recorded, all woody stems of less than 10 

cm in diameter were tallied, and all disturbance 

types were noted with the constrained vocabulary found in the NVC system. A battery of soil 

and landscape characterization data were taken 

(the same as those for polygon assessment), including topographic position, landform, surface 

cover, parent material, slope, aspect, and erosion 

features. Finally, narrative descriptions of both 
Chapter 2: Classification and Mapping of Plant Communities 11

vegetation and the landscape/soils were written 

to best characterize the community found in the 

plot.

At Tumacácori, we completed 60 plots associated 

with RRQRR points (29 at the Mission unit, 19 

at Calabazas, and 12 at Guevavi), but these left 

some tentative alliance types undersampled, so 

we sampled an additional 11 plots (5 Mission, 4 

Calabazas, 2 Guevavi), subjectively placed, to represent these types. This provided a dataset with at 

least two plots per tentative alliance type.

After each day of field work, two copies were 

made of completed data sheets, and safely stored. 

Periodically during the course of field-data collection, completed field data sheets and the annotated hard-copy prints were analyzed by the whole 

project team at the Arizona Remote Sensing Center. The digital (shapefile) draft formation map was 

extensively edited in ArcMap to incorporate all of 

the changes indicated on the annotated prints, 

and the polygon attribute database was built.

After data collection, all plot and polygon data 

were assembled for classification analysis. In 

general, data were collected at a finer thematic 

resolution than the alliance level, or even the association level, and a process of aggregation was 

needed to define desired map classes and attribute each polygon with a final map class. The aggregation condensed 29 tentative vegetation types 

into 19. The text descriptions of the tentative map 

classes were aggregated and adjusted to accommodate the range of variability in each of the 19 

final map classes.

2.2 Results

2.2.1 Map classes

Table 2.2.1 (table and figures are shown at end 

of this chapter) shows a summary of mapping 

results: map class names, number of polygons 

of each map class present in the study area, and 

area of each map class in hectares. Formationlevel data are also indicated in bold font. Most 

of the classes are considered alliances, but where 

the word “alliance” is absent, the class is an NVC 

association or one of the three special classes 

identified by this project: Developed Woodland, 

Cropland and Pasture, and Park Facilities. Alliances marked with (P) are provisional, not yet accepted into the NVC system. 

One-page text and spatial summaries of each 

class are presented at the end of this chapter; full 

descriptions of all map classes can be found in 

Appendix D. The completed maps of the three 

TUMA units are presented in Figures 2.2-1 and 

2.2-2. Readers may refer to the digital maps and 

databases accompanying this report for more detail.

2.2.2 Additional areas of interest

In a scoping meeting held prior to mapping, Tumacácori NHP personnel identified three specific areas of interest to the park: (1) the location 

of the invasive Nicotiana glauca, or tree tobacco; 

(2) an assessment of the amount of trash found in 

the park; and (3) an assessment of trespass cattle 

found in the park. 

In the course of field work from November 2007 to 

April 2008, tree tobacco was found to be growing 

only along the riparian corridor through the Mission unit. Every specimen of tree tobacco located 

by the field crew was recorded as a GPS point on 

the RECON unit, and then eradicated. The field 

crew noted that the presence of tree tobacco was 

correlated with debris piles found in close proximity to the strand. The suggestion for future management of this plant is that periodic survey in the 

fall, after the monsoon, may prove necessary for 

preventing widespread establishment.

Trash is common at Tumacácori NHP. There are 

three specific types of trash: river-borne trash, 

trash left by migrants in camps and along trails, 

and incidental trash. The first type of trash is significant in every woody debris pile found along 

the river, where it gets concentrated. The profusion of plastic in river-borne debris is most widely 

evident in the stretch of river through the Mission 

unit. There is considerable debris at Calabazas, 

but it is highly localized, and there is very little at 

Guevavi. Exploration of Nogales Wash near the 

International Wastewater Treatment Plant revealed that tributary to be the most likely source 

of debris and trash to the river system. The relative scarcity of trash in the river and among the 

debris at Guevavi, upstream of Nogales Wash, 

supports this contention. 

The second type of trash found at Tumacácori 

is clearly correlated with the movement of undocumented immigrants through the area. At all 

three park units, there are numerous sites where 

abandoned backpacks, bedding, clothing, empty 

water bottles, and empty food cans and wrappers can be found. These sites are often obvious 
12 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

because of their size. They may be grouped in 

areas of significant cover, hidden from both aerial 

surveillance and from roads, but can also be in 

close proximity to roads, apparently where entrants have been picked up by vehicles. Although 

frequent throughout the three park units, such 

camps are often localized accumulations of trash. 

The third type of trash is incidental. This includes 

trash blowing in from adjacent urban areas, and 

from visitors dropping food wrappers and drink 

containers along trails. It also includes a few large 

dump piles near the southern boundary of the 

Mission unit. These were clearly established prior to 2002 and the subsequent expansion of the 

park. 

Cattle were present in the main unit of the park 

the entire time field work was conducted. At the 

Mission unit, a fence along the western boundary was discovered to be damaged and cattle were 

common along the riparian corridor throughout 

the course of fieldwork. Initial discussions with 

park resource managers had settled on a presence-absence method to determine the extent of 

cattle in the park. It soon became clear, however, 

that the determination of presence-absence was 

essentially meaningless because of the ubiquity of 

cattle in the park. Cattle were not damaging resources per se, as there was no evidence that they 

were present in sufficient numbers to overgraze 

the park. However, there was localized damage 

being done in the form of a network of trails being repeatedly used by enough cattle to pulverize 

the soil and destroy plants, making the trails easily 

discernible. In marked contrast to the main unit, 

neither Guevavi nor Calabazas had indications of 

any cattle inside the park boundaries, while there 

was evidence of grazing right up to the boundary 

fence at both units.
Chapter 2: Classification and Mapping of Plant Communities 13

Table 2.2. Summary of vegetation classification and mapping results. 

Map class Abbreviation # polygons Area (ha)

Forest

Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest POPFRE Forest 6 41.99

Prosopis velutina Forest Alliance (P) PROVEL Forest 7 17.43

Celtis laevigata var. reticulata Forest Alliance CELLAE Forest 4 3.73

Forest total 17 63.16

Woodland

Populus fremontii - Salix gooddingii Woodland POPFRE Woodland 3 16.46

Prosopis velutina Woodland Alliance PROVEL Woodland 8 17.56

Acacia greggii Woodland Alliance (P) ACAGRE Woodland 1 2.08

Woodland total 12 36.11

Wooded Shrubland

Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded 

Shrubland Alliance (P)

PROVEL Wooded 

Shrubland

2 7.09

Shrubland

Prosopis velutina - Acacia greggii Shrubland PROVEL-ACAGRE 

Shrubland

3 8.96

Acacia constricta Shrubland Alliance (P) ACACON Shrubland 1 6.12

Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance TAMRAM Shrubland 1 1.13

Shrubland total 5 16.22

Wooded Herbaceous

Populus fremontii / Mixed Annual Wooded Herbaceous Alliance (P) POPFRE Wooded 

Herbaceous

3 14.17

Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance (P) PROVEL Wooded 

Herbaceous

4 9.17

Wooded Herbaceous total 6 21.34

Shrub Herbaceous

Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance (P) PROVEL Shrub Herbaceous 3 7.09

Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] Shrub 

Herbaceous Alliance (P)

HYMMON Shrub 

Herbaceous

1 10.19

Shrub Herbaceous total 4 17.28

Herbaceous

[Amaranthus palmeri - Salsola kali - Chenopodium spp.] Annual 

Herbaceous Alliance (P)

AMAPAL Herbaceous 5 3.52

Sparsely Vegetated

Inland Freshwater Strand Beach Sparse Vegetation 2 5.12

Developed Woodland 1 26.46

Cropland and Pasture 2 32.24

Park Facilities 2 9.11

Grand total 58 237.65

Map classes marked with (P) are proposed, not yet accepted in the NVC system.
14 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Figure 2.2-1. Vegetation map of the Mission unit of Tumacácori National Historical Park.

Tumacácori National Historical Park

Arizona

Vegetation Map, 

Mission Unit

Produced by OALS March 2009

National Park Service

U.S. Department of the Interior

0 200 400 800

Meters

Vegetation and Land Cover

Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest

Prosopis velutina Forest Alliance (P)

Celtis laevigata var. reticulata Forest Alliance

Populus fremontii - Salix gooddingii Woodland

Prosopis velutina Woodland Alliance

Acacia greggii Woodland Alliance (P)

Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded Shrubland Alliance (P)

Prosopis velutina - Acacia greggii Shrubland

Acacia constricta Shrubland Alliance (P)

Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance

Populus fremontii / Mixed Annual Wooded Herbaceous Alliance (P)

Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance (P)

Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance (P)

Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] Shrub

Herbaceous Alliance (P)

[Amaranthus palmeri - Salsola kali - Chenopodium spp.] Annual Herbaceous Alliance (P)

Inland Freshwater Strand Beach Sparse Vegetation

Developed Woodland

Cropland and Pasture

Park Facilities

(P) = Proposed
Chapter 2: Classification and Mapping of Plant Communities 15

Figure 2.2-2. Vegetation map of the Calabazas and Guevavi units of Tumacácori National Historical Park.

0 125 250 500

Tumacácori National Historical Park

Arizona

Vegetation Maps, 

Calabazas and Guevavi Units

Produced by OALS March 2009

National Park Service

U.S. Department of the Interior

Meters

Vegetation and Land Cover

Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest

Prosopis velutina Forest Alliance (P)

Celtis laevigata var. reticulata Forest Alliance

Populus fremontii - Salix gooddingii Woodland

Prosopis velutina Woodland Alliance

Acacia greggii Woodland Alliance (P)

Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded Shrubland Alliance (P)

Prosopis velutina - Acacia greggii Shrubland

Acacia constricta Shrubland Alliance (P)

Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance

Populus fremontii / Mixed Annual Wooded Herbaceous Alliance (P)

Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance (P)

Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance (P)

Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] Shrub

Herbaceous Alliance (P)

[Amaranthus palmeri - Salsola kali - Chenopodium spp.] Annual Herbaceous Alliance (P)

Inland Freshwater Strand Beach Sparse Vegetation

Developed Woodland

Cropland and Pasture

Park Facilities

(P) = Proposed

Calabazas unit

Guevavi unit
16 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Populus fremontii - Salix gooddingii Forest

Fremont cottonwood - Goodding’s willow Forest

The dominant Populus fremontii is diagnostic of the type, while Salix gooddingii is a subdominant, characteristic species found in clumps and often as a secondary canopy of 6–8 m in height. The canopy of Populus fremontii averages 

10–20 m high throughout the type and is generally open beneath, except for 

areas of thick Tamarix ramosissima along the river channel. Baccharis salicifolia is widely dispersed and is not consistent in its distribution. Overall, woody 

species distribution in this community is a very patchy mosaic apart from the 

consistent Populus fremontii and Salix gooddingii, with a mixture of Prosopis 

velutina, Celtis laevigata var. reticulata, and Sambucus nigra ssp. caerulea trees 

and shrubs. Other associates are Baccharis sarothroides, Baccharis salicifolia, 

and Anisacanthus thurberi. The herbaceous layer is a mosaic as well, but with 

Cynodon dactylon present consistently along the river channel throughout the 

park, especially in areas that are flooded regularly. Conium maculatum, Amaranthus palmeri, and Chloris virgata are common elements of the herbaceous 

layer.

0 5 25 0 100 150

Meters

Common species

Populus fremontii

Salix gooddingii 

Baccharis salicifolia

Prosopis velutina 

Celtis laevigata var. reticulata 

Sambucus nigra ssp. caerulea

Anisacanthus thurberi

Cynodon dactylon

Amaranthus palmeri

Figure 2.2-3. Populus fremontii - Salix gooddingii Forest.
Chapter 2: Classification and Mapping of Plant Communities 17

Prosopis velutina Forest Alliance (P)

Velvet mesquite Forest Alliance

This alliance usually occupies alluvial terraces along the outermost edges of 

the Santa Cruz River floodplain, outside the band of Populus fremontii - Salix 

gooddingii forest along the channel, in areas that are relatively moist but rarely 

inundated, sometimes existing in narrow bands along the base of cliffs and 

embankments bordering the floodplain, as well as at the mouths of tributary 

drainages as they enter the floodplain. The alliance contains several recognizable associations with different subdominant species as well as different structure and cover, and with Prosopis stands of apparently different ages. Older, 

larger Prosopis stands may have Celtis laevigata var. reticulata, Sambucus nigra 

ssp. caerulea, and occasional Salix gooddingii interspersed, with a significant 

shrub understory of sapling trees, Acacia greggii, Baccharis salicifolia, Ziziphus obtusifolia, Lycium andersonii, and Anisacanthus thurberi. In addition, 

there may be a diverse herbaceous layer of annual and perennial grasses and 

forbs, and ground-to-crown vines, such as Phaseolus ritensis, Clematis drummondii, and Ipomoea spp.

0 6 30 0 120 180

Meters

Common species

Prosopis velutina

Celtis laevigata var. reticulata

Sambucus nigra ssp. caerulea

Baccharis salicifolia

Anisacanthus thurberi

Cynodon dactylon

Amaranthus palmeri

Acacia greggii

Ziziphus obtusifolia

Lycium andersonii

Figure 2.2-4. Prosopis velutina Forest Alliance.
18 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Celtis laevigata var. reticulata Forest Alliance

Netleaf hackberry Forest Alliance

This alliance is found on shallow slopes that run along old agricultural fencelines. This dense forest is comprised of Celtis laevigata var. reticulata and 

Prosopis velutina that range in height from 9 to 13 m in the uppermost canopy, 

with considerable numbers of Sambucus nigra ssp. caerulea growing up underneath to a height of 4–8 m. The largest Celtis specimens are found immediately along the fencelines, which, in isolated instances, still receive runoff 

from actively cultivated agricultural land. This type is notable because of the 

multi-layered density of the entire forest, from the interlocking top canopy 

to the dense sub-canopy. In the sub-canopy, there is significant recruitment 

of Celtis, Prosopis, and Sambucus, and occasional Ziziphus obtusifolia, Acacia 

greggii, and Lycium andersonii shrubs. The herbaceous layer is notably sparse 

in areas beneath the denser canopies, where there is also considerable downed woody debris, but in openings, there 

is a higher diversity of both forbs and occasional grasses. In isolated sections of this type, there are Cynodon dactylon

patches, often along foot trails. 

0 5 25 0 100 150

Meters

Common species

Celtis laevigata var. reticulata

Prosopis velutina

Sambucus nigra ssp. caerulea 

Ziziphus obtusifolia

Acacia greggii

Lycium andersonii

Figure 2.2-5. Celtis laevigata var. reticulata Forest Alliance.
Chapter 2: Classification and Mapping of Plant Communities 19

Populus fremontii - Salix gooddingii Woodland

Fremont cottonwood - Goodding’s willow Woodland

This type is similar in composition to the Populus fremontii - Salix gooddingii / 

Baccharis salicifolia Forest type that spans the park, but has lower plant density and cover. The type is located in the 100-year floodplain. It is dominated by 

Populus fremontii, with a patchy canopy and the inclusion of Salix gooddingii

in specific areas. Baccharis salicifolia is generally the dominant shrub. The entire type is on a slightly elevated sandy-silty island, with considerable amounts 

of downed, woody debris piled up throughout. Beneath the Populus fremontii canopy, the understory is relatively open and includes more herbaceous 

plants, dominated by Hilaria belangeri, Cynodon dactylon, and the annual 

grass, Chloris virgata. The annual forb, Bidens leptocephala, is characteristically found in dense concentrations in the shade. Shrubs are often distinctly 

clumped and diverse, ranging from Hymenoclea monogyra, Baccharis salicifolia, and Senecio flaccidus to specimens of 

Opuntia spinosior and young Alnus arizonica. Amaranthus palmeri and Salsola kali are present throughout the type, 

but not in the same density as in neighboring wooded- or shrub-herbaceous types.

0 6 30 0 120 180

Meters

Common species

Populus fremontii

Salix gooddingii

Baccharis salicifolia

Hymenoclea monogyra

Hilaria belangeri

Cynodon dactylon

Figure 2.2-6. Populus fremontii - Salix gooddingii Woodland.
20 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Prosopis velutina Woodland Alliance

Velvet mesquite Woodland Alliance

This woodland alliance occurs further away from the river channel than the 

forest alliances, in more xeric sites. Plant canopy cover varies, with significant 

open or nearly-open patches possibly present. Prosopis velutina is usually 

clearly dominant in both height and canopy cover, but in places, Acacia greggii, commonly the second-dominant species, is a close rival. Within this type, 

A. greggii (and, to a lesser extent, P. velutina) can be found as a tree lifeform, a 

shrub lifeform, or anything in between. The Prosopis-dominated upper canopy averages 6–8 m in height, ranging to 10 m. A. greggii and occasional Sambucus nigra ssp. caerulea and Celtis laevigata var. reticulata individuals may 

reach this height, also. In the sub-canopy, Prosopis and Acacia still dominate 

(as caespitose shrubs to sapling trees), with common associates being Celtis

and Sambucus saplings, Ziziphus obtusifolia shrubs, Mimosa aculeaticarpa var.

biuncifera, Baccharis sarothroides, B. salicifolia, Anisacanthus thurberi, and 

Hymenoclea monogyra. The herbaceous layer is almost everywhere dominated by Amaranthus palmeri, occasionally by Cynodon dactylon.

0 5 25 0 100 150

Meters

Common species

Prosopis velutina

Acacia greggii

Celtis laevigata var. reticulata

Sambucus nigra ssp. caerulea

Ziziphus obtusifolia

Mimosa aculeaticarpa 

Baccharis sarothroides

Anisacanthus thurberi

Amaranthus palmeri

Figure 2.2-7. Prosopis velutina Woodland Alliance.
Chapter 2: Classification and Mapping of Plant Communities 21

Acacia greggii Woodland Alliance (P)

Catclaw acacia Woodland Alliance

This type is dominated by Acacia greggii and Prosopis velutina trees 6–8 m tall, 

and shorter Acacia greggii and Ziziphus obtusifolia shrubs. Associated shrub 

species, such as Condalia warnockii, Baccharis sarothroides, Lycium andersonii, Hymenoclea monogyra, and Anisacanthus thurberi, are scattered across 

the type. Most of the trees and shrubs in this alliance have such thick, dense 

canopies that herbaceous plants are largely confined to the interspaces between overstory canopies. The herbaceous layer is dominated by the annual 

forbs, Amaranthus palmeri and Bidens leptocephala, with a variety of other 

forbs and grasses interspersed widely.

0 6 30 0 120 180

Meters

Common species

Acacia greggii

Prosopis velutina

Ziziphus obtusifolia

Condalia warnockii

Baccharis sarothroides

Lycium andersonii

Hymenoclea monogyra

Anisacanthus thurberi 

Amaranthus palmeri

Figure 2.2-8. Acacia greggii Woodland Alliance.
22 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded Shrubland Alliance (P)

Velvet mesquite / [Velvet mesquite - Catclaw acacia] Wooded Shrubland Alliance

Although primarily found on gently sloped upland, this type also extends 

down steeper, relatively xeric slopes. It is characterized by an open canopy of 

Prosopis velutina shrubs, mostly 2–4 m tall but with many larger, tree-lifeform 

individuals up to 7.5 m. These Prosopis and the other trees present make up 

>10% cover. Acacia greggii is common in the shrub layer; it is usually, but not 

always, less abundant than Prosopis, and also averages 2–4 m tall. Density of 

the shrub layer is variable. In more xeric areas, Baccharis sarothroides may 

have significant cover and A. greggii may be absent or nearly so. Acacia constricta and Mimosa aculeaticarpa var. biuncifera are generally present. A few 

individuals of Juniperus coahuilensis, Condalia warnockii, and Opuntia spinosior may be present on hilltop flats and adjacent upper slopes, while Ziziphus 

obtusifolia, Celtis laevigata var. reticulata, and Anisacanthus thurberi may be 

found on more mesic lower slopes. Amaranthus palmeri and Bidens leptocephala are the only abundant forbs in an otherwise grass-dominated (Bouteloua curtipendula, Sporobolus wrightii, Chloris virgata, Muhlenbergia porteri) herbaceous layer.

0 5 25 0 100 150

Meters

Common species

Prosopis velutina

Acacia greggii

Baccharis sarothroides

Acacia constricta 

Mimosa aculeaticarpa 

Ziziphus obtusifolia

Celtis laevigata var. reticulata

Anisacanthus thurberi

Amaranthus palmeri

Figure 2.2-9. Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded Shrubland Alliance.
Chapter 2: Classification and Mapping of Plant Communities 23

Prosopis velutina - Acacia greggii Shrubland

Velvet mesquite - Catclaw acacia Shrubland

This alliance is dominated by moderate-sized Prosopis velutina shrubs 1–3.5 m 

tall, with Acacia greggii shrubs common on the hillslopes. In areas with greater 

than 5% slope, the species commingle. The slopes have a higher percentage of 

Bouteloua curtipendula in the herbaceous layer compared with the flats of the 

mesa-tops, where there is far more of the annual forb, Amaranthus palmeri, 

and Bouteloua aristidoides, in addition to other mixed Bouteloua spp. (likely 

including B. rothrockii and B. barbata) that were not reliably identifiable due 

to seasonal dormancy. Other woody species associated with this type include 

Acacia constricta, Opuntia spinosior, O. engelmannii, Baccharis sarothroides,

and Ferocactus wislizenii, although there are rarely more than a few individuals of these species present. At Guevavi, this type includes the adobe ruins, 

a historically disturbed area. This may account for distributional differences 

among some species in the areas immediately adjacent to the ruins, including 

the presence of Sporobolus wrightii. Eragrostis lehmanniana and Aristida spp. 

may also be significant in the understory. 

0 5 25 0 100 150

Meters

Common species

Prosopis velutina

Acacia greggii

Acacia constricta

Opuntia spinosior

O. englemanii

Baccharis sarothroides

Ferocactus wislizenii

Amaranthus palmeri 

Bouteloua aristidoides

Figure 2.2-10. Prosopis velutina - Acacia greggii Shrubland.
24 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Acacia constricta Shrubland Alliance (P)

Whitethorn acacia Shrubland Alliance

This association is found on steeper, well-drained slopes that have thin, gravelly soils, often with exposed bedrock. Acacia constricta, Acacia greggii, and

Prosopis velutina shrubs usually average 1.5–2.5 m tall and form dense thickets. Some P. velutina may attain tree size, especially where slopes are not as 

steep. Acacia constricta is dominant overall, but in patches, either A. greggii

or Prosopis velutina may be the dominant species. The understory is notable 

for its diversity, usually composed of a mixture of native bunchgrasses, such 

as Bouteloua curtipendula, Muhlenbergia porteri, Aristida purpurea, and Setaria spp. Several other species, rare in the Calabazas site, are found in limited 

numbers in this type, including Ceanothus greggii, Mimosa aculeaticarpa var.

biuncifera, Ferocactus wislizenii, Yucca elata, Echinocereus spp., and Opuntia 

spinosior. This type maintains a high percentage of native species and relatively low levels of human and livestock disturbance due to its rugged topographic position, thorny shrub cover, and 

protection within NPS fencelines.

0 4 20 0 80 120

Meters

Common species

Acacia constricta

Acacia greggii 

Prosopis velutina

Bouteloua curtipendula

Muhlenbergia porteri

Aristida purpurea

Setaria spp.

Figure 2.2-11. Acacia constricta Shrubland Alliance.
Chapter 2: Classification and Mapping of Plant Communities 25

Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance

Saltcedar Shrubland Alliance

This association is found along the northern boundary of the Mission unit, 

with the bulk of the association found in the buffer outside the park boundary. The topography of the area is notable because of two elevated sand bars 

with north-south channels running between them. On top of the sand bars 

are dense stands of 2–3-m tall tamarisk shrubs (Tamarix ramosissima), with 

annual forbs scattered in openings where there is less litter cover. Along the 

margins of the dense tamarisk patches are found occasional Populus fremontii, 

infrequent Baccharis sarothroides recruits, and rare Cynodon dactylon and Sporobolus cryptandrus patches. In the 

near future, this association is expected to radically change inside the park boundary because of a tamarisk-eradication project being conducted by NPS at the time of mapping. Without the tamarisk, the portion inside the park 

boundary would become herbaceous-dominated.

0 4 20 0 80 120

Meters

Common species

Tamarix ramosissima

Populus fremontii

Figure 2.2-12. Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance.
26 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Populus fremontii / Mixed Annual Wooded Herbaceous Alliance (P)

Fremont cottonwood / Mixed Annual Wooded Herbaceous Alliance

Populus fremontii is found in small-to-large patches throughout the type, often with Salix gooddingii and/or Prosopis velutina, and clumps of Tamarix ramosissima in some places. Large Populus fremontii may reach 16–18 m, Salix

somewhat less, and Prosopis usually 3–6 m. A few Sambucus nigra ssp. caerulea

may be found in this type. Shrubs are generally sparse, and include Hymenoclea monogyra, Prosopis velutina, Baccharis salicifolia, Acacia greggii, Baccharis sarothroides, and Senecio flaccidus. The herbaceous layer is dominated 

by Amaranthus palmeri, with significant patches of Aristida purpurea widely 

dispersed throughout the type. Annual grasses are also commonly present, 

including Chloris virgata and Bouteloua aristidoides, frequently in conjunction with sandier, sloped areas, dictating slightly more xeric condtions. Associated herbaceous species include Boerhavia coccinea, Boerhavia spicata, 

Cynodon dactylon, Ipomoea spp., Tithonia thurberi, Sporobolus cryptandrus, Bouteloua curtipendula, and Eragrostis 

lehmanniana.

0 6 30 0 120 180

Meters

Common species

Populus fremontii

Salix gooddingii

Prosopis velutina

Amaranthus palmeri

Aristida purpurea

Chloris virgata

Bouteloua aristidoides

Figure 2.2-13. Populus fremontii / Mixed Annual Wooded Herbaceous Alliance.
Chapter 2: Classification and Mapping of Plant Communities 27

Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance (P)

Velvet mesquite / Mixed Annual Wooded Herbaceous Alliance

Where a single herbaceous species dominates, it is usually Amaranthus palmeri, 

though there are areas dominated by Cynodon dactylon (found in most of the 

open areas of the type) or Sporobolus wrightii. There are significant areas without a single dominant species, with the herbaceous layer comprising a diverse 

mosaic of annuals and perennials, including some combination of the aforementioned species and Aristida purpurea, Chloris virgata, Hilaria belangeri, 

Sporobolus cryptandrus, Sporobolus contractus, Bothriochloa barbinodis, Aristida ternipes, Chloris virgata, and the forbs, Amaranthus palmeri, Salsola kali, 

Chenopodium spp., and Helianthus annuus. The overstory usually has 5–25% 

cover of Prosopis velutina trees, sometimes clumped, usually interspersed 

with Sambucus nigra ssp. caerulea, Celtis laevigata var. reticulata, Acacia greggii, and Populus fremontii. P. velutina and A. greggii can appear as both trees 

and shrubs. Other associated shrubs include Ziziphus obtusifolia and Hymenoclea monogyra. Average height of the 

overstory is commonly 3–6 m; some Populus fremontii specimens can reach 14 m.

0 3 15 0 60 90

Meters

Common species

Prosopis velutina

Sambucus nigra ssp. caerulea 

Celtis laevigata var. reticulata

Acacia greggii

Populus fremontii

Amaranthus palmeri

Sporobolus wrightii

Figure 2.2-14. Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance.
28 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance (P)

Velvet mesquite / Palmer amaranth Shrub Herbaceous Alliance

Overall, this type is dominated by Amaranthus palmeri, with other tall annuals and Sporobolus wrightii interspersed throughout. In addition to the Prosopis velutina shrubs, there may be a number of trees in this type, including 

P. velutina, Celtis laevigata var. reticulata, Sambucus nigra ssp. caerulea, and 

Populus fremontii, but they are often solitary individuals, perhaps with seedlings of these species interspersed between. In areas not mowed or cultivated 

in the last 3–4 years, the dominance of A. palmeri is apparently giving way to 

a mixture of annual and perennial grasses: Cynodon dactylon, Bouteloua aristidoides, Sporobolus cryptandrus, Bouteloua curtipendula, Hilaria belangeri, 

Aristida purpurea, and Aristida ternipes. Scattered throughout are numerous 

small P. velutina and Baccharis sarothroides shrubs, ranging from 0.5–1.5 m 

tall. The absence of disturbance and grazing has apparently allowed the widespread growth of woody species, still small and shrubby. A. palmeri, present throughout the area, constituted a plurality of roughly 30% of the total cover.

Common species

Prosopis velutina

Baccharis sarothroides

Amaranthus palmeri

Sporobolus wrightii

Celtis laevigata var. reticulata

Sambucus nigra ssp. caerulea

Populus fremontii

0 7 35 0 140 210

Meters

Figure 2.2-15. Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance.
Chapter 2: Classification and Mapping of Plant Communities 29

Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] Shrub Herbaceous Alliance (P)

Singlewhorl burrobush / [Palmer amaranth - Feather windmill grass] Shrub Herbaceous Alliance

This alliance is generally found in the 100-year floodplain adjacent to the west 

side of the Santa Cruz River at the Mission unit. It consists of sandy-to-silty 

soils with a diversity of annual and perennial herbaceous species, though 

these are widely dispersed across a large area and do not account for much 

cover. The herbaceous layer is dominated by Amaranthus palmeri and Chloris 

virgata. Hymenoclea monogyra is the dominant shrub throughout the type, 

appearing to have grown up within the last five years, as indicated by repeat 

photographs from an earlier inventory. Hymenoclea monogyra shrubs range 

from 2 to 4 m in height, and are generally clumped together, leaving large areas more open between them. Associated shrubs interspersed throughout the 

type include Baccharis salicifolia, Baccharis sarothroides, Prosopis velutina, 

and Senecio flaccidus. A few trees may be present, commonly Populus fremontii or Sambucus nigra ssp. caerulea, but these make up less than 10% cover.

Common species

Hymenoclea monogyra

Amaranthus palmeri

Chloris virgata

Baccharis salicifolia

Baccharis sarothroides

Prosopis velutina 

Senecio flaccidus

Populus fremontii

Sambucus nigra ssp. caerulea

0 7 35 0 140 210

Meters

Figure 2.2-16. Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] Shrub Herbaceous Alliance.
30 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

[Amaranthus palmeri - Salsola kali - Chenopodium spp.] Herbaceous Alliance (P)

[Palmer amaranth - Tumbleweed - Goosefoot spp.] Herbaceous Alliance

This annual forb-dominated community is found on sandy soils adjacent to 

the Santa Cruz River. Use of brackets in the type name indicates that these 

species should be considered co-dominant overall, and their relative abundance may differ spatially within the type. There are areas of fairly homogeneous distribution of both A. palmeri and S. kali as co-dominants (with or 

without some Chenopodium spp.), and areas where one of the three species is 

clearly the single dominant, with more or less of the others possibly present. 

Local abundance and composition of this type may vary significantly from 

year to year. Grasses, both annual and perennial, grow sparsely in patches 

in this community: Chloris virgata, Bouteloua aristidoides, Sporobolus cryptandrus, Sporobolus wrightii, Aristida ternipes and Hilaria belangeri. The forb, 

Bidens leptocephala, may be prominent in patches. Along the edges of the herbaceous type, sparse low shrubs are often found, including Baccharis salicifolia, Hymenoclea monogyra, and Prosopis 

velutina, and occasionally trees, such as Populus fremontii, Sambucus nigra ssp. caerulea, or Salix gooddingii.

Common species

Amaranthus palmeri 

Salsola kali 

Chenopodium spp.

Chloris virgata

Bouteloua aristidoides 

Sporobolus cryptandrus

Bidens leptocephala

0 6 30 0 120 180

Meters

Figure 2.2-17. [Amaranthus palmeri - Salsola kali - Chenopodium spp.] Herbaceous Alliance.
Chapter 2: Classification and Mapping of Plant Communities 31

Inland Freshwater Strand Beach Sparse Vegetation

This type is composed of mostly-bare sand in the Santa Cruz River’s active 

channel. Some forbs may be present in areas colonized since the last flood 

event. Seedlings or saplings of Populus fremontii and Salix gooddingii may also 

be present. The position of strand beaches tends to shift with flood events in 

the fluvial system.

Common species

Xanthium strumarium

annual forbs

Cynodon dactylon

Populus fremontii

Salix gooddingii

0 6 30 0 120 180

Meters

Figure 2.2-18. Inland Freshwater Strand Beach Sparse Vegetation.
32 Vegetation Classification, Distribution, and Mapping Report: Tumacácori National Historical Park

Developed Woodland

This type, in the Mission-unit area, comprises homes, commercial buildings, 

and roads built in former mesquite forest or woodland, with minimal-to-extensive clearing of trees. Occurs primarily outside park boundary, in studyarea buffer.

Common species

Prosopis velutina

Acacia greggii

Celtis laevigata var. reticulata

Tamarix ramosissima

Ziziphus obtusifolia

Mimosa aculeaticarpa 

Baccharis sarothroides

Anisacanthus thurberi

Amaranthus palmeri

0 6 30 0 120 180

Meters

Figure 2.2-19. Developed Woodland.
Chapter 2: Classification and Mapping of Plant Communities 33

Cropland and Pasture

Anderson Level 2 class, applied to active irrigated pasture (in buffer), and historic cultivated area adjacent to the Mission unit. Common species

Cynodon dactylon

Sorghum halepense

Amaranthus palmeri

Salsola kali

Ambrosia spp.

0 7 37.5 5 150 225

Meters

Figure 2.2-20. Cropland and Pasture.

Chapter 3: Accuracy Assessment 35

3.1 Methods

Following program guidelines for small parks under 300 ha, a census-based accuracy assessment 

was done at TUMA, rather than a sample-based 

one. Tumacácori NHP Resources Manager/Archeologist Jeremy Moss (hereafter “the assessor”) carried out the accuracy assessment after a 

thorough briefi ng on the methods used for classifi cation and mapping, and on the map classes. 

This was to ensure that the methods and thinking 

used to evaluate each polygon for accuracy assessment were essentially the same as those used for 

classifi cation and mapping, and that the assessment would be done by an objective, knowledgeable observer who was not part of the mapping 

team. The briefi ng included discussion of plant 

lifeforms; familiarization with the NVC hierarchy 

and criteria for identifying formations, alliances, 

and associations; techniques for estimating species cover classes by stratum; subtleties of visual 

interpretation of satellite imagery for evaluation of 

vegetation; use of the RECON GPS-linked handheld computer; and other necessary methods.

The assessor was provided with tools similar to 

those used by the mappers, including a RECON

unit loaded with draft map polygon boundaries, 

and printed map sections showing each polygon 

labeled with a simple ID number. Also provided 

were a vegetation formation key (Appendix A), a 

set of map class descriptions (similar to the Tumacácori NHP Summaries in Appendix D), and 

a stack of datasheets (Appendix F) for recording 

accuracy assessment (AA) data. These datasheets 

contained a checklist of the map classes at TUMA, 

and requested some redundant data to guard 

against erroneously checking the wrong box. 

The task of the assessor was to visit each polygon, 

walking through it to evaluate the lifeform and 

canopy cover of the dominant species in each 

stratum, consider the text descriptions of relevant vegetation types, and check the best-fi tting 

map-class name for the polygon on the datasheet. 

A rating of goodness-of-fi t was also requested, as 

well as any notes or observations that might help 

future interpretation of the accuracy assess ment, 

including notes on the polygon boundary. The assessor was asked to choose a class name for the 

polygon as mapped, consider ing the whole area 

of the polygon. The accuracy assessment was 

completed in about four full fi eld days in January 

2009.

3.2 Results

Table 3.2-1 (see tables at end of chapter) is an 

error matrix showing the results of the accuracy 

assessment, including user’s and producer’s accuracy per class, overall accuracy for all classes 

(90.2%) and Khat, or Kappa (89.4%), which is a 

measure of overall accuracy minus chance agreement.* Of the 19 map classes, only four had user’s 

or producer’s accuracy of less than 80%. However, this matrix refl ects data that are somewhat 

misleading due to the small sample size (actually, 

census size; i.e., the small number of polygons of 

most types that were present). The small sample 

size resulted in too many classes with measured 

accuracy of 100%, infl ating the overall accuracy, 

and too many classes dropping below 80% accuracy if just one of the 2–4 polygons was misclassifi ed. 

Also, the data as reported in the matrix somewhat 

overstate some class accuracies because of the 

way ambiguity in the reference data was handled. 

For nine polygons of six vegetation types, the assessor recorded two possible types, such as “mesquite forest OR mesquite woodland” in cases of 

uncertainty about whether mesquite cover was 

more or less than the 60% minimum for forest. 

Chapter 3

Accuracy Assessment

*User’s accuracy: The probability that a sample from the mapped data actually represents that category on the ground, also 

known as error of commission. This quantity is computed by dividing the number of correctly classifi ed samples by the total 

number of samples that were classifi ed as belonging to that category (Story and Congalton 1986).

Producer’s accuracy: The probability that a reference sample (the ground data) has been classifi ed correctly, also known as error 

of omission. This quantity is computed by dividing the number of samples that have been classifi ed correctly by the total number 

of reference samples in that class (Story and Congalton 1986).
36 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

In all nine of these cases, the mapped class was 

scored as correct in the error matrix if the map 

class matched one of the assessor’s recorded 

classes, which they all did. Each of these cases is 

shown in Table 3.2-2. All resulted from the assessor’s acknowledged diffi culty in estimating species cover or lifeform (tree vs. shrub), rather than 

from errors of species identifi cation or dominance.

Six polygons were scored as true errors in the matrix (Table 3.2-3) due to unambiguous mismatches 

between the mapped class and the assessed class. 

Because the mapping and accuracy assessment at 

TUMA were both census-based, we decided the 

best course of action would be to examine and 

resolve all of the true errors and the ambiguities, 

and correct the map to achieve 100% accuracy for 

each class. The adjustments are described in the 

next section.

3.3 Resolution of Discrepancies

The discrepancies and ambiguities between 

map data and accuracy assessment reference 

data shown in Tables 3.2-2 and 3.2-3 were all 

investigated and resolved. In eight cases, the AA 

data were proven to be correct and the map was 

changed to refl ect that. In seven cases, the map 

data were found to be correct and the AA data 

were overruled, with no change in the map. Table 

3.3 explains each case in turn, with reference to 

polygons by their ID numbers in Tables 3.2-2 and 

3.2-3.

3.4 Spatial Accuracy Assessment

The U.S. National Map Accuracy Standards 

(NMAS) for spatial or positional accuracy, in use 

since 1947, stipulate that no more than 10% of 

tested points on a 1:24,000-scale map can be in 

error by more than 0.02 inch (0.51 mm), or 40 feet 

(12.2 m) ground distance. The revised National 

Cartographic Standards for Spatial Accuracy state 

accuracy as a standard error (RMSE) in the x- and 

y-coordinate directions, rather than as a circular 

error with a 90% confi dence level (as is indirectly implied by the NMAS of 1947). For a Class 1 

product of 1:24,000 scale, the maximum allowable RMSE is 6.0 meters (20 ft) ground distance; 

for a Class 2 product, the RMSE must be no more 

than 12.0 meters (39 ft). For digital products with 

no set scale, the reference to a 1:24,000 standard 

scale loses some relevance, but the implied ground 

distances can still be used as benchmarks.

The positional accuracy being measured is that 

of “well-defi ned points” on the map; that is, discrete features that can be clearly identifi ed and 

located in the map product as well as the source 

of higher accuracy used for comparison (the reference data). Boundaries subject to interpretive 

judgement or certain natural boundaries subject 

to environmental fl uctuations (e.g., river banks) 

generally do not qualify as well-defi ned points, 

even if they form intersections. Because vegetation boundaries are nearly always interpretive, 

positional accuracy statements for the TUMA 

vegetation map do not directly apply to the primary mapped features in the product, but instead 

should be understood to indicate how well the 

map product is registered (geocoded) to its control, and not to indicate how well the vegetation 

polygon boundaries refl ect their true positions on 

the ground (ESRI et al. 1994).

For this project, the highest-accuracy spatial reference data available were a set of DOQQs from 

2006; our spatial accuracy measurements were 

done in comparison with these. At each of the 

three units at TUMA, 20 test points were selected 

that were small, discrete, and could be defi nitively 

located in both the base satellite imagery used for 

mapping and in the DOQQs. Most of these were 

individual shrub canopies against a contrasting 

background. The georeferencing tool in ArcGIS 

was used to visually select point pairs (one in the 

imagery and a corresponding one in the DOQQ), 

record coordinates, and calculate an overall 

RMSE (Appendix G). MS Excel was used to calculate additional error values (Table 3.4) from the 

point coordinates.

As shown in Table 3.4, the TUMA vegetation map 

easily met the spatial accuracy standards. Features 

were estimated to lie within two meters, generally 

much less, of their “true” position on the DOQQ 

reference imagery. None of the test points approached the 12-m error allowable (for 10% of 

tested points) under the NMAS, and the maximum measured RMSE of 1.03 meters was well 

below the 6.0-m limit imposed by the National 

Cartographic Standards for a Class 1 product.
Chapter 3: Accuracy Assessment 37

Table 3.2-1. Accuracy assessment error matrix.

Map class #

Accuracy assessment fi eld reference data

User’s 

accuracy

POPFRE Forest

PROVEL Forest

CELLAE Forest

POPFRE Woodland

PROVEL Woodland

ACAGRE Woodland

PROVEL Wooded Shrubland

PROVEL-ACAGRE Shrubland

ACACON Shrubland

TAMRAM Shrubland

POPFRE Wooded Herbaceous

PROVEL Wooded Herbaceous

PROVEL Shrub Herbaceous

HYMMON Shrub Herbaceous

AMAPAL Herbaceous

Strand

Developed Woodland

Cropland & Pasture

Park Facilities

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

1 5 1 0.83

2 6 1.00

3 4 1.004 3 1.00

5 9 1.00

6 1 1.007 2 1.00

8 4 1 0.809 1 1.00

10 1 1.0011 2 1 0.6712 1 4 0.80

13 1 1 0.5014 1 1.00

15 4 1.0016 1 2 0.6717 1 1.0018 2 1.0019 2 1.00

Producer’s accuracy

1.00 1.00 1.00 0.75 1.00 1.00 1.00 1.00 1.00 1.00 0.67 0.80 0.33 1.00 0.80 1.00 1.00 1.00 1.00

Overall accuracy 0.902

Khat 0.894

See Table 2.2 for abbreviations.
38 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Table 3.2-2. Cases of ambiguity in accuracy-assessment fi eld data.

ID AA fi eld class Map class

34 POPFRE Woodland or Forest POPFRE Forest

75 PROVEL Wooded Herbaceous or PROVEL Woodland PROVEL Woodland

21 PROVEL Forest or Woodland PROVEL Woodland

27 PROVEL Forest or PROVEL Woodland PROVEL Woodland

77 PROVEL/[PROVEL-ACAGRE] WS or PROVEL Woodland PROVEL Woodland

73 PROVEL/[PROVEL-ACAGRE] WS or PROVEL Woodland PROVEL/[PROVEL-ACAGRE] WS

70 PROVEL Wooded Herbaceous or PROVEL Woodland PROVEL Wooded Herbaceous

43 HYMMON Shrub Herbaceous or POPFRE Wooded Herbaceous HYMMON Shrub Herbaceous

13 AMAPAL Herbaceous or POPFRE Wooded Herbaceous AMAPAL Herbaceous

In all cases, the map class matched one of the two alternative AA-assigned classes. Polygon ID numbers are arbitrary, used for 

reference during accuracy assessment. WS = Wooded Shrubland. See Table 2.2 for class abbreviations.

Table 3.2-3. Cases of true error or discrepancy between map data and accuracyassessment fi eld data.

ID AA fi eld class Map class

32 POPFRE Woodland POPFRE Forest

71 POPFRE/Mixed Annual Wooded Herbaceous PROVEL Wooded Herbaceous

65 PROVEL/AMAPAL Shrub Herbaceous POPFRE/Mixed Annual Wooded Herbaceous

52 PROVEL/AMAPAL Shrub Herbaceous PROVEL-ACAGRE Shrubland

45 PROVEL Wooded Herbaceous PROVEL/AMAPAL Shrub Herbaceous

56 AMAPAL Herbaceous Strand

Polygon ID numbers are arbitrary, used for reference during accuracy assessment. See Table 2.2 for class abbreviations.
Chapter 3: Accuracy Assessment 39

Table 3.3. Resolution of discrepancies. Polygon

Changed

Explanation Yes No

13 X The boundary of this polygon (H-AP01-M) was adjusted to exclude some tree cover at its margins, 

resulting in <10% total tree cover and a less-ambiguous map class of AMAPAL Herbaceous.

21 X

This polygon (F-PV06-M) was changed from woodland to forest. In the GIS lab, the polygon was overlaid 

with 50 randomly located dots, which were scored as hitting tree canopy or interspace. This analysis 

produced an estimate of 71% tree cover, ample for the Forest label.

27 X After a slight adjustment of the boundary of this polygon (F-PV08-G), its tree cover was estimated at 

84%, and it was also changed from woodland to forest.

43 X

The boundary of this polygon (SH-HM01-M) was changed to exclude some POPFRE trees at its margins 

that were confounding its identifi cation. With less tree cover included, the map class HYMMON Shrub 

Herbaceous fi t well.

56 X

This polygon (H-AP02-M) was changed from Strand to AMAPAL Herbaceous. It may once have been a 

strand, but its isolation and distance from the current active channel, plus its well-established cover of 

AMAPAL, led to the decision that AMAPAL Herbaceous was the best label.

65 X

This polygon (WH-PF01-M) was actually a disjunct, two-part polygon comprising one large and one small 

stand. The assessor was not cognizant of this and evaluated each part separately. The AA data for the 

larger stand matched the map data, so there was no error there. For the smaller stand, the AA data were 

judged to be a better fi t than the map data. The smaller stand was re-attributed as PROVEL/AMAPAL 

Shrub Herbaceous.

70 X

This polygon (WPV04-M) was changed from PROVEL Wooded Herbaceous to PROVEL Woodland based 

on analysis of the satellite imagery, which indicated about 40% tree cover, but more tree cover than 

herbaceous cover due to a signifi cant amount of bare ground.

71 X

This polygon was large and heterogeneous, with the map class fi tting one part best and the assessed 

class fi tting another. The polygon was split, and the north part was re-labeled as POPFRE Wooded 

Herbaceous (WH-PF03-M), while the south part remained PROVEL Wooded Herbaceous (WH-PV01-M) as 

mapped.

32 X

This polygon (F-PF05-M) was not changed. The apparent error (woodland vs. forest) resulted from 

different estimates of the tree canopy cover. GIS analysis produced an estimate of 74% tree cover, 

confi rming the Forest label.

34 X

Ambiguity between woodland and forest for this polygon (F-PF03-M) was resolved by using the GIS 

random-point method as for polygon 32 above, which provided an estimate of 70% tree cover. The map 

class of POPFRE-SALGOO forest was not changed.

45 X

This polygon (SH-PV02-G) was not changed. The apparent error was due to different interpretations 

of the lifeform of the PROVEL plants in the polygon. After discussion with the mapping fi eld crew, the 

Prosopis were judged to be large shrubs, rather than trees, so the PROVEL/AMAPAL Shrub Herbaceous 

label fi t best.

52 X

This polygon (S-PV02-G) was not changed. Review of the polygon and classifi cation plot datasheets 

showed that PROVEL-ACAGRE Shrubland was a better fi t than PROVEL/AMAPAL Shrub Herbaceous, 

because ACAGRE was common and shrub cover exceeded herbaceous cover.

73 X This polygon (WS-PV01-M) was confi rmed to be a wooded shrubland by review of classifi cation/mapping 

data. It was not changed.

75 X This polygon (W-PV02-M) was confi rmed to be a woodland, as mapped, based on review of imagery and 

mapping/classifi cation datasheets to re-estimate tree cover vs. herbaceous cover.

77 X This polygon (W-PV03-M) was judged to be a woodland rather than a wooded shrubland, based on the 

classifi cation/mapping data on mesquite lifeform. It was not changed.

See Table 2.2 for class abbreviations.
40 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Table 3.4. Spatial accuracy assessment summary for 

each of the three units at TUMA. 

Unit

Absolute error RMS error

Max-X Max-Y RMS-X RMS-Y RMS-All

Mission 1.93 1.13 0.61 0.61 0.77

Calabazas -0.88 1.15 0.44 0.43 0.40

Guevavi -1.92 0.71 1.03 0.29 0.85

Values are meters, ground distance. Twenty test points were used for each 

unit. RMS = root mean square
Chapter 4: Discussion 41

4.1 Strata and Growth Form

One note on the adoption of NVC methodology at Tumacácori NHP concerns the diffi culty 

encountered in arid southwestern ecosystems in 

determining the nature of both strata and growth 

form among certain species. Within the NVC hierarchy, the tree stratum is defi ned as plants taller 

than 5 m, the shrub stratum is from 0.5 to 5 m, 

and the fi eld stratum is from 0 to 0.5 m (Jennings 

et al. 2006). Also, the NVC makes allowance for 

breaking up these categories into subcategories, 

which at Tumacácori we defi ned as a top-canopy 

over 5 m, a canopy from 2.5 to 5 m, a sub-canopy 

from 0.5 to 2.5 m, and fi eld stratum from 0 to 0.5 

m. Within these categories, it was often diffi cult to 

assess growth form according to a strict interpretation of the NVC hierarchy, although the NVC 

states, “not all plant species will fi t clearly into 

the recognized strata or growth form categories” 

(Jennings et al. 2006). 

Examples at TUMA are mesquite and catclaw 

acacia, in which growth form varies considerably. At Tumacácori, these species grow as shrubs, 

trees, and forms in between. It is often diffi cult to 

assign individuals or stands to a distinct growth 

form. Often, individuals over 5 m tall with multiple stems are encountered. In the course of fi eld 

work, it was decided fi rst that plants larger than 5 

m were trees, regardless of the number of stems. 

Second, plants with multiple stems that were of 

a more brushy habit, meaning they had multiple 

similarly sized stems and no discernible upwardtrending central leader, were considered shrubs if 

they were under 5 m. Finally, in instances where 

a single trunk dominated, the growth form was 

always considered a tree, but noted in the proper 

stratum depending on the size of the specimen.

4.2 Notable Vegetation Patterns

In the course of fi eld work for classifi cation and 

mapping, patterns of apparent vegetation community succession were observed that are seemingly related to long-term aspects of land-use history at particular sites. The observation was made 

that the vegetation on abandoned agricultural 

fi elds at the Tumacácori Mission unit is apparently undergoing a succession to mesquite bosque, 

and there are diff erent stages of this in diff erent 

locations around the park. While it is diffi cult to 

discern the specifi c mechanisms driving this succession, including what role water and exotic herbaceous vegetation may play, the patterns observable today suggest that a series of developmental 

stages have occurred since a particular site was 

cultivated.

The fi rst stage of the succession is represented 

by a polygon labeled as agriculture that had been 

abandoned only within the last few years. This 

fi eld is immediately to the east of the mission’s 

historical orchard. This abandoned fi eld has not 

been mowed since about 2002 (J. Moss, pers. 

comm.), unlike a similar fi eld to the southwest 

that continues to be mowed regularly. The lack 

of mowing apparently has allowed the establishment and growth of woody species such as mesquite and desert broom. While the fi eld is still 

dominated, in large part, by amaranth and a wide 

diversity of both annual and perennial grasses, 

the development of the woody shrubs is the fi rst 

notable compositional change in the successional 

pattern.

The second stage is the growth of mesquite and 

desert broom into much larger shrubs, with mesquite becoming treelike. This stage is represented 

along the western boundary of the park, running 

from north of the Fiesta Grounds to an east-west 

trending arroyo and an old, relict stand of trees 

that was never cut—essentially, all the agricultural land abandoned in the late 1970s. This shrubland is dominated by mesquite shrubs, ranging 

in height from 2 to 4 m, and desert broom specimens averaging around 2.5 m tall. Another example of this stage was found immediately to the 

north of the agricultural fi eld thought to be in the 

fi rst stage. In this polygon, Prosopis and Baccharis 

were much more dense than along the western 

boundary, which may be explained by their proximity to a consistent water table.

In the third stage, the development of the bosque 

becomes more clearly discernible. Commonly, 

the mesquites are mid-size (5–7 m) and evenaged, and there is very little density or diversity 

Chapter 4

Discussion
42 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

of herbaceous growth beneath them. This stage is 

found in places immediately adjacent to the second stage, often with a distinct boundary between 

them. The tree canopy becomes interlocked, and 

the community type changes from woodland to 

forest. In apparently longer-established patches 

of this type, one encounters the addition of elderberry to the community, as well as vines that grow 

into the canopy, appearing diagnostic of the maturing bosque. The canopy in this stage appears 

to push upward, allowing for a distinct layering 

of vegetation, fi rst from the ground to about 2 

m, where the understory is open and allows the 

growth of diverse herbaceous and sub-shrub species, including Thurber’s honeysuckle (Anisacanthus thurberi).

The fi nal stage of bosque maturity seems to be 

marked by dense and tall mesquites, the inclusion of hackberry, many as large trees, and the 

highest diversity of sub-canopy shrub and herbaceous species. The growth of morning glory vine 

(Ipomoea) and leather fl ower (Clematis) vines is 

notable, and recruits of mesquite and hackberry 

are present. Soil development is critical to moving 

from the fi rst stage, where the shrubland is actually more of a shrub savanna, to this fi nal stage. In 

the fi rst two stages, the soils are sandy-gravellyloam and support little in the way of herbaceous 

forbs. However, as the mesquite matures into 

larger trees, there is a noticeable increase in the 

soil being formed beneath the canopies. As the 

canopies continue to thicken, the soil appears to 

deepen and become loamier and darker with organic matter.

This assessment of the development of the 

bosque is only observational, and is not based on 

quantitative data. However, the fi eld crew found 

the developmental stages to be suffi ciently distinct and intriguingly correlated with possible 

dates of abandonment of cultivation to warrant 

future studies on the course and precise ecological mechanisms of bosque development.

4.3 Implications for Management

Tumacácori NHP presents a unique opportunity 

for ecological restoration in the Santa Cruz River 

valley. Situated along the central axis of the river 

basin, the main unit of Tumacácori NHP is a signifi cant parcel of rare cottonwood-willow gallery 

forest and mesquite bosque riparian ecosystems. 

While these ecosystems are currently protected, 

they have been heavily impacted for centuries, 

through a long history of livestock grazing, agricultural conversion, and fl uctuations in surface 

and groundwater profi les. Due to the highly disturbed nature of the ecosystems found in the 

park and the increasing prevalence of a variety 

of invasive and exotic species, Tumacácori NHP 

is uniquely situated to investigate and implement 

ecological restoration strategies with potentially 

basin-wide implications. 

Referred to as the “lessening stream” for its onceconsistent fl ow that diminished to a trickle and 

eventually disappeared under the pressures of 

human development (Logan 2002), agricultural 

abandonment immediately upstream of and along 

the Santa Cruz River in the vicinity of Tumacácori 

NHP, beginning fi rst in the 1930s, has allowed for 

a resurgence of riparian vegetation (Webb et al. 

2007). This resurgence, coupled with an increasing fl ow of effl uent released by the International 

Wastewater Treatment plant (beginning in the 

1970s), has resulted in a well-developed riparian 

forest through Tumacácori NHP. Additionally, 

the abandonment of agricultural land around the 

park, beginning in the 1970s, has resulted in the 

apparent development of conditions necessary 

for the successional development of mesquite 

bosques once present in the area (see discussion 

above.)

The central challenge to ecological restoration 

of the riparian corridor may be the composition 

of the park’s herbaceous communities. While 

the overstory conditions appear to be on an ecological trajectory toward sustainability of nativespecies forest and woodland (with a caveat due 

to the currently limited presence of tamarisk), 

the monocultural presence of Bermuda grass and 

poison hemlock (Conium maculatum) along the 

river and the widespread distribution and high 

density of amaranth and Russian thistle throughout the park indicate that the herbaceous community remains highly disturbed. Whether this is 

a consequence of persistent cattle grazing or the 

near-total dominance of Bermuda grass upstream 

and downstream from Tumacácori along the river, this level of disturbance presents an opportunity to explore alternative management strategies. 

Considered within a regional context, it is notable 

that the more-common obligate riparian herbaceous plant species, such as rushes (Juncus spp.) 

and horsetail (Equisetum spp.), were not found in 

any signifi cant abundance along the river through 

the park. Also notable is the only occasional presence of big sacaton in scattered patches through 

all three units. Historically, it is thought that saca-
Chapter 4: Discussion 43

ton was a central component of these intermittently fl ooded riparian ecosystems throughout 

southern Arizona and northern Sonora (Richter 

and Stutz 2002). The presence of these species in 

reduced abundance is an indication of the impoverishment of the overall riparian ecosystem, but 

is also an indicator that the opportunity exists to 

alter management practices to support and enhance the restoration of herbaceous plant communities.

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Appendix A: Vegetation Formation Key 47

Appendix A

Vegetation Formation Key

1. What is the dominant surface cover?

Trees ......................go to ...........2

Shrubs ....................go to ...........3

Herbaceous ...........go to ...........4

Rock/Bare Soil .......go to ...........5

2. Trees

A. Tree Cover >60%?

YES = Forest

NO = Woodland

3. Shrubs

A. Tree Cover >10%?

YES = Wooded Shrubland

NO = Shrubland

4. Herbaceous

A. Tree cover <10% AND Shrub cover <10%?

YES = Herbaceous

NO = go to B.

B. Tree cover > Shrub cover?

YES = Wooded Herbaceous

NO = Shrub Herbaceous

5. Rock/Bare Soil

A. Is the total vegetation cover <1%?

YES = Non-Vegetated

NO = go to B.

B. Is the total vegetation cover <10%?

YES = Sparse Vegetation

NO = go to C.

C. Determine dominant vegetation lifeform and go to 2, 3 or 4.

Appendix B: Polygon Data Sheets 49

Appendix B

Polygon Data Sheets

Park: Sub-Map #: Date (mm/dd/yyyy): Time (00:00):

Keyed Formation:

Poly ID(s): Field Poly ID:Observer(s): Recorder: Tentative Formation:Protocol Name: VegMap Protocol Version: 0.05

Proofread by: ______ Copied by: ______ Entered by: ______ Verified by: ______ GIS Edits done by: _____ New Poly ID: ____________________

List top three dominant species by stratum. Rank (R) 1=dominant or co-dominant, 2=second dominant, 3=least dominant.Record species cover class (C) and average height (H, in meters to nearest tenth) by stratum. Record LF, lifeform (T or S).

1 = < 1% 2 = 1-5% 3 = 6-10% 4 = 11-25% 5 = 26-33% 6 = 34-50% 7 = 51-75% 8 = 76-95% 9 = 96-100%

Total cover all sp Total cover all sp Total cover all sp Total cover all species

C

R Field 0 – 0.5m

C

R

LF

Sub-canopy

0.5 – 2m 

H

C

R

LF Canopy 2 – 5m 

H

C

R

LF Canopy >5m

List other common associates 

C Field 0 – 0.5m

C

LF

Sub-canopy

0.5 – 2m 

H

C

LF Canopy 2 – 5m 

H

C

LF Canopy >5m

USGS-NPS Vegetation Mapping Program Field Data Sheet: Polygon Vegetation Version: 0.04

Association name: Use “—” within strata, “/” between strata and “( )” to denote minor species

Polygon_Veg_Datasheet_v004.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.

National Park Service 

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Inventory and Monitoring Program

Page ____ of ____

Location and Event Information
50 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park (X) Stand Maturity Young/ regenerating Even age/ aggrading Mature/ even-age Transition/ break up Old growth/ senescent Uneven age Other: (X) Poly Homogeneity Homogeneous Compositional trend Conspicuous inclusions Irregular Pattern mosaic

Polygon_Veg_Datasheet_v004.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.

Disturbance Types:

Camera Name: NorthEastSouthWest

NOTES: Describe the overall vegetative community, especially noting differences from other similar communities.

Explain or diagram any polygon splits/additions/subtractions/boundary changes.

PHOTOS: From approximate center of polygon take 4 photos, one in each cardinal direction, in order (N E S W). Write photo number (last four digits from upper right 

corner) in table and record camera used.

** Please note the numbers of any additional photos taken and a description of what they depict.

National Park Service 

Sonoran Desert Network U.S. Department of the Interior

Inventory and Monitoring Program

Page ____ of ____
Appendix B: Polygon Data Sheets 51Polygon_Soil_Landscape_Datasheet_v004.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.

(X) Landform (X all that apply)

Upper Alluvial FanLower Alluvial FanFloodplainAlluvial TerraceWashArroyoMountainHillColluvial TalusOutcropDrainage (IFW/IFF)

(X)

Topographic 

Position

(X all that apply)

Crest/summitUpper slopeMidslopeFootslopeToeslopeHigh flatLow flatBasin floorChannel bed/ gullyOther:

Area Surface Cover (circle one class per feature)

Feature Class

Bare Soil None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%)Gravel: 2-75 mm None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%)Rock: 75 + mm None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%)Bedrock Outcrops None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%)Physical Crust None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%)Biological Crust None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%)Down Wood None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%)Litter None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Horizonated

Intrusive Igneous BedrockExtrusive Igneous BedrockVolcanic Ash BedrockMetamorphic BedrockNon-calcareous sedimentary rockCalcareous sedimentary rockColluviumOld AlluviumNew AlluviumAeolian - Windblown

Parent Material

(X all that apply) (X)

None Rare Common Prolific BurrowingNone Rare Common Prolific TerracettesNone Rare Common Prolific PedestalsNone Rare Common Prolific GullyNone Rare Common Prolific RillNone Rare Common Prolific SheetNone Rare Common Prolific Tunneling

Erosion Features (circle one class per feature)

N NW W SW S SE E NE

Aspect (circle all that apply) Slope Class

(X all that apply)

0-1%1-6%6-15%15-35%35-50%50+%

(X)

National Park Service 

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Inventory and Monitoring Program

Page ____ of ____

USGS-NPS Vegetation Mapping Program Field Data Sheet: Polygon Soil/Landscape Version: 0.04

Proofread by: ______ Copied by: ______ Entered by: ______ Verified by: ______ New Poly ID: ____________________

Protocol Version: 0.04 Protocol Name: VegMap

Time Keyed Formation:

(00:00): Sub-Map #:

Tentative Formation: Recorder: Observer(s):

Field Poly ID: Poly ID(s):Date (mm/dd/yyyy):

Location and Event Information

Park:

Soil/Landscape Parameters
52 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park NOTES: 1) Write a short descriptive paragraph on the major soil type, slope position, and geomorphic features. 2) Sketch any soil or geologic features within the polygon; e.g., arroyos, changes in soils, rock outcrops. National Park Service Sonoran Desert Network U.S. Department of the Interior Inventory and Monitoring Program Page ____ of ____

Polygon_Soil_Landscape_Datasheet_v004.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.
Appendix C: Plot Data Sheets 53

Appendix C

Plot Data Sheets

Proofread by: ______ Copied by: ______ Entered by: ______ Verified by: ______ New Poly ID: _________________

List top three dominant species by stratum. Rank (R) 1=dominant or co-dominant, 2=second dominant, 3=least dominant.Record species cover class (C) and average height (H, in meters to nearest tenth) by stratum. Record LF, lifeform (T or S).

1 = < 1% 2 = 1-5% 3 = 6-10% 4 = 11-25% 5 = 26-33% 6 = 34-50% 7 = 51-75% 8 = 76-95% 9 = 96-100%

Total Cover All Spp Total Cover All Spp Total Cover All Spp Total Cover All Species

C R Field 0 – 0.5m C R LF Sub-canopy 0.5 – 2m H C R LF Canopy 2 – 5m H C R LF Canopy >5m

List other common associates 

C Field 0 – 0.5m C LF Sub-canopy 0.5 – 2m H C LF Canopy 2 – 5m H C LF

USGS-NPS Vegetation Mapping Program Field Data Sheet:

Canopy >5m

Intermediate Plot Vegetation Version: 0.00

Association name: Use “—” within strata, “/” between strata and “( )” to denote minor species

Intermediate_Plot_Veg_Datasheet_v000.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.

National Park Service 

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Inventory and Monitoring Program

Page ____ of ____

50m Bearing: 20m Bearing: Protocol Version: 0.04 Protocol Name: VegMap UTM NAD83: 

Keyed Formation:

Time (00:00): Sub-Map #:

Tentative Formation: Recorder: Observer(s):

Plot ID: Field Poly ID: Poly ID(s):

Date (mm/dd/yyyy):

Location and Event Information

Park:
54 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park Stand Maturity Young/ regenerating Even age/ aggrading Mature/ even-age Transition/ break up Old growth/ senescent Uneven age Other: (X) Plot Homogeneity Homogeneous Compositional trend Conspicuous inclusions Irregular Pattern mosaic (X) Pole/Stem Count Basal Diameter(s) over 10 cm Species Disturbance Types NOTES: Describe the overall vegetative community, especially noting differences from other similar communities. 

Intermediate_Plot_Veg_Datasheet_v000.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.

Camera Name & Photo Number(s): 

Basal Diameter and Pole Count for Tree Species
Appendix C: Plot Data Sheets 55Intermediate_Plot_Soil_Landscape_Datasheet_v000.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.

(X) Landform (X all that apply)

Upper Alluvial FanLower Alluvial FanFloodplainAlluvial TerraceWashArroyoMountainHillColluvial TalusOutcropDrainage (IFW/IFF)

(X)

Topographic 

Position

(X all that apply)

Crest/summitSholderBackslopeFootslopeToeslopeNo Slope (N/A)Other:

(X)

Parent Material

(X all that apply)

Intrusive Igneous BedrockExtrusive Igneous BedrockVolcanic Ash BedrockMetamorphic BedrockNon-calcareous sedimentary rockCalcareous sedimentary rockColluviumOld AlluviumNew AlluviumAeolian - Windblown

Erosion Features (circle one class per feature)

Tunneling None Rare Common ProlificSheet None Rare Common ProlificRill None Rare Common ProlificGully None Rare Common ProlificPedestals None Rare Common ProlificTerracettes None Rare Common ProlificBurrowing None Rare Common Prolific

Slope Class

(X all that apply)

0-1%1-6%6-15%15-35%35-50%50+%

(X)

National Park Service 

Sonoran Desert Network U.S. Department of the Interior

Inventory and Monitoring Program

Page ____ of ____

USGS-NPS Vegetation Mapping Program Field Data Sheet: Intermediate Plot Soil/Landscape Version: 0.00

Proofread by: ______ Copied by: ______ Entered by: ______ Verified by: ______ New Poly ID: ___________________

Protocol Version: 0.04 Protocol Name: VegMap UTM NAD83:

Keyed Formation:

Time (00:00): Sub-Map #:

Tentative Formation: Recorder: Observer(s):

Plot ID: Field Poly ID: Poly ID(s):

Date (mm/dd/yyyy): Park:

None Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Bare SoilNone Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Horizonated LitterNone Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Down WoodNone Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Physical CrustNone Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Biological CrustNone Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Bedrock OutcropsNone Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Rock: 75 + mmNone Sparse (1-15%) Medium (15-35%) Common (35-60%) Dominant (>60%) Gravel: 2-75 mm

Class Feature

Area Surface Cover (circle one class per feature)

N NW W SW S SE E NE

Aspect (circle all that apply)

Location and Event Information

Soil/Landscape Parameters
56 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park NOTES: 1) Write a short descriptive paragraph on the major soil type, slope position, and geomorphic features. 2) Sketch any soil or geologic features within the plot; e.g., arroyos, changes in soils, rock outcrops. National Park Service Sonoran Desert Network U.S. Department of the Interior Inventory and Monitoring Program Page ____ of ____

Intermediate_Plot_Soil_Landscape_Datasheet_v000.ppt If you find this datasheet completed, please call (520) 731-3420 ext. 5.
Appendix D: Vegetation Type Descriptions 57

This appendix includes information on the vegetation type descriptions identifi ed for Tumacácori 

National Historical Park. All information not identifi ed as specifi c to Tumacácori NHP was collected 

from NatureServe Explorer (http://www.natureserve.org/explorer/), including the NatureServe codes, 

global descriptions, vegetation hierarchy, ecological systems placement, and references. Distinctions 

between types are based on the vegetation formation key (see Appendix A).

Forest

Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest

Prosopis velutina Forest Alliance

Celtis laevigata var. reticulata Forest Alliance

Woodland

Populus fremontii - Salix gooddingii Woodland

Prosopis velutina Woodland Alliance

Acacia greggii Woodland Alliance

Wooded Shrubland

Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded Shrubland Alliance

Shrubland

Prosopis velutina - Acacia greggii Shrubland

Acacia constricta Shrubland Alliance

Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance

Wooded Herbaceous

Populus fremontii / Mixed Annual Wooded Herbaceous Alliance

Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance

Shrub Herbaceous

Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance

Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] Shrub Herbaceous Alliance

Herbaceous

[Amaranthus palmeri - Salsola kali - Chenopodium sp.] Annual Herbaceous Alliance

Sparsely Vegetated

Inland Freshwater Strand Beach Sparse Vegetation

Developed Woodland

Cropland and Pasture

Park Facilities

Appendix D

Vegetation Type Descriptions
58 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.1 Forest

D.1.1 Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest

Translated name: Fremont cottonwood - Goodding’s willow / Mule’s-fat Forest

NatureServe code: A.313 / CEGL002683

Summary

Globally—This is a lowland forested riparian association known from the Gila River watershed in New Mexico, and potentially occurring elsewhere in southwestern New Mexico and 

southern Arizona. It occurs in lowland river valleys at elevations ranging from 1,220 to 1,410 

m (4,000–4,625 ft). Stream gradients are moderate (0.3–0.9%), and channel substrates gravelly 

or fi ner. Occurring on low- to mid-elevation bars within and along channels, fl ood-recurrence 

intervals vary widely, but typically range between two and fi ve years. Some sites are considerably higher in the fl oodplain and are rarely fl ooded (25–100 years). Soils are young, weakly 

developed Entisols that are commonly sandy with a cobbly matrix. Others, particularly those 

of higher terraces, are sandy or loamy throughout. The soils are generally dry on the surface 

most of the year, but they may be periodically moist within the rooting zone (40–150 cm). 

The vegetation of this association is characterized by young to middle-aged stands of Populus 

fremontii and Salix gooddingii with moderate to closed canopies (usually greater than 60% 

cover). Celtis laevigata var. reticulata, Fraxinus velutina, Juglans major, Juniperus monosperma, 

and Platanus wrightii can occur as subcanopy associates, but are never dominant. Baccharis 

salicifolia is well-represented to abundant in the shrub layer and is diagnostic. Other shrubs 

are scattered and may include Amorpha fruticosa, Ericameria nauseosa (= Chrysothamnus 

nauseosus), Rhus trilobata, and Salix exigua. The herbaceous layer can range from sparse and 

species-poor to well-represented and species-rich, but variable. A total of 54 grasses and forbs 

have been recorded for the type, 7 of which were wetland indicators. The most common were 

Hydrocotyle verticillata, Schoenoplectus pungens (= Scirpus pungens), Phyla lanceolata, Juncus 

balticus, and Muhlenbergia asperifolia.

Tumacácori National Historical Park—This is the most prevalent type at Tumacácori, following both sides of the Santa Cruz River for its length through the Mission unit of the park. 

Populus fremontii is the dominant tree species in both cover and height, forming a canopy 

averaging 10–20 m high. Beneath this, the subdominant Salix gooddingii occurs at variable 

density and generally 6–8 m in height, though some individuals are larger. Below the cottonwood–willow canopy, the ground is relatively open except for areas of thick Tamarix 

ramosissima along the river channel that are interspersed throughout the park. At the time of 

mapping, the NPS was conducting a tamarisk eradication program; therefore, tamarisk cover 

is indeterminate, as the effi cacy of the treatment is not yet known. Baccharis salicifolia is a 

widely dispersed associate, and is not consistent in its distribution, but is generally present. 

Overall, woody species distribution in this community is a patchy mosaic, apart from the 

consistent Populus fremontii and Salix gooddingii, with a mixture of Prosopis velutina, Celtis 

laevigata var. reticulata, and Sambucus nigra ssp. caerulea trees and shrubs. Other associates 

include the shrubs Baccharis sarothroides and Anisacanthus thurberi. The herbaceous layer is 

a mosaic as well, but with the non-native grass, Cynodon dactylon, frequently present along 

the river channel, especially in areas that are fl ooded regularly. In areas where river debris 

is signifi cant there is little herbaceous growth, except for stands of the non-native tall forb, 

Conium maculatum, in and around debris piles where soil has been exposed. In other areas, 

especially those away from persistent river fl ows, Amaranthus palmeri and Chloris virgata are 

generally dominant. Throughout the association, there is a diversity (25–30 species) of annual 

and perennial herbaceous plants, but they are sparse and widely dispersed.

Classifi cation

Classifi cation confi dence: 1 - Strong

Classifi cation comments: Globally—This is a mid-successional community that forms 
Appendix D: Vegetation Type Descriptions 59

between the herbaceous/shrub types established on lower bars following fl oods and mature 

forests of upper terraces. The moist, sandy soils are suitable for the development of a rich 

herbaceous understory. This type is closely related to both Populus fremontii / Baccharis salicifolia Woodland (CEGL000941) and Populus fremontii - Salix gooddingii / Salix exigua Forest 

(CEGL002684) (Muldavin et al. 2000). All three types, in turn, are probably refi nements of 

the Fremont cottonwood - willow type of Laurenzi et al. (1983) and Brown et al. (1979), and 

the Populus fremontii / Salix gooddingii community type of Reichenbacher (1984) and Szaro 

(1989) documented for Arizona, and by Campbell and Dick-Peddie (1964) and Dick-Peddie 

(1993) in New Mexico.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data 

(10 classifi cation plots and 6 censused polygons). The global summary and classifi cation comments apply fairly well, but at TUMA the association generally has less abundant B. salicifolia, 

and Prosopis velutina is a common associate. At TUMA, this forest is supported by perennial 

fl ow in the Santa Cruz River channel derived from a municipal wastewater treatment plant.

Vegetation hierarchy

Formation class I Forest

Formation subclass I.B Deciduous forest

Formation group I.B.2 Cold-deciduous forest

Formation subgroup I.B.2.N Natural/Semi-natural cold-deciduous forest

Formation name I.B.2.N.d Temporarily fl ooded cold-deciduous forest

Alliance name Populus fremontii Temporarily Flooded Forest Alliance

Association name Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest

Ecological systems placement

Ecological system unique ID Ecological system name

CES302.748 North American Warm Desert Lower Montane Riparian 

Woodland and Shrubland

CES302.753 North American Warm Desert Riparian Woodland and 

Shrubland

NatureServe conservation status 

Global status: G2 (01Dec2000)

Rounded global status: G2 - Imperiled

Distribution

Globally—This association is restricted to the Gila River watershed (Grant County) and 

probably elsewhere in southwestern New Mexico and southern Arizona.

Tumacácori National Historical Park—This type is found in 6 polygons, all in the Mission unit: F-PF01-M (20.6 ha), F-PF02-M (8.2 ha), F-PF03-M (7.0 ha), F-PF04-M (3.0 ha), 

F-PF05-M (2.0 ha), F-PF06-M (1.1 ha).

Environmental setting

USFWS wetland system: Yes

Environmental summary: Globally—This community type occurs in lowland river valleys 

at elevations ranging from 1,220 to 1,410 m (4,000–4,625 ft). Stream gradients are moderate 

(0.3–0.9%), and channel substrates are gravelly or fi ner. Occurring on low- to mid-elevation 

bars within and along channels, fl ood recurrence intervals vary widely but typically range 

between two and fi ve years. Some sites are considerably higher in the fl oodplain and are 
60 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

rarely fl ooded (25–100 years). Soils are young, weakly developed Entisols that are commonly 

sandy with a cobbly matrix. Others, particularly those of higher terraces, are sandy or loamy 

throughout. The soils are generally dry on the surface most of the year, but they may be periodically moist within the rooting zone (40–150 cm).

Tumacácori National Historical Park—The global environmental summary generally applies at TUMA, but with the association occurring at elevations down to about 900 m. A municipal wastewater treatment facility upstream of the Mission unit provides a perennial base 

fl ow in the Santa Cruz River channel supporting this association. It is not found at Calabazas 

or Guevavi, upstream of the facility, due to insuffi cient natural fl ow. All reaches of the river are 

subject to short-duration seasonal fl ooding.

Vegetation

Globally—This type is characterized by young to middle-aged stands of Populus fremontii

and Salix gooddingii with moderate to closed canopies (usually greater than 60% cover). Celtis 

laevigata var. reticulata, Fraxinus velutina, Juglans major, Juniperus monosperma, and Platanus 

wrightii can occur as subcanopy associates but are never dominant. Baccharis salicifolia is 

well-represented to abundant in the shrub layer and is diagnostic. Other shrubs are scattered 

and may include Amorpha fruticosa, Ericameria nauseosa (= Chrysothamnus nauseosus), Rhus 

trilobata var. trilobata, and Salix exigua. The herbaceous layer can range from sparse and 

species-poor to well-represented and species-rich but variable. A total of 54 grasses and forbs 

have been recorded for the type, 7 of which were wetland indicators. The most common were 

Hydrocotyle verticillata, Schoenoplectus pungens (= Scirpus pungens), Phyla lanceolata, Juncus 

balticus, and Muhlenbergia asperifolia.

Tumacácori National Historical Park—Populus fremontii is the dominant tree species of the 

type, while Salix gooddingii is a subdominant, characteristic species and is found in clumps 

and often as a secondary canopy of 6–8 m in height. The canopy of Populus fremontii averages 

10–20 m high throughout the type and is generally open beneath, except for areas of thick 

Tamarix ramosissima along the river channel that are interspersed throughout the park. At the 

time of mapping, the NPS was conducting a tamarisk eradication program; therefore, tamarisk cover is indeterminate, as the effi cacy of the treatment is yet to be determined. Baccharis 

salicifolia is widely dispersed and is not consistent in its distribution. Overall, woody species 

distribution in this community is a patchy mosaic, apart from the consistent Populus fremontii 

and Salix gooddingii, with a mixture of Prosopis velutina, Celtis laevigata var. reticulata, and 

Sambucus nigra ssp. caerulea trees and shrubs. Other associates are Baccharis sarothroides and 

Anisacanthus thurberi. The herbaceous layer is a mosaic as well, but with Cynodon dactylon

present consistently along the river channel, especially in areas that are fl ooded regularly. In 

areas where river debris is signifi cant there is little herbaceous growth, outside of a dominance 

of Conium maculatum in and around debris piles where soil has been exposed. In other areas, 

especially those away from persistent river fl ows, Amaranthus palmeri and Chloris virgata are 

generally dominant. Throughout the type there is a diversity of annual and perennial herbaceous plants, but they are sparse and widely dispersed.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Populus fremontii, Salix gooddingii

Canopy (2–5m) Baccharis salicifolia, Prosopis velutina

Sub-canopy (0.5–2m) Baccharis salicifolia, B. sarothroides, P. velutina

Field (0–0.5m) Cynodon dactylon, Conium maculatum, Bidens leptocephala

Other noteworthy species: Globally—Data are not available.
Appendix D: Vegetation Type Descriptions 61

Tumacácori National Historical Park—Celtis laevigata var. reticulata, Sambucus nigra 

ssp. caerulea, Fraxinus velutina, Hymenoclea monogyra, Anisacanthus thurberi, Amaranthus 

palmeri, Chloris virgata, Xanthium strumarium

Element sources

Global description authors: E. Muldavin et al.

Local description authors: S. Buckley and S. Drake

References: NatureServe. 2008. NatureServe Explorer: An online encyclopedia of life [web 

application]. Version 7.0. NatureServe, Arlington, Virginia. Available http://www.natureserve.

org/explorer. (Accessed: January 7, 2009 ).

• Brown, D. E., C. H. Lowe, and C. P. Pase. 1979. A digitized classifi cation system for 

the biotic communities of North America with community (series) and association 

examples for the Southwest. Journal of the Arizona-Nevada Academy of Science 

14:1-16.

• Campbell, C. J. and W. A. Dick-Peddie. 1964. Comparison of phreatophyte communities on the Rio Grande in New Mexico. Ecology 45:492-501.

• Dick-Peddie, W. A. 1993. New Mexico vegetation: Past, present, and future. University of New Mexico Press, Albuquerque. 244 pp.

• Laurenzi, A. W., R. D. Ohmart, and N. C. Hink. 1983. Classifi cation of mixed broadleaf riparian forests in Tonto National Forest. Pages 72-81 in: Proceedings of the 

workshop on Southwestern habitat types. USDA Forest Service, Southwestern Region.

• Muldavin, E., P. Durkin, M. Bradley, M. Stuever, and P. Mehlhop. 2000. Handbook of 

wetland vegetation communities of New Mexico: Classifi cation and community descriptions (volume 1). Final report to the New Mexico Environment Department and 

the Environmental Protection Agency prepared by the New Mexico Natural Heritage 

Program, University of New Mexico, Albuquerque, NM.

• Reichenbacher, F. W. 1984. Ecology and evolution of southwestern riparian plant 

communities. Desert Plants 6(1):15-23.

• Szaro, R. C. 1989. Riparian forest and scrubland community types of Arizona and 

New Mexico. Desert Plants Special Issue 9(3-4):70-139.
62 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.1.2 Prosopis velutina Forest Alliance

Translated name: Velvet mesquite Forest Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance is very prevalent at TUMA, usually 

occupying alluvial terraces along the outermost edges of the Santa Cruz River fl oodplain, outside the 

band of Populus fremontii - Salix gooddingii forest along the channel, in areas that are relatively moist 

but rarely inundated. It sometimes occurs in narrow bands along the base of cliff s and embankments 

bordering the fl oodplain as well as at the mouths of tributary drainages as they enter the fl oodplain. 

These areas receive concentrated rainfall runoff and a steady supply of fresh alluvium from adjacent 

uplands, resulting in relatively deep soils and higher moisture availability without the disturbance 

associated with frequent fl ood events. Soils are sandy or sandy loam, often contain signifi cant gravel, 

and have at least a thin but nearly continuous litter layer. The alliance contains several recognizable 

associations with diff erent subdominant species, diff erent structure and cover, and with Prosopis

stands of apparently diff erent ages. It may occur on former agricultural fi elds, appearing as even-aged 

stands of nearly uniform Prosopis velutina averaging 3–6 m in height, with individuals closely spaced 

and forming an interlocking canopy, with relatively little understory. Or it may be composed of older, 

larger Prosopis with Celtis laevigata var. reticulata, Sambucus nigra ssp. caerulea, and occasional Salix 

gooddingii interspersed, with a signifi cant shrub understory of sapling trees, Acacia greggii, Baccharis 

salicifolia, Ziziphus obtusifolia, Lycium andersonii and Anisacanthus thurberi. In addition, there may 

be a diverse herbaceous layer of annual and perennial grasses and forbs, and ground-to-crown vines 

such as Phaseolus ritensis, Clematis drummondii and Ipomoea species. Sporobolus wrightii or Cynodon 

dactylon may dominate the herbaceous layer in places.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (6 classifi -

cation plots and 7 censused polygons).

Vegetation hierarchy

Formation class I Forest

Formation subclass I.B Deciduous forest

Formation group I.B.2 Cold-deciduous forest

Formation subgroup I.B.2.N Natural/Semi-natural cold-deciduous forest

Formation name I.B.2.N.a Lowland or submontane cold-deciduous forest

Alliance name Prosopis velutina Forest Alliance

Association name Data are not available.

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status

Global status: Data are not available.

Rounded global status: Data are not available.
Appendix D: Vegetation Type Descriptions 63

Distribution

Globally—Data are not available.

Tumacácori National Historical Park—This type is found in 7 polygons: 5 at the Mission 

unit, 1 at Calabazas and 1 at Guevavi: F-PV01-M (7.4 ha), F-PV02-M (6.1 ha), F-PV03-M (1.2 

ha), F-PV04-M (0.7 ha), F-PV05-M (0.5 ha), F-PV06-C (1.0 ha), F-PV07-G (0.6 ha).

Environmental setting

USFWS wetland system: Data are not available.

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance is very prevalent at TUMA, 

usually occupying alluvial terraces along the outermost edges of the Santa Cruz River fl oodplain, outside the band of Populus fremontii - Salix gooddingii forest along the channel, in areas 

that are relatively moist but rarely inundated. It sometimes occurs in narrow bands along the 

base of cliff s and embankments bordering the fl oodplain as well as at the mouths of tributary 

drainages as they enter the fl oodplain. These areas receive concentrated rainfall runoff and a 

steady supply of fresh alluvium from adjacent uplands, resulting in relatively deep soils and 

higher moisture availability without the disturbance associated with frequent fl ood events. 

Soils are sandy or sandy loam, often contain signifi cant gravel, and have at least a thin but 

nearly continuous litter layer. Other surface cover types that may be present at 1–15% include 

bare soil, gravel or rock, and downed wood.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—The alliance contains several recognizable associations with diff erent subdominant species, diff erent structure and cover, and with Prosopis

stands of apparently diff erent ages. It may occur on former agricultural fi elds, appearing as 

even-aged stands of nearly uniform Prosopis velutina averaging 3–6 m in height, with individuals closely spaced and forming an interlocking canopy, with relatively little understory. Or it 

may be composed of older, larger Prosopis with Celtis laevigata var. reticulata, Sambucus nigra 

ssp. caerulea, and occasional Salix gooddingii interspersed, with a signifi cant shrub understory 

of sapling trees, Acacia greggii, Baccharis salicifolia, Ziziphus obtusifolia, Lycium andersonii and 

Anisacanthus thurberi. In addition, there may be a diverse herbaceous layer (often dominated 

by Amaranthus palmeri) of annual and perennial grasses and forbs, and ground-to-crown 

vines such as Phaseolus ritensis, Clematis drummondii and Ipomoea species. Sporobolus 

wrightii or Cynodon dactylon may dominate the herbaceous layer in places.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Prosopis velutina, Sambucus nigra ssp. caerulea, Celtis laevigata var.

reticulata

Canopy (2–5m) Prosopis velutina, Acacia greggii, Celtis laevigata var. reticulata, 

Sambucus nigra ssp. caerulea

Sub-canopy (0.5–2m) Prosopis velutina, Ziziphus obtusifolia, Celtis laevigata var.

reticulata, Anisacanthus thurberi

Field (0–0.5m) Amaranthus palmeri, Sporobolus wrightii, Bidens leptocephala, 

Cynodon dactylon

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Acacia greggii (rarely in top canopy), Ziziphus 

obtusifolia (rarely in canopy), Baccharis salicifolia, Opuntia spinosior, Yucca elata, Lycium spp., 

Helianthus annuus.
64 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
Appendix D: Vegetation Type Descriptions 65

D.1.3 Celtis laevigata var. reticulata Forest Alliance

Translated name: Netleaf hackberry Forest Alliance

NatureServe code: A.226

Summary

Globally—Dune thickets, to 6 m tall, salt-pruned, with variable admixture of other species of 

shrubs and dwarfed trees. These forests resemble dwarf forests or shrublands in some cases. 

Associations in this alliance are dominated by Celtis laevigata, sometimes codominated by 

Zanthoxylum clava-herculis, with Vitis mustangensis and Acacia farnesiana (= Acacia smallii)

often abundant. Grazing has aff ected the structure and species composition of many examples. Soils are dune sands with no profi le development.

Tumacácori National Historical Park—The above global description does not apply well 

to the appearance of this alliance at TUMA. Only a single association within the alliance is 

described (from coastal Texas and Louisiana), and it does not resemble the community at 

TUMA. At TUMA, this alliance is found primarily on shallow slopes that run along old agricultural fencelines. This dense forest is comprised of Celtis laevigata var. reticulata and Prosopis velutina that range in height from 8 to 12 m in the uppermost canopy, with considerable 

numbers of Sambucus nigra ssp. caerulea or Acacia greggii growing up underneath to a height 

of 4–8 m. The largest Celtis specimens are found immediately along the fencelines, which in 

isolated instances still receive runoff from actively cultivated agricultural land. This type is 

notable because of the multi-layered structure and density of the forest, from the interlocking top canopy to the dense sub-canopy. In the sub-canopy there is signifi cant recruitment of 

Celtis, Prosopis, and Sambucus, with some Acacia greggii and occasional Ziziphus obtusifolia

and Lycium andersonii shrubs. The herbaceous layer is notably sparse in areas beneath the 

denser canopies, where there is also considerable downed woody debris, but in openings 

there is a higher diversity of both forbs and occasional grasses. In isolated sections of this type 

there are Cynodon dactylon patches, often along foot trails.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (3 

classifi cation plots and 4 censused polygons).

Vegetation hierarchy

Formation class I Forest

Formation subclass I.B Deciduous forest

Formation group I.B.2 Cold-deciduous forest

Formation subgroup I.B.2.N Natural/Semi-natural cold-deciduous forest

Formation name I.B.2.N.a Lowland or submontane cold-deciduous forest

Alliance name Celtis laevigata var. reticulata Forest Alliance

Association name Data are not available

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.
66 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Distribution

Globally—United States

Tumacácori National Historical Park—This type is found in 4 polygons: 2 at the Mission 

unit, 1 at Calabazas and 1 at Guevavi: F-CL01-M (1.1 ha), F-CL02-M (0.7 ha), F-CL03-C (1.3 

ha), F-CL04-G (0.7 ha).

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Grazing has aff ected the structure and species composition of many examples. Soils are dune sands with no profi le development.

Tumacácori National Historical Park—This alliance is found primarily on shallow slopes 

that run along old agricultural fencelines.

Vegetation

Globally—Associations in this alliance are dominated by Celtis laevigata, sometimes codominated by Zanthoxylum clava-herculis, with Vitis mustangensis often abundant.

Tumacácori National Historical Park—This dense forest is comprised of Celtis laevigata 

var. reticulata and Prosopis velutina that range in height from 8 to 12 m in the uppermost 

canopy, with considerable numbers of Sambucus nigra ssp. caerulea or Acacia greggii growing 

up underneath to a height of 4–8 m. The largest Celtis specimens are found immediately along 

old fencelines, which in isolated instances still receive runoff from actively cultivated agricultural land. This type is notable because of the multi-layered structure and density of the forest, 

from the interlocking top canopy to the dense sub-canopy. In the sub-canopy there is signifi -

cant recruitment of Celtis, Prosopis, and Sambucus, with some Acacia greggii and occasional 

Ziziphus obtusifolia and Lycium andersonii shrubs. The herbaceous layer is notably sparse in 

areas beneath the denser canopies, where there is also considerable downed woody debris, 

but in openings there is a higher diversity of both forbs and occasional grasses. In isolated sections of this type there are Cynodon dactylon patches, often along foot trails.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Celtis laevigata var. reticulata, Prosopis velutina

Canopy (2–5m) Celtis, Prosopis, Sambucus nigra ssp. caerulea, Acacia greggii

Sub-canopy (0.5–2m) Celtis, Prosopis, Sambucus, Acacia greggii, Ziziphus obtusifolia

Field (0–0.5m) Sporobolus wrightii, Amaranthus palmeri

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Salix gooddingii, Anisacanthus thurberi, Bouteloua 

curtipendula, Cynodon dactylon, Rivina humilis, Bidens leptocephala, Helianthus annuus, Chenopodium spp.

Element sources

Global description authors: A. S. Weakley/L. M. Smith. Ecological data developed by NatureServe and its network of natural heritage programs and other contributors and cooperators.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
Appendix D: Vegetation Type Descriptions 67

D.2 Woodland

D.2.1 Populus fremontii - Salix gooddingii Woodland

Translated name: Fremont cottonwood - Goodding’s willow Woodland

NatureServe code: A.644, CEGL000944

Summary

Globally—This community occurs as small isolated stands or as linear bands that parallel 

stream channels in the Trans-Pecos region of western Texas, in southwestern New Mexico, 

southeastern Arizona, and south into northern Mexico. It has also been reported from isolated tributary drainages in southern Utah. The vegetation is dependent upon a subsurface water 

supply and varies considerably with the height of the water table. Major fl ood events and 

consequent fl ood scour, overbank deposition of water and sediments, and stream meandering are important factors that shape this community. Soils are typically stratifi ed sands, loams, 

and gravels. This deciduous woodland typically towers above the surrounding vegetation. 

Populus fremontii and Salix gooddingii may be nearly equal in abundance, or either may dominate. Individuals of Populus fremontii are scattered or occur in groves and may reach 30 m in 

height and 2 m in diameter. Other species that may occur in the canopy/subcanopy include 

Populus deltoides ssp. wislizeni, Salix lasiolepis, Salix amygdaloides, Fraxinus berlandieriana, 

Celtis laevigata var. reticulata, Juglans microcarpa, Prosopis pubescens, Prosopis glandulosa, 

and Prosopis velutina. The understories of most examples have been considerably altered by 

grazing and other factors, thus the composition and cover of the native understory is diffi cult 

to ascertain but frequently consists of shrubs and small trees (1–5 m tall). The herbaceous 

stratum varies in composition and coverage but is characterized by mixed annuals and shortlived perennials.

Tumacácori National Historical Park—This woodland association is similar in composition 

to the Populus fremontii - Salix gooddingii / Baccharis salicifolia Forest that occurs throughout 

the park, but has lower plant density and cover. In particular, it has less than 60% tree cover, 

and Forest has more than 60% tree cover, following the NVC defi nitions. The type is located 

in the river fl oodplain, between an ephemeral channel on the west and savanna types surrounding it on the south, north, and east. It is dominated by Populus fremontii, with a patchy 

canopy and the inclusion of Salix gooddingii in specifi c areas. Baccharis salicifolia is generally 

the dominant shrub. The entire type is on a slightly elevated sandy-silty island and has considerable downed woody debris piled up throughout. Beneath the Populus fremontii canopy, 

the understory is relatively open and has more herbaceous plants than shrubs, dominated by 

Hilaria belangeri, Cynodon dactylon, and the annual grass Chloris virgata. The annual forb 

Bidens leptocephala is characteristically found in dense concentrations in the shade. Shrubs 

are often distinctly clumped and diverse, ranging from Hymenoclea monogyra, Baccharis 

salicifolia and Senecio fl accidus to specimens of Opuntia spinosior. Throughout the type, Amaranthus palmeri and Salsola kali are present but not in the same density as they are found in 

neighboring wooded-herbaceous or shrub-herbaceous types.

Classifi cation

Classifi cation confi dence: 2 - Moderate

Classifi cation comments: Globally—In Trans-Pecos Texas, this woodland is dependent on 

a subsurface water supply and varies considerably with the water table levels. Major fl ood 

events and consequent fl ood scour, overbank deposition of water and sediments, and stream 

meandering are important factors that shape this community. These woodlands once occupied the fl oodplains and riverbanks of most perennial waterways within its range, but have 

mostly been replaced by disturbance types dominated by exotic species.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (6 

classifi cation plots and 3 censused polygons). At TUMA, this woodland is supported by perennial fl ow in the Santa Cruz river channel derived from a municipal wastewater treatment plant.
68 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Vegetation hierarchy

Formation class II Woodland

Formation subclass II.B Deciduous woodland

Formation group II.B.2 Cold-deciduous woodland

Formation subgroup II.B.2.N Natural/Semi-natural cold-deciduous woodland

Formation name II.B.2.N.b Temporarily fl ooded cold-deciduous woodland

Alliance name Populus fremontii Temporarily Flooded Woodland Alliance

Association name Populus fremontii - Salix gooddingii Woodland

Ecological systems placement

Ecological system unique ID Ecological system name

CES302.748 North American Warm Desert Lower Montane Riparian 

Woodland and Shrubland

CES302.753 North American Warm Desert Riparian Woodland and 

Shrubland

CES306.821 Rocky Mountain Lower Montane-Foothill Riparian Woodland 

and Shrubland

NatureServe conservation status 

Global status: G2 (23Feb1994)

Rounded global status: G2 - Imperiled

Distribution

Globally—AZ, CA, CO, NM, TX, UT

Tumacácori National Historical Park—This type is found in 3 polygons, all at the Mission 

unit: W-PF01-M (0.6 ha), W-PF02-M (13.4 ha), W-PF03-M (2.5 ha).

Environmental setting

USFWS wetland system: Yes

Environmental summary: Globally—This deciduous woodland is best developed along 

alluvial fl oodplains of large, low-gradient, perennial streams that fl ow through wide, unconstrained valleys. It has also been recorded surrounding perennially wet potholes within intermittent canyon drainages, as well as in the fl oodplains of intermittent streams. The vegetation 

is dependent upon a subsurface water supply and varies considerably with the height of the 

water table. Major fl ood events and consequent fl ood scour, overbank deposition of water 

and sediments, and stream meandering are important factors that shape this community. Soils 

are typically stratifi ed sands, loams, and gravels classifi ed as Torrifl uvents or Ustifl uvents, with 

Haplustolls on more stable sites. These coarse-textured, alluvial sediments have a low waterholding capacity and low nutrient availability.

Tumacácori National Historical Park—The global environmental summary applies to this 

association at TUMA. At TUMA, the association is located in the river fl oodplain, between 

an ephemeral channel on the west and savanna types surrounding it on the south, north, and 

east.

Vegetation

Globally—This community occurs as small isolated stands or as narrow bands that parallel 

the stream channel or border a pothole. This deciduous woodland typically towers above the 

surrounding vegetation, with Populus fremontii and Salix gooddingii as the dominant species. These species may be nearly equal in abundance, or either may dominate. Individuals of 
Appendix D: Vegetation Type Descriptions 69

Populus fremontii are scattered or occur in groves and may reach 30 m in height and 2 m in 

diameter. Other species that may occur in the canopy/subcanopy include Populus deltoides 

ssp. wislizeni, Salix lasiolepis, Salix amygdaloides, Fraxinus berlandieriana, Celtis laevigata var.

reticulata, Fraxinus velutina, Juglans microcarpa, Prosopis pubescens, Prosopis glandulosa, and 

Prosopis velutina. The understory of most examples has been considerably altered by grazing and other factors, thus the composition and cover of the native understory is diffi cult to 

ascertain. The understory can be dense to open and frequently consists of shrubs and small 

trees 1–5 m tall, including Prosopis spp., Baccharis salicifolia, Salix exigua, Sambucus mexicana, 

Rhamnus spp., Morus microphylla, and Amorpha fruticosa. The woody exotics Elaeagnus angustifolia and various species of Tamarix now dominate the understory of most examples. The 

herbaceous stratum varies in composition and coverage but is characterized by mixed annuals 

and short-lived perennials. While most examples now have a herbaceous fl ora dominated by 

exotic species, in particular Cynodon dactylon, native species reported from this community 

include Amaranthus palmeri, Amsinckia spp., Anemopsis californica, Boerhavia coccinea, 

Bowlesia incana, Carex spp., Chloracantha spinosa, Conyza canadensis var. canadensis, Cucurbita spp., Datura wrightii, Distichlis spicata, Euthamia occidentalis, Gutierrezia sarothrae, 

Juncus balticus, Lemna spp., Oenothera spp., Sorghum halepense, Sporobolus wrightii, and Trifolium longipes ssp. shastense.

Tumacácori National Historical Park—This type is similar in composition to the Populus 

fremontii - Salix gooddingii / Baccharis salicifolia Forest found throughout the park, but has 

lower plant density and cover. It is dominated by Populus fremontii, with a patchy canopy and 

the inclusion of Salix gooddingii in specifi c areas. Baccharis salicifolia is generally the dominant shrub. The association is confi ned to a slightly elevated sandy-silty island and has considerable downed woody debris piled up throughout. Beneath the Populus fremontii canopy 

the understory is relatively open and has more herbaceous plants than shrubs, dominated by 

Hilaria belangeri, Cynodon dactylon, and the annual grass Chloris virgata. The annual forb 

Bidens leptocephala is characteristically found in dense concentrations in the shade. Shrubs 

are often distinctly clumped and diverse, ranging from Hymenoclea monogyra, Baccharis 

salicifolia and Senecio fl accidus to specimens of Opuntia spinosior. Throughout the type, Amaranthus palmeri and Salsola kali are present but at lower density than is found in neighboring 

wooded-herbaceous or shrub-herbaceous types.

Most abundant species: Globally—

Stratum Species

Tree canopy Populus fremontii, Salix gooddingii

Tree sub-canopy Fraxinus velutina

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Populus fremontii, Salix gooddingii

Canopy (2–5m) Baccharis salicifolia, Prosopis velutina, Hymenoclea monogyra, 

Sambucus nigra ssp. caerulea, Tamarix ramosissima

Sub-canopy (0.5–2m) Baccharis salicifolia, Hymenoclea monogyra

Field (0–0.5m) Cynodon dactylon, Amaranthus palmeri, Chloris virgata

Other noteworthy species: Globally—

Tumacácori National Historical Park—Celtis laevigata var. reticulata, Baccharis sarothroides, Ziziphus obtusifolia, Bidens leptocephala

Element sources

Global description authors: E. Milford and E. Muldavin

Local description authors: S. Buckley and S. Drake

References: Data are not available.
70 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.2.2 Prosopis velutina Woodland Alliance

Translated name: Velvet mesquite Woodland Alliance

Alternative name: Prosopis (glandulosa, velutina) Woodland Alliance; Honey mesquite, Velvet mesquite Woodland Alliance

NatureServe code: A.661

Summary

Globally—This alliance occurs in southern California, Arizona, and possibly southwestern 

New Mexico and adjacent Mexico on a variety of sites. Sites include mesic areas such as 

fl oodplains, streambanks, intermittently fl ooded arroyo terraces, alkali sinks and washes, and 

extends into the upland on dry terraces above streams and arroyos. Substrates are generally 

coarse-textured, gravelly alluvium. Prosopis spp. trees extract groundwater with extensive root 

systems, but grow best where water tables are shallow such as along drainages. Woodlands included in this alliance are characterized by a moderate to dense tall woody canopy dominated 

by Prosopis glandulosa and/or Prosopis velutina. The diversity of other species can vary greatly 

with geography and substrate. The dominant understory shrubs are often species of Atriplex, 

but may include many other species. Succulents may include several species of Opuntia and 

Yucca. The herbaceous layer is variable from moderately dense to nearly absent. Characteristic perennial grasses may include Aristida spp., Bouteloua spp., Buchloe dactyloides, Pleuraphis 

mutica (= Hilaria mutica), Muhlenbergia porteri, and Sporobolus spp. Sparse annual grasses 

may also be present. Forb cover is also sparse, but it can be relatively diverse. Common forbs 

may include species of Amaranthus, Chenopodium, Croton, Eriogonum, Euphorbia, Solanum, 

and Zinnia. Diagnostic of this woodland alliance is the dominance of tree-sized Prosopis glandulosa or Prosopis velutina in the upper canopy.

Tumacácori National Historical Park—This woodland alliance generally occurs further 

away from the river channel than the forest alliances, in more xeric sites. Plant canopy cover 

varies, up to about 50%, with signifi cant open or nearly-open patches possibly present. Prosopis velutina is usually clearly dominant in both height and canopy cover, but in places, Acacia 

greggii, commonly the second-dominant species, is a close rival. Within this type, A. greggii

(and to a lesser extent P. velutina) can be found as a tree lifeform, a shrub lifeform, or something intermediate. The Prosopis-dominated upper canopy averages 6–8 m in height, ranging 

to 10 m. In addition to A. greggii, occasional Sambucus nigra ssp. caerulea and Celtis laevigata 

var. reticulata individuals may also reach this height and, in one patch of this alliance, a few 

Populus fremontii and Salix gooddingii exceed it. In the sub-canopy, Prosopis and Acacia still 

dominate (as caespitose shrubs to sapling trees), with common associates being Celtis and 

Sambucus saplings, Ziziphus obtusifolia, Mimosa aculeaticarpa var. biuncifera, Baccharis sarothroides, B. salicifolia, Anisacanthus thurberi, Hymenoclea monogyra, Lycium andersonii and 

Condalia warnockii. The herbaceous layer is almost everywhere dominated by Amaranthus 

palmeri, occasionally by Cynodon dactylon. Important associates are Bouteloua curtipendula, 

Salsola kali, Chenopodium sp., Bidens leptocephala and Chloris virgata, but a variety of other 

grasses and forbs may occur.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Classifi cation of Prosopis glandulosa- and Prosopis velutina-dominated stands needs clarifi cation. Because Prosopis glandulosa and Prosopis velutina

can have both shrub and tree growth forms, there may be confusion classifying a given stand. 

For example, what characteristic separates a Prosopis glandulosa or Prosopis velutina arroyo 

riparian shrubland from a Prosopis glandulosa and/or Prosopis velutina ‘bosque’ or riparian 

woodland. Riparian shrublands can mature into woodlands if given time and adequate water 

resources. 

Currently, this alliance has only one provisional association from California and Arizona with 

possible occurrences in New Mexico and Baja California and Sonora, Mexico. There are 
Appendix D: Vegetation Type Descriptions 71

several references to Prosopis (glandulosa, velutina) riparian woodland/forests from sub-Mogollon Arizona such as Minckley and Clark (1981, 1984) and Szaro (1989). Warren et al. (1981) 

describe Prosopis glandulosa riparian woodlands from southwestern Arizona that could be included in the provisional association within Prosopis (glandulosa, velutina) Woodland Alliance 

(A.661). Another provisional association may need to be created for the Prosopis glandulosa

woodlands occurring in the San Joaquin Valley in California. 

No associations outside of Texas have been described in the Prosopis glandulosa woodland 

or Prosopis glandulosa intermittently fl ooded woodland alliances. These woodlands appear 

signifi cantly diff erent, but more study is needed to clarify the boundaries between the Texas 

and California/Arizona alliances. Some arroyo riparian stands in Arizona are similar to stands 

in the Parkinsonia fl orida - Olneya tesota Woodland Alliance (A.588) as far as species composition and must be separated mainly by dominance. 

The taxonomy of Prosopis may further complicate the classifi cation. There are three varieties of Prosopis glandulosa, Prosopis glandulosa var. glandulosa which occurs in New Mexico, 

Texas, Colorado, Kansas, Oklahoma and Louisiana, Prosopis glandulosa var. torreyana which 

occurs in California, Nevada, Utah, Arizona, New Mexico and Texas, and Prosopis glandulosa 

var. prostrata which occurs only in Texas. Prosopis velutina is restricted to California, Arizona 

and New Mexico. Szaro (1989) describes a Prosopis velutina riparian community type (shrublands and woodlands) from southwestern New Mexico to western Arizona. In addition, 

Prosopis glandulosa var. torreyana and Prosopis velutina are known to intergrade where ranges 

overlap in southern Arizona (Kearney and Peebles 1969). See Benson and Darrow (1981) for 

more discussion.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data 

(11 classifi cation plots and 8 censused polygons). At TUMA, velvet mesquite, Prosopis velutina, is the dominant; no P. glandulosa was observed.

Vegetation hierarchy

Formation class II Woodland

Formation subclass II.B Deciduous woodland

Formation group II.B.3 Extremely xeromorphic deciduous woodland

Formation subgroup II.B.3.N Natural/Semi-natural extremely xeromorphic 

deciduous woodland

Formation name II.B.3.N.a Thorn extremely xeromorphic deciduous woodland

Alliance name Prosopis (glandulosa, velutina) Woodland Alliance

Association name Data are not available

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.

Distribution

Globally—Mexico, United States. Woodlands included in this alliance occur along drainages 

in southern California, Arizona and possibly in southwestern New Mexico, and the Mexican 

states of Baja California, Sonora, and Chihuahua.
72 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Tumacácori National Historical Park—This type is found in 8 polygons: 4 at the Mission 

unit, 3 at Guevavi and 1 at Calabazas: W-PV01-M (9.6 ha), W-PV02-M (1.4 ha), W-PV03-M 

(1.2 ha), W-PV04-M (1.7 ha), W-PV05-G (1.3 ha), W-PV06-G (0.8 ha), W-PV07-G (0.5 ha), 

W-PV08-C (1.0 ha).

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Woodlands included in this alliance occur in southern 

California, Arizona, and possibly southwestern New Mexico and adjacent Mexico. Elevations 

range from sea level to 1,200 m. Climate is arid to semi-arid. Amount and season of precipitation is varies with geography. Mean annual precipitation ranges from 23 cm distributed bimodally with about half occurring during the late summer monsoons and half in the winter in 

southwestern New Mexico, to approximately 15 cm of mostly winter precipitation in southeastern California. This vegetation occurs on a variety of sites. Mesic sites include fl oodplains, 

streambanks, intermittently fl ooded arroyo terraces, alkali sinks and washes. Upland sites 

such as the rarely fl ooded and dry terraces above streams and arroyos. Sites are generally fl at 

or gently sloping on any aspect. Parent material is usually sandy or gravelly alluvium. Substrates are generally coarse-textured, but may include gravelly silty loams. Some soils are moderately saline. Prosopis spp. trees extract ground water with extensive root systems, but grow 

best where water tables are shallow such as along drainages. These woodlands may grade into 

upland grasslands dominated by species of Bouteloua, Sporobolus or Hilaria, or be surrounded by a matrix of desertscrub that is dominated by Larrea tridentata or Ambrosia spp. In the 

San Joaquin Valley, Holland (1986) describes sites occurring on sandy loams with high water 

tables, hot-dry summers and foggy winters. The water table is fed from Sierran snowmelt.

Dynamics: Prosopis and other shrubs have extensive root systems that allow them to exploit 

deep soil water that is unavailable to shallower rooted grasses and cacti (Burgess 1995). This 

strategy works well except on sites that have well-developed argillic or calcic soil horizons 

that limit infi ltration and storage of winter moisture in the deeper soil layers (McAuliff e 1995). 

McAuliff e (1995) found Prosopis spp. invasion on these sites limited to a few, small individuals. 

This has implications in plant geography and grassland revegetation work in the southwestern 

U.S.

Tumacácori National Historical Park—This woodland alliance generally occurs further 

away from the river channel than the forest alliances, in more xeric sites on terraces above the 

active channel. Surface cover is generally mesquite litter and bare soil, but may be gravelly or 

rocky. Stands vary in density, layered structure (complexity) and height, probably as a function 

of their age and grazing history.

Vegetation

Globally—Woodlands included in this alliance occur primarily along drainages in southern 

California and possibly southwestern New Mexico, Arizona, and adjacent Mexico. Stands 

have moderate to dense cover dominated by the xeromorphic deciduous shrubs Prosopis glandulosa and/or Prosopis velutina. The diversity of other species can vary greatly with geography 

and substrate. The dominant understory shrubs are often species of Atriplex, but may include 

Acacia greggii, Acacia constricta, Ambrosia spp., Artemisia fi lifolia, Baccharis spp., Chilopsis linearis, Ericameria laricifolia, Gutierrezia sarothrae, Larrea tridentata, Lycium spp., Parkinsonia

spp., Olneya tesota, and Ziziphus obtusifolia. Succulents may include Opuntia acanthocarpa, 

Opuntia leptocaulis, Opuntia imbricata, Opuntia phaeacantha, Yucca baccata, and Yucca elata. 

The herbaceous layer can be moderately dense to insignifi cant depending on geography, 

substrate, land use history and annual precipitation the herbaceous layer can be moderately 

dense to insignifi cant. Characteristic perennial grasses may include Aristida spp., Bouteloua 

curtipendula, Bouteloua eriopoda, Bouteloua gracilis, Buchloe dactyloides, Pleuraphis mutica (= 

Hilaria mutica), Muhlenbergia porteri, Sporobolus fl exuosus, and Sporobolus wrightii. Sparse 

annual grasses may include Aristida adscensionis, Bouteloua barbata, and Dasyochloa pulchella 
Appendix D: Vegetation Type Descriptions 73

(= Erioneuron pulchellum). Forb cover is also sparse, but it can be relatively diverse. Common 

forbs may include species of Amaranthus, Chenopodium, Croton, Eriogonum, Euphorbia, Solanum, and Zinnia. In more saline areas, shrubs are more sparse and grasses and forbs are more 

common, including Sporobolus airoides, Distichlis spicata, and Sesuvium verrucosum. Holland 

(1986) described open Prosopis glandulosa woodlands in the San Joaquin Valley in southern 

California, that have a shrub layer dominated by Atriplex polycarpa with Isocoma acradenia 

var. bracteosa. The herbaceous layer is sparse except during wet years when annual cover, 

dominated by the exotic grass Bromus rubens, is abundant. Perennial plant cover is sparse.

Tumacácori National Historical Park—In this woodland alliance, plant canopy cover varies, up to about 50%, with signifi cant open or nearly-open patches possibly present. Prosopis 

velutina is usually clearly dominant in both height and canopy cover, but in places Acacia greggii, commonly the second-dominant species, is a close rival. Within this type, A. greggii (and, 

to a lesser extent, P. velutina) can be found as a tree lifeform, a shrub lifeform, or something 

intermediate. The Prosopis-dominated upper canopy averages 6–8 m in height, ranging to 10 

m. In addition to A. greggii, occasional Sambucus nigra ssp. caerulea and Celtis laevigata var.

reticulata individuals may reach this height also, and in one patch of this type a few Populus 

fremontii and Salix gooddingii exceed it. In the sub-canopy Prosopis and Acacia still dominate 

(as caespitose shrubs to sapling trees), with common associates being Celtis and Sambucus

saplings, Ziziphus obtusifolia shrubs, Mimosa aculeaticarpa var. biuncifera, Baccharis sarothroides, B. salicifolia, Anisacanthus thurberi, Hymenoclea monogyra, Lycium andersonii and 

Condalia warnockii. The herbaceous layer is almost everywhere dominated by Amaranthus 

palmeri, occasionally by Cynodon dactylon. Important associates are Bouteloua curtipendula, 

Salsola kali, Chenopodium sp., Bidens leptocephala and Chloris virgata, but a variety of other 

grasses and forbs may occur.

Most abundant species: Globally—

Stratum Species

Tree canopy Prosopis glandulosa or P. velutina

Tall shrub/sapling Acacia greggii

Short shrub/sapling Atriplex canescens

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Prosopis velutina, Acacia greggii

Canopy (2–5m) Prosopis velutina, Acacia greggii, Celtis laevigata var. reticulata

Sub-canopy (0.5–2m) Prosopis velutina, Acacia greggii,Baccharis sarothroides, Ziziphus 

obtusifolia, Mimosa aculeaticarpa var. biuncifera

Field (0–0.5m) Amaranthus palmeri, Salsola kali,Bidens leptocephala, Bouteloua 

spp.

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Celtis laevigata var. reticulata and Sambucus nigra 

ssp. caerulea (in top canopy), Lycium andersonii, Hymenoclea monogyra, Anisacanthus thurberi, Cynodon dactylon, Chloris virgata.

Element sources

Global description authors: K. Schulz. Ecological data developed by NatureServe and its 

network of natural heritage programs and other contributors and cooperators

Local description authors: S. Buckley and S. Drake
74 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

References:

• Benson and Darrow 1981: Data are not available.

• Burgess, T. L. 1995. Desert grassland, mixed shrub savanna, shrub steppe, or semidesert scrub. Pages 31-67 in: M. P. McClaran and T. R. Van Devender, editors. The 

Desert Grassland. University of Arizona Press, Tucson.

• Holland, R. F. 1986. Preliminary descriptions of the terrestrial natural communities 

of California. Unpublished report prepared for the California Department of Fish 

and Game, Nongame-Heritage Program and Natural Diversity Database, Sacramento. 

156 pp.

• Kearney, T. H., and R. H. Peebles, and collaborators. 1969. Arizona fl ora. University 

of California, Berkeley, CA. 1085 pp.

• McAuliff e, J. R. 1995. Landscape evolution, soil formation, and Arizona's desert 

grasslands. Pages 100-129 in: M. P. McClaran and T. R. Van Devender, editors. The 

Desert Grassland. University of Arizona Press, Tucson.

• Minckley, W. L., and T. O. Clark. 1981. Vegetation of the Gila River resource area, 

eastern Arizona. Desert Plants 3:124-140.

• Minckley, W. L., and T. O. Clark. 1984. Formation and destruction of a Gila River 

mesquite bosque community. Desert Plants 6(1):23-30.

• Szaro, R. C. 1989. Riparian forest and scrubland community types of Arizona and 

New Mexico. Desert Plants Special Issue 9(3-4):70-139.

• Warren et al. 1995: Data are not available.
Appendix D: Vegetation Type Descriptions 75

D.2.3 Acacia greggii Woodland Alliance

Translated name: Catclaw acacia Woodland Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance is dominated by Acacia 

greggii and Prosopis velutina trees 6–8 m tall, and shorter Acacia greggii and Ziziphus obtusifolia 

shrubs. Associated shrub species, such as Condalia warnockii, Baccharis sarothroides, Lycium 

andersonii, Hymenoclea monogyra, and Anisacanthus thurberi, are scattered across the type. 

Most of the trees and shrubs in this alliance have such thick, dense canopies that herbaceous 

plants are largely confi ned to the interspaces between overstory canopies. The herbaceous 

layer is dominated by the annual forbs, Amaranthus palmeri and Bidens leptocephala, with a 

variety of other forbs and grasses possibly present and generally sparsely distributed.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data 

(2 classifi cation plots and 1 censused polygon). Lifeform of the A. greggii (and many Prosopis) 

in this type is somewhat ambiguous, as individuals are generally multi-stemmed at or near the 

ground surface, but are about 6.5 m tall and have an elevated canopy, so they were considered 

trees for classifi cation. This alliance and its position in the hierarchy below are proposed.

Vegetation hierarchy

Formation class II Woodland

Formation subclass II.B Deciduous woodland

Formation group II.B.3 Extremely xeromorphic deciduous woodland

Formation subgroup II.B.3.N Natural/Semi-natural extremely xeromorphic 

deciduous woodland

Formation name II.B.3.N.a Thorn extremely xeromorphic deciduous woodland

Alliance name Acacia greggii Woodland Alliance

Association name Data are not available

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.

Distribution

Globally—Data are not available.

Tumacácori National Historical Park—This type is found in 1 polygon at the Mission unit: 

W-AG01-M (2.1 ha).

Environmental setting

USFWS wetland system: No
76 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—The single stand of this type lies on the west boundary of the Mission unit, on a terrace relatively distant from the present river channel and 

adjacent to upland shrub-dominated vegetation. Surface cover is primarily litter, bare soil and 

rock (smooth river cobbles).

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—This type is dominated by Acacia greggii and Prosopis velutina trees 6–8 m tall, and shorter Acacia greggii and Ziziphus obtusifolia shrubs. Associated shrub species, such as Condalia warnockii, Mimosa aculeaticarpa var. biuncifera, Baccharis sarothroides, Lycium andersonii, Hymenoclea monogyra, and Anisacanthus thurberi, are 

scattered across the type. Most of the trees and shrubs in this alliance have such thick, dense 

canopies that herbaceous plants are largely confi ned to the interspaces between overstory 

canopies. The herbaceous layer is dominated by the annual forbs Amaranthus palmeri and 

Bidens leptocephala, with a variety of other forbs and grasses possibly present and generally 

sparsely distributed.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Acacia greggii, Prosopis velutina

Canopy (2–5m) Acacia greggii, Prosopis velutina

Sub-canopy (0.5–2m) Ziziphus obtusifolia, Acacia greggii, Lycium andersonii

Field (0–0.5m) Amaranthus palmeri, Salsola kali, Bidens leptocephala

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Celtis laevigata var. reticulata, Mimosa aculeaticarpa 

var. biuncifera, Baccharis sarothroides, Prospois velutina, Chenopodium sp., Bouteloua radicosa, 

Eragrostis cilianensis.

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
Appendix D: Vegetation Type Descriptions 77

D.3 Wooded Shrubland

D.3.1 Prosopis velutina / [Prosopis velutina - Acacia greggii] Wooded 

Shrubland Alliance

Translated name: Velvet mesquite / [Velvet mesquite - Catclaw acacia] Wooded Shrubland Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance covers the largest area at the Calabazas unit, including the portion surrounding the ruins. Although primarily found on gently sloped 

upland, this type also extends down steeper, relatively xeric slopes south and west of the ruins. These 

areas have very thin, sandy, or gravelly soils, with minimal litter except on toe slopes. Larger rocks or 

bedrock outcrops are usually visible. There is one stand of this type at the Mission unit adjacent to 

abandoned agricultural land, on deeper, loamier soil. This alliance is characterized by an open canopy 

of Prosopis velutina shrubs, mostly 2–4 m tall but with many larger, tree-lifeform individuals up to 

7.5 m. These Prosopis and the other trees present make up >10% cover. Acacia greggii is common in 

the shrub layer; it is usually, but not always, less abundant than Prosopis, and also averages 2–4 m tall. 

Density of the shrub layer is variable. In more xeric areas, Baccharis sarothroides may have signifi cant 

cover and A. greggii may be absent or nearly so. Acacia constricta and Mimosa aculeaticarpa var. biuncifera are generally present. Other woody associates vary by topographic position: a few individuals of 

Juniperus coahuilensis, Condalia warnockii, and Opuntia spinosior are present on the hilltop fl ats and 

adjacent upper slopes, while Ziziphus obtusifolia, Celtis laevigata var. reticulata, Anisacanthus thurberi, 

and Lycium andersonii may be found on more mesic middle- and toe-slopes. Most of the larger P. velutina are also found in these more mesic areas. Amaranthus palmeri and Bidens leptocephala, which may 

be dense in localized patches, are the only abundant forbs in an otherwise grass-dominated (Bouteloua 

curtipendula, Sporobolus wrightii, Chloris virgata, Muhlenbergia porteri) herbaceous layer.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (8 classifi -

cation plots and 2 censused polygons).

Vegetation hierarchy

Formation class Data are not available

Formation subclass Data are not available

Formation group Data are not available

Formation subgroup Data are not available

Formation name Wooded Shrubland

Alliance name Prosopis velutina / [Prosopis velutina – Acacia greggii] Wooded 

Shrubland Alliance

Association name Data are not available

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.
78 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Distribution

Globally—Data are not available.

Tumacácori National Historical Park—This type is found in 2 polygons: 1 at the Mission 

unit and 1 at Calabazas: WS-PV01-M (0.6 ha), WS-PV02-C (6.5 ha).

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This alliance covers the largest area at the Calabazas 

unit, including the portion surrounding the ruins. Although primarily found on gently sloped 

upland, this type also extends down steeper, relatively xeric hillslopes. These areas have very 

thin, sandy or gravelly soils with minimal litter except on toe slopes. Larger rocks or bedrock 

outcrops are usually visible. There is one stand of this type at the Mission unit adjacent to 

abandoned agricultural land, on deeper, loamier soil.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—This alliance is characterized by an open canopy 

of Prosopis velutina shrubs, mostly 2–4 m tall but with many larger, tree-lifeform individuals 

up to 7.5 m. These Prosopis and the other trees present make up >10% cover. Acacia greggii is 

common in the shrub layer; it is usually, but not always, less abundant, and also averages 2–4 

m tall. Density of the shrub layer is variable. In more xeric areas, Baccharis sarothroides may 

have signifi cant cover and A. greggii may be absent or nearly so. Acacia constricta and Mimosa 

aculeaticarpa var. biuncifera are generally present. Other woody associates vary by topographic position: a few individuals of Juniperus coahuilensis, Condalia warnockii and Opuntia 

spinosior are present on the hilltop fl ats and adjacent upper slopes, while Lycium andersonii,

Ziziphus obtusifolia, Anisacanthus thurberi, and Celtis laevigata var. reticulata, may be found on 

more mesic middle- and toe-slopes. Most of the larger P. velutina are also found in these more 

mesic areas. Amaranthus palmeri and Bidens leptocephala, which may be dense in localized 

patches, are the only abundant forbs in an otherwise grass-dominated (Bouteloua curtipendula, Sporobolus wrightii, Chloris virgata, Muhlenbergia porteri) herbaceous layer.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Prosopis velutina, Acacia greggii

Canopy (2–5m) Acacia greggii, Prosopis velutina, Lycium andersonii

Sub-canopy (0.5–2m) Acacia greggii, Lycium andersonii

Field (0–0.5m) Chloris virgata, Bouteloua curtipendula, Amaranthus palmeri, 

Bidens leptocephala

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Ziziphus obtusifolia, Baccharis sarothroides, Acacia 

constricta, Mimosa aculeaticarpa var. biuncifera, Anisacanthus thurberi, Sporobolus wrightii, 

Sporobolus cryptandrus

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
Appendix D: Vegetation Type Descriptions 79

D.4 Shrubland

D.4.1 Prosopis velutina - Acacia greggii Shrubland

Translated name: Velvet mesquite - Catclaw acacia Shrubland

NatureServe code: A.1043 / CEGL001388

Summary

Globally (Alliance)—This shrubland alliance occurs in the Chihuahuan and Sonoran deserts. Sites include sandy plains, mesas, bajadas, drainage terraces and channels, fl oodplains, 

and rocky slopes. Although Prosopis velutina is deep-rooted, it typically occurs on sites with 

shallow water tables, especially along arroyos. Sites are generally fl at or on gentle to moderate 

south-facing slopes. Substrates are generally coarse-textured, but may include gravelly clay 

loams. Some sites are moderately saline. Shrublands included in this alliance are dominated 

by the shrub/small tree Prosopis velutina. Acacia greggii and Celtis laevigata var. reticulata are 

frequent riparian scrub co-dominants. These shrublands often have high shrub diversity and 

may include Acacia constricta, Chilopsis linearis, Ericameria laricifolia, Gutierrezia sarothrae, 

Hymenoclea salsola, Isocoma tenuisecta, Juniperus monosperma, Larrea tridentata, Mimosa 

aculeaticarpa var. biuncifera (= Mimosa biuncifera), and Rhus spp. The herbaceous layer has 

sparse to moderate cover of medium-tall and short perennial grasses. Characteristic perennial 

grasses include Aristida spp., Bouteloua curtipendula, Bouteloua eriopoda, Dasyochloa pulchella (= Erioneuron pulchellum), Elymus elymoides, Hilaria belangeri, Muhlenbergia porteri, and 

Sporobolus spp. Annual grasses are present, but have sparse cover. Forbs are also sparse, but 

may include species of Datura, Mentzelia, Polanisia, and Rumex. Succulents are often present 

and may include Agave spp., Ferocactus wislizeni, Opuntia spp., Yucca baccata, or Yucca elata

depending on geography. Diagnostic of this alliance is the dominance of Prosopis velutina in 

the shrub layer.

Tumacácori National Historical Park (Association)—Note: NatureServe Explorer describes 

this type as an alliance (A.1043), as in the paragraph above, and lists this type as an association 

(CEGL 001388), but does not describe it. The following description is for a proposed association 

as it occurs at TUMA.

This association is found primarily on mesa-tops and along the crest of hillslopes at the 

Guevavi unit. It is dominated by moderate-sized Prosopis velutina shrubs 1–3.5 m tall, with 

Acacia greggii shrubs common on the hillslopes. In areas with greater than 5% slope, the species commingle. The slopes have a higher percentage of Bouteloua curtipendula in the herbaceous layer compared with the fl ats of the mesa-tops, where there is far more of the annual 

forbs, Amaranthus palmeri and Bouteloua aristidoides, in addition to other mixed Bouteloua 

spp. (likely including B. rothrockii and B. barbata), which were not reliably identifi able due to 

seasonal dormancy. Other woody species associated with this type include Acacia constricta, 

Opuntia spinosior, O. englemanii, Baccharis sarothroides, and Ferocactus wislizenii, although 

there are rarely more than a few individuals of these species present. This type includes the 

adobe ruins at the center of the Guevavi unit, which accounts for some disturbance, with the 

presence of the entrance trail, an interpretive ramada, and the church ruins themselves. There 

also appear to be other subsurface modifi cations that may account for distributional diff erences among some species in the areas immediately adjacent to the ruins, including the presence of Sporobolus wrightii. Eragrostis lehmanniana and Aristida spp. may also be signifi cant 

in the understory. The indication is that the mesa-top is more mesic than the slopes, as well as 

having more sandy soils in areas, while the slopes are rockier.

Classifi cation

Classifi cation confi dence: 3 - weak

Classifi cation comments: Globally (Alliance)—Classifi cation of Prosopis velutina-dominated stands needs clarifi cation. Because Prosopis velutina can have both shrub and tree growth 
80 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

forms, there may be confusion classifying a given stand. For example, what characteristic 

separates a Prosopis velutina arroyo riparian shrubland from a Prosopis velutina “bosque” or 

riparian woodland. Some arroyo riparian stands in Arizona are similar to stands in the Baccharis sarothroides-, Acacia greggii- and Parkinsonia spp.-dominated alliances as far a species 

composition and separated mainly by dominance. Also, the formation that this alliance is classifi ed in does not allow succulents. However, many stands in this alliance have a fairly consistent presence of succulents, usually species of Opuntia and Yucca.

Tumacácori National Historical Park (Association)—The Prosopis velutina - Acacia greggii

Shrubland is the only association within the Prosopis velutina Shrubland Alliance that occurs 

at TUMA. Note that the local Tumacácori elements of this description apply to the association, while the global elements apply to the alliance, and are included for additional context. 

Global information is from NatureServe (http://www.natureserve.org/explorer). Field data to 

support the association description at TUMA were collected in 2007–2008 from 7 classifi cation plots and 3 censused polygons.

Vegetation hierarchy

Formation class III Shrubland

Formation subclass III.B Deciduous shrubland

Formation group III.B.3 Extremely xeromorphic deciduous shrubland

Formation subgroup III.B.3.N Natural/Semi-natural extremely xeromorphic 

deciduous shrubland

Formation name III.B.3.N.a Extremely xeromorphic deciduous subdesert 

shrubland without succulents

Alliance name Prosopis velutina Shrubland Alliance

Association name Prosopis velutina - Acacia greggii Shrubland

Ecological systems placement

Ecological system unique ID Ecological system name

CES302.733 Apacherian-Chihuahuan Mesquite Upland Scrub

CES302.752 North American Warm Desert Riparian Mesquite Bosque

CES302.755 North American Warm Desert Wash

NatureServe conservation status 

Global status: GUQ (23Feb1994) 

Rounded global status: GU - Unrankable

Distribution

Globally (Alliance)—Data are not available. 

Tumacácori National Historical Park (Association)—This association is found in 3 polygons: 2 at Guevavi and 1 at Calabazas: S-PV01-G (5.2 ha), S-PV02-G (1.7 ha), S-PV03-C (2.0 

ha).

Environmental setting

USFWS wetland system: No

Environmental summary: Globally (Alliance)—Shrublands included in this alliance occur 

in the Chihuahuan and Sonoran deserts. Elevation ranges from 400 to 1,520 m. Climate is arid 

to semi-arid. Summers are hot. Winter temperature are generally mild with freezing temperature more common in the higher elevation Chihuahuan Desert. Precipitation varies with geography. Mean annual precipitation ranges from about 22 cm in southeastern New Mexico at 
Appendix D: Vegetation Type Descriptions 81

the Jornada Experimental Range to 28 cm at Tucson, Arizona, but can vary greatly from year 

to year. At the Jornada Experimental Range, annual precipitation ranged from 7 to 45 cm, with 

drought not uncommon (Herbel et al. 1972). Annual precipitation has bimodal distribution 

with the proportion of summer precipitation decreasing westward (Barbour and Major 1977). 

At the Jornada Experimental Range, about two-thirds of the annual precipitation occurs in 

July through October and a third during the winter months. At Tucson, Arizona, about half of 

the annual rain falls in July to October, with the balance during the winter months. The most 

arid season is late spring and early summer. The summer rain often occurs as high-intensity 

convective storms. Sites include sandy plains, mesas, bajadas, drainage terraces and channels, 

fl oodplains and rocky slopes. Although Prosopis velutina is deep-rooted, tapping water tables 

as deep as 50 m (Burgess 1995), it typically occurs on shallow water tables, especially along 

arroyos. Sites are generally fl at or on gentle to moderate south-facing slopes. Parent material 

is usually sandy or gravelly alluvium, or eolian sand derived from limestone and metamorphic 

rocks. Substrates are generally coarse-textured, but may include gravelly clay loams. Some 

sites are moderately saline. These shrublands may grade into grasslands dominated by Bouteloua gracilis, Sporobolus airoides, Pleuraphis mutica, or be surrounded by a matrix of desert 

shrublands dominated by Larrea tridentata or Ambrosia spp.

Dynamics: Shrublands dominated by Prosopis spp. have replaced large areas of desert 

grasslands, especially those formerly dominated by Bouteloua eriopoda in Trans-Pecos Texas, 

southern New Mexico, and southeastern Arizona (Hennessy et al. 1983, York and Dick-Peddie 1969). Studies on the Jornada Experimental Range suggest that combinations of drought, 

overgrazing by livestock, wind and water erosion, seed dispersal by livestock, fi re suppression, shifting dunes, and changes in the seasonal distribution of precipitation have caused this 

recent, dramatic shift in vegetation physiognomy (Buffi ngton and Herbel 1965, Gibbens et 

al. 1983, Herbel et al. 1972, Hennessy et al. 1983, Humphrey 1974, McLaughlin and Bowers 

1982, McPherson 1995, Schlesinger et al. 1990). Prosopis and other shrubs have extensive 

root systems that allow them to exploit deep soil water that is unavailable to shallower-rooted 

grasses and cacti (Burgess 1995). This strategy works well, except on sites that have welldeveloped argillic or calcic soil horizons that limit infi ltration and storage of winter moisture 

in the deeper soil layers (McAuliff e 1995). McAuliff e found Prosopis velutina invasion on these 

sites limited to a few, small individuals. This has implications in plant geography and grassland 

revegetation work in the southwestern U.S.

Tumacácori National Historical Park (Association)—This association occurs on toe-slopes 

or low fl ats, on sandy loam soils, sometimes rocky. Predominant surface cover is gravel, generally 35–60%, with less cover of bare soil or rock.

Vegetation

Globally (Alliance)—Shrublands included in this alliance cover extensive areas of sandy 

plains, bajadas, and mesas across southwestern New Mexico and southeastern Arizona, 

invading open grasslands and often forming thickets. It also occurs as arroyo riparian vegetation, where it forms a tall, often dense shrub canopy. Stands have a moderate to dense 

(30–80%) woody canopy cover dominated by the xeromorphic deciduous shrub/small tree 

Prosopis velutina. Frequent riparian scrub co-dominants are Acacia greggii, Celtis laevigata var.

reticulata. These shrublands often have a diverse shrub layer. Other common woody species include Acacia constricta, Chilopsis linearis, Ericameria laricifolia, Gutierrezia sarothrae, 

Hymenoclea salsola, Isocoma tenuisecta, Juniperus monosperma, Larrea tridentata, Mimosa 

aculeaticarpa var. biuncifera (= Mimosa biuncifera), and Rhus spp. The herbaceous layer has 

sparse to moderate (to 60%) cover of perennial medium-tall and short perennial grasses. 

Characteristic perennial grasses include Aristida spp., Bouteloua curtipendula, Bouteloua 

eriopoda, Dasyochloa pulchella (= Erioneuron pulchellum), Elymus elymoides, Hilaria belangeri, 

Muhlenbergia porteri, and Sporobolus spp. Annual grasses are present, but have sparse cover. 

Forbs are also sparse, but may include species of Datura, Mentzelia, Polanisia, and Rumex. 

Succulents are often present and may include Agave spp., Ferocactus wislizeni, Opuntia acanthocarpa, Opuntia engelmannii, Opuntia leptocaulis, Opuntia imbricata, Opuntia phaeacantha, 
82 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Opuntia spinosior, Yucca baccata, or Yucca elata, depending on geography.

Tumacácori National Historical Park (Association)—This association is found primarily 

on mesa-tops and along the crest of hillslopes at the Guevavi unit, with limited distribution 

at Calabazas. It is dominated by moderate-sized Prosopis velutina shrubs 1–3.5 m tall, with 

Acacia greggii shrubs common on the hillslopes. In areas with greater than 5% slope, the species commingle. The slopes have a higher percentage of Bouteloua curtipendula in the herbaceous layer compared with the fl ats of the mesa-tops, where there is far more of the annual 

forb Amaranthus palmeri and Bouteloua aristidoides in addition to other mixed Bouteloua 

spp. (likely including B. rothrockii and B. barbata), which were not reliably identifi able due to 

seasonal dormancy. Other woody species associated with this type include Acacia constricta, 

Opuntia spinosior, O. engelmannii, Baccharis sarothroides, and Ferocactus wislizenii, although 

there are rarely more than a few individuals of these species present. This type includes the 

adobe ruins at the center of the Guevavi unit, which accounts for some disturbance, with the 

presence of the entrance trail, an interpretive ramada, and the church ruins themselves. There 

also appear to be other subsurface modifi cations that may account for distributional diff erences among some species in the areas immediately adjacent to the ruins, including the presence of Sporobolus wrightii. Eragrostis lehmanniana and Aristida spp. may also be signifi cant 

in the understory. The indication is that the mesa-top is more mesic than the slopes, as well as 

having more sandy soils in areas, while the slopes are rockier.

Most abundant species: Globally (Alliance)—Data are not available.

Tumacácori National Historical Park (Association)—

Stratum Species

Top canopy (>5m) Prosopis velutina (rare)

Canopy (2–5m) Prosopis velutina, Acacia greggii

Sub-canopy (0.5–2m) Prosopis velutina, Acacia greggii

Field (0–0.5m) Amaranthus palmeri, mixed Bouteloua spp.

Other noteworthy species: Globally (Alliance)—Data are not available.

Tumacácori National Historical Park (Association)—Mimosa biuncifera, Baccharis sarothroides, Ferocactus wislizenii, Ziziphus obtusifolia, Opuntia spinosior, Sporobolus wrightii, 

Eragrostis lehmanniana, Aristida spp.

Element sources

Global description authors (Alliance): K. Schulz.

Local description authors (Association): S. Buckley and S. Drake

References: K. Schulz. NatureServe. 2008. NatureServe Explorer: An online encyclopedia of 

life [web application]. Version 7.0. NatureServe, Arlington, Virginia. Available http://www.

natureserve.org/explorer. (Accessed: September 15, 2008)

• Barbour, M. G., and J. Major, editors. 1977. Terrestrial vegetation of California. John 

Wiley and Sons, New York. 1002 pp.

• Buffi ngton, L. C., and C. H. Herbel. 1965. Vegetational changes on a semidesert grassland range from 1858 to 1963. Ecological Monographs 35(2):139-164.

• Burgess, T. L. 1995. Desert grassland, mixed shrub savanna, shrub steppe, or semidesert scrub. Pages 31-67 in: M. P. McClaran and T. R. Van Devender, editors. The 

Desert Grassland. University of Arizona Press, Tucson.

• Gibbens, R. P., J. M. Tromble, J. T. Hennessy, and M. Cardenas. 1983. Soil movement 
Appendix D: Vegetation Type Descriptions 83

in mesquite dunelands and former grasslands of southern New Mexico. Journal of 

Range Management 36(2):145-148.

• Hennessy, J. T., R. P. Gibbens, J. M. Tromble, and M. Cardenas. 1983. Vegetation 

changes from 1935 to 1980 in mesquite dunelands and former grasslands of southern 

New Mexico. Journal of Range Management 36(3):370-374.

• Herbel, C. H., F. N. Ares, and R. Wright. 1972. Drought eff ects on a semidesert grassland range. Ecology 53:1084-1093.

• Humphrey, R. R. 1974. Fire in the deserts and desert grassland of North America. 

Pages 365-400 in: T. T. Kozlowski and C. E. Ahlgren, editors. Fire and Ecosystems. 

Academic Press, New York.

• McAuliff e, J. R. 1995. Landscape evolution, soil formation, and Arizona's desert 

grasslands. Pages 100-129 in: M. P. McClaran and T. R. Van Devender, editors. The 

Desert Grassland. University of Arizona Press, Tucson.

• McLaughlin, S. P., and J. E. Bowers. 1982. Eff ects of wildfi re on a Sonoran Desert 

plant community. Ecology 63(1):246-248.

• McPherson, G. R. 1995. The role of fi re in the desert grasslands. Pages 130-151 in: M. 

P. McClaran and T. R. Van Devender, editors. The Desert Grassland. University of 

Arizona Press, Tucson.

• Schlesinger, W. H., J. F. Reynolds, G. L. Cunningham, L. F. Huenneke, W. M. Jarrell, 

R. A. Virginia, and W. G. Whitford. 1990. Biological feedbacks in global desertifi cation. Science 247:1043-1048.

• York, J. C., and W. A. Dick-Peddie. 1969. Vegetation changes in southern New 

Mexico during the past hundred years. Pages 157-166 in: W. O. McGinnies and B. J. 

Goldman, editors. Arid lands in perspective. University of Arizona Press, Tucson.
84 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.4.2 Acacia constricta Shrubland Alliance

Translated name: Whitethorn acacia Shrubland Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance is found on steeper, well-drained 

slopes in the eastern portion of the Calabazas unit. These sites have thin, gravelly soils, often with 

exposed bedrock. Prevailing winds appear to seriously reduce retention of moisture, topsoil and litter. 

Acacia constricta, Acacia greggii, and Prosopis velutina shrubs are all usually present, average 1.5–2.5 

m tall and compose a moderately open shrubland, but may form dense thickets. Some P. velutina may 

attain tree size, especially where slopes are not as steep. Acacia constricta is dominant overall, but in 

patches, either A. greggii or Prosopis velutina may be the dominant species. The understory is notable 

for its diversity, usually composed of a mixture of native bunchgrasses, such as Bouteloua curtipendula, 

Muhlenbergia porteri, Aristida purpurea, and Setaria spp. Several other species rare in the Calabazas 

unit are found in limited numbers in this type, including Ceanothus greggii, Mimosa aculeaticarpa var.

biuncifera, Ferocactus wislizenii, Yucca elata, Echinocereus spp., and Opuntia spinosior. This type maintains a high percentage of native species and relatively low levels of human and livestock disturbance 

due to its rugged topographic position, thorny shrub cover and protection within NPS fencelines.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (6 classifi -

cation plots and 1 censused polygon). This alliance and its position in the hierarchy below are proposed.

Vegetation hierarchy

Formation class III Shrubland

Formation subclass III.B Deciduous shrubland

Formation group III.B.3 Extremely xeromorphic deciduous shrubland

Formation subgroup III.B.3.N Natural/Semi-natural extremely xeromorphic deciduous 

shrubland

Formation name III.B.3.N.a Extremely xeromorphic deciduous subdesert shrubland without 

succulents

Alliance name Acacia constricta Shrubland Alliance

Association name Data are not available

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.

Distribution

Globally—Data are not available.

Tumacácori National Historical Park—This type is found in 1 polygon at Calabazas: S-AC01-C (6.1 ha).
Appendix D: Vegetation Type Descriptions 85

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This alliance is found on steeper, well-drained 

slopes in the eastern portion of the Calabazas unit. These sites have thin, gravelly soils, often 

with exposed bedrock. Prevailing winds appear to seriously reduce retention of moisture, 

topsoil and litter. This type maintains a high percentage of native species and relatively low 

levels of human and livestock disturbance due to its rugged topographic position, thorny 

shrub cover and protection within NPS fencelines.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—Acacia constricta, Acacia greggii, and Prosopis 

velutina shrubs are all usually present, average 1.5–2.5 m tall and compose a moderately open 

shrubland, but may form dense thickets. Some P. velutina may attain tree size, especially where 

slopes are not steep. Acacia constricta is dominant overall, but in patches, either A. greggii

or Prosopis velutina may be the dominant species. The understory is notable for its diversity, usually composed of a mixture of native bunchgrasses, such as Bouteloua curtipendula, 

Aristida purpurea, Muhlenbergia porteri, and Setaria spp. Several other species rare in the 

Calabazas site are found in limited numbers in this type, including Ceanothus greggii, Mimosa 

aculeaticarpa var. biuncifera, Ferocactus wislizenii, Yucca elata, Echinocereus spp., and Opuntia 

spinosior.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Prosopis velutina

Canopy (2–5m) Prosopis velutina

Sub-canopy (0.5–2m) Acacia constricta, Acacia greggii, Mimosa aculeaticarpa var.

biuncifera

Field (0–0.5m) Bouteloua curtipendula, Aristida purpurea, Amaranthus palmeri

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Juniperus coahuilensis, Ceanothus greggii, Ferocactus 

wislizenii, Yucca elata, Echinocereus spp., and Opuntia spinosior (all occasional).

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
86 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.4.3 Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance

Translated name: Tamarisk (or saltcedar) species Semi-natural Temporarily Flooded Shrubland Alliance

NatureServe code: A.842 / CEGL003114

Summary

Globally—This alliance is composed of shrublands that form moderately dense to dense thickets on 

banks of larger streams, rivers, and playas across the western Great Plains, interior and southwestern U.S., and northern Mexico. Stands are dominated by introduced species of Tamarix, including 

Tamarix ramosissima, Tamarix chinensis, Tamarix gallica, and Tamarix parvifl ora. Introduced from 

the Mediterranean, Tamarix spp. have become naturalized in various sites, including salt fl ats, springs, 

and especially along streams and regulated rivers, often replacing Salix or Prosopis spp. shrublands or 

other native vegetation. A remnant herbaceous layer may be present, depending on the age and density 

of the shrub layer. These species have become a critical nuisance along most large rivers in the semiarid western U.S. Because of the diffi culty to remove it, Tamarix spp. may have irreversibly changed the 

vegetation along many rivers.

Tumacácori National Historical Park—This alliance is found along the northern boundary of the 

Mission unit, with the bulk of the stand found in the study area buff er, outside the park boundary. The 

topography of the area is notable because of two elevated sand bars with north-south channels running between them. On top of the sand bars are dense stands of 2–3-m tall tamarisk shrubs (Tamarix 

ramosissima) with small annual forbs scattered in openings where there is less litter cover. Along the 

margins of the dense tamarisk patches, occasional Populus fremontii, infrequent Baccharis salicifolia and Baccharis sarothroides recruits, moderate growth of Amaranthus palmeri, and often Chloris 

virgata are found, with less common Cynodon dactylon and Sporobolus cryptandrus patches. This type 

may radically change inside the park boundary because of a tamarisk eradication project being conducted by NPS at the time of mapping. The portion inside the park boundary would be herbaceousdominated without the tamarisk.

Classifi cation

Classifi cation confi dence: Confi dent or certain.

Classifi cation comments: Globally—This broadly defi ned alliance is composed of many diverse Tamarix spp.-dominated vegetation communities from a wide variety of environments. Common species 

of Tamarix include Tamarix ramosissima, Tamarix chinensis, and Tamarix parvifl ora, but other species 

are reported from the western U.S., such as Tamarix africana, Tamarix aphylla, Tamarix aralensis, 

Tamarix canariensis, Tamarix gallica, and Tamarix tetragyna (Kartesz 1999). Powell (1988) reports that 

Tamarix spp. are a critical nuisance, most notably along the Rio Grande and Pecos River. Muldavin et 

al. (2000a) described 8 community types that will be reviewed as possible USNVC associations. Currently the sole USNVC tamarix association, Tamarix spp. Temporarily Flooded Semi-natural Shrubland (CEGL003114), is equally broadly defi ned.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (1 classifi -

cation plot and 1 censused polygon). The tamarisk eradication program being carried out by the NPS 

may eliminate the presence of this alliance within the TUMA boundary, but without management it 

will probably continue to exist north of the Mission unit and elsewhere outside the park.
Appendix D: Vegetation Type Descriptions 87

Vegetation hierarchy

Formation class III Shrubland

Formation subclass III.A Evergreen shrubland

Formation group III.A.4 Microphyllous evergreen shrubland

Formation subgroup III.A.4.N Natural/Semi-natural microphyllous evergreen 

shrubland

Formation name III.A.4.N.c Temporarily fl ooded microphyllous shrubland

Alliance name Tamarix spp. Semi-natural Temporarily Flooded Shrubland Alliance

Association name Tamarix spp. Semi-natural Temporarily Flooded Shrubland

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.

Distribution

Globally—Mexico, United States. This semi-natural shrubland alliance is found along 

drainages in the semi-arid western Great Plains, interior western and southwestern U.S., and 

northern Mexico, from central and eastern Montana south to Colorado, western Oklahoma 

and Texas west to California.

Tumacácori National Historical Park—This type is found in 1 polygon at the Mission unit: 

S-TM01-M (1.1 ha). It also exists to the north (downstream) of the Mission unit, outside the 

park boundary.

Environmental setting

USFWS wetland system: Yes

Environmental summary: Globally—The riparian shrublands included in this alliance 

occur across the western Great Plains, interior western and southwestern U.S., and northern 

Mexico. These widespread shrublands are common along larger streams, rivers, and around 

playas. Elevation ranges from 75 m below sea level to 1,860 m. Tamarix spp. have become 

naturalized in various sites, including riverbanks, fl oodplains, basins, sandbars, side channels, 

springs, salt fl ats, and other saline habitats. Stands grow especially well along regulated rivers 

where fl ood-regenerated native species of Populus are declining. Substrates are commonly 

thin sandy loam soil over alluvial deposits of sand, gravel or cobbles.

Dynamics: Tamarix spp. are highly competitive shrubs that have invaded many riparian 

and wetland environments in the western U.S. Hansen et al. (1995) report that these shrubs 

are extremely drought- and salt-tolerant, produce prolifi c wind-dispersed seeds over much 

of the growing season, can resprout after burning or cutting, and, if kept moist, buried or 

broken branches will develop adventitious roots and grow. Stands seem to favor disturbed 

and fl ow-regulated rivers, but establish well in pristine areas, too. Under optimum conditions 

riparian areas can be converted to a dense thicket in less than 10 years (Hansen et al. 1995). 

Once established, stands are extremely diffi cult to eradicate, requiring cutting and herbicide 

application on stumps to prevent resprouting (Smith 1989).

Tumacácori National Historical Park—This alliance is found along the northern boundary 

of the Mission unit, with the bulk of the stand found in the study area buff er, outside the park 

boundary.
88 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Vegetation

Globally—This semi-natural shrubland alliance occurs along streams, rivers, and playas, 

where it forms a moderate to dense tall-shrub layer that is solely or strongly dominated by 

species of Tamarix, including Tamarix ramosissima, Tamarix chinensis, Tamarix gallica, and 

Tamarix parvifl ora. Other shrubs may include species of Salix (especially Salix exigua) and 

Prosopis, Rhus trilobata, and Sarcobatus vermiculatus, but with low cover (if shrub species are 

co-dominant, then stand is classifi ed as a natural shrubland). Scattered Acer negundo, Salix 

amygdaloides, Populus spp., or Elaeagnus angustifolia trees may also be present. Depending 

on stand age and density of the shrub layer, an herbaceous layer may be present. Associated 

species include Distichlis spicata, Sporobolus airoides, and introduced forage species such as 

Agrostis gigantea, Agrostis stolonifera, and Poa pratensis. Introduced herbaceous species such 

as Polypogon monspeliensis, Conyza canadensis, Lepidium latifolium, and others have been 

reported from shrublands in this association. Tamarix spp. have become a critical nuisance 

along most large rivers in the semi-arid western U.S. and, because of the diffi culty to remove, 

may have irreversibly changed the vegetation along many rivers.

Tumacácori National Historical Park—This alliance is dominated by dense stands of 2–4-m 

tall tamarisk shrubs (Tamarix ramosissima), with small annual forbs scattered in openings 

where there is less litter cover. Along the margins of the dense tamarisk patches, occasional 

Populus fremontii, infrequent Baccharis salicifolia and Baccharis sarothroides recruits, moderate growth of Amaranthus palmeri, and often Chloris virgata are found, with less-common 

Cynodon dactylon and Sporobolus cryptandrus patches. This type may radically change inside 

the park boundary because of a tamarisk eradication project being conducted by the NPS at 

the time of mapping. The portion inside the park boundary would be herbaceous-dominated 

without the tamarisk.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Populus fremontii (rare)

Canopy (2–5m) Tamarix ramosissima

Sub-canopy (0.5–2m) none

Field (0–0.5m) Amaranthus palmeri, Chloris virgata

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Baccharis sarothroides, Baccharis salicifolia, Cynodon dactylon, Sporobolus cryptandrus

Element sources

Global description authors: M.S. Reid, mod. K.A. Schulz

Local description authors: S. Buckley and S. Drake

References: Ecological data developed by NatureServe and its network of natural heritage 

programs and other contributors and cooperators.

• Hansen, P. L., R. D. Pfi ster, K. Boggs, B. J. Cook, J. Joy, and D. K. Hinckley. 1995. Classifi cation and management of Montana's riparian and wetland sites. Montana Forest 

and Conservation Experiment Station, School of Forestry, University of Montana, 

Miscellaneous Publication No. 54. 646 pp. + posters.

• Kartesz 1999. Data are not available.

• Muldavin, E., P. Durkin, M. Bradley, M. Stuever, and P. Mehlhop. 2000a. Handbook 
Appendix D: Vegetation Type Descriptions 89

of wetland vegetation communities of New Mexico: Classifi cation and community 

descriptions (volume 1). Final report to the New Mexico Environment Department 

and the Environmental Protection Agency prepared by the New Mexico Natural 

Heritage Program, University of New Mexico, Albuquerque, NM.

• Powell, A. M. 1988b. Trees and shrubs of Trans-Pecos Texas including Big Bend and 

Guadalupe Mountains national parks. Big Bend Natural History Assoc., Inc. 536 pp.

• Smith, T. L. 1989. An overview of old-growth forests in Pennsylvania. Natural Areas 

Journal 9:40-44.
90 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.5 Wooded Herbaceous

D.5.1 Populus fremontii / Mixed Annual Wooded Herbaceous Alliance

Translated name: Fremont cottonwood / Mixed Annual Wooded Herbaceous Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance occupies portions of the fl oodplain at the Mission unit and at Guevavi. Populus fremontii is found singly or in small to large patches 

throughout the type, often with Salix gooddingii, and clumps of Tamarix ramosissima in some places. 

Sambucus nigra ssp. caerulea and/or Prosopis velutina may be found in this type. Large Populus fremontii may reach 16–18 m, Salix somewhat less, and Prosopis usually 3–6 m. At the time of mapping, the 

NPS was conducting a tamarisk eradication program, so this species may be insignifi cant in the future. 

Shrubs are generally sparse, and associated species include Hymenoclea monogyra, Prosopis velutina, 

Baccharis salicifolia, Acacia greggii, Baccharis sarothroides, and Senecio fl accidus. The herbaceous layer 

is dominated by Amaranthus palmeri, with signifi cant patches of Salsola kali and Chenopodium spp. 

widely dispersed throughout the type. Annual grasses are also commonly present, including Chloris 

virgata, Aristida purpurea, and Bouteloua aristidoides, frequently in conjunction with sandier, sloped 

areas, indicating slightly more xeric conditions. The topography of this type is undulating, having 1–3-

m relief, with braided fl ood channels or swales dominated by herbaceous vegetation and occasional 

shrubs (Baccharis salicifolia, B. sarothroides, Hymenoclea monogyra), and sandbars dominated by trees. 

Associated herbaceous species include Boerhavia coccinea, Boerhavia spicata, Cynodon dactylon, Ipomoea spp., Tithonia thurberi, Sporobolus cryptandrus, Bouteloua curtipendula, and Eragrostis lehmanniana.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (6 classifi cation plots and 3 censused polygons). This alliance and its position in the hierarchy below are 

proposed.

Vegetation hierarchy

Formation class V Herbaceous vegetation

Formation subclass V.D ? Annual graminoid or forb vegetation (with a sparse tree layer)

Formation group Data are not available

Formation subgroup Data are not available

Formation name Data are not available

Alliance name Populus fremontii / mixed annual Wooded Herbaceous Alliance

Association name Data are not available.

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available. Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.
Appendix D: Vegetation Type Descriptions 91

Distribution

Globally—Data are not available.

Tumacácori National Historical Park—This type is found in 3 polygons: 2 at the Mission 

unit and 1 at Guevavi: WH-PF01-M (10.6 ha), WH-PF03-M (2.0 ha), WH-PF02-G (1.6 ha).

Environmental setting

USFWS wetland system: Yes

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This type occupies portions of the fl oodplain at the 

Mission unit and at Guevavi, on characteristic undulating terrain having 1–3-m relief, with 

braided fl ood channels or swales dominated by herbaceous vegetation and occasional shrubs, 

and sandbars dominated by trees.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—While herbaceous species dominate this type by 

cover, Populus fremontii is found singly or in small to large patches throughout, often with 

Salix gooddingii and clumps of Tamarix ramosissima in some places. Sambucus nigra ssp.

caerulea and/or Prosopis velutina may be found in this type. Large Populus fremontii may reach 

16–18 m, Salix somewhat less, and Prosopis usually 3–6 m. At the time of mapping, NPS was 

conducting a tamarisk eradication program, so this species may be insignifi cant in the future. 

Shrubs are generally sparse, and associated species include Hymenoclea monogyra, Prosopis 

velutina, Baccharis salicifolia, Acacia greggii, Baccharis sarothroides, and Senecio fl accidus. The 

herbaceous layer is dominated by Amaranthus palmeri, with signifi cant patches of Salsola 

kali and Chenopodium spp. widely dispersed throughout the type. Annual grasses are also 

commonly present, including Chloris virgata, Aristida purpurea, and Bouteloua aristidoides, 

frequently in conjunction with sandier, sloped areas, indicating slightly more xeric conditions. 

The topography of this type is undulating, having 1–3-m relief, with braided fl ood channels or 

swales dominated by herbaceous vegetation and occasional shrubs (Baccharis salicifolia, B. sarothroides, Hymenoclea monogyra), and sandbars dominated by trees. Associated herbaceous 

species include Boerhavia coccinea, Boerhavia spicata, Cynodon dactylon, Ipomoea spp., Tithonia thurberi, Sporobolus cryptandrus, Bouteloua curtipendula and Eragrostis lehmanniana.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Populus fremontii, Salix gooddingii

Canopy (2–5m) Tamarix ramosissima, Sambucus nigra ssp. caerulea

Sub-canopy (0.5–2m) Hymenoclea monogyra, Baccharis salicifolia

Field (0–0.5m) Amaranthus palmeri, Chloris virgata, Salsola kali, Chenopodium sp.

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Aristida purpurea, Eriogonum sp., Helianthus annuus, Boerhavia coccinea

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
92 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.5.2 Prosopis velutina / Mixed Annual Wooded Herbaceous Alliance

Translated name: Velvet mesquite / Mixed Annual Wooded Herbaceous Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance is often found in wide, shallow 

drainages between mesa-top shrublands or on long, narrow alluvial terraces above the river’s fl oodplain. Where a single herbaceous species dominates, it is usually Amaranthus palmeri, though there 

are areas dominated by Cynodon dactylon (found in most of the open areas of the type) or Sporobolus 

wrightii. In addition, there are signifi cant areas without a single dominant species, with the herbaceous 

layer comprising a diverse mosaic of annual and perennial plants, including some combination of the 

aforementioned species and Aristida purpurea, Chloris virgata, Hilaria belangeri, Sporobolus cryptandrus, Sporobolus contractus, Bothriochloa barbinodis, and Aristida ternipes. The overstory usually has 

5–25% cover of Prosopis velutina trees, sometimes clumped, usually interspersed with Sambucus nigra 

ssp. caerulea, Celtis laevigata var. reticulata, Acacia greggii, and Populus fremontii. P. velutina and A. 

greggii can appear as both trees and shrubs. Other associated shrubs include Ziziphus obtusifolia and

Hymenoclea monogyra. Average height of the overstory is commonly 3–6 m, with some larger individuals possibly present. Populus fremontii specimens can reach 14 m. In areas within this type, Sambucus 

nigra ssp. caerulea may be the dominant tree, or nearly so. This variant of the type is likely to be dominated in absolute terms by weedy (often non-native) annual forbs, such as Amaranthus palmeri, Salsola 

kali, Chenopodium spp., Helianthus annuus, and the grass Chloris virgata. Closer to the active channel, 

Cynodon dactylon and Xanthium strumarium may also be abundant. Shrub and tree cover are sparse. 

There is often abundant evidence of cattle grazing and trampling, which combines with fl ood events to 

chronically disturb the topsoil and maintain the dominance of the invasive forbs.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (9 classifi cation plots and 4 censused polygons). This alliance and its position in the hierarchy below are 

proposed.

Vegetation hierarchy

Formation class V Herbaceous vegetation

Formation subclass V.D ? Annual graminoid or forb vegetation (with a sparse tree layer)

Formation group Data are not available

Formation subgroup Data are not available

Formation name Data are not available

Alliance name Prosopis velutina / mixed annual Wooded Herbaceous Alliance

Association name Data are not available

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.
Appendix D: Vegetation Type Descriptions 93

Distribution

Globally—Data are not available.

Tumacácori National Historical Park—This type is found in 4 polygons: 2 at the Mission unit, 1 at 

Calabazas and 1 at Guevavi: WH-PV01-M (2.0 ha), WH-PV02-M (1.5 ha), WH-PV03-G (0.8 ha), WHPV04-C (2.8 ha).

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This type is often found in wide, shallow drainages between 

mesa-top shrublands, or on long, narrow alluvial terraces above the river’s fl oodplain. Shrub and tree 

cover are sparse. There is often abundant evidence of cattle grazing and trampling, which combines 

with fl ood events to chronically disturb the topsoil and maintain the dominance of the invasive forbs.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—Where a single herbaceous species dominates this alliance, it 

is usually Amaranthus palmeri, though there are areas dominated by Cynodon dactylon (found in most 

of the open areas of the type) or Sporobolus wrightii. In addition, there are signifi cant areas without 

a single dominant species, with the herbaceous layer comprised of a diverse mosaic of annual and 

perennial plants, including some combination of the aforementioned species and Aristida purpurea,

Chloris virgata, Hilaria belangeri, Sporobolus cryptandrus, Sporobolus contractus, Bothriochloa barbinodis, and Aristida ternipes. The overstory usually has 5–25% cover of Prosopis velutina trees, sometimes 

clumped, usually interspersed with Sambucus nigra ssp. caerulea, Celtis laevigata var. reticulata, Acacia 

greggii, and Populus fremontii. P. velutina and A. greggii can appear as both trees and shrubs. Other 

associated shrubs include Ziziphus obtusifolia, Hymenoclea monogyra, Baccharis sarothroides, and 

Mimosa aculeaticarpa var. biuncifera. Average height of the overstory is commonly 3–6 m, with some 

larger individuals possibly present. Populus fremontii specimens can reach 14 m. In areas within this 

type, Sambucus nigra ssp. caerulea may be the dominant tree, or nearly so. This variant of the type is 

likely to be dominated in absolute terms by weedy (often non-native) annual forbs, such as Amaranthus palmeri, Salsola kali, Chenopodium spp., Helianthus annuus, and the grass Chloris virgata. Closer 

to the active channel, Cynodon dactylon and Xanthium strumarium may also be abundant.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Prosopis velutina

Canopy (2–5m) Prospois, Sambucus nigra ssp. caerulea, Acacia greggii

Sub-canopy (0.5–2m) Ziziphus obtusifolia, Mimosa aculeaticarpa var. biuncifera, 

Hymenoclea monogyra

Field (0–0.5m) Amaranthus palmeri, Chloris virgata, Cynodon dactylon 

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Celtis laevigata var. reticulata, Populus fremontii, Baccharis 

sarothroides, Salsola kali, Bouteloua curtipendula, Sporobolus wrightii, Aristida purpurea, Bidens leptocephala, Helianthus annuus, Ambrosia confertifl ora

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
94 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.6 Shrub Herbaceous

D.6.1 Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance

Translated name: Velvet mesquite / Palmer amaranth Shrub Herbaceous Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance is found at both the Mission unit 

and at Guevavi. At Guevavi, the area is an alluvial terrace in the fl oodplain beside the Santa Cruz 

River, where it is notable because of the signifi cant amount of dead and downed wood that litters this 

portion of the river channel, as well as the numerous large Populus fremontii snags, some as tall as 14 

m. In addition to the Prosopis velutina shrubs, there are a number of trees in this area, including P. 

velutina , Celtis laevigata var. reticulata, Sambucus nigra ssp. caerulea, and Populus fremontii, but they 

are often solitary individuals with numerous shrubs of these species interspersed between, predominantly found in small clumps along the upper ridges of the sandbars. Celtis appears to be using the 

dead and down cottonwood as a nurse/mulch. The type overall is dominated by Amaranthus palmeri, 

with other tall annuals and Sporobolus wrightii interspersed throughout. One location at the Mission 

unit supporting this type is an abandoned agricultural fi eld. According to information provided by the 

NPS, this fi eld has not been mowed or cultivated in the last 3–4 years. As a result, the dominance of 

Amaranthus palmeri is apparently giving way to a mixture of annual and perennial grasses: Cynodon 

dactylon, Bouteloua aristidoides, Sporobolus cryptandrus, Bouteloua curtipendula, Hilaria belangeri, 

Aristida purpurea, and Aristida ternipes. Scattered throughout are numerous small Prosopis velutina 

and Baccharis sarothroides shrubs, ranging from 0.5–1.5 m tall. The absence of disturbance and grazing 

has apparently allowed the widespread growth of woody species, still small and shrubby. Amaranthus 

palmeri, present throughout the area, constitutes a plurality of roughly 30% of the total cover here.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (3 classifi cation plots and 3 censused polygons). This alliance and its position in the hierarchy below are 

proposed.

Vegetation hierarchy

Formation class V Herbaceous Vegetation

Formation subclass V.D ? Annual graminoid or forb vegetation (with a sparse shrub layer)

Formation group Data are not available

Formation subgroup Data are not available

Formation name Data are not available

Alliance name Prosopis velutina / Amaranthus palmeri Shrub Herbaceous Alliance

Association name Data are not available.

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available. Data are not available.

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.
Appendix D: Vegetation Type Descriptions 95

Distribution

Globally—Data are not available.

Tumacácori National Historical Park—This type is found in 3 polygons: 2 at the Mission 

unit and 1 at Guevavi: SH-PV01-M (1.5 ha), SH-PV02-M (3.9 ha), SH-PV03-G (1.7 ha).

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This type is found at both the Mission unit and at 

Guevavi. At Guevavi, the area is an alluvial terrace in the fl oodplain beside the Santa Cruz 

River, where it is notable because of the signifi cant amount of dead and downed wood that 

litters this portion of the river channel, as well as the numerous large Populus fremontii snags, 

some as tall as 14 m. One stand of this type at the Mission unit is notable for being an abandoned agricultural fi eld, which has not been mowed or cultivated in the last 3–4 years. As a 

result, the dominance of Amaranthus palmeri is apparently giving way to a mixture of annual 

and perennial grasses, and the growth of shrubby Prosopis velutina is apparent.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—In addition to the Prosopis velutina shrubs, there 

may be a number of trees in this alliance, including P. velutina , Celtis laevigata var. reticulata, 

Sambucus nigra ssp. caerulea, and Populus fremontii, but they are often solitary individuals 

with numerous shrubs of these species interspersed between, predominantly found in small 

clumps along the upper ridges of the sandbars. The type overall is dominated by Amaranthus 

palmeri, with other tall annuals and Sporobolus wrightii interspersed throughout. One location at the Mission unit supporting this type is an abandoned agricultural fi eld. According 

to information provided by NPS, this fi eld has not been mowed or cultivated in the last 3–4 

years. As a result, the dominance of Amaranthus palmeri is apparently giving way to a mixture 

of annual and perennial grasses: Cynodon dactylon, Bouteloua aristidoides, Sporobolus cryptandrus, Bouteloua curtipendula, Hilaria belangeri, Aristida purpurea, and Aristida ternipes. 

Scattered throughout are numerous small Prosopis velutina and Baccharis sarothroides shrubs, 

ranging from 0.5–1.5 m tall. The absence of disturbance and grazing has apparently allowed 

the widespread growth of woody species, still small and shrubby. Amaranthus palmeri, present throughout the area, constituted a plurality of roughly 30% of the total cover here.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Prosopis velutina, Celtis laevigata var. reticulata (both rare)

Canopy (2–5m) Prosopis velutina, Sambucus nigra ssp. caerulea

Sub-canopy (0.5–2m) Prosopis velutina, Baccharis sarothroides

Field (0–0.5m) Amaranthus palmeri, Cynodon dactylon

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Populus fremontii, Baccharis salicifolia, Bouteloua 

aristidoides, Bouteloua curtipendula
96 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
Appendix D: Vegetation Type Descriptions 97

D.6.2 Hymenoclea monogyra / [Amaranthus palmeri - Chloris virgata] 

Shrub Herbaceous Alliance

Translated name: Singlewhorl burrobrush / [Palmer amaranth - Feather windmill grass] 

Shrub Herbaceous Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This proposed alliance is generally found in the 100-

year fl oodplain adjacent to the west side of the Santa Cruz River at Tumacácori. It consists of 

sandy to silty soils with a diversity of annual and perennial herbaceous species, though these 

are widely dispersed across a large area and account for only moderate cover. The herbaceous layer is dominated by Amaranthus palmeri and Chloris virgata. Hymenoclea monogyra 

is the dominant shrub throughout the type, appearing to have grown up within the last fi ve 

years, as indicated by repeat photographs from an earlier inventory. Hymenoclea monogyra 

shrubs range from 2 to 4 m in height, and are generally clumped together, leaving large areas 

in between more open. Associated shrubs interspersed throughout the type include Baccharis 

salicifolia, Baccharis sarothroides, Prosopis velutina, and Senecio fl accidus. Some trees may be 

present, commonly Populus fremontii or Sambucus nigra ssp. caerulea, but making up less than 

10% cover.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data 

(5 classifi cation plots and 1 censused polygon). This alliance and its position in the hierarchy 

below are proposed.

Vegetation hierarchy

Formation class V Herbaceous Vegetation

Formation subclass V.D ? Annual graminoid or forb vegetation (with a sparse shrub 

layer)

Formation group Data are not available

Formation subgroup Data are not available

Formation name Data are not available

Alliance name Hymenoclea monogyra / [Amaranthus palmeri – Chloris virgata]

Shrub Herbaceous Alliance

Association name Data are not available

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available. 

Rounded global status: Data are not available.

Distribution

Globally—Data are not available.
98 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Tumacácori National Historical Park—This type is found in one nominal polygon (in two 

parts), at the Mission unit: SH-HM01-M (10.2 ha). It lies along the central (river) axis of the 

Mission unit, with most of its area toward the north.

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This alliance is found in the 100-year fl oodplain adjacent to the west side of the Santa Cruz River at the Tumacácori Mission unit. Soils are sandy 

to silty, with a diversity of annual and perennial herbaceous species, though these are widely 

dispersed across a large area and do not account for much cover. Surface cover is diverse, 

including bare soil, gravel, river rock, down wood, and plant litter.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—The herbaceous layer is dominated by Amaranthus 

palmeri and Chloris virgata. Hymenoclea monogyra is the dominant shrub throughout the 

type, appearing to have grown up within the last fi ve years, as indicated by repeat photographs 

from an earlier inventory. Hymenoclea monogyra shrubs range from 2 to 4 m in height, and 

are generally clumped together, leaving large areas in between more open. Associated shrubs 

interspersed throughout the type include Baccharis salicifolia, Baccharis sarothroides, Prosopis 

velutina, and Senecio fl accidus. Some trees may be present, commonly Populus fremontii or 

Sambucus nigra ssp. caerulea, but making up less than 10% cover.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Populus fremontii, Sambucus nigra ssp. caerulea (both rare)

Canopy (2–5m) Hymenoclea monogyra

Sub-canopy (0.5–2m) Opuntia spinosior, O. engelmannii (both rare)

Field (0–0.5m) Amaranthus palmeri, Chloris virgata

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Baccharis salicifolia, B. sarothroides, Prosopis velutina, Cynodon dactylon

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
Appendix D: Vegetation Type Descriptions 99

D.7 Herbaceous

D.7.1 [Amaranthus palmeri - Salsola kali - Chenopodium spp.] Annual 

Herbaceous Alliance

Translated name: [Palmer amaranth - Tumbleweed - Goosefoot species] Annual Herbaceous 

Alliance

NatureServe code: Data are not available (proposed).

Summary

Globally—Data are not available.

Tumacácori National Historical Park—This annual forb-dominated community is found 

on sandy soils adjacent to the Santa Cruz River at all three units. Use of brackets in the type 

name indicates that these species should be considered co-dominant overall, and their relative 

abundance may diff er spatially within the type. There are areas of fairly homogeneous distribution of both Amaranthus palmeri and Salsola kali as co-dominants (with or without some 

Chenopodium spp.), and areas where one of the three species is clearly the single dominant, 

with more or less of the others possibly present. This alliance is apparently highly dependent 

on seasonal precipitation for its local abundance and perhaps composition, which may vary 

signifi cantly from year to year. The type is made up almost entirely of non-native vegetation. 

The bulk of associated species grow beneath the upper layer of tall forbs. Grasses, both annual and perennial, grow sparsely in patches in this community: Chloris virgata, Bouteloua aristidoides, Sporobolus cryptandrus, Sporobolus wrightii, Aristida ternipes, and Hilaria belangeri. 

The forb, Bidens leptocephala, may be prominent in patches. Along the edges of the herbaceous type, sparse low shrubs are often found, including Baccharis salicifolia, Hymenoclea 

monogyra, and Prosopis velutina, and occasionally trees such as Populus fremontii, Sambucus 

nigra ssp. caerulea, or Salix gooddingii. Climbing vines, such as Ipomoea spp., may be found in 

this type growing up from the ground around the taller annual forb vegetation.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—Data are not available.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (2 

classifi cation plots and 5 censused polygons). Because the species composition of this vegetation type can vary over short time and spatial scales, it is best thought of as a complex. This 

alliance and its position in the hierarchy below are proposed.

Vegetation hierarchy

Formation class V Herbaceous Vegetation

Formation subclass V.D Annual graminoid or forb vegetation

Formation group V.D.2 Temperate or subpolar annual grasslands or forb 

vegetation

Formation subgroup V.D.2.N Natural/Semi-natural temperate or subpolar annual 

grasslands or forb vegetation

Formation name V.D.2.N.c Low desert or subdesert ephemeral or episodic annual 

forb vegetation

Alliance name [Amaranthus palmeri – Salsola kali – Chenopodium spp.] Annual 

Herbaceous Alliance

Association name Data are not available
100 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available Data are not available

NatureServe conservation status 

Global status: Data are not available. 

Rounded global status: Data are not available.

Distribution

Globally—Data are not available. 

Tumacácori National Historical Park—This type is found in 5 polygons: 2 at the Mission 

unit, 2 at Guevavi, and 1 at Calabazas: H-AP01-M (1.1 ha), H-AP02-M (0.6 ha), H-AP03-G 

(0.5 ha), H-AP04-G (0.6 ha), H-AP05-C (0.7 ha).

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This annual forb-dominated community is found 

on sandy soils adjacent to the Santa Cruz River at all three units. All sites are in the basin fl oor 

topographic position and are generally fl at. Sites are disturbed by grazing and/or fl ooding. 

Predominant ground cover, other than plant bases, is bare soil (10–35%), litter (1–35%) and 

gravel (1–35%).

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—Amaranthus palmeri, Salsola kali, and Chenopodium

spp. should be considered co-dominant overall, and their relative abundance may diff er spatially within the type. There are areas of fairly homogeneous distribution of both Amaranthus 

palmeri and Salsola kali as co-dominants (with or without some Chenopodium spp.), and areas 

where one of the three species is clearly the single dominant, with more or less of the others 

possibly present. This alliance is apparently highly dependent on seasonal precipitation for 

its local abundance and perhaps composition, which may vary signifi cantly from year to year. 

The type is made up almost entirely of non-native vegetation. Trees and shrubs make up less 

than 10% cover. The bulk of associated species grow beneath the upper layer of tall forbs. 

Grasses, both annual and perennial, grow sparsely in patches in this community: Chloris virgata, Bouteloua aristidoides, Sporobolus cryptandrus, Sporobolus wrightii, Aristida ternipes, and 

Hilaria belangeri. The forb, Bidens leptocephala, may be prominent in patches. Along the edges 

of the herbaceous type, sparse, low shrubs are often found, including Baccharis salicifolia, 

Hymenoclea monogyra, and Prosopis velutina, and occasionally trees such as Populus fremontii, 

Sambucus nigra ssp. caerulea, or Salix gooddingii. Climbing vines, such as Ipomoea spp., may 

be found in this type growing up from the ground around the taller annual forb vegetation.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) Not applicable, none

Canopy (2–5m) Not applicable, none

Sub-canopy (0.5–2m) Not applicable, none

Field (0–0.5m) Amaranthus palmeri, Salsola kali, Chenopodium sp.
Appendix D: Vegetation Type Descriptions 101

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—Chloris virgata, Bouteloua aristidoides, Sporobolus 

cryptandrus, Sporobolus wrightii, Aristida ternipes, Hilaria belangeri, and Bidens leptocephala.

Element sources

Global description authors: Data are not available.

Local description authors: S. Buckley and S. Drake

References: Data are not available.
102 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.8 Sparsely Vegetated

D.8.1 Inland Freshwater Strand Beach Sparse Vegetation

Translated name: Inland Strand Beach Sparsely Vegetated Alliance

Inland Freshwater Strand Beach Sparse Vegetation

NatureServe code: A.1862 / CEGL002310

Summary

Globally—This is technically not an alliance. It is a placeholder for a group of sparsely vegetated associations that do not have adequate vegetation descriptions but do share certain 

substrate characteristics.

Tumacácori National Historical Park—This type is composed of mostly-bare sand in the 

Santa Cruz River’s active channel. Some forbs may be present in areas colonized since the last 

fl ood event. Seedlings or saplings of Populus fremontii and Salix gooddingii may also be present. The position of strand beaches tends to shift with fl ood events in the fl uvial system.

Classifi cation

Classifi cation confi dence: Data are not available.

Classifi cation comments: Globally—This is technically not an alliance. It is a placeholder for 

a group of sparsely vegetated associations that do not have adequate vegetation descriptions 

but do share certain substrate characteristics.

Tumacácori National Historical Park—This description is based on 2007–2008 fi eld data (2 

censused polygons). At TUMA, this is a riverine, fl ood-scoured strand rather than a lacustrine 

beach strand, as described by NatureServefor the Great Lakes region.

Vegetation hierarchy

Formation class VII Sparse Vegetation

Formation subclass VII.C Unconsolidated material sparse vegetation

Formation group VII.C.2 Sparsely vegetated sand fl ats

Formation subgroup VII.C.2.N Natural/Semi-natural sparsely vegetated sand fl ats

Formation name VII.C.2.N.a Sand fl ats

Alliance name Inland Strand Beach Sparsely Vegetated Alliance

Association name Inland Freshwater Strand Beach Sparse Vegetation

Ecological systems placement

Ecological system unique ID Ecological system name

Data are not available. Data are not available.

NatureServe conservation status 

Global status: Data are not available.

Rounded global status: Data are not available.

Distribution

Globally—United States: IN, ME, MI, MN, NY, VT, WI. Canada: MB, ON, SK

Tumacácori National Historical Park—This type is found in 2 polygons: 1 at Guevavi and 1 

at Calabazas: St01-G (2.7 ha), St02-C (2.4 ha).
Appendix D: Vegetation Type Descriptions 103

Environmental setting

USFWS wetland system: No

Environmental summary: Globally—Data are not available.

Tumacácori National Historical Park—This type is composed of mostly-bare sand in the 

Santa Cruz river’s active channel. Some forbs may be present in areas colonized since the last 

fl ood event. Seedlings or saplings of Populus fremontii and Salix gooddingii may also be present. The position of strand beaches tends to shift with fl ood events in the fl uvial system.

Vegetation

Globally—Data are not available.

Tumacácori National Historical Park—This type is composed of mostly-bare sand in the 

Santa Cruz river’s active channel. Some forbs may be present in areas colonized since the last 

fl ood event. Seedlings or saplings of Populus fremontii and Salix gooddingii may also be present. The position of strand beaches tends to shift with fl ood events in the fl uvial system.

Most abundant species: Globally—Data are not available.

Tumacácori National Historical Park—

Stratum Species

Top canopy (>5m) none

Canopy (2–5m) none

Sub-canopy (0.5–2m) Populus fremontii, Salix gooddingii (seedlings)

Field (0–0.5m) annual forbs

Other noteworthy species: Globally—Data are not available.

Tumacácori National Historical Park—None.

Element sources

Global description authors: Midwestern Ecology Group

Local description authors: S. Buckley and S. Drake

References: Data are not available.
104 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

D.9 Developed Woodland

DW-01-M

This is a park-special map class. This type in the TUMA area is comprised of homes, commercial buildings, and roads built in former mesquite forest or woodland, with minimal to 

extensive clearing of trees. Occurs primarily outside park boundary, in study-area buff er.

D.10 Cropland and Pasture

CP-01-M, CP-02-M

IPMOW01, IPMOW02, IPMOW03, IPMOW04, IPMOW05, IPMOW06

This is an Anderson Level 2 class, applied to active irrigated pasture (in study area buff er), and 

historic cultivated area adjacent to Mission.

D.11 Park Facilities

PF-01-M, PF-02-C

This is a park-special map class, as no Anderson class is applicable. Includes park ruins, 

historic orchard area, Fiesta Grounds, maintenance facilities, access roads, and visitor center 

area.
Appendix E: Species List 105

Appendix E

Species List

Table E-1. Plant species observed at Tumacácori National Historical Park, organized by family.

Family Scientifi c name Common name Mission Calabazas Guevavi

Acanthaceae Anisacanthus thurberi Thurber’s desert 

honeysuckle

XX X

Acanthaceae Dicliptera resupinata Arizona foldwing X

Acanthaceae Ruellia nudifl ora violet wild petunia X

Acanthaceae Tetramerium nervosum hairy fournwort X X X

Agavaceae Yucca elata soaptree yucca X

Amaranthaceae Amaranthus palmeri carelessweed X X X

Anacardiaceae Rhus trilobata skunkbush sumac X

Apiaceae Bowlesia incana hoary bowlesia X

Apiaceae Conium maculatum poison hemlock X X

Asteraceae Acourtia nana dwarf desertpeony X

Asteraceae Ambrosia ragweed X X X

Asteraceae Ambrosia confertifl ora weakleaf burr ragweed X X X

Asteraceae Aster aster X

Asteraceae Baccharis salicifolia mule’s fat X X

Asteraceae Baccharis sarothroides desertbroom X X X

Asteraceae Bidens lemmonii Lemmon’s beggarticks X X

Asteraceae Bidens leptocephala fewfl ower beggarticks X X X

Asteraceae Chaenactis douglasii Douglas’ dustymaiden X

Asteraceae Cirsium neomexicanum New Mexico thistle X

Asteraceae Conyza canadensis Canadian horseweed X

Asteraceae Erigeron fl eabane X

Asteraceae Erigeron divergens spreading fl eabane X

Asteraceae Gnaphalium cudweed X

Asteraceae Gnaphalium palustre western marsh cudweed X

Asteraceae Gutierrezia microcephala threadleaf snakeweed X X

Asteraceae Helianthus annuus common sunfl ower X X X

Asteraceae Hymenoclea monogyra singlewhorl burrobrush X X X

Asteraceae Isocoma tenuisecta burroweed X

Asteraceae Senecio fl accidus threadleaf groundsel X

Asteraceae Sonchus asper spiny sowthistle X X

Asteraceae Tagetes micrantha licorice marigold

Asteraceae Tithonia thurberi Arizona sunfl owerweed X X X

Asteraceae Xanthium strumarium rough cockleburr X X X

Asteraceae Zinnia acerosa desert zinnia X

Betulaceae Alnus oblongifolia Arizona alder X

Boraginaceae Cryptantha cryptantha X

Brassicaceae Brassicaceae mustards X

Brassicaceae Descurainia pinnata western tansymustard X X X

Brassicaceae Lepidium pepperweed X

Brassicaceae Lesquerella gordonii gordon bladderpod X X

Brassicaceae Sisymbrium irio London rocket X X X
106 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Family Scientifi c name Common name Mission Calabazas Guevavi

Cactaceae Echinocereus hedgehog cactus X

Cactaceae Ferocactus wislizeni candy barrelcactus X X

Cactaceae Opuntia engelmannii cactus apple X X

Cactaceae Opuntia leptocaulis Christmas cactus X

Cactaceae Opuntia spinosior walkingstick cactus X X X

Caprifoliaceae Sambucus nigra European black elderberry X X

Caprifoliaceae Sambucus nigra ssp. canadensis common elderberry X X

Caprifoliaceae Sambucus nigra ssp. cerulea blue elderberry X X X

Chenopodiaceae Atriplex canescens fourwing saltbush X

Chenopodiaceae Atriplex elegans wheelscale saltbush X

Chenopodiaceae Chenopodium goosefoot X X X

Chenopodiaceae Chenopodium album lambsquarters X

Chenopodiaceae Chenopodium berlandieri pitseed goosefoot X X

Chenopodiaceae Chenopodium rubrum red goosefoot X

Chenopodiaceae Salsola kali Russian thistle X X X

Convolvulaceae Convolvulus arvensis fi eld bindweed X

Convolvulaceae Ipomoea morning-glory vine X X X

Convolvulaceae Ipomoea coccinea redstar X

Convolvulaceae Ipomoea hederacea ivyleaf morning-glory X

Cucurbitaceae Cucurbita foetidissima Missouri gourd X

Cupressaceae Juniperus coahuilensis redberry juniper X X

Cyperaceae Cyperus fl atsedge X

Cyperaceae Cyperus odoratus fragrant fl atsedge X

Equisetaceae Equisetum arvense fi eld horsetail X

Ericaceae Arctostaphylos pungens pointleaf manzanita X

Euphorbiaceae Acalypha ostryifolia pineland threeseed mercury X

Euphorbiaceae Chamaesyce sandmat X

Euphorbiaceae Chamaesyce albomarginata whitemargin sandmat X

Euphorbiaceae Euphorbia heterophylla Mexican fi replant X

Fabaceae Acacia constricta whitethorn acacia X

Fabaceae Acacia greggii catclaw acacia X X X

Fabaceae Astragalus astragalus X

Fabaceae Calliandra eriophylla fairyduster X

Fabaceae Lotus humistratus foothill deervetch X

Fabaceae Lupinus lupine X

Fabaceae Mimosa aculeaticarpa catclaw mimosa X X

Fabaceae Mimosa aculeaticarpa var.

biuncifera

catclaw mimosa X X X

Fabaceae Parkinsonia aculeata Jerusalem thorn X

Fabaceae Phaseolus ritensis Santa Rita Mountain bean X

Fabaceae Prosopis velutina velvet mesquite X X X

Fabaceae Senna bauhinioides twinleaf senna X

Geraniaceae Erodium texanum Texas stork’s bill X

Hydrophyllaceae Phacelia phacelia X X X

Juncaceae Juncus cooperi Cooper’s rush X

Lamiaceae Marrubium vulgare horehound X

Lamiaceae Salazaria mexicana Mexican bladdersage X X X

Loasaceae Mentzelia blazingstar X X

Loasaceae Mentzelia albicaulis whitestem blazingstar X X X

Plant species observed at Tumacácori National Historical Park, organized by family, cont.
Appendix E: Species List 107

Family Scientifi c name Common name Mission Calabazas Guevavi

Malvaceae Anoda cristata crested anoda X

Malvaceae Sida fanpetals X

Malvaceae Sida abutifolia spreading fanpetals X

Malvaceae Sphaeralcea globemallow X X

Malvaceae Sphaeralcea coccinea scarlet globemallow X

Malvaceae Sphaeralcea laxa caliche globemallow X

Malvaceae Sphaeralcea wrightii Wright’s globemallow X X X

Moraceae Morus microphylla Texas mulberry X X

Nyctaginaceae Allionia incarnata trailing windmills X

Nyctaginaceae Boerhavia boerhavia X

Nyctaginaceae Boerhavia coccinea scarlet spiderling X X X

Nyctaginaceae Boerhavia intermedia fi vewing spiderling X

Nyctaginaceae Boerhavia spicata creeping spiderling X X X

Nyctaginaceae Mirabilis tenuiloba longlobe four o’clock X

Oleaceae Fraxinus velutina velvet ash X X

Onagraceae Camissonia suncup X

Onagraceae Gaura coccinea scarlet beeblossom X

Onagraceae Gaura mollis velvetweed X

Onagraceae Oenothera evening-primrose X X X

Onagraceae Oenothera primiveris desert evening-primrose X

Papaveraceae Argemone pricklypoppy X

Papaveraceae Argemone pleiacantha southwestern pricklypoppy X

Papaveraceae Eschscholzia californica California poppy X

Papaveraceae Eschscholzia californica ssp.

mexicana

California poppy X

Passifl oraceae Passifl ora mexicana Mexican passionfl ower X X

Pedaliaceae Proboscidea parvifl ora doubleclaw X X

Phytolaccaceae Rivina humilis rougeplant X X

Platanaceae Platanus wrightii Arizona sycamore X

Poaceae Aristida threeawn X X

Poaceae Aristida purpurea purple threeawn X X X

Poaceae Aristida ternipes spidergrass X X X

Poaceae Bothriochloa barbinodis cane bluestem X X X

Poaceae Bouteloua grama X X

Poaceae Bouteloua aristidoides needle grama X X X

Poaceae Bouteloua aristidoides var.

arizonica

Arizona needle grama X

Poaceae Bouteloua barbata sixweeks grama X

Poaceae Bouteloua curtipendula sideoats grama X X X

Poaceae Bouteloua radicosa purple grama X X

Poaceae Bouteloua rothrockii Rothrock’s grama X X X

Poaceae Bromus carinatus California brome X

Poaceae Bromus catharticus rescuegrass X

Poaceae Chloris virgata feather fi ngergrass X X X

Poaceae Cottea pappophoroides cotta grass X X

Poaceae Cynodon dactylon Bermudagrass X X X

Poaceae Digitaria californica Arizona cottontop X

Poaceae Eragrostis lovegrass X X

Poaceae Eragrostis cilianensis stinkgrass X X X

Plant species observed at Tumacácori National Historical Park, organized by family, cont.
108 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Family Scientifi c name Common name Mission Calabazas Guevavi

Poaceae Eragrostis curvula weeping lovegrass X

Poaceae Eragrostis lehmanniana Lehmann lovegrass X X X

Poaceae Erioneuron avenaceum shortleaf woollygrass X

Poaceae Hilaria belangeri curly-mesquite X

Poaceae Leptochloa dubia green sprangletop X X X

Poaceae Leptochloa panicea green sprangletop X

Poaceae Muhlenbergia fragilis delicate muhly X X X

Poaceae Muhlenbergia polycaulis cliff muhly X

Poaceae Muhlenbergia porteri bush muhly X X

Poaceae Panicum panicgrass X

Poaceae Panicum miliaceum broomcorn millet X

Poaceae Panicum obtusum vine mesquite X

Poaceae Phragmites australis common reed X

Poaceae Setaria bristlegrass X X X

Poaceae Setaria leucopila streambed bristlegrass X

Poaceae Sorghum halepense Johnsongrass X X X

Poaceae Sporobolus contractus spike dropseed X

Poaceae Sporobolus cryptandrus sand dropseed X X X

Poaceae Sporobolus wrightii big sacaton X X X

Polygonaceae Eriogonum buckwheat X X

Polygonaceae Eriogonum infl atum desert trumpet X

Polygonaceae Rumex hymenosepalus canaigre dock X

Pteridaceae Cheilanthes villosa villous lipfern X X X

Ranunculaceae Clematis leather fl ower X

Ranunculaceae Clematis drummondii Drummond’s clematis X

Rhamnaceae Ceanothus greggii desert ceanothus X X

Rhamnaceae Condalia warnockii Warnock’s snakewood X X X

Rhamnaceae Ziziphus obtusifolia lotebush X X X

Rhamnaceae Ziziphus obtusifolia var.

obtusifolia

lotebush X

Rosaceae Fragaria vesca woodland strawberry X

Rosaceae Pyracantha fortuneana Chinese fi rethorn X

Salicaceae Populus fremontii Fremont cottonwood X X X

Salicaceae Salix gooddingii Goodding’s willow X X

Salicaceae Salix taxifolia yewleaf willow X

Sapindaceae Sapindus saponaria wingleaf soapberry X X

Scrophulariaceae Mimulus cardinalis scarlet monkeyfl ower X

Scrophulariaceae Penstemon parryi Parry’s beardtongue X

Solanaceae Datura jimsonweed X X

Solanaceae Datura stramonium jimsonweed X

Solanaceae Lycium desert-thorn X X X

Solanaceae Lycium andersonii water jacket X X

Solanaceae Nicotiana glauca tree tobacco X

Solanaceae Solanum elaeagnifolium silverleaf nightshade X

Tamaricaceae Tamarix ramosissima saltcedar X X

Ulmaceae Celtis laevigata sugarberry X X X

Ulmaceae Celtis laevigata var. reticulata netleaf hackberry X X

Ulmaceae Celtis pallida spiny hackberry X

Urticaceae Parkinsonia fl orida blue paloverde X

Plant species observed at Tumacácori National Historical Park, organized by family, cont.
Appendix E: Species List 109

Family Scientifi c name Common name Mission Calabazas Guevavi

Violaceae Hybanthus greenviolet X

Vitaceae Vitis arizonica canyon grape X

Zygophyllaceae Tribulus terrestris puncturevine X

Nomenclature follows the Integrated Taxonomic Information System (http://www.itis.gov/)

Highlighted species are non-native (introduced).

Plant species observed at Tumacácori National Historical Park, organized by family, cont.
110 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Table E-2. Plant species observed at Tumacácori National Historical Park, by scientifi c name.

Scientifi c name Common name Family Mission Calabazas Guevavi

Acacia constricta whitethorn acacia Fabaceae X

Acacia greggii catclaw acacia Fabaceae X X X

Acalypha ostryifolia pineland threeseed mercury Euphorbiaceae X

Acourtia nana dwarf desertpeony Asteraceae X

Allionia incarnata trailing windmills Nyctaginaceae X

Alnus oblongifolia Arizona alder Betulaceae X

Amaranthus palmeri carelessweed Amaranthaceae X X X

Ambrosia ragweed Asteraceae X X X

Ambrosia confertifl ora weakleaf burr ragweed Asteraceae X X X

Anisacanthus thurberi Thurber’s desert 

honeysuckle

Acanthaceae X X X

Anoda cristata crested anoda Malvaceae X

Arctostaphylos pungens pointleaf manzanita Ericaceae X

Argemone pricklypoppy Papaveraceae X

Argemone pleiacantha southwestern pricklypoppy Papaveraceae X

Aristida threeawn Poaceae X X

Aristida purpurea purple threeawn Poaceae X X X

Aristida ternipes spidergrass Poaceae X X X

Aster aster Asteraceae X

Astragalus astragalus Fabaceae X

Atriplex canescens fourwing saltbush Chenopodiaceae X

Atriplex elegans wheelscale saltbush Chenopodiaceae X

Baccharis salicifolia mule’s fat Asteraceae X X

Baccharis sarothroides desertbroom Asteraceae X X X

Bidens lemmonii Lemmon’s beggarticks Asteraceae X X

Bidens leptocephala fewfl ower beggarticks Asteraceae X X X

Boerhavia boerhavia Nyctaginaceae X

Boerhavia coccinea scarlet spiderling Nyctaginaceae X X X

Boerhavia intermedia fi vewing spiderling Nyctaginaceae X

Boerhavia spicata creeping spiderling Nyctaginaceae X X X

Bothriochloa barbinodis cane bluestem Poaceae X X X

Bouteloua grama Poaceae X X

Bouteloua aristidoides needle grama Poaceae X X X

Bouteloua aristidoides var.

arizonica

Arizona needle grama Poaceae X

Bouteloua barbata sixweeks grama Poaceae X

Bouteloua curtipendula sideoats grama Poaceae X X X

Bouteloua radicosa purple grama Poaceae X X

Bouteloua rothrockii Rothrock’s grama Poaceae X X X

Bowlesia incana hoary bowlesia Apiaceae X

Brassicaceae mustards Brassicaceae X

Bromus carinatus California brome Poaceae X

Bromus catharticus rescuegrass Poaceae X

Calliandra eriophylla fairyduster Fabaceae X
Appendix E: Species List 111

Scientifi c name Common name Family Mission Calabazas Guevavi

Camissonia suncup Onagraceae X

Ceanothus greggii desert ceanothus Rhamnaceae X X

Celtis laevigata sugarberry Ulmaceae X X X

Celtis laevigata var. reticulata netleaf hackberry Ulmaceae X X

Celtis pallida spiny hackberry Ulmaceae X

Chaenactis douglasii Douglas’ dustymaiden Asteraceae X

Chamaesyce sandmat Euphorbiaceae X

Chamaesyce albomarginata whitemargin sandmat Euphorbiaceae X

Cheilanthes villosa villous lipfern Pteridaceae X X X

Chenopodium goosefoot Chenopodiaceae X X X

Chenopodium album lambsquarters Chenopodiaceae X

Chenopodium berlandieri pitseed goosefoot Chenopodiaceae X X

Chenopodium rubrum red goosefoot Chenopodiaceae X

Chloris virgata feather fi ngergrass Poaceae X X X

Cirsium neomexicanum New Mexico thistle Asteraceae X

Clematis leather fl ower Ranunculaceae X

Clematis drummondii Drummond’s clematis Ranunculaceae X

Condalia warnockii Warnock’s snakewood Rhamnaceae X X X

Conium maculatum poison hemlock Apiaceae X X

Convolvulus arvensis fi eld bindweed Convolvulaceae X

Conyza canadensis Canadian horseweed Asteraceae X

Cottea pappophoroides cotta grass Poaceae X X

Cryptantha cryptantha Boraginaceae X

Cucurbita foetidissima Missouri gourd Cucurbitaceae X

Cynodon dactylon Bermudagrass Poaceae X X X

Cyperus fl atsedge Cyperaceae X

Cyperus odoratus fragrant fl atsedge Cyperaceae X

Datura jimsonweed Solanaceae X X

Datura stramonium jimsonweed Solanaceae X

Descurainia pinnata western tansymustard Brassicaceae X X X

Dicliptera resupinata Arizona foldwing Acanthaceae X

Digitaria californica Arizona cottontop Poaceae X

Echinocereus hedgehog cactus Cactaceae X

Equisetum arvense fi eld horsetail Equisetaceae X

Eragrostis lovegrass Poaceae X X

Eragrostis cilianensis stinkgrass Poaceae X X X

Eragrostis curvula weeping lovegrass Poaceae X

Eragrostis lehmanniana Lehmann lovegrass Poaceae X X X

Erigeron fl eabane Asteraceae X

Erigeron divergens spreading fl eabane Asteraceae X

Eriogonum buckwheat Polygonaceae X X

Eriogonum infl atum desert trumpet Polygonaceae X

Erioneuron avenaceum shortleaf woollygrass Poaceae X

Plant species observed at Tumacácori National Historical Park, organized by scientifi c name, cont.
112 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Scientifi c name Common name Family Mission Calabazas Guevavi

Erodium texanum Texas stork’s bill Geraniaceae X

Eschscholzia californica California poppy Papaveraceae X

Eschscholzia californica ssp.

mexicana

California poppy Papaveraceae X

Euphorbia heterophylla Mexican fi replant Euphorbiaceae X

Ferocactus wislizeni candy barrelcactus Cactaceae X X

Fragaria vesca woodland strawberry Rosaceae X

Fraxinus velutina velvet ash Oleaceae X X

Gaura coccinea scarlet beeblossom Onagraceae X

Gaura mollis velvetweed Onagraceae X

Gnaphalium cudweed Asteraceae X

Gnaphalium palustre western marsh cudweed Asteraceae X

Gutierrezia microcephala threadleaf snakeweed Asteraceae X X

Helianthus annuus common sunfl ower Asteraceae X X X

Hilaria belangeri curly-mesquite Poaceae X

Hybanthus greenviolet Violaceae X

Hymenoclea monogyra singlewhorl burrobrush Asteraceae X X X

Ipomoea morning-glory vine Convolvulaceae X X X

Ipomoea coccinea redstar Convolvulaceae X

Ipomoea hederacea ivyleaf morning-glory Convolvulaceae X

Isocoma tenuisecta burroweed Asteraceae X

Juncus cooperi Cooper’s rush Juncaceae X

Juniperus coahuilensis redberry juniper Cupressaceae X X

Lepidium pepperweed Brassicaceae X

Leptochloa dubia green sprangletop Poaceae X X X

Leptochloa panicea green sprangletop Poaceae X

Lesquerella gordonii gordon bladderpod Brassicaceae X X

Lotus humistratus foothill deervetch Fabaceae X

Lupinus lupine Fabaceae X

Lycium desert-thorn Solanaceae X X X

Lycium andersonii water jacket Solanaceae X X

Marrubium vulgare horehound Lamiaceae X

Mentzelia blazingstar Loasaceae X X

Mentzelia albicaulis whitestem blazingstar Loasaceae X X X

Mimosa aculeaticarpa catclaw mimosa Fabaceae X X

Mimosa aculeaticarpa var.

biuncifera

catclaw mimosa Fabaceae X X X

Mimulus cardinalis scarlet monkeyfl ower Scrophulariaceae X

Mirabilis tenuiloba longlobe four o’clock Nyctaginaceae X

Morus microphylla Texas mulberry Moraceae X X

Muhlenbergia fragilis delicate muhly Poaceae X X X

Muhlenbergia polycaulis cliff muhly Poaceae X

Muhlenbergia porteri bush muhly Poaceae X X

Plant species observed at Tumacácori National Historical Park, organized by scientifi c name, cont.
Appendix E: Species List 113

Scientifi c name Common name Family Mission Calabazas Guevavi

Nicotiana glauca tree tobacco Solanaceae X

Oenothera evening-primrose Onagraceae X X X

Oenothera primiveris desert evening-primrose Onagraceae X

Opuntia engelmannii cactus apple Cactaceae X X

Opuntia leptocaulis Christmas cactus Cactaceae X

Opuntia spinosior walkingstick cactus Cactaceae X X X

Panicum panicgrass Poaceae X

Panicum miliaceum broomcorn millet Poaceae X

Panicum obtusum vine mesquite Poaceae X

Parkinsonia fl orida blue paloverde Urticaceae X

Parkinsonia aculeata Jerusalem thorn Fabaceae X

Passifl ora mexicana Mexican passionfl ower Passifl oraceae X X

Penstemon parryi Parry’s beardtongue Scrophulariaceae X

Phacelia phacelia Hydrophyllaceae X X X

Phaseolus ritensis Santa Rita Mountain bean Fabaceae X

Phragmites australis common reed Poaceae X

Platanus wrightii Arizona sycamore Platanaceae X

Populus fremontii Fremont cottonwood Salicaceae X X X

Proboscidea parvifl ora doubleclaw Pedaliaceae X X

Prosopis velutina velvet mesquite Fabaceae X X X

Pyracantha fortuneana Chinese fi rethorn Rosaceae X

Rhus trilobata skunkbush sumac Anacardiaceae X

Rivina humilis rougeplant Phytolaccaceae X X

Ruellia nudifl ora violet wild petunia Acanthaceae X

Rumex hymenosepalus canaigre dock Polygonaceae X

Salazaria mexicana Mexican bladdersage Lamiaceae X X X

Salix gooddingii Goodding’s willow Salicaceae X X

Salix taxifolia yewleaf willow Salicaceae X

Salsola kali Russian thistle Chenopodiaceae X X X

Sambucus nigra European black elderberry Caprifoliaceae X X

Sambucus nigra ssp. canadensis common elderberry Caprifoliaceae X X

Sambucus nigra ssp. cerulea blue elderberry Caprifoliaceae X X X

Sapindus saponaria wingleaf soapberry Sapindaceae X X

Senecio fl accidus threadleaf groundsel Asteraceae X

Senna bauhinioides twinleaf senna Fabaceae X

Setaria bristlegrass Poaceae X X X

Setaria leucopila streambed bristlegrass Poaceae X

Sida fanpetals Malvaceae X

Sida abutifolia spreading fanpetals Malvaceae X

Sisymbrium irio London rocket Brassicaceae X X X

Solanum elaeagnifolium silverleaf nightshade Solanaceae X

Sonchus asper spiny sowthistle Asteraceae X X

Sorghum halepense Johnsongrass Poaceae X X X

Plant species observed at Tumacácori National Historical Park, organized by scientifi c name, cont.
114 Vegetation Classifi cation, Distribution, and Mapping Report: Tumacácori National Historical Park

Scientifi c name Common name Family Mission Calabazas Guevavi

Sphaeralcea globemallow Malvaceae X X

Sphaeralcea coccinea scarlet globemallow Malvaceae X

Sphaeralcea laxa caliche globemallow Malvaceae X

Sphaeralcea wrightii Wright’s globemallow Malvaceae X X X

Sporobolus contractus spike dropseed Poaceae X

Sporobolus cryptandrus sand dropseed Poaceae X X X

Sporobolus wrightii big sacaton Poaceae X X X

Tagetes micrantha licorice marigold Asteraceae

Tamarix ramosissima saltcedar Tamaricaceae X X

Tetramerium nervosum hairy fournwort Acanthaceae X X X

Tithonia thurberi Arizona sunfl owerweed Asteraceae X X X

Tribulus terrestris puncturevine Zygophyllaceae X

Vitis arizonica canyon grape Vitaceae X

Xanthium strumarium rough cockleburr Asteraceae X X X

Yucca elata soaptree yucca Agavaceae X

Zinnia acerosa desert zinnia Asteraceae X

Ziziphus obtusifolia lotebush Rhamnaceae X X X

Ziziphus obtusifolia var.

obtusifolia

lotebush Rhamnaceae X

Nomenclature follows the Integrated Taxonomic Information System (http://www.itis.gov/)

Highlighted species are non-native (introduced).

Plant species observed at Tumacácori National Historical Park, organized by scientifi c name, cont.
Appendix F: Accuracy Assessment Data Sheets 115

Appendix F

Accuracy Assessment Data Sheet

Celtis laevigata var. reticulata Forest

Prosopis velutina Forest

Populus fremontii – Salix gooddingii Forest

Tumacácori NHP Vegetation Mapping

Field Data Sheet: Thematic Accuracy Assessment

TUMA_AA_Datasheet.ppt If you find this datasheet completed, please call (520) 621-4501.

Unit Code: 

Approximate polygon center (UTM NAD83):

Time (00:00): Recorder:

Polygon ID: Sub-map:

Date (mm/dd/yyyy): Observer(s):

Based on your observation of this polygon and the vegetation type descriptions provided to you, check 

the label that best fits this polygon:

Record any notes pertinent to your assessment of this polygon. Describe any recent (within the past year) disturbance that may 

have changed the vegetation type in this polygon, such as flooding, fire, tree cutting, etc. Use back of sheet as needed.

Dominant Formation-defining SPECIES:

Trees Shrubs Herbaceous Other/None

Keyed Formation:

Acacia greggii Woodland

Prosopis velutina Woodland

Populus fremontii – Salix gooddingii Woodland

Prosopis velutina / [Prosopis velutina – Acacia 

greggii] Wooded Shrubland

Tamarix ramosissima Shrubland

Acacia constricta Shrubland

Prosopis velutina – Acacia greggii Shrubland

Prosopis velutina / mixed annual Wooded Herbaceous

Populus fremontii / mixed annual Wooded Herbaceous

Hymenoclea monogyra / [Amaranthus palmeri –

Chloris virgata] Shrub Herbaceous

Prosopis velutina / Amaranthus palmeri Shrub 

Herbaceous

Amaranthus palmeri – Salsola kali – Chenopodium 

spp. Herbaceous

Park Facilities

Cropland and Pasture

Developed Woodland

Strand

The fit of the vegetation type description to this polygon is (circle one) :

Excellent Good Fair Poor

If poor or fair, write in name of alternate vegetation type (does not need to be from above list)

Appendix G: Root Square Mean Error 117

Appendix G

Root Mean Square Error

Table G-1. RMSE, Mission Unit

Pt. X source Y source X map Y map

1 494840.7 3494464.6 494840.7 3494464.9

2 496166.1 3493860.6 496166.0 3493861.0

3 494964.5 3491597.8 494964.9 3491597.5

4 496276.1 3491651.7 496275.4 3491652.4

5 494672.2 3492994.5 494672.1 3492994.1

6 496246.2 3493254.4 496244.3 3493253.7

7 495145.1 3492572.4 495145.0 3492571.8

8 495493.6 3492649.9 495493.9 3492649.1

9 495737.1 3493990.7 495737.3 3493990.7

10 495390.5 3494200.5 495390.0 3494200.1

11 495077.7 3494011.8 495077.0 3494011.6

12 495408.0 3491993.0 495407.5 3491992.5

13 495236.3 3492166.0 495236.6 3492164.9

14 495959.7 3491770.1 495960.3 3491771.3

15 494957.1 3493271.1 494956.5 3493270.7

16 495469.8 3493284.5 495469.7 3493284.7

17 495577.1 3493680.6 495576.6 3493680.0

18 495156.2 3492948.8 495156.1 3492949.0

19 495837.8 3492633.1 495838.7 3492633.2

20 495558.7 3491933.4 495559.2 3491932.4

MISSION RMS ERROR 0.7697

Table G-2. RMSE, Calabazas Unit

Pt. X source Y source X map Y map

1 504588.7 3479151.3 504589.3 3479151.6

2 503230.7 3480191.4 503230.8 3480191.1

3 504477.8 3479948.5 504478.7 3479948.8

4 503075.0 3479768.8 503074.6 3479768.3

5 503793.0 3480426.4 503793.4 3480426.2

6 503893.4 3479077.1 503893.9 3479077.0

7 503833.3 3479720.7 503833.4 3479720.3

8 503700.2 3479827.2 503699.8 3479826.8

9 503943.6 3479803.0 503943.1 3479802.9

10 503911.8 3479444.8 503912.2 3479444.3

11 504100.2 3479664.4 504100.9 3479664.3

12 504050.7 3479874.8 504050.7 3479874.5

13 503778.7 3480023.1 503779.1 3480023.4

14 503257.1 3479185.4 503257.5 3479184.3

15 503761.6 3479520.0 503762.0 3479519.4

16 503988.7 3479576.3 503989.1 3479575.6

17 503801.9 3479879.1 503802.0 3479878.9

18 504121.4 3479775.9 504121.5 3479775.7

19 503574.1 3479728.4 503573.9 3479728.3

20 504217.2 3480217.8 504217.6 3480217.6

CALABAZAS RMS ERROR 0.3991

Table G-3. RMSE, Guevavi Unit

Pt. X source Y source X map Y map

1 508820.7 3475507.6 508822.0 3475507.5

2 510093.7 3474193.3 510094.3 3474193.0

3 510178.3 3475531.1 510179.6 3475531.0

4 508580.1 3474168.0 508580.9 3474167.9

5 509262.2 3474917.3 509263.9 3474917.0

6 509518.3 3475034.0 509517.5 3475034.1

7 509477.2 3475028.4 509476.8 3475028.0

8 509146.1 3475094.6 509147.1 3475093.9

9 509502.6 3474819.6 509503.3 3474819.9

10 509501.3 3474603.6 509503.3 3474603.4

11 509345.7 3474714.8 509346.2 3474715.1

12 509342.6 3474861.8 509344.0 3474861.4

13 509393.1 3474961.5 509393.5 3474961.1

14 509272.8 3475067.0 509274.0 3475067.1

15 509475.3 3475114.8 509475.0 3475115.1

16 509331.3 3475206.4 509331.4 3475206.3

17 509080.9 3475281.6 509079.9 3475281.2

18 509012.2 3474704.0 509014.0 3474703.9

19 509901.1 3475229.2 509901.3 3475229.4

20 510070.8 3474878.8 510070.6 3474878.6

GUEVAVI RMS ERROR 0.8538

The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides 

scientifi c and other information about those resources; and honors its special responsibilities to American Indians, Alaska 

Natives, and affi liated Island Communities.

NPS NPS 311/100300, September 2009
Natural Resource Program Center 

1201 Oak Ridge Drive, Suite 150 

Fort Collins, Colorado 80525

www.nature.nps.gov

National Park Service

U.S. Department of the Interior

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