United States 

Department of 

Agriculture 

Forest Service 

Southern 

Research Station 

Forest Resources of 

Puerto Rico, 1990 

Peter A. Franco, Peter L. Weaver, and 

Susan Eggen-McIntosh 

Resource Bulletin 

3RS-22 
The Authors: 

Peter A. Franco is a Research Forester with the Forest Inventory 

and Analysis Research Work Unit, Southern Research Station, 

U.S. Department of Agriculture, Forest Service, Starkville, MS 39759; 

Peter L. Weaver is a Research Forester with the International 

Institute of Tropical Forestry, Southern Research Station, U.S. 

Department of Agriculture, Forest Service, Rio Piedras, PR 00928; 

and Susan Eggen-McIntosh is a former Research Forester with the 

Forest Inventory and Analysis Research Work Unit, Southern 

Research Station, U.S. Department of Agriculture, Forest Service, 

Starkville, MS 39759. 

October 1997 

Southern Research Station 

P.O. Box 2680 

Asheville, North Carolina 28802 
An error occurred in the preparation of camera copy for Resource Bulletin SRS-22, Forest 

Resources of Puerto Rico, 1990 by Peter A. Franco, Peter L. Weaver, and Susan EggenMchtosh. On the inside fkont cover, the address for Peter L. Weaver should have read as 

follows: "Peter L. Weaver is a Research Forester with the International Institute of Tropical 

Forestry, U. S. Department of Agriculture, Forest Service, Rio Piedras, PR 00928." 

--SRS, October 1997 

ERRATA 

An error occurred in the preparation of camera copy for Resource Bulletin SRS-22, Forest 

Resarrces of Puerto Rico, 1990 by Peter A. Franco, Peter L. Weaver, and Susan EggenMcIntosh. On the inside front cover, the address for Peter L. Weaver should have read as 

follows: ''Peter L. Weaver is a Research Forester with the International Institute of Tropical 

Forestry, U. S. Department of Agriculture, Forest Service, Rio Piedras, PR 00928." 

--SRS, October 1997 

Contents 

Page 

Introduction .................................................... 1 

Previous Forest Area Trends ....................................... 2 

Highlights ...................................................... 3 

The 1990 Forest Survey ........................................... 4 

Area ......................................................... 4 

Standsize .................................................... 6 

Species Composition ............................................ 6 

Basal Area Distribution .......................................... 7 

Timbervolume ................................................. 8 

SawtimberVolume .............................................. 10 

Trends in Secondary Forests ....................................... 11 

Trends in Coffee Shade Forests .................................... 12 

Abandoned coffee shade forest .................................. 12 

Active coffee shade forest ...................................... 13 

Conclusions ..................................................... 14 

Literature Cited ................................................. 14 

Appendix ....................................................... 15 

SurveyMethods ................................................. 15 

1980Survey ................................................... 15 

1985Update ................................................... 15 

1990Resurvey ................................................. 15 

Reliability of the Data ............................................. 16 

Definitions ...................................................... 16 

Conversion Factors ............................................... 19 

List of Tree Species Included in Standard Tables ....................... 20 

IndexofTables .................................................. 22 

Tablesl-26 ............................................... 23 

)rest Resources of Puerto Rico, 1990 

er A. Franco, Peter L. Weaver, and Susan Eggen-McIntosh 

980, the Southern Forest Experiment Station, Forest 

:ntory and Analysis Research Work Unit (SOFIA), in 

peration with the International Institute of Tropical 

estry, established a forest survey of the Commonwealth 

'uerto Rico. The primary objective was to assess the 

ber-production potential of the island's forest resources. 

: main island, occupying about 8900 square kilometers, 

; partitioned into commercial and noncommercial survey 

ions (fig. I). Field sampling was concentrated in the 

~mercial survey region, which included all areas having 

the potential to produce commercial timber. The commercial 

region was delineated to exclude urban areas, agricultural 

lands, critical watersheds, areas with adverse site conditions, 

such as excessive rainfall and excessive slope, and other 

areas not likely, either for physiographic or economic 

reasons, to sustain commercial timber production. 

Because complete photographic coverage was unavailable 

for the 1980 survey, aerial photography was acquired for a 

1985 update of forest area estimates of both the commercial 

and noncommercial survey regions. The 1985 update 

provided more current estimates of forest area by detailed 

Excessive slope (2 60 percent) 

Excessive rainfall (t 2500 dyr) 

Unproductive soils and higher priority uses1 

Subtropical Dry Life Zone (I 1000 mm/yr rainfall) 

Commercial survey region 

'Mangroves, swamps, alluvial flats, and metropolitan regions. 

ure I-Exclusions from the commercial survey region of Puerto Rico (adapted from Birdsey and Weaver 1982). 
cover classes for the commercial region, refined forest area 

estimates for the noncommercial region, and estimated 

rates of change in the timberland area (Birdsey and Weaver 

1987). In 1990, another forest survey was conducted in the 

commercial region of Puerto Rico. This publication 

describes the results of that survey and changes that 

occurred within the region between 1980 and 1990. 

The forests of Puerto Rico were previously classified 

according to the Life Zone system (Ewe1 and Whitmore 

1973, Holdridge 1967). The primary advantage of this 

classification system is that it provides a means of 

comparison among tropical forests based on climatic data 

(Birdsey and Weaver 1982). The commercial region is 

located in only two of the island's six Life Zones, the 

Subtropical Moist Forest and the Subtropical Wet Forest. The 

Subtropical Moist Forest occupies about 58 percent of Puerto 

Rico; the Subtropical Wet Forest covers about 23 percent. 

Broad soil associations, which reflect geologic origin, 

formed the basis for stratifying the data within both Life 

Zones (fig. 2) because they yielded the most important 

prior knowledge of the commercial survey region (Birdsey 

and Weaver 1982). Four soil groups were recognized in the 

surveys. Soils of volcanic origin were divided into deep 

and shallow clays. Together, these soils make up about 70 

percent of the commercial region. Granitic soils and 

limestone soils account for about 10 and 20 percent of the 

commercial region, respectively. Forest area statistics for 

both the 1980 and 1990 surveys were compiled using this 

stratification rather than the county-based system used in 

the United States. 

Previous Forest Area Trends 

In the early 16th century, Puerto Rico's 890000 hectares of 

land were covered with mature forests containing a wide 

variety of species. These forest formations were typical of 

the Caribbean region at the time of discovery (Durland 1929, 

Little and others 1974, Little and Wadsworth 1964). In the 

years that followed, European settlers cleared most of the 

Subtropical Life Zones: 

Wet Moist 

Deep volcanic soils 

Shallow volcanic soils 

II( Granitic soils 

a Limestone soils 

Figure 2-Life Zones and soil groups in the commercial survey region of Puerto Rico (adapted from Birdsey and Weaver 1982). 
kind and coastal forests for pasture and cropland. 

hough the clearing of forests for timber, fuelwood, and 

moal had modified the land, clearing for agriculture was 

far the most destructive in terms of the area affected 

rdsey and Weaver 1982). By 1828, pasture and cultivated 

d represented one-third of Puerto Rico's total land area 

adsworth 1950). To accommodate the rapidly growing 

wlation, most of the remaining mature forests were 

ared in the 19th century (fig. 3 ). By 1899, forest cover 

s reduced to 182 000 hectares, with pasture alone 

:ounting for 55 percent of the land area. Cultivating coffee 

~eath shade trees (coffee shade) had recently begun; this 

tctice used an additional 77 000 hectares (Wadsworth 

50). Tree cover continued to decline slowly over the next 

years, greatly diminishing the capability of the forests to 

,vide products other than fuelwood and charcoal. 

Q Coffee shade 

Forested 

1828 1899 1912 1916 1931 1941 1948 1960 1980 1990 

Year 

gure 3-Area with tree cover in Puerto Rico for selected years 

;28- 1990 (adapted from Birdsey and Weaver 1987). 

fter 19 16, another period of heavy cutting caused forest 

-ea to decline sharply, depleting tree cover to 81 000 

zctares by 193 1 (Gill 193 1). By the late 19401s, Puerto 

ico's forests had dwindled to only 6 percent of the total 

~nd area, and coffee shade occupied about the same area 

(oenig 1953). The 1950's marked the beginning of a 

eriod of recovery for the forests of Puerto Rico. 

,bandoned cropland and pasture on eroded hillsides began 

:verting to secondary forest during this time. Widespread 

:version from agricultural land to secondary forest was the 

rimary reason Puerto Rico's total forest area increased to 

ver 30 percent by 1980. These reverted areas, mainly 

bandoned hillside farms in the mountainous region of the 

lain island (Birdsey and Weaver 1982, 1987), comprise 

le forest resource addressed in this study. 

Highlights 

The 10 years between the 1980 and 1990 surveys was a 

period of major change in Puerto Rico's timberland, one 

that reveals a positive outlook for the future quality and 

utility of the island's timber resources. The most noticeable 

areal trend was the substantial increase in secondary forests 

from less than one-half to more than three-fourths of the 

timberland area. Reverted cropland and pasture accounted 

for about two-thirds of the increase in secondary forest 

area. Reclassification of former abandoned coffee shade 

forest stands also contributed to this increase. 

Accompanying the expansion of secondary forests was a 

reduction in the areas of both abandoned and active coffee 

shade forests. Most of the abandoned coffee shade lands 

not reclassified as secondary forest were converted to other 

agricultural uses. Some formerly active coffee shade areas 

were abandoned since 1980, but most of the decline in 

coffee shade forests resulted from the replacement of coffee 

with other agricultural crops. 

Some of the most dramatic areal trends resulted from the 

reclassification of some forest types (coffee shade and 

secondary forest). This reclassification helps illustrate the 

frequently changing land use patterns found in Puerto Rico, 

where people recurrently clear their land for agriculture or 

pasture. The island's high population density (about 1,050 

people per square mile) and the high proportion of privately 

owned land (95 percent) equate to many small landholdings, 

numerous property sales, and an ever changing mosaic of land 

uses. Previously abandoned lands, once sold, may be placed in 

agricultural use, such as hit trees or vegetable crops, used for 

pasture, or developed for a homesite or commercial venture. 

In terms of timberland coverage, sawtimber-size stands 

gained a slight dominance over poletimber stands, whereas 

sapling-seedling stands declined. In secondary forests, 

sapling-seedling stands gained 4600 hectares by 1990, 

though their proportion of secondary forest area fell from 

43 to 26 percent. Poletimber stands covered only an 

additional 2700 hectares in 1990, the same area by which 

sapling-seedling stands decreased. These trends reflect the 

emergence of many of the former poletimber-size stands 

(the dominant stand size in 1980) into sawtimber-size 

stands and the ascendance of the former sapling-seedling 

stands into the poletimber stand-size class. 

Trends in basal area and stocking showed an overall 

improvement in Puerto Rico's timber resource, both in terms 

of quantity and quality. The combined basal area of 

poletimber and sawtimber trees was substantially higher, 

increasing from 1.0 to 1.5 million square meters. Average 

basal area per hectare of sawtimber-size trees rose most 
sharply in secondary forests, whereas average basal area of 

poletimber had the greatest gains in abandoned coffee shade 

areas. The average basal area of sapling-size trees across 

timberland remained the same since 1980 but diminished 

slightly in secondary forests. The average level of stoclung 

for both sawtimber-size and poletimber-size stands was 

higher in 1990. Sawtimber and poletimber stands with basal 

areas of 25 or more square meters per hectare covered 

14500 hectares, compared to 8500 hectares in 1980. 

Timberland was not only better stocked, but stocked with 

better quality trees, as supported by a greater proportion of 

basal area in growing-stock trees. More than 70 percent of 

timberland basal area was comprised of growing-stock 

quality trees, compared to 50 percent in 1980. 

Increases in volume from 1980 to 1990 were remarkable and 

offered further evidence of a higher quality timber resource. 

These notable gains in timber volume resulted from both the 

growth of the timber surveyed and the lack of commercial 

timber extraction. The average timber volume per hectare in 

timberland doubled, with growing-stock trees contributing the 

majority of this accrual. Furthermore, two-thirds of the timber 

volume in all forest classes was growing-stock volume. In 

secondary forests, growing-stock volume was about evenly 

divided between sawtirnber and poletimber trees. Sawtimber 

volume in timberland approximately doubled, both in terms 

of total volume (2.6 million cubic meters) and volume per 

hectare (18 cubic meters). The volume of sawtimber on 

secondary forests nearly tripled to 1.8 million cubic meters, 

representing an increase from 11 to 16 cubic meters per 

hectare. On a per hectare basis, abandoned coffee shade forest 

had the greatest increase in timber volume (53 to 102 cubic 

meters) and growing-stock volume (28 to 66 cubic meters), 

whereas active coffee shade forest had the greatest increase in 

sawtirnber volume (7 to 26 cubic meters). 

Active coffee shade 

21 400 ha (16%) 

are 

:9?4 

Abandoned coffee 

shade 38 200 ha (299 

Much of the notable increase in sawtimber volume may be 

attributed to the ascendence of formerly poletimber-size 

trees into the sawtimber-size class. Likewise, many of the 

previously submerchantable trees have since crossed the 

threshold of merchantability into either the poletimber or 

sawtimber-size class. The lack of commercial timber 

harvesting on the island has particularly favored the 

accumulation of volume in the sawtimber component. 

The 1990 Forest Survey 

Area 

Puerto Rico's total forest area increased from 279 000 

hectares in 1980 to 287 000 hectares in 1990. Nonforest land 

uses amounted to 68 percent of the total land area, slightly 

less than in 1980. Forest area in the commercial region 

increased by more than 17 000 hectares, whereas that in the 

noncommercial region decreased by about 9000 hectares. 

The positive net change in the commercial region's forested 

area resulted because reversions of cropland and pasture 

exceeded the clearing of forested areas to nonforest uses. 

Forest land classified as timberland increased to almost 

144000 hectares. Since 1980, about 35 000 hectares reverted 

from cropland, pasture, and other nonforest land uses to 

timberland. At the same time, about 21 000 hectares of 

timberland were cleared for nonforest uses. Therefore, the 

net increase in timberland area was about 14000 hectares. 

Nearly four-fifths of the commercial region's forests were 

classified as secondary forest compared to less than onehalf in 1980 (fig. 4). The remaining 30000 hectares of 

timberland represented either former or current coffee 

producing areas (fig. 5). Over two-thirds of that timberland 

Abandoned coffee 

shade 23 365 ha (16%) 

as Active coffee shade 

1) 7 010 ha (5%) 

Secondary forest 

59 200 ha (46%) 

1980 Timberland 

(130 500 ha) 

1990 Timberland 

(143 933 ha) 

igure &Timberland area by forest class, Puerto Rico, 1980 and 1990. 
Active coffee shade 

7 010 ha (23%) 

ondary forest 

557 ha (79%) Abandoned coffee shade 

23 365 ha (77%) 

A11 timberland 

(143 933 ha) 

Coffee shade 

(30 375 ha) 

ure 5-Distribution of components of timber volume, Puerto Rico timberland, 1990. 

:a was secondary forest land resulting specifically from 

: abandonment of coffee production under shade trees 

3andoned coffee shade). Only about 7000 hectares in 

90 supported forest stands, which were being used as 

ffee shade (active coffee shade). Reversions from 

~nforest land uses accounted for almost one-third of the 

3 000 hectares of secondary forest land in the 

lmmercial region. Most of the other 67 percent of 

condary forest land was classified as such in 1980. Other 

inor additions to secondary forest land came from the 

classification of active and abandoned coffee shade and 

her previously cutover areas to secondary forest. Unlike 

e 1980 survey, no areas were classified as nonstocked in 

$90. 

dditions to secondary forest land amounted to about 

I000 hectares in the Subtropical Moist Forest and about 

I000 hectares in the Subtropical Wet Forest. Secondary 

,rests accounted for about two-thirds of the Subtropical 

[oist Forest's timberland area in 1980 but represented 

lore than 90 percent of its timberland in 1990. The 

,rgest accretion in the Subtropical Moist Forest, about 

5 000 hectares, occurred on shallow volcanic soils. In the 

ubtropical Wet Forest, the proportion of secondary 

)rests in timberland increased from about one-third to 

vo-thirds. Deep volcanic soils and granitic soils of the 

ubtropical Wet Forest each amassed about 10000 

ectares. 

'he areas of both abandoned and active coffee shade 

,rests decreased by about one-half. In 1980, both forest 

lasses combined covered about 59 000 hectares. By 1990, 

le estimated total area was 30000 hectares, of which 

000 hectares were in active coffee shade. These active 

offee shade forests fell from 16 percent to 5 percent of all 

timberland. The Life Zone soil group stratum with the 

greatest loss of active coffee shade forest area, more than 

10 000 hectares, was the deep volcanic classification within 

the Subtropical Wet Forest. About one-half of the total 

reduction in active coffee shade area resulted from the 

conversion of these lands to alternative agricultural uses; 

the remainder was simply abandoned. 

Many of the older, abandoned coffee shade areas are very 

difficult to distinguish from reverted pasture and cropland 

(Birdsey and Weaver 1987). The estimated area of forests 

classified as abandoned coffee shade decreased from 

38 000 to 23 000 hectares between 1980 and 1990. About 

one-half of this decrease resulted from reclassifying these 

areas to secondary forest. About one-third of the abandoned 

coffee shade areas were converted to agricultural uses 

other than coffee production. The remaining 15 percent 

were either developed for nonforest land uses such as 

roads and rights-of-way or returned to active coffee 

production. 

Deep volcanic soils of the Subtropical Wet Forest are the 

stratum encompassing the main coffee-producing region 

of the island. Consequently, this stratum had the most 

extensive coverage of abandoned and active coffee shade 

areas in both 1980 and 1990. By 1990, however, there 

were about 5500 fewer hectares of abandoned coffee 

shade and about 10500 fewer hectares of active coffee 

shade than in 1980. Active coffee shade forests were also 

present, albeit to a lesser degree, on limestone and 

granitic soils in 1980. In 1990, the 7000 hectares of 

active coffee shade were confined only to deep soils of 

volcanic origin, with about 80 percent in the Subtropical 

Wet Forest and the remainder on the Subtropical Moist 

Forest. 
Stand Size 

In 1980, timberland was about evenly divided among 

sawtimber, poletimber, and sapling-seedling stands (fig. 6). 

By 1990, sawtimber stands occupied nearly 66 000 hectares 

and dominated Puerto Rico's timberland. These stands 

covered about 1.4 times the area of poletimber stands and 

2.2 times the area of sapling-seedling stands. 

The area of sapling-seedling stands on all timberland fell 

from 33 200 hectares to about 30544 hectares, despite a 

20-percent increase in the area of sapling-seedling stands in 

secondary forests. This decrease resulted from a large loss of 

sapling-seedling stands in abandoned and active coffee shade 

forests. Sapling-seedling stands in both coffee shade forests 

occupied more than 8000 hectares in 1980 but only 700 

hectares in 1990, all in abandoned coffee shade forest. 

Moreover, poletimber stands in coffee shade forests 

decreased from 19000 to 7000 hectares. By 1990, most of 

the poletimber stands were found in abandoned coffee shade 

forest. In contrast, sawtirnber stands in abandoned and active 

coffee shade forests remained fairly stable, covering about 

23 000 hectares in 1980 and 1990. The majority of these 

sawtimber stands were in abandoned coffee shade forest. 

In secondary forests, the area of sawtimber stands almost 

tripled, and the area of poletimber stands more than doubled 

between 1980 and 1990. Poletimber and sawtirnber stands 

combined occupied over 80 000 hectares, almost threefourths of all secondary forest land. This total area was 

almost evenly divided between these two stand-size classes. 

The increased coverage of poletimber and sawtimber stands 

is supported by comparison of the 1980 and 1990 diameter 

Nonstocked areas 

11 700 ha (9%) Sap.-seed. stands 

1980 Timberland 

(130 500 ha) 

distributions (fig. 7). Numbers of live trees in the 

poletimber diameter classes (15,20, and 25 centimeters) 

increased by an average of 37 percent. Numbers of live 

trees in the sawtirnber diameter classes (30 centimeters and 

larger) increased by an average of 50 percent. 

Species Composition 

Ten species accounted for about one-half of all live basal 

area both in 1980 and in 1990. Nine of these species were 

the same in both surveys, while Evthrina poeppigiann 

15 20 25 30 35 40 45+ 

Diameter class (cm) 

Figure 7-Number of live trees by diameter class, Puerto Rico 

timberland. 1980 and 1990. 

Poletimber stands 

Sawtimber stands 

Sap.-seed. stands 

30 544 ha (21%) 

1990 Timberland 

(143 933 ha) 

:igure 6-Timberland area by stand-size class, Puerto Rico, 1980 and 1990. 

I 
laced Citrus sinensis (fig. 8). However, their rankings by 

a1 area plurality changed. Two species, Iizga Vera and 

rthoden campnnzrlnta, showed significant changes in 

ir relative contributions to live basal area. S. 

tzpanulata, formerly ranked seventh in basal area 

rality, replaced I. vera as the species with the most basal 

a. This species tripled its relative proportion of live basal 

a from 3 percent to 10 percent. The proportion of live 

;a1 area represented by I. Vera decreased by about onef to 5 percent. Furthermore, I. vera and I. fagifolia were 

only two species for which basal area decreased. 

1980, coffee shade forests were less complex than 

:ondary forests, containing fewer than half the number of 

:cies found in the latter (Birdsey and Weaver 1982). This 

ne trend in species diversity between coffee shade and 

:ondary forests was apparent in 1990. The 10 most 

mmon species in secondary forests accounted for 47 

rcent of total basal area. In contrast, the 10 most common 

xies in abandoned and active coffee shade forests 

zounted for 68 and 83 percent, respectively, of their total 

sal areas. 

isal Area Distribution 

le Subtropical Wet Forest continued to carry a larger 

oportion of timberland basal area than the Subtropical 

oist Forest; however, timberland basal area did become 

are evenly distributed between the two Life Zones. In 

180, timberland basal area in the Subtropical Wet Forest 

3s almost twice that found in the Subtropical Moist 

Species name 

Forest. By 1990, timberland basal area in the Subtropical 

Wet Forest was only about 1.5 times greater than in the 

Subtropical Moist Forest, Total timberland basal area in the 

Subtropical Moist Forest increased 78 percent to over 

650 000 square meters. Growing-stock quality trees 

accounted for 90 percent of that increase. In addition, 

average basal area increased from 6 to 9 square meters per 

hectare in the Subtropical Moist Forest and from 10 to 13 

square meters per hectare in the Subtropical Wet Forest. 

Total basal area changes in the Subtropical Wet Forest were 

most noticeable for sawtimber-size trees, which increased by 

33 percent, whereas the total basal area of poletimber trees 

increased by 25 percent. Within the sawtimber tree-size 

class, basal area of the growing-stock component more than 

doubled, whereas that of the rough-and-rotten component 

decreased to almost one-half the amount present in 1980. 

In 1990, about 60 percent of the sawtimber-size stands in 

timberland had basal areas >I5 square meters per hectare. 

This reflects an improvement in the stocking of these 

stands since 1980 when over 50 percent of these sawtimber 

stands had basal areas <15 square meters per hectare. 

Stocking levels in poletimber stands also showed 

improvement. The area of poletimber stands having basal 

areas >20 square meters per hectare increased from 10 000 

to over 16 000 hectares since 1980. 

The total area of sapling-seedling stands decreased by <10 

percent, but no sapling-seedling stands had basal areas of 

> 15 square meters per hectare by 1990. In addition, more 

lathodea campanulata 

Guarea guidonia 

lnga Vera 

Cecropia peltata 

A ndira iner-irz is 

raltebuia hetevophylla 

Eugenia jam bos 

Inga fag<folia 

Efythrina poeppigiana 

iWangrfera indica 

0 50 100 150 200 250 

Basal area (thousand square meters) 

gure 8-Relative species importance by basal area plurality. Puerto Rico timberland, 1990. 
than one-half of the 30000 hectares of sapling-seedling 

stands had basal areas averaging <5 square meters per 

hectare. 

The average basal area of all live trees in timberland 

increased from 13.2 to 15.2 square meters per hectare 

during the decade, with the poletimber and sawtimber-size 

classes each representing an increase of 1 square meter per 

hectare (fig. 9). The average basal area of sapling trees 

remained about the same at 4.3 square meters per hectare. 

Of the three forest classes, abandoned coffee shade had the 

greatest increase in average basal area of all live trees, 

almost 3 square meters per hectare (fig. 10). An almost 

twofold increase in the basal area of poletimber trees 

effected this change (fig. 11). In active coffee shade forests, 

average basal area of poletimber trees increased by over 2 

square meters per hectare. Average basal area of sawtimbersize trees decreased in abandoned coffee shade forests but 

remained the same in active coffee shade forests. In 

contrast, sawtimber-size tree basal area increased in 

secondary forests, whereas poletimber-size tree basal area 

remained stable. 

In 1980, the ratio of growing-stock tree basal area to roughand-rotten tree basal area for poletimber-size trees was 

about 1.5 to 1 .O; for sawtimber-size trees, about 1 to 1. 

Since 1980, the basal area of poletimber trees of growingstock quality more than doubled, and the basal area of 

sawtimber-size, growing-stock trees almost tripled. As a 

-esult, the ratio of growing-stock basal area to rough-and- 

-otten basal area reached 2 to 1 for poletimber-size trees 

ind 3 to 1 for sawtimber-size trees by 1990. 

1980 Year 1990 

gure 9-Average basal area by tree-size class, Puerto Rico timberland, 

j80 and 1990. 

Secondary forest Abandoned Active coffee 

coffee shade shade 

Figure lO---Average basal area of all live trees by forest class, Puerto 

Rico timberland, 1980 and 1990. 

II Poletimber 

Sapling 

10 

1980 1990 1980 1990 1980 1990 

Secondary Abandoned Active 

forest coffee shade coffee shade 

Figure 11-Average basal area by forest class and tree-size class, Puerto 

Rico timberland, 1980 and 1990. 

A 

Timber Volume 

€#I Sawtimber 

Average timber volume on all timberland increased from 42 

to 80 cubic meters per hectare between 1980 and 1990. Ten 

species accounted for about 55 percent of all timber volume 

in both surveys (fig. 12). 
Species name 

?athodea campanulata 

Guarea guidonia 

Inga Vera 

Cecropia peltata 

lnga fagifolia 

Tabebuia heterophylla 

Andira inermis 

Evythrina poeppigiana 

Roystonea borinquena 

dymopanax morototoni 

0 200 400 600 800 1000 1200 1400 

Timber volume (thousand cubic meters) 

;ure 12-Relative species importance by timber volume, Puerto Rico timberland, 1990. 

120 

J 1990, the Subtropical Moist and Subtropical Wet 

zests supported average timber volumes of 59 and 103 

Lbic meters per hectare, respectively, compared to 31 and 100 

cubic meters per hectare in 1980 (fig. 13). Total timber 

dume became more evenly distributed between the two z 

m 

.y 

fe Zones. The timber volume ratio between the g 80 

lbtropical Moist Forest and the Subtropical Wet Forest 4 

L 

as 1.0 to 1.9 in 1980 and 1.0 to 1.6 in 1990. a2 

a 

13 60 Q) 

1e Subtropical Moist Forest, with 39 percent of the total .y 

nber volume by 1990, had more than doubled to 4.5 3 

. u 40 C.l 

illion cubic meters during the decade. Growing-stock =I 

rality trees, responsible for over 80 percent of this increase, U 

most tripled in timber volume. Within the growing-stock 20 

)mponent, the volume of timber in sawtimber-size trees 

lore than tripled to almost 2 million cubic meters. 

0 

he Subtropical Wet Forest, accounting for 61 percent of 

1 timber volume, supported over 7 million cubic meters in 

390, almost two times the volume in 1980. Growing-stock 

ees, whose timber volume more than doubled to 5.4 

tillion cubic meters, accounted for 90 percent of this 

crease. Timber volume of growing-stock trees in the 

ubtropical Wet Forest continued to be almost equally 

ivided between poletimber and sawtimber-size trees. 

'he total volume of timber in sawtimber-size, growing- 

,ock trees across all timberland increased from 1.8 million 

) almost 4.9 million cubic meters (fig. 14). Volume 

ccretion in the saw-log portion of these trees contributed 

almost one-half the total increase in timber volume. 

;ranch and fork sections accounted for over one-fourth of 

le volume increase. 

1980 1990 1980 1990 

Subtropical moist Subtropical wet 

forest forest 

Figure 13-Timber volume by Life Zone and tree class, Puerto Rico 

timberland, 1980 and 1990. 

In poletimber trees, volume increment in the bole sections 

accounted for about one-half the increase in timber volume 

(fig. 15); branch and fork sections and the sound cull 

component made up the remainder. Pronounced gains in the 

volumes of branches and forks (figs. 14, 15) are 

characteristic of stands in the late poletimber-early 

sawtimber stages of development. 
6 

Sound cull 

Upper stem 

Branches and forks 

II Saw log portion 

1980 1990 

Year 

Figure 14-Distribution of components of timber volume in sawtimbersize, growing-stock trees, Puerto Rico timberland, 1980 and 1990. 

1980 1990 

Year 

'igure 15-Distribution of components of timber volume in poletimberize, growing-stock trees, Puerto Ricn timbeland, 1980 and 1990. 

lmong the Life Zone-soil group strata, both the highest 

~nd lowest timber volumes were found in the Subtropical 

Net Forest. The highest volume, 4.8 million cubic meters, 

)ccurred on deep volcanic soils, and the lowest volume, 

40000 cubic meters, occurred on limestone soils. About 

hree-fourths of all timber volume was on slopes >25 

bercent. More than one-half of this portion occurred on 

lopes >45 percent. 

The proportions of timber volume represented by 

sawtimber trees, poletimber trees, and rough-and-rotten 

trees showed similar patterns of change among the three 

forest classes (fig. 16). In all forest classes, the proportion 

of timber volume in sawtimber trees increased, whereas the 

proportion of timber volume in rough-and-rotten trees 

decreased. The proportion of timber volume in poletimber 

trees changed little or not at all. 

Sawtimber Volume 

Sawtimber volume, the volume in the saw-log portion of 

sawtimber-size trees of growing-stock quality, doubled 

from 1.3 to 2.6 million cubic meters across all timberland. 

Averaging 18 cubic meters per hectare, sawtimber volume 

accounted for about one-third of growing-stock volume and 

about one-fourth of timber volume (fig. 17). These 

sawtirnber volume proportions remained relatively 

unchanged since 1980. Active coffee shade was the only 

forest class in which average sawtimber volume became a 

greater relative proportion of average growing-stock 

volume and average timber volume, increasing from 36 to 

48 percent and 20 to 32 percent, respectively (fig. 18). Ten 

species represented slightly more than two-thirds of the 

total sawtirnber volume in all timberland (fig. 19). 

Sawtimber volume in secondary forests almost tripled to 1.8 

million cubic meters but stayed relatively unchanged in the 

remaining forest classes (fig. 20). Almost 80 percent of the 

total sawtirnber volume, over 2 million cubic meters, was in 

Rough-and-rotten 

Poletirnber 

Sawtiinber 

0 

1980 1990 1980 1990 1980 1990 

Secondary Abandoned Active 

forest coffee shade coffee shade 

Figure 1 &Timber volume by class of timber and forest class, Puerto 

Rico timberland, 1980 and 1990. 
Trends in Secondary Forests 

Sawtimber Growing-stock Timber volume 

volume volume 

;ure 17-Average sawtimber, growing-stock, and timber volume, 

erto Rico timberland, 1980 and 1990. 

I Sawtimber volume 

( H Timber volume 

1980 1990 1980 1990 1980 1990 

Secondary Abandoned Active 

forest coffee shade coffee shade 

lgure 18-Average growing-stock, sawtimber, and timber volume by 

rest class. Puerto Rico timberland 1980 and 1990. 

~wtimber-size stands. Over one-half the total sawtimber 

olume was present in trees belonging to the 30-, 35-, and 

0-centimeter diameter classes. Forty-two percent of the 

awtimber volume was present in trees with a butt log grade 

f 1 or 2. Over 80 percent of that volume was in log grade 2 

-ees. Only 7 percent of the total sawtimber volume 

ccurred in trees having a butt log grade of 1. 

The area of secondary forests nearly doubled during the 

decade to over 113 000 hectares. The net change in the 

basal area of all live trees was minor. increasing from 13.8 

to 15.1 square meters per hectare. Average basal area of 

growing-stock trees increased from 5.0 to 7.6 square meters 

per hectare, primarily due to the growth of sawtimber trees. 

Basal area of the rough-and-rotten component fell from 3.4 

to 2.8 square meters per hectare. The average combined 

basal area of all poletimber and sawtimber trees in 

secondary forests therefore rose from 8.3 to 10.4 square 

meters per hectare. The other component of all live basal 

area, sapling trees, decreased from 5.5 to 4.7 square meters 

per hectare. 

With a total timber volume of 8.6 million cubic meters by 

1990, secondary forests accounted for about three-fourths 

of the total timber volume of Puerto Rico's commercial 

region. Over three-fourths of that timber volume was 

found in growing-stock trees (fig. 21). Less than onefourth of the timber volume in secondary forests was in 

rough trees, whereas rotten trees comprised only 1 

percent. Growing-stock volume was 5.7 million cubic 

meters, about two-thirds of the total timber volume in 

secondary forests. That proportion was nearly the same in 

1980; however, growing-stock volume was more evenly 

distributed between the poletimber and sawtimber-size 

classes in 1990. The remaining one-tenth of total timber 

volume found in growing-stock trees was sound cull 

volume. Sound cull amounted to 14 percent of the total 

timber volume present in growing-stock trees only. The 

total sawtimber volume of 2.6 million cubic meters 

reached by 1990 was comparable to the 1980 volume of 

all sound wood (timber volume) of sawtimber trees in all 

timberland. 

Average timber volume increased from 44 to 75 cubic 

meters per hectare, and average growing-stock volume 

increased from 29 to 50 cubic meters per hectare in 

secondary forests. Sawtimber volume on the average 

hectare in secondary forests rose from 11 to 16 cubic 

meters, but its relative proportions of growing-stock 

volume and timber volume fell slightly to 32 percent and 

22 percent, respectively. These changes in volume 

component proportions described for secondary forests 

closely typify the trends observed in timberland as a 

whole. 

Just over one-third of the secondary forest stands supported 

50 or more cubic meters of timber volume per hectare, up 

slightly from 30 percent in 1980. Stands with between 50 

and 75 cubic meters per hectare covered over 15 000 

hectares, four times the area covered in 1980. The 
Species name 

I~ga veru 

Didymopanax 

Inga 

morofotoni 

fag folia - - 

Calophyllum brasiliense 1 

Tabebuia heterophylla 

Dacryodes excelsea - 

0 100 200 300 400 500 

Sawtimber volume (thousand cubic meters) 

Figure 19-Relative species importance by sawtimber volume,' Puerto Rico timberland, 1990. 

I Growing-stock volume I 

III Sawtimber volume 

13 Timber volume 

---- 

-- -- 

The character of secondary forests improved during the 

decade as shown by the greater coverage of stands 

composed of higher quality trees. Poletimber and 

sawtimber stands of secondary forests rose from 57 to 74 

percent of the total area by 1990. Moreover, the 

poletimber and sawtimber trees of growing-stock quality 

in these stands accounted for almost three-fourths of the 

total basal area and just over three-fourths of the total 

volume compared to 60 and 68 percent, respectively, in 

1980. Such changes indicate that stands in secondary 

forest stands are experiencing good growth and 

development, particularly those containing the higher 

quality trees. 

Trends in Coffee Shade Forests 

Abandoned coffee shade forest-S tands formerly 

1980 1990 1980 1990 1980 1990 managed as coffee shade covered an estimated 15 000 

Secondary Abandoned Active fewer hectares in 1990 than in 1980 and supported stands 

forest coffee shade coffee shade with basal areas ranging from 5 to 30 square meters per 

hectare. Average basal area of all live trees in these forested 

gure 20-Total growing-stock, sawtimber, and timber volume by forest 

ass. Puerto Rico timberland, 1980 and 1990. areas increased from 14 to 17 square meters per hectare. 

The only observed decrease in basal area was for 

-oportion of all secondary forest stands represented by this 

~lume class increased from 6 to 13 percent. The coverage 

' stands having 100 or more cubic meters of timber 

dume per hectare increased from 8000 to over 13 000 

:ctares, although their proportion of all secondary forest 

mds dropped slightly from 14 to 12 percent. Additions to 

ese two stand-volume classes increased the average 

nber volume of secondary forests from 44 to 75 cubic 

zters per hectare. 

sawtimber-size trees, which fell from 6.0 to 4.7 square 

meters per hectare. The basal area of poletimber and 

sapling trees increased from 4.9 to 8.7 and 3.0 to 3.5 square 

meters per hectare, respectively. 

Fifty-five percent of the abandoned coffee shade area was 

composed of stands with an average volume of at least 50 

cubic meters per hectare. Only about 700 hectares, 

however, supported stands with average volumes 

exceeding 100 cubic meters per hectare. Sawtimber stands 
irowing-stock trees Growing-stock volume Sawtimber trees 

6 million m3 (77%) 5.7 million m3 (86%) 2.9 million m' (52%) 

Sound cull volume ough-and-rotten trees 

Timber volume Timber volume in Growing-stock volume 

growing-stock trees 

(8.6 million cubic meters) (6.6 million cubic meters) (5.7 million cubic meters) 

gure 21-Distribution of components of timber volume (thousand cubic meters) in secondary forests, Puerto Rico timberland, 1990. 

wing 25 to 100 cubic meters per hectare occupied 

3 percent of the abandoned coffee shade area. Poletimber 

ands, covering 90 percent of the remaining abandoned 

~ffee shade area, generally supported <25 cubic meters 

:r hectare. 

I both surveys, abandoned coffee shade forests had the 

lghest average volume of timber. The average volumes 

F growing stock and sawtimber in 1980 were very nearly 

le same as those found in secondary forests; but by 

990, these too had climbed well above those of 

:condary forests. Average sawtimber volume in 

bandoned coffee shade forests reached 26 cubic meters 

er hectare, 10 cubic meters per hectare more than in 

xondary forests. Abandoned coffee shade forest in 1990 

nly had about 350 000 cubic meters more timber volume 

Ian in 1980. However, because of the lower area 

stimate in 1990, average timber volume of abandoned 

offee shade forests almost doubled from 53 to 102 cubic 

leters per hectare. These changes effected a shift in the 

stio of growing-stock volume to timber volume from 

ne-half to two-thirds. The ratio of sawtimber to timber 

olume remained stable at about one-fourth in this forest 

lass. 

~ctive coffee shade forest-With an estimated 7000 

~ectares, active coffee shade forest covered about onehird of the area that it occupied in 1980 and contained 

he lowest total basal areas of any forest classification. 

iverage basal area of all live trees in these forested areas 

ncreased from 10 to 12 square meters per hectare. Total 

awtimber basal area decreased to about one-third of the 

980 estimate, closely paralleling the reduction in area of 

lctive coffee shade forest. The average basal area per 

lectare of sawtimber trees, however, remained unchanged 

rom 1980 at 3.5 square meters per hectare. Excluding 

sapling trees, the total basal area of active coffee shade 

forest in 1990 averaged 10.2 square meters per hectare, 

with poletimber and sawtimber trees at 6.7 and 3.5 square 

meters per hectare, respectively. The average basal area 

for all size classes in 1980 was also 10.2 square meters 

per hectare, but this average included saplings. No stands 

in active coffee shade areas had basal area <5 square 

meters per hectare or >20 square meters per hectare in 

1990. 

Active coffee shade forest, as the smallest forest 

classification sampled, had the lowest total volume of live 

trees. Sixty percent of the 7000 hectares of active coffee 

shade forest supported stands having 25 to 50 cubic meters 

per hectare. Stands comprising the remaining 2800 hectares 

of active coffee shade forest had volumes between 50 and 

100 cubic meters per hectare. 

Although active coffee shade supported the lowest total 

volume, the average timber and growing-stock volumes 

per hectare in this forest class were very comparable to 

those found in secondary forests (fig. 18). The total timber 

volume found in active coffee shade in 1990 was about 

574000 cubic meters. The volume decrease of about 

200000 cubic meters since 1980 did not proportionately 

parallel the more significant areal decrease in active coffee 

shade forest. Consequently, the average timber volume of 

active coffee shade forests rose substantially from 36 to 82 

cubic meters per hectare. Growing-stock volume 

comprised about two-thirds of that timber volume. 

Sawtimber volume per hectare more than tripled to 26 

cubic meters and accounted for about one-half the average 

hectare's volume of growing stock. Sawtimber volume, 

formerly one-fifth of timber volume, represented about 

one-third of total timber volume on the average hectare in 

1990. 
Conclusions 

Puerto Rico's forest resources are recovering from the 

land use practices prevalent in the 19th and first half of 

the 20th centuries. The 1990 survey revealed an increase 

in forest land, better stocking with larger and higher 

quality timber trees, and a maturing secondary forest. 

Area and volume trends, such as the decreased area of 

sapling-seedling stands and the substantial increase in 

sawtimber volume, are primarily the result of the absence 

of management activity and commercial timber harvesting 

on the island. 

The results of the 1990 survey portray Puerto Rico as an 

example of how once heavily degraded tropical forests can 

recover to a level of productivity and usefulness. 

Knowledge of these trends can facilitate the development 

of management techniques to enhance the value of the 

timber resource and provide other forest-related benefits for 

the residents of Puerto Rico. 

Literature Cited 

Birdsey, Richard A.; Weaver, Peter L. 1982. The forest resources of 

Puerto Rico. Resour. Bull. SO-85. New Orleans, LA: U.S. Department 

of Agriculture, Forest Service, Southern Forest Experiment Station. 59 p. 

Birdsey, Richard A.; Weaver, Peter L. 1987. Forest area trends in Puerto 

Rico. Res. Note SO-331. New Orleans, LA: U.S. Department of 

Agriculture, Forest Service, Southern Forest Experiment Station. 5 p. 

Durland, W.D. 1929. Forest regeneration in Puerto Rico. Economic 

Geography. 5: 369-38 1. 

Ewel, J.J.; Whitmore, J.L. 1973. The ecological life zones of Puerto 

Rico and the U.S. Virgin Islands. Res. Pap. ITF-18. Rio Piedras, PR: 

Institute of Tropical Forestry. 72 p. 

Gill, Tom. 193 1. Tropical forests of the Caribbean. Baltimore: Tropical 

Plant Research Foundation. 3 18 p. 

Holdridge, L.R. 1967. Life zone ecology. Revised. San Josk, Costa Rica: 

Tropical Science Center. 206 p. 

Husch, Bertram; Miller, Charles I.; Beers, Thomas W. 1972. Forest 

mensuration. New York: Ronald Press Co. 410 p. 

Koenig, N. 1953. A comprehensive agricultural program for Puerto Rico. 

Washington, DC: U.S. Department of Agriculture and Commonwealth 

of Puerto Rico. 290 p. 

Little, Elbert L., Jr.; Wadsworth, Frank H. 1964. Common trees of 

Puerto Rico and the Virgin Islands. Agric. Handb. 249. Washington, 

DC: U.S. Department of Agriculture, Forest Service. 548 p. 

Little, Elbert L., Jr.; Woodbury, R.O.; Wadsworth, Frank H. 1974. 

Trees of Puerto Rico and the Virgin Islands. Agric. Handb. 449. 

Washington, DC: U.S. Department of Agriculture, Forest Service. 1024 p. 

Vol. 2. 

Wadsworth, F.H. 1950. Notes on the climax forests of Puerto Rico and 

their destruction and conservation prior to 1900. Caribbean Forester. 

11(1): 38-47. 

Zambrana, J.A. 1978. Asociaciones de suelos de Puerto Rico y su 

potencial para la siembra de Lboles. Rio Piedras, PR: Dept. Agric. de 

EEUU, Servicio Forestal, Area Sureste, Divisibn de Dasonomia. 6 p. 
lrvey Methods 

80 Survey 

e 1980 survey of Puerto Rico's forest resources was 

signed to evaluate the production potential of the island's 

:ondary timber resources and to describe their ecological 

aracteristics (Birdsey and Weaver 1982). The 1980 

rvey also provided baseline information from which 

anges in forest areas, species compositions, and growth 

uld be assessed in subsequent inventories. 

le purpose of the sample design was to partition the island 

.o two major areas: (1) the area with potential for 

mmercial production of timber where an intensive 

ventory would be conducted, and (2) noncommercial areas 

?ere limiting physiographic or economic factors would 

eclude the commercial production of timber. The 

tncommercial area encompassed lands designated as critical 

atersheds, areas with adverse site conditions such as steep 

3pes or high rainfalls, and areas with higher priority uses 

ich as urban expansion or agriculture. Noncommercial areas 

ere delineated on a 1 : 120,000 scale base map but excluded 

om the ground sample. The remainder of the island, the 

)mmercial timber production area, is concentrated in the 

:ntral highlands. This area was stratified by Life Zone 

;ubtropical Moist and Subtropical Wet Forests) and soils 

leep volcanics, shallow volcanics, granitic, and limestone). 

orest resource statistics were obtained using a systematic 

tmpling method involving forest-nonforest classification 

F temporary points on aerial photographs and on-theround measurements of trees on permanent plots. The 

3mple locations were at the intersections of a 3- by 

-kilometer grid design. There were 978 of these permanent 

lots on the entire island and 437 in the commercial region. 

;round sample locations were first selected on U.S. 

;eological Survey maps, then transferred to aerial 

hotographs. Initial forest area estimates were derived from 

~terpretation of 10,925 photopoints on black-and-white 

erial photographs from the mid- 1970's. The photo- 

~terpretation estimates were adjusted based on ground 

erification at the 437 permanent ground plots. Aerial 

lhotographs were also obtained for most of the 

 onc commercial region. Forest cover for the remaining land 

rias estimated using reference material. 

:ach ground sample location consisted of a cluster of three 

lariable radius subplots spaced 25 meters apart and running 

[long a north-south line. The center of each sample location 

vas the center of the middle subplot in the cluster. This point 

was established on the ground by running a computed 

azimuth and distance from a selected starting point. Each 

sample tree on the variable radius subplot represented 2.5 

square meters of basal area per hectare, or 0.83 square meters 

of basal area per hectare when the subplots were clustered. 

Each sample location was classified according to several 

site characteristics, including the slope and aspect at each 

of the three subplots. Sample trees smaller than 12.5 

centimeters in diameter at breast height (d.b.h.) were tallied 

on fixed radius plots of approximately 40 square meters 

around each of the three subplot centers. Sample trees 12.5 

centimeters and larger were measured to estimate volume 

and assessed to determine wood quality. 

Volumes were derived from detailed measurements of trees at 

all sample locations. These measurements included d.b.h., total 

height, bole length, log length, and two upper stem diameters. 

Volume of the bole and saw-log portions were computed using 

the International 1/4-inch rule. Regression equations were 

developed for five species groups and used to estimate branch 

and fork volumes in the sections above the bole. 

1985 Update 

The primary objective of the 1985 "midcycle" update 

(Birdsey and Weaver 1987) was to refine the procedures 

developed for the 1980 survey in preparation for the 1990 

resurvey. Complete color infrared aerial photographic 

transparencies at a scale of 1 :64,000 were acquired for the 

Commonwealth in 1984 to compensate for the lack of 

complete coverage in 1980. The increased spectral resolution 

of the aerial photography allowed for the development of a 

more detailed forest cover type assessment. 

A dot-count method was used to identify 12 forest and 3 

nonforest land cover classes on the film transparencies. A 5- 

by 5-dot grid was centered over each of the 978 permanent 

sample plot locations. Land-cover class was estimated for 

each plot location and for each dot, resulting in a total of 

22,4 18 photographic interpretations. Most forested locations 

were identified by 8 of the 12 possible classes. The 3- by 3- 

kilometer grid sample did not include montane (tabonuco) 

forest types or plantations also present in Puerto Rico. 

1990 Resurvey 

All plots in the commercial forest region were remeasured 

in the spring of 1990. The expanded forest classes used in 

the 1985 midcycle were used. Only four of these classes 

were found within the commercial region (table 1) because 

that area by definition excluded specific forest types such 

as mangroves and cloud forests found on steep, wet slopes. 
Black-and-white 1988-89 aerial photographs at a scale of 

1:20,000 were purchased, and a 5- by %dot grid was 

interpreted for each photographic location. There was a 

total of 10,545 photointerpretations and 430 field-verified 

sample plot interpretations. 

All trees were remeasured using the same methodology 

established in 1980. Three subplots were measured using 

variable radius sampling for timber evaluation and fixed 

radius for regeneration. The basal area factor for the 

variable radius was 2.5 square meters or 0.83 square meters 

of basal area per hectare when the subplots were clustered. 

The minimum d.b.h. for trees on the variable radius plot 

was 12.5 centimeters. 

Regeneration was assessed by tallying all trees between 2.5 

3nd 12.4 centimeters within a 3.6-meter fixed radius plot 

:about 40 square meters per subplot). Tree variables 

ncluded form and damage factors that would affect 

nerchantability of timber. Trees were assigned log grades 

tnd estimates for both total cull and log cull. Volume 

:omputation procedures duplicated those used in 1980. 

or volume under consideration is subdivided according to 

various strata. Sampling errors for estimates of volume in 

the Puerto Rico survey are consistent with this approach. A 

different methodology was used to derive sampling errors 

for area estimates. Area sampling for the Puerto Rico 

survey involved pre-stratification of the commercial region 

into various forest classes, and the proportion represented 

by each forest class was estimated based on a binomial 

classification of the photoplots. Because of the different 

type of area stratification and the assumption of a binomial 

distribution, sampling errors for areas were estimated by a 

different method and, thus, do not follow the usual pattern. 

These errors were estimated using the procedure described 

by Husch and others (1972) for calculating the variance of 

adjusted proportions of stratified stand classes. 

The following tabulation shows the sampling errors to 

which the area and volume estimates for secondary forest, 

abandoned and active coffee shade, and all timberland are 

liable: 

Sampling Sampling 

Stratum Area error1 Volume error23 

Reliability of the Data 

'iyo types of errors affect the reliability of the estimates. 

'he first source of error--estimating error--derives from 

nistakes in measurement, judgment, recording or 

ompiling, and from limitations of the equipment. The 

,OFIA minimizes estimating error through comprehensive 

-aining, supervision, quality-control programs, and 

mphasis on precision. The second type of error-sampling 

rror-arises from the use of a sample to estimate 

opulation parameters and from variability of the items 

eing sampled. This deviation is susceptible to a 

lathematical evaluation of the probability of error. 

he second survey of Puerto Rico again required a special 

,am approach to meet fieldwork requirements for 

:curacy. In addition to the logistical problems associated 

ith adapting field sampling techniques to a tropical 

~vironment, expertise in Puerto Rican dendrology was 

:eded. The approach teamed the most experienced timber 

uisers from the SOFIA with dendrologists and botanists 

3m Puerto Rico. 

atistical analysis of the data indicates a sampling error of 

us or minus 1.7 percent for the estimate of total 

nberland and 8.0 percent for the timber-volume estimate. 

regular State surveys, sampling errors are estimated for 

lth area and volume using the random sampling formula. 

le sampling error therefore normally increases as the area 

Thousand 

Hectares Percent cubic meters Percent 

Secondary forest 11 3 558 4.0 8570.1 10.5 

Abandoned coffee 

shade forest 23 365 3.5 2380.2 7.8 

Active coffee 

shade forest 7010 2.4 574.2 21.1 

All forest land 143 933 1.7 11 524.6 8.0 

Definitions 

Forest Land Classes 

Abandoned coffee shade. Secondary forest land resulting 

from the abandonment of coffee production under shade 

trees. 

Coffee shade. A multistory, multicrop system used 

principally for the production of coffee. An upper story of 

shade trees is characteristic. 

'By variance formula for adjusted proportions of a binomially distributed 

random variable. 

'By random sampling formula. 

'The sampling errors for volume are equal to one standard deviation for the 

sample data. 
pmmercial survey region. Area designated as having 

btential for commercial timber production and where field 

mpling was carried out. This area remained after the 

:lineation and exclusion of areas with higher priority uses 

rban areas, better agricultural land, reserved areas), dry 

basta1 areas, areas with adverse site conditions (extreme 

ctpe, excessive rainfall, etc.), and critical watershed areas. 

west land. Land at least 10 percent stocked4 by forest 

3es of any size, or formerly having had such tree cover and 

)t currently developed for nonforest use. The minimum area 

Ir classification of forest land is one-half hectare, and the 

inimum width for forest strips is 35 meters. Unimproved 

lads and trails, streams, and clearings in forest areas are 

assed as forest if less than 35 meters in width. 

oncommercial forest land. Forest land incapable of 

lelding crops of industrial wood because of adverse site 

~nditions, forest land withdrawn from timber utilization 

rough statute or administrative regulation, or forest land 

ith higher priority use (except coffee shade). 

'onstocked land. Commercial forest land less than 10 

ercent stocked with growing-stock trees. This includes 

reas covered by inhibiting vegetation (brush, vines, ferns, 

LC.) classed as forest land. 

econdary forest land. Forest land resulting from the 

bandonment of cropland or pasture, forest resulting from 

le regeneration of previously cutover or disturbed forest 

ind, and reclassification of both types of coffee shade. 

'imberland. Forest land that is producing or is capable of 

roducing crops of industrial wood and not withdrawn from 

mber utilization. Forest lands with higher priority uses, 

et not specifically withdrawn from timber utilization, are 

xcluded from this class of forest land. These excluded 

mds were delineated on a base map. Coffee shade is 

~cluded in this category. 

Joncommercial Forest Strata 

Llluviul regions. River floodplains with agricultural land 

Ise. 

Jritical watersheds. Upland areas with an average slope 

~60 percent or rainfall >2500 millimeters per year. These 

.reas require a continuous protective forest cover. Some 

imber removal would be feasible; however, much of the 

,rea is not highly productive. 

Ten percent of "normal" stocking as defined for the Midsouth Forest 

hrvey. 

Mangrove and swamp. Coastal wetlands with unique 

characteristics and values requiring special management 

considerations. 

Metropolitan regions. Regions with primarily urban or 

residential use. 

Subtropical Dry Forest. An ecological Life Zone 

delineated by a mean annual rainfall of between 600 

millimeters and 1000 or 1100 millimeters, and a mean 

annual biotemperature between about 18 and 24 "C 

(Holdridge 1967). 

Unproductive soils. Soils incapable of yielding crops of 

industrial wood. 

Stand-size Classes 

Poletimber stands. Stands with 25 square meters per 

hectare of basal area in sawtimber or poletimber-size trees, 

and with poletimber basal area exceeding that of sawtimber 

basal area. 

Sapling-seedling stands. Stands with 25 square meters per 

hectare of basal area, with more than one-half of this basal 

area in saplings or seedlings, or stands with <5 square 

meters per hectare of basal area, regardless of the size of 

existing trees. 

Sawtimber stands. Stands with 25 square meters per 

hectare of basal area in sawtimber or poletimber-size trees, 

and with sawtimber basal area at least equal to poletimber 

basal area. 

Timber Classes 

Acceptable trees. Trees meeting the specifications for 

growing stock but not qualifying as desirable trees. 

Desirable trees. Growing-stock trees that have no serious 

defects to limit present or prospective use, are of relatively 

high vigor, and contain no pathogens that may result in 

death or serious deterioration before rotation age. These 

trees would be favored in silvicultural operations. 

Growing-stock trees. Sawtimber trees, poletimber trees, 

saplings and seedlings; that is, all live trees except roughand-rotten trees, regardless of species. 

Poletimber trees. Growing-stock trees 12.5 to 22.5 

centimeters in d.b.h. for softwoods and 12.5 to 27.5 

centimeters for hardwoods and of good form and vigor. 
Rough-and-rotten trees. Live trees that are unmerchantable 

for saw logs now or prospectively because of defect or rot. 

Salvable dead trees. Standing or down dead trees that are 

currently or potentially merchantable. 

Saplings. Growing-stock trees 2.5 to 12.5 centimeters in 

d.b.h. and of good form and vigor. 

Sawtimber trees. Growing-stock trees 22.5 centimeters and 

larger in d.b.h. for softwoods and 27.5 centimeters and 

larger for hardwoods, and containing at least one 3.5-meter 

saw log. 

Timberland Strata 

Deep volcanic soils. Deep soils of the wet volcanic uplands 

with clayey texture, typically red and acid (Zambrana 

1978). The soil depth is generally >SO centimeters. 

Granitic soils. Shallow soils of the wet uplands with 

granitic origin and with a typically sand-clay loam texture 

[Zambrana 1978). 

Limestone soils. Shallow soils over limestone found in the 

noist coastal hills (Zambrana 1978). 

$hallow volcanic soils. Shallow soils of the wet volcanic 

lplands with clayey texture (Zambrana 1978). The soil 

lepth is generally <50 centimeters. 

iubtropical Moist Forest. Forest occurring in an ecological 

,ife Zone delineated by a mean annual rainfall of about 

000 to 2000 millimeters and a mean annual 

~iotemperature between about 18 and 24 "C (Holdridge 

967). 

;ubtropical Wet Forest. Forest occurring in an ecological 

,ife Zone delineated by a mean annual rainfall of about 

:000 to 4000 millimeters and a mean annual 

iotemperature between about 18 and 24 "C (Holdridge 

967). 

Volumes 

Volume ofgrowing stock. Volume of sound wood (less cull 

volume) in the bole and branches of sawtimber and 

poletimber trees from stump to a minimum 10-centimeter 

diameter outside bark or to the point past which a 1-meter 

section meeting minimum qualifications can no longer be 

measured because of limbs or other cull. 

Volume ofsawtimber. Net volume of the saw log portion of 

sawtimber trees in cubic meters, calculated according to the 

International 114-inch rule. 

Volume of timber. Volume of all sound wood (including 

sound cull) in the bole and branches of growing stock, 

rough, rotten, and salvable dead trees 12.5 centimeters and 

larger in d.b.h. from stump to a minimum 10-centimeter 

diameter outside bark. The minimum length of any section 

indluded is I meter. 

Miscellaneous Definitions 

Basal area. The area in square meters of the cross section 

at breast height of a single tree or of all the trees in a stand, 

expressed as square meters per hectare. 

D.b.h. Tree diameter in centimeters, outside bark, measured 

at 1.3 meters aboveground. 

Diameter class. Each 5-centimeter diameter class extends 

from 2.5 centimeters below to 2.4 centimeters above the 

stated midpoint. For example, the 30-centimeter diameter 

class includes trees 27.5 centimeters through 32.4 

centimeters in d.b.h. 

Log grades. A classification of logs based on external 

characteristics as indicators of quality or value. Logs are 

graded according to standards used for hardwoods in the 

Southern United States. Grade 1 logs have very little 

sweep, crook, cull, or other defects, are the largest, and are 

suitable for stangard lumber. Grade 4 logs need only be 20 

centimeters in diameter outside bark at the small end, and 

are used only for ties and timbers. Grades 2 and 3 are 

between the two extremes. 
ONVERSION FACTORS 

etric to English and English to Metric conversions 

centimeter = 0.3937 inch 

rneter = 3.281 feet 

kilometer = 0.6214 mile 

square meter = 10.7639 square feet 

square kilometer = 0.3861 square mile 

hectare = 2.47 1 acres 

cubic meter = 35.3145 cubic feet 

square meter per hectare = 4.356 square feet per acre 

cubic meter per hectare = 14.29 cubic feet per acre 

[etric inventory standards used in the 1990 survey 

rism size 

[rid spacing 

luster point spacing 

ixed plot size 

treast height 

tump height 

hameter classes 

'ree-size classes 

Sapling 

Poletimber (hardwood) 

Sawtimber (hardwood) 

Sawtimber (softwood) 

dinimum top diameter, outside bark 

Cubic volume 

Hardwood saw log 

Softwood saw log 

Sapling 

Jlinimum saw-log diameter, inside bark 

Hardwood 

Softwood 

vlinimum length 

Cubic section 

Saw log 

Sawtimber tree 

1 inch = 2.54 centimeters 

1 foot = 0.3048 meter 

1 mile = 1.6093 kilometers 

1 square foot = 0.0929 square meter 

1 square mile = 2.590 square kilometers 

1 acre = 0.4047 hectare 

1 cubic foot = 0.0283 cubic meter 

1 square foot per acre = 0.2296 square meter per hectare 

1 cubic foot per acre = 0.07 cubic meter per hectare 

Metric standard 

BAF 2.5 

3 kilometers 

25 meters 

40 square meters (r = 3.6 meters) 

15 square meters (r = 2.2 meters) 

1.3 meters 

30 centimeters 

5-centimeter = 2.5 to 7.5 centimeters d.b.h., 

10-centimeter = 7.5 to 12.5 centimeters d.b.h., 

15-centimeter = 12.5 to 17.5 centimeters d.b.h., 

20-centimeter = 17.5 to 22.5 centimeters d.b.h., etc. 

2.5 to 12.5 centimeters d.b.h. 

12.5 to 27.5 centimeters d.b.h. 

27.5+ centimeters d.b.h. 

22.5+ centimeters d.b.h. 

10 centimeters 

22.5 centimeters 

17.5 centimeters 

2.5 centimeters 

20 centimeters 

15 centimeters 

1 meter 

2.5 meters 

3.5-meter saw log 
List of Tree Species Included in Standard Tables 

Code 

number Species name Common name 

Cyathea arborea (L.) J. E. Smith 

Euterpe globosa Gaertn." 

Roystonea boringuena 0. F. Cook 

Artocarpus altilis (Parkinson) Fosberg 

Castilla elastica Cervantes 

Cecropia peltata L. 

Ficus laevigata Vahlb 

Torrubia fragrans (Durn.-Cours.) Standley 

Magnolia portoricensis Bello 

Ocotea leucoxylon (Sw.) Mez 

Persea americana Mill. 

Albizia procera (Roxb.) Benth. 

Inga fagifolia (L.) 

Inga quaternata Poepp. & Endl. 

Inga Vera Willd. 

Cassia siamea Lam. 

Hymenaea courbaril L. 

Andira inermis (W. Wright) H.B.K.' 

Erythrina poeppigiana (Walp.) 0. F. Cook 

Lonchocarpus latifolius (Willd.) H.B. K. 

Ormosia krugii Urban 

Citrus paradisi Macfadyen 

Citrus sinensis Osbeck 

Zanthoxylum martinicense (Lam.) DC. 

Bursera simaruba (L.) Sarg. 

Dacryodes excelsea Vahl 

Tetragastris balsamifera (Sw.) Kuntze 

Cedrela odorata L. 

Guarea g uidonia (L.) Sleumer 

Trichilia pallida (Sw.) 

Byrsonima coriacea (Sw.) DC. 

Alchornea latifolia Sw. 

Hura crepitans L. 

Sapium laurocerasus Desf. 

Mangifera indica L. 

Spondias dulcis Parkinson 

Spondias mombin L. 

Turpinia paniculata Vent. 

Cupania arnericana L. 

Thouinia striata Radlk. 

Meliosma herbertii Rolfe 

Sloanea berteriana Choisy 

Montezuma speciossirna Sess6 & Moc. 

Ochroma pyramidale (Cav.) Urban 

Quararib~a turbinata (Sw.) Poir 

Guazuma ulmifolia Lam. 

Calophyllum brasiliense Camb. 

Clusia rosea Jacq. 

Mammea americana L. 

Helecho gigante, tree-fern 

Palrna de sierra, sierra palm 

Palma real, royal palm, Puerto Rico 

Panapkn, pana de pepitas, breadfruit 

Caucho, Central American rubber, castilla 

Yagrumo hembra, trumpet-tree 

Jagiiey blanco, shortleaf fig 

Corcho, black mampoo 

Jaguilla 

Laurel geo 

Aguacate, avocado 

Albizia, tall albizia 

Guamii, "sweetpea" 

Guamii venezolano 

Guaba 

Casia de Siam, Siamese cassia 

Algarrobo, West-Indian-locust, courbaril 

Moca, cabbage angelin 

Bucayo gigante, mountain immortelle 

Retama 

Palo de matos 

Toronja, grapefruit 

China, sweet orange 

Espino rubial, white-prickle, Martinique 

Alrngcigo, turpentine-tree, gumbo-limbo 

Tabonuco 

Masa 

Cedro hembra, Spanish-cedar 

Guaraguao, American muskwood 

Gaeta 

Maricao 

Achiotillo 

Molinillo, sandbox, hura 

Tabaiba 

Mango 

Jobo de la India, ambarella 

Jobo, hogplum, yellow mombin 

Sauco cimarrcin 

Guara 

Ceboruquillo 

Aguacatillo 

Motillo 

Maga 

Guano, balsa 

Garrocho 

Guiicima, jacocalalu 

Maria, santa-maria 

Cupey, wild-mammee, copey clusia 

Mamey , mammee-apple 
,ist of Tree Species Included in Standard Tables (continued) 

lode 

umber Species name Common name 

Casearia arborea (L. C. Rich.) Urban 

Casearia decandra Jacq. 

Casearia guianensis (Aubl.) Urban 

Casearia sylvestris Sw. 

Buchenavia capitata (Vahl) Eichl. 

Bucida buceras L. 

Teminalia catappa L. 

Eugenia aeruginea DC. 

Eugenia jumbos L. 

Myrcia deflexa (Poir.) DC. 

Myrcia splendens (Sw.) DC. 

Psidium guajava L. 

Miconia prasina (Sw.) DC. 

Tetrazygia elaeagnoides (Sw.) DC. 

Dendropanax arboreus (L.) Decne. & Planch. 

Didymopanax morototoni (Aubl.) Decne. & Planch. 

Rapanea ferruginea (Ruiz & Pav.) Mez 

Dipholis salicifolia (L.) A. DC. 

Manilkara bidentata (A. DC.) Chev. 

Micropholis chrysophy lloides Pierre 

Micropholis garciniaefolia Pierre 

Pouteria multiflora (A.DC.) Eyma 

Cordia alliodora (Ruiz & Pav.) Oken 

Cordia sulcata DC. 

Citharexylum fruticosum L. 

Petitia domingensis Jacq. 

Vitex divaricata Sw. 

Spathodea campanulata Beauv. 

Tabebuia heterophylla (DC.) Britton 

Cofea arabica L. 

Terebraria resinosa (Vahl) Sprague 

Pinus caribaea Morelet 

Piper amalago L. 

Ficus stahlii Warb. (E) 

Nectandra antillana Meisn. 

Nectandra sintenisii Mez 

Phoebe elongata (Vahl) Nees 

Calyptranthes pallens Griseb. 

Clidemia umbrosa (Sw.) Cogn. 

Miconia subcorymbosa Britton 

Coflea dewevrei Wildern. & T. Dur. 

Rabo ratcin 

Tostado, wild honey-tree 

Palo blanco, wild-coffee 

Cafeillo 

Granadillo 

Ucar, gregre, oxhorn bucida 

Almendra, Indian-almond 

Guasabara 

Pomarrosa, Rose-apple 

Cieneguillo 

Hoja menuda 

Guayaba, common guava 

Camase y 

Verdiseco 

Poll0 

Yagrumo macho, matchwood 

Mantequero 

Sanguinaria, wild mespel, willow bustic 

Ausubo, balata 

Caimitillo 

Caimitillo verde 

Jhcana 

Capa prieto, capa 

Moral, white rnanjack 

Pkndula, pasture fiddlewood, Florida 

Cap6 blanco 

Higuerillo, white fiddlewood 

Tulipan africano, African tuliptree 

Roble blanco, "white-cedar" 

Cafk, coffee 

Aquilcin 

Pino hodureiio, Caribbean pine 

Higuillo de limcin 

Jaguey 

Aguacatillo 

Laurel arnarillo 

Laurel avispillo 

Tapcin blanco, pale lidflower 

Camasey 

Camasey 

Cafk excelsa, dewevre coffee 

Referred to as Prestoea montana (R. Grah.) Nichols. In 1980 survey. 

Referred to as Fiscus citrifolia Mill. In 1980 survey. 

Referred to as Andika inemis (W. Wright) DC. In 1980 survey. 
Cndex of Tables 15. Number of live trees on timberland by diameter 

class and forest class, Puerto Rico, 1990 

Forest Area 

16a. Basal area and number of live trees per hectare of 

timberland for selected species, secondary forests, 

Puerto Rico. 1990 

1. Land area by detailed land cover class and survey 

region, Puerto Rico, 1990 

16b. Basal area and number of live trees per hectare of 

timberland for selected species, abandoned coffee 

shade, Puerto Rico, 1990 

2. Land area by survey region and broad land cover 

class, Puerto Rico, 1980- 1990 

3. Area of timberland by Life Zone, soil group, and 

forest class, Puerto Rico, 1990 16c. Basal area and number of live trees per hectare of 

timberland for selected species, active coffee 

4. Area of shade, Puerto Rico, 1990 timberland by stand-volume class and 

forest class, Puerto Rico, 1990 

17. Basal area of poletimber and sawtimber trees by 

5. Area of tree class and forest class, Puerto Rico, 1990 timberland by stand-volume class and soil 

group, Puerto Rico, 1990 

18. Basal area of poletimber and sawtirnber trees by 

tree class, Life Zone, and soil group, Puerto Rico, 

1990 

6. Area of timberland by stand-size class and forest 

class, Puerto Rico, 1990 

7. Area of timberland by stand-size class and soil Timber Volume 

group, Puerto Rico, 1990 

19. Volume of timber on timberland by class of timber 

8. Area of timberland by stand-age class and forest and forest class, Puerto Rico, 1990 

class, Puerto Rico, 1990 

20. Volume of timber on timberland by Life Zone, soil 

9. Area of timberland by stand-age class and soil group, and tree class, Puerto Rico, 1990 

group, Puerto Rico, 1990 

21. Volume of timber on timberland by species and 

10. Area of timberland by basal area class and forest diameter class, Puerto Rico, 1990 

class, Puerto Rico, 1990 

22. Volume of growing stock on timberland by species 

11. Area of timberland by basal area class and stand- and diameter class, Puerto Rico, 1990 

size class, Puerto Rico, 1990 

23. Volume of sawtirnber on timberland by species 

12. Area of stocked timberland by Life Zone, soil and diameter class, Puerto Rico, 1990 

group, and slope class, Puerto Rico, 1990 

24. Volume of sawtimber on timberland by species 

ipecies Composition and butt log grade, Puerto Rico, 1990 

13. Number of live trees by species and diameter class, 

ranked by basal area plurality, Puerto Rico, 1990 

25. Volume of timber, growing stock, and sawtimber 

on timberland by stand-size class, Puerto Rico, 

1990 

14. Number of growing-stock trees by species and 

diameter class, ranked by basal area plurality, 

Puerto Rico, 1990 

26. Volume of timber on timberland by Life Zone, soil 

group, and slope class, Puerto Rico, 1990 
Table 1-Land area by detailed land cover class and survey region, Puerto Rico, 1990 

Land cover class 

Forest 

Secondary 

Abandoned coffee shade 

Active coffee shade 

Upper mountain 

Palm 

Dwarf 

Xeric scrubh 

Mangrove 

Total 

Nonforest 

Cropland 

Pasture 

Other 

Total 

Total land 

Commercial Noncommercial All 

survey region survey region" regions 

-- = Dashes indicate the corresponding cell was not sampled. 

" 1985 estimate. 

'~ot included in "timberland in subsequent tables. 

Table %Land area by survey region and broad land cover class, 

Puerto Rico, 1980-1990 

Survey region and Survey year 

land cover class 1980 1990 

----- --- Hectares - - - - - - - 

Commercial survey region 

Forest 

Nonforest 

Total 436 600 436 600 

Noncommercial survey region" 

Forest 148 200 139 399 

Nonforest 305 500 3 14 400 

Total 453 700 453 700 

All regions 

Forest 278 700 287 400 

Nonforest 611 600 602 900 

Total 890 300 890 300 

"The noncommercial region was not surveyed; estimates reported are from the 

1985 forest area assessment. 
Table %Area of timberland by Life Zone, soil group, and forest class, Puerto Rico, 1990 

Forest class 

Life Zone 

and soil group 

Other All Abandoned Active 

All secondary secondary coffee coffee 

classes Reversion forest forest shade shade 

Subtropical Moist Forest 

Deep volcanic soils 

Shallow volcanic soils 

Granitic soils 

Limestone soils 

Total 

Subtropical Wet Forest 

Deep volcanic soils 43 862 1 947 22 147 24 094 14 161 5608 

Shallow volcanic soils 5 628 974 1 114 2 088 3 540 0 

Granitic soils 16 574 1 947 13 919 15 866 708 0 

Limestone soils 1 947 1 947 0 1 947 0 0 

Total 

Total, all areas 

Table +Area of timberland by stand-volume class and forest class, Puerto Rico, 1990 

Forest class 

Timber volume 

(m3 per hectare) 

Other All Abandoned Active 

All secondary secondary coffee coffee 

classes Reversion forest forest shade shade 

Total 143 933 35 049 78 507 113 557 23 365 7010 
Table %Area of timberland by stand-volume class and soil group, Puerto Rico, 1990 

Soil group 

Timber volume All Deep Shallow 

(m' per hectare) groups volcanic volcanic Granitic Limestone 

Total 143 933 56 790 34 567 29 568 23 009 

Table +Area of timberland by stand-size class and forest class, Puerto Rico, 1990 

Other All Abandoned Active 

All secondary secondary coffee coffee 

Stand-size class classes Reversion forest forest shade shade 

Sawtimber 65 930 5 841 37 488 43 329 16 993 5608 

Poletimber 47 458 7 789 32 603 40 392 5 664 1402 

Sapling and seedling 30 544 21 419 8 417 29 836 708 0 

Total 143 932 35 049 78 508 113 557 23 365 7010 

Table 7-Area of timberland by stand-size class and soil group, Puerto Rico, 1990 

Soil group 

Stand-size class 

All Deep Shallow 

groups volcanic volcanic Granitic Limestone 

Sawtimber 65 930 30 980 14 872 15 741 4 337 

Poletimber 47 458 20 801 8 968 8 893 8 795 

Sapling and seedling 30 544 5 009 10 725 4 933 9 876 

Total 143 932 56 790 34 565 29 567 23 008 
Table &Area of timberland by stand-age class and forest class, Puerto Rico, 1990 

Forest class 

Stand age (years) 

Other Ail Abandoned Active 

All secondary secondary coffee coffee 

classes Reversion forest forest shade shade 

< 30 78 588 35 049 31 559 66 608 6 372 5608 

> 30 27 679 0 17 072 17 072 9 205 1402 

Mixed ages 5 684 0 4 268 4 268 1416 0 

Mature without past age" 31 981 0 25 609 25 609 6 372 0 

Total 143 932 35 049 78 508 113 557 23 365 7010 

"Stand age could not be reliably estimated for these stands because past age data were unavailable. 

Table 9-Area of timberland by stand-age class and soil group, Puerto Rico, 1990 

Soil group 

Stand age (years) 

All Deep Shallow 

groups volcanic volcanic Granitic Limestone 

< 30 78 588 25 564 24 620 13 210 15 193 

> 30 27 679 14 180 6 392 2 845 4 262 

Mixed ages 5 684 2 131 0 1 423 2 131 

Mature without past age" 31 981 14 915 3 553 12 090 1 423 

Total 143 932 56 790 34 565 29 568 23 009 

"Stand age could not be reliably estimated for these stands because past age data were unavailable. 

Table 10-Area of timberland by basal area class and forest class, Puerto Rico, 1990 

Forest class 

Other All Abandoned Active 

Basal area All secondary secondary coffee coffee 

(m2 per hectare) classes Reversion forest forest shade shade 

Total 143 933 35 049 78 508 113 557 23 365 7010 
Table 11-Area of timberland by basal area class and stand-size class, Puerto Rico, 1990 

Stand-size class 

Basal area All Sapling 

(m' per hectare) classes Sawtimber Poletimber and seedling 

- - - - - - - - - - - - - - - - - - - Hectares - - - - - - - - - - - - - - - - - - - - - 

Total 

Table 12-Area of stocked timberland by Life Zone, soil group, and slope class, Puerto Rico, 1990 

Percent slope class 

Life Zone 

and soil group All classes 0 to 10 11 to 25 26 to 45 > 45 

--------------------------Hemes-------------------------- 

Subtropical Moist Forest 

Deep volcanic soils 12 928 2 287 1 123 4 164 5 353 

Shallow volcanic soils 28 938 3 107 6 325 10 239 9 267 

Granitic soils 12 994 474 2 166 3 011 7 343 

Limestone soils 21 061 2 614 2 571 4 841 11 036 

Total 

Subtropical Wet Forest 

Deep volcanic soils 43 862 4 007 6 609 12 609 20 637 

Shallow volcanic soils 5 628 0 944 1 303 3 381 

Granitic soils 16 575 0 1 659 4 380 10 536 

Limestone soils 1 947 0 649 1 298 0 

Total 

Total, all areas 143 933 12 489 22 046 41 845 67 553 
bt, 'lhble 13---Number of live trees by species and diameter class, ranked by basal area plurality, Puerto Rico, 1990" 

Diameter class (centimeters) 

Species 

code Species name 

Total basal All 

area (mz) classes 5 10 15 20 25 30 35 40 45 50 55+ 

Spathodea campanulata Beauv. 

Guareu guidonia (L.) Sleumer 

fnga vera Willd. 

Cecropia peltuta L. 

Andira inermis (W. Wright) H.B.K. 

Tubebuia heterophylla (DC.) Britton 

Eugenia jumbos L. 

fnga fagijolia (I,.) 

Erythrina poeppigianu (Walp.) 0. F. Cook 

Mangijera indica L. 

Didymopanax morototoni (Aubl.) Decne. & Planch. 

Euterpe globosa Gaertn. 

Ocotea leucoxylon (Sw.) Mez 

Ro.ystonea borinquena 0. F. Cook 

Caseuria guiunetzsis (Aubl.) Urban 

Citrus sinensis Osbeck 

Dendropanax urboreus (L.) Decne. & Planch. 

Cyathea arborea (L.) J. E. Smith 

Caseuriu .sylvestris Sw. 

Cupania americanu L. 

Clidemiu umbrosa (Sw.) Cogn. 

Alchornea lutijblia Sw. 

Calophyllum brasiliense Camb. 

Cordia sulcata DC. 

Clusia rt,sea Jacq. 

Spondias mombin L. 

Myrcia splendens (Sw.) DC. 

Nectandra sintenisii Mez (E) 

Miconia pra~ina (Sw.) DC. 

Citharexylurn fi-uticosum L. 

Artocarpus altilis (Parkinson) Fosberg 

Znnthoxylum martinicense (Lam.) DC. 

Ficus laevigata Vahl 

Terebraria re.sinosa (Vahl) Sprague 

Petitia domingensis Jacq. 

Ffymenaea courbaril L. 

Cordiu allioclora (Ruiz & Pav.) Oken 

Micropholis chrysophylloides Pierre 

Buchenavia capitata (Vahl) Eichl. 

Cofeu dewevrei Wildem. & T. Dur. 

Psidium guitj~zva L. 

Terminiiliu catappu L. 

Casearia decundra Jacq. 

--- - 

- - - ---- - - Thousand trees - - - 

5 529 1 550 929 

2614 1463 740 

1 397 898 415 

902 362 419 

2 820 1 025 389 

1680 1487 470 

1 531 677 348 

969 266 315 

254 0 108 

0 52 3 1 

778 472 222 

117 929 575 

739 203 213 

80 44 91 

552 0 30 

867 708 79 

58 190 142 

1 405 524 79 

44 1 79 0 

1 159 220 60 

45 8 57 36 

117 232 224 

0 5 3 0 

440 244 163 

779 39 201 

0 228 0 

873 64 35 

350 197 23 

64 1 153 0 

598 70 120 

80 109 56 

367 108 36 

0 7 8 59 

1 109 205 3 3 

0 236 15 

208 74 0 

116 32 93 

350 112 117 

117 0 56 

622 120 36 

25 1 0 0 

0 0 44 

0 95 39 
Diameter class (centimeters) 

Species Total basal All 

code Species name area (m2) classes 5 10 15 20 25 30 35 40 45 50 5% 

Tetrazygia r~laecrgnoides (SW.) DC. 

Coff'ea arabica L. 

Ormoria krugii lJrban 

Dacroyodes excensea Vahl 

Unidentified species 

Casearm arborea (L. C. Rich.) Urban 

Hum crepitan~ L. 

Bvr~oniina coriacea (Sw.) DC. 

Montezurnu specio.ssirna Sesse & Moc. 

Myrciu deflexcr (Poir.) DC. 

Guazuma ullrzifolia Lam. 

Sloatzeu berteriatza Choisy 

Dipholis saliciJolia (L.) A. DC. 

Bur~eras imaruba (L.) Sarg. 

Torrubia fragrans (Durn.-Cours.) Standley 

Pouteria ~nultiflora (A. DC.) Eyma 

Albizia procera (Roxb.) Benth. 

Phoebe elongata (Vahl) Nees 

Cedrela odorata L. 

Trichilia pallidu Sw. 

Spondias dulcis Parkinson 

Thouinia striata Radlk. 

Other species ( 134) 

Thousand trees - - - 

125 0 

0 0 

201 126 

0 62 

47 3 8 

50 77 

0 55 

0 3 1 

0 0 

73 0 

136 40 

133 7 1 

117 169 

0 27 

74 0 

0 0 

45 106 

62 42 

0 66 

0 0 

0 0 

0 72 

958 402 

Total 2194205 308780 232253 40615 15676 8425 5104 2717 1665 893 593 329 511 

"Columns may not add up to totals as a result of rounding numbers. 
Table 14-Number of growing-stock trees by species and diameter class, ranked by basal area plurality, Puerto Rico, 1990" 

Diameter class (centimeters) 

Species 

code Species name 

Total basal All 

area (m2) classes 5 10 15 20 25 30 35 40 45 50 55+ 

Spathodea ccrrnpanulata Beauv. 

Guarea guidonia (L.) Sleumer 

Cecropin peltat~i L. 

hzga Vera Willd. 

Tabebuiu heteroplzylla (DC.) Britton 

Andiru inerrnis (W.Wright) H.B.K. 

Erythrirza poeppigiana (Walp.) 0. F. Cook 

Didymopnrzax morototoni (Aubl.) Decne. & Planch. 

Euterpe globo~cr Gaertn. 

hlga fngifolra (L,.) 

Roystonea borirzquencl 0. F. Cook 

Eugenia jambos I,. 

Ocotea leuco~ylon (Sw.) Mez 

Cyathea arl?oreu (L.) J. E. Smith 

C~dophyllutn bra.siliense Camb. 

Alchotlzea lat[folia Sw. 

Cupunia crmeric.ana L. 

Clusia rosea Jacy . 

Artocurpus ~lltilis (Parkinson) Fosberg 

Hjir?tennea courbnril L. 

Nectandra sinteni.5ii (E) 

Cordia sulcat(i DC. 

Spondia~ mornhin L. 

Clidetniu umbrosa (Sw.) Cogn. 

Pctitia domingen~is Jacq. 

Terebrctriu resinosa (Vahl) Sprague 

Dncryodes excel.sea Vahl 

Zixrztlztxyl~tm rnurtirzic~~rz~se (Lam.) DC. 

Tenjzinaliu catappa L. 

Cordia alliodorcl (Ruiz & Pav.) Oken 

Myrciu splerlderzs (Sw.) DC. 

Dendropanux arboreus (L.) Decne. & Planch. 

Microplzolis chry~ophylloides Pierre 

Orrnosia krugii Urban 

Mungifem irtdica L. 

Bucherzavia cclpitatn (Vahl) Eichl. 

Fic~ls l~zevigatn Vahl 

Casearia guiarzensis (Aubl.) Urban 

Dipholis .salicifolia (L.) A. DC. 

Unidentified species 

Myrciu dej7e.xa (Poir.) DC. 

Cassia siarnea Lam. 

Byrsorzitna corincen (Sw.) DC. 

- - - - - - - - - Thousand trees - - - 

4 522 1 229 807 

662 872 485 

669 316 402 

582 765 380 

1 404 1 235 397 

1 532 789 212 

5 8 0 31 

66 1 427 222 

0 838 575 

472 142 180 

80 44 91 

1 092 128 184 

408 203 145 

1 199 448 79 

0 5 3 0 

117 232 224 

598 168 30 

583 0 121 

80 109 56 

9 1 74 0 

117 197 23 

116 128 70 

0 0 0 

5 8 57 36 

0 236 0 

950 141 0 

0 0 62 

80 53 36 

0 0 44 

116 32 93 

582 64 0 

5 8 104 65 

117 112 73 

117 118 92 

0 52 0 

0 0 32 

0 0 43 

0 0 30 

233 59 169 

350 47 0 

350 0 0 

478 40 0 

0 0 31 
Diameter class (centimeters) 

Species 

code Species name 

Total basal All 

area (m2) classes 5 10 15 20 25 30 35 40 45 SO 55+ 

Montezuma specios.sima Sessk & Moc. 

Cedrela odorata L. 

Pouteria multiJFZoru (A. DC.) Eyma 

Citrus sinensis Osbeck 

Sloanea berteriana Choisy 

Casearia arborea (L. C. Rich.) Urban 

Lonchocarl~us latijblius (Willd.) H.B.K. 

Casearia decundra Jacq. 

Albizia procera (Roxb.) Benth. 

Casearia sylvestris Sw. 

Coflea dewcvrei Wildem. & T.Dur. 

Micropholis garciniaefolia Pierre 

Sapium laurocerusus Desf. 

Citharexylum fruticosum I,. 

Phoebe elongata (Vahl) Nees 

Bucida buceras L. 

Hura erepituns L. 

Miconia prasina (Sw.) DC. 

Spondias dulcis Parkinson 

Rupanea .ferruginea (Ruiz & Pav.) Mez 

Bursera imaruha (L.) Sarg. 

Manilkara bidentata (A. DC.) Chev. 

Other species (93) 

Thousand trees - - - 

0 0 

0 66 

0 0 

147 39 

76 7 1 

50 53 

0 0 

95 39 

45 52 

0 0 

6 1 0 

0 0 

158 0 

0 41 

0 42 

0 4 

0 30 

47 0 

0 0 

60 0 

0 0 

0 0 

618 309 

Total 1 405 530 126 305 77 467 22 971 10 869 6296 3969 1936 1224 658 370 224 329 

"Columns may not add up to totals as a result of rounding numbers. 
Table 15-Number of life trees on timberland by diameter class and forest class, Puerto Rico, 1990 

Forest class 

Other AH Abandoned Active 

Diameter class All secondary secondary coffee coffee 

(centimeters) classes Reversion forest forest shade shade 

Total 2146 1865 2423 2253 1990 945 
Table 16a-Basal area and number of live trees per hectare of timberland for selected species, secondary forests, Puerto Rico, 

1990" 

Species 

code Species name Basal area 

Number of 

trees 

Spathodea campanulata Beauv. 

Guarea guidonia (L.) Sleumer 

Tabebuia heterophylla (DC.) Britton 

Andira inermis (W. Wright) H.B.K. 

Cecropia peltata L. 

Eugenia jumbos L. 

Inga Vera Willd. 

Euterpe globosa Gaertn. 

Inga fagifolia (L.) 

Roystonea borinquena 0. F. Cook 

Casearia guianensis (Aubl.) Urban 

Didymopanax morototoni (Aubl.) Decne. & Planch. 

Ocotea leucoxylon (Sw.) Mez 

Erythrina poeppigiana (Walp.) 0. F. Cook 

Mangifera indica L. 

Calophyllum brasiliense Camb. 

Cupania americana L. 

Clusia rosea Jacq. 

Casearia sylvestris Sw. 

Alchornea latifolia Sw. 

Clidemia umbrosa (Sw.) Cogn. 

Cyathea arborea (L.) J. E. Smith 

Myrcia splendens (Sw.) DC. 

Citharexylum fruticosum L. 

Spondias mombin L. 

Artocarpus altilis (Parkinson) Fosberg 

rMiconia prasina (Sw.) DC. 

Terebraria resinosa (Vahl) Sprague 

Hymenaea courbaril L. 

Citrus sinensis Osbeck 

Other species (1 57) 

Percent Hectares 

Total 15.07 100.0 2248 

"Columns may not add up to totals as a result of rounding numbers. 
Table 16b-Basal area and number of live trees per hectare of timberland for selected species, abandoned coffee shade, Puerto 

Rico. 1990" 

Species 

code Species name Basal area 

Number of 

trees 

Guarea guidonia (L.) Sleumer 

Inga Vera Willd. 

Cecropia peltata L. 

Mangifera indica L. 

Inga fagifolia (L.) 

Dendropanax arboreus (L.) Decne. & Planch. 

Erythrina yoeppigiana (Walp.) O.F. Cook 

Spathodea campanulata Beauv. 

Andira inermis (W. Wright) H.B.K. 

Eugenia jumbos L. 

Didymopanax morototoni (Aubl.) Decne. & Planch. 

Cordia sulcata DC. 

Cofbea arabica L. 

Cordia alliodora (Ruiz & Pav.) Oken 

Ocotea leucoxylon (Sw.) Mez 

Zanthoxylum martinicerzse (Lam.) DC. 

Citrus sinensis Osbeck 

Nectandra sintenisii Mez (E) 

Pouteria multiflora (A.DC.) Eyma 

Cofhea dewevrei Wildem. & T. Dur. 

Roystonea borinquena O.F. Cook 

Sporzdias mombin L. 

Wtex divaricata Sw. 

Phoebe elongata (Vahl) Nees 

Miconia prasina (Sw.) DC. 

Other species (46) 

Percent Hectares 

Total 16.94 100.0 1694 

"Columns may not add up to totals as a result of rounding numbers. 
Table 16c-Basai area and number of live trees per hectare of timberland for selected species, active coffee shade, Puerto Rico, 

1990" 

Species 

code Species name Basal area 

Number of 

trees 

Ingct vera WillJ. 

Guarea guidorzia (L.) Sleumer 

Citrus sinensis Osbeck 

Erythrinu poeppigiana (Walp.) 0. F. Cook 

Cyathea arborea (L.) J. E. Smith 

Cecropia peltata L. 

Mangijer-a irzdica L. 

Inga fagifolia (L.) 

Spathoden cnmpanulata Beauv. 

Ficus laevigata Vahl 

Andira inerrnis (W. Wright) H.B.K. 

Coflea dewevrei Wildern. & T. Dur. 

CofSea arabica L. 

Persea americana Mill. 

Byrsonima coriacea (Sw.) DC. 

Citrus paradisi Macfadyen 

Alchornea latijolia Sw. 

Tabebuia heterophylla (DC.) Britton 

Ficus stahlii Warb. (E) 

Cordia alliodora (Ruiz & Pav.) Oken 

Cedrela odorata L. 

Clidemia umbrosa (Sw.) Cogn. 

Zanthoxylum rnartirzicense (Lam.) DC. 

Ocotea leucoxylon (Sw.) Mez 

Piper amalago L. 

Percent Hectares 

Total 

"Columns may not add up to totals as a result of rounding numbers. 
Table 17-Basal area of poletimber and sawtimber trees by tree class and forest class, Puerto Rico, 1990 

Forest class 

Tree class 

Other All Abandoned Active 

All secondary secondary coffee coffee 

classes Reversion forest forest shade shade 

Poletimber-size trees 

Growing stock 544 257 39 738 47 926 387 665 127 398 29 195 

Rough-and-rotten 254 642 29 195 132 435 161 630 75 495 17 517 

Total 798 899 68 933 480 361 549 295 202 893 46 712 

Sawtimber-size trees 

Growing stock 

Rough-and-rotten 

Total 

Total, growing stock 1 116481 107 861 754 297 862 158 207 612 46 712 

Total, rough-and-rotten 452 111 56 768 265 244 322 012 105 575 24 524 

Total, poletimber and 

sawtimber trees 1 568 592 164 629 1 019 541 1 184 170 313 187 71 236 
Table 18-Basal area of poletimber and sawtimber trees by tree class, Life Zone, and soil group, Puerto Rico, 1990 

Soil group 

Tree class All Deep Shallow 

and Life Zone groups volcanic volcanic Granitic Limestone 

-------------em-------- Squaremefersofbnsalarea - - - - - - - - - - - - - - - - - - - - - 

Subtropical Moist Forest 

Poletimber-size trees 

Growing stock 

Rough-and-rotten 

Total 324 286 117 651 92 425 67 353 46 857 

Sawtimber-size trees 

Growing stock 

Rough-and-rotten 

Total 

Total, growing stock 

Total, rough-and-rotten 

Total, Subtropical Moist Forest 

Subtropical Wet Forest 

Poletimber-size trees 

Growing stock 

Rough-and-rotten 

Total 

Sawtimber-size trees 

Growing stock 

Rough-and-rotten 

Total 

Total, growing stock 

Total, rough-and-rotten 

Total, Subtropical Wet Forest 

Total, Life Zones 
Table 19-Volume of timber on timberland by class of timber and forest class, Puerto Rico, 1990" 

Forest class 

Class of timber 

Other All Abandoned Active 

All secondary secondary coffee coffee 

classes Reversion forest forest shade shade 

Growing-stock trees 

Sawtimber trees 

Saw-log portion 

Upper stem 

Branches and forks 

Sound cull 

Total, timber volume 4 877.5 283.0 3 187.8 3470.8 1 136.3 270.5 

Poletimber trees 

Bole volume 

Branches and forks 

Sound cull 

Total, timber volume 

Total, all growing-stock trees 

Rough-and-rotten trees 

Rough trees 

Bole volume 

Branches and forks 

Sound cull 

Total, timber volume 

Rotten trees 

Bole volume 

Branches and forks 

Sound cull 

Total, timber volume 

Total, all rough-and-rotten trees 

Total, all timber 

"Columns may not add up to totals as a result of rounding numbers. 
Table 20-Volume of timber on timberland by Life Zone, soil group, and tree class, Puerto Rico, 1990" 

Soil group 

Life zone All Deep Shallow 

and tree class groups volcanic volcanic Granitic Limestone 

- - - - - - - - - - - - - - - - - - - - - - - - - Thousand cubic nz,oter,y- - - - - - - - - - - - - - - - - - - - - - 

Subtropical Moist Forest 

Sawtimber trees 

Poletimber trees 

Total, all growing-stock trees 

Rough trees 

Rotten trees 

Total, all rough-and-rotten trees 

Total, all timber 

Subtropical Wet Forest 

Sawtimber trees 

Poletimber trees 

Total, all growing-stock trees 

Rough trees 1 525.4 944.5 207.8 303.0 70.2 

Rotten trees 83.7 72.6 5.0 6.1 0 

Total, all rough-and-rotten trees 1 609.1 1017.1 212.7 309.1 70.2 

Total, all timber 

Total, all Life Zones 11 524.6 6165.6 1773.9 2490.5 1094.5 

"Columns Inay not add up to totals as a result of rounding numbers. 
Table 21-Volume of timber on timberland by species and diameter class, Puerto Rico, 1990" 

Diameter class (centimeters) 

Species 

code Species name 

All 

classes 15 20 25 30 35 40 45 50 55+ 

Guarea guidonia (L.) Sleumer 1 282.4 

Spathodea campanulata Beauv. 1 109.4 

Inga Vera Willd. 820.6 

Cecropia peltata L. 812.0 

Inga fagifolia (L.) 398.9 

Tabebuia heterophylla (DC.) Britton 395.0 

Andira inermis (W. Wright) H.B.K. 38 1.5 

Erythrina poeppigiana (Walp.) 0. F. Cook 364.4 

Roystonea borinquena 0. F. Cook 310.7 

Didymopanax morototoni (Aubl.) Decne. & Planch. 295.7 

Eugenia jumbos L. 291.0 

Mangifera indica L. 234.8 

Calophyllum brasiliense Camb. 201.3 

Ocotea leucoxylon (Sw.) Mez 200.7 

Euterpe globosa Gaertn. 189.3 

Alchornea latifolia Sw. 146.6 

Ficus laevigata Vahl 144.3 

Hymenaea courbaril L. 141.0 

Dendropanax arboreus (L.) Decne. & Planch. 133.4 

Spondias mombin L. 120.4 

Cordia sulcata DC. 110.9 

Dacryodes excelsea Vahl 110.2 

Zanthoxylum martinicense (Lam.) DC. 109.8 

Clusia rosea Jacq. 109.0 

Nectandra sintenisii Mez (E) 106.4 

Petitia domingensis Jacq. 103.8 

Artocarpus altilis (Parkinson) Fosberg 102.7 

Byrsonima coriacea (Sw.) DC. 101.0 

Citrus sinensis Osbeck 100.1 

Cupania americana L. 98.0 

Buchenavia capitata (Vahl) Eichl. 97.9 

Terminalia catappa L. 87.3 

Montezuma speciossima SessC & Moc. 83.8 

Ormosia krugii Urban 81.0 

Micropholis chrysophylloides Pierre 76.2 

Sloanea berteriana Choisy 74.5 

Citharexylum fruticofum L. 71.1 

Cojfea dewevrei Wildem. & T. Dur. 52.5 

Hura crepitans L. 48.5 

Guazuma ulrnifolia Lam. 47.4 

Myrcia defexa (Poir.) DC. 40.7 

Casearia arborea (L. C. Rich) Urban 38.9 

Cyathea arborea (L.) J. E. Smith 37.8 

Myrcia splendens (Sw.) DC. 37.2 

Terebraria resinosa (Vahl) Sprague 33.8 

Casearia decandra Jacq. 30.9 

Tetrazygia elaeagnoides (Sw.) DC. 27.6 

Unidentified species 26.8 

Other Species (149) 1 316.3 

----- Thousand cubic meters - - - - 

142.5 161.6 178.9 85.8 

195.5 146.7 140.2 51.2 

176.6 121.2 104.1 90.2 

129.3 131.5 135.1 77.3 

42.2 119.6 27.1 55.3 

89.3 29.8 51.7 14.7 

94.6 54.7 20.1 5.7 

28.9 18.0 53.2 14.1 

18.4 64.8 79.6 96.8 

77.1 67.7 18.8 16.0 

69.8 34.7 28.7 5.2 

4.7 26.4 16.5 2.7 

28.2 45.6 11.6 36.9 

93.4 14.5 26.4 0 

33.4 1.4 0 0 

27.8 21.6 0 0 

0 6.3 16.4 11.8 

20.2 30.8 22.2 19.5 

24.2 30.0 12.6 0 

10.0 16.8 0 12.6 

31.0 18.3 23.8 0 

0 37.7 12.4 29.7 

14.0 36.0 13.9 8.7 

50.6 0 10.3 0 

11.6 15.5 6.4 5.8 

0 60.6 14.0 0 

0 4.4 22.3 19.9 

19.8 32.3 0 24.0 

20.6 0 0 0 

18.7 10.8 0 29.4 

5.7 10.4 6.5 27.4 

5.9 0 7.5 33.1 

40.5 5.1 9.9 19.5 

25.8 0 0 0 

0 29.0 10.9 0 

10.4 10.8 0 14.2 

43.9 10.6 0 0 

10.8 0 0 0 

5.1 2.8 3.5 5.0 

0 0 0 12.9 

0 15.5 0 0 

0 0 0 0 

0 0 0 0 

0 0 0 0 

0 0 0 0 

1.7 0 0 0 

7.7 0 0 0 

0 12.3 0 0 

155.8 193.2 193.7 109.0 

Total 11 524.8 1374.9 1818.7 1831.5 1661.8 1333.9 965.8 757.8 481.6 1200.2 

"Columns may not add up to totals as a result of rounding numbers. 
ble 22-Volume of growing stock on timberland by species and diameter class, Puerto Rico, 1990" 

Diameter class (centimeters) 

ecies 

3e Species name 

All 

classes 15 20 25 30 35 40 45 50 55+ 

Spathodea campanulata Beauv. 

Guarea guidonia (L.) Sleumer 

Cecropia peltata L. 

Inga Vera Willd. 

Tabebuia heterophylla (DC.) Britton 

Erythrina poeppigiana (Walp.) 0. F. Cook 

Didyrnopanax morototoni (Aubl.) Decne. & Planch. 

Inga fagifolia (L.) 

Andira inermis (W. Wright) H.B.K. 

Calophyllum brasiliense Camb. 

Alchornea latifolia Sw. 

Dacryodes excelsea Vahl 

Eugenia jumbos L. 

Hymenaea courbaril L. 

Ocotea leucoxylon (Sw.) Mez 

Nectandra sintenisii Mez (E) 

Cordia sulcata DC. 

Spondias mombin L. 

Clidemia umbrosa (Sw.) Cogn. 

Zanthoxylum martinicense (Lam.) DC. 

Terminalia catappa L. 

Artocarpus altilis (Parkinson) Fosberg 

Ficus laevigata Vahl 

Petitia domingensis Jacq. 

Clusia rosea Jacq. 

Buchenavia capitata (Vahl) Eichl. 

Cordia alliodora (Ruiz & Pav.) Oken 

Cupania americana L. 

Dipholis salicijblia (L.) A. DC. 

Ormosia krugii Urban 

Sloanea berteriana Choisy 

Pouteria multijlora (A.DC.) Eyma 

Montezuma speciossima SessC & Moc. 

Byrsonima coriacea (Sw.) DC. 

Lonchocarpus latifolius (Willd.) H.B.K. 

Albizia procera (Roxb.) Benth. 

Cedrela odorata L. 

Dendropanax urboreus (L.) Decne. & Planch. 

Micropholis chrysophyllozdes Pierre 

Mangifera indica L. 

Myrciu defle-wcl (Poir.) DC. 

Micr~pholi~c garcinaefolia Pierre 

Castillu elastlca Cervantes 

Spondia~ dulci:, Parkinson 

Cusearin decandra Jacq. 

Caseuriu arboreu (L. C. Rich) Urban 

Coffea de~-evrei Wildem. & T. Dur. 

Citrus .sinensis Osbeck 

Other species 

Total 7636.9 939.5 1200.7 1311.9 1141.7 862.9 619.6 439.9 320.6 761.3 

'olumns may not add up to totals as a result of rounding numbers. 
Table 23-Volume of sawtimber on timberland by species and diameter class, Puerto Rico, 1990" 

Diameter class (centimeters) 

Species 

code Species name 

All 

classes 30 35 40 45 50 55+ 

Sp~rtlzodecz cutnpanulntu Beauv. 

Cecropln peltiitci L. 

Guuiea guz~Iotzin (L.) Sleumer 

Ervthrtrzu /,oc1/~pigrarza (Walp.) 0. F. Cook 

Itigu Leru Willd. 

Ingu fugrfoliu (L.) 

I)rd,tnt>l7una r rnorotofonl (Aubl.) Decne & Planch. 

Ceilo~~h~llunl brti~lllense Camb. 

Tuheburu heteroptiylla (DC.) Britton 

Dnt rjodes excelseu Vahl 

Andir~i itzenzis (W. Wright) A.B.K. 

l'i~nnirzulrt~ cutuppa L. 

S/Joriclta.s inonzbtn L. 

Nectcrnciru slntcnl.sri Mez (E) 

H\nzrizaea courbarll L. 

Pouleriu nzultiflora (A. DC.) Eyrna 

Artoctirpw altill., (Parkinson) Fosberg 

Buchrrzu\~in cupttut~~ (Vahl) Eichl. 

Ficu., laevrgatct Vahl 

Cllckenzin utrzhro.ta (Sw.) Cogn. 

BJ rsonimn t orrucea (Sw.) DC. 

Zt~izthorjlum martinlcen,te (Lam.) DC. 

Petitiu dctmirzgeiui.~ Jacq. 

Lont. hocaq7u~ latlfoltu.~ (Wrlld.) H.B.K. 

Alchomea latlfolla Sw. 

Mcrizglfc~ru ~rzhc~r L. 

Cori11tz (iIlz(~tOru (Rui7 & Pav.) Oken 

Ct~drelrr odortztu L. 

Mvrcia tieJ1e ~u (Poir.) DC. 

hign quuterncrtu Poepp. & Endl. 

COI.~~LI ~ulcuttt DC. 

Ptnul ccrrihara Morelet 

Spondra~ du1c.i~ Parkinson 

Mtcropholrs gnrctniuefolla Pierre 

Cu~trllu elnstlcn Cervantes 

Slocztzetx I7ertt.r-runu Choisy 

Etrgcnru jarnbo 5 L. 

M~ittilXarti btcicrntutu (A. DC.) Chev. 

L)endropuniz~ arborzus (L.) Decne. & Planch. 

Phc>che eloiz~crtu (Vahl) Nees 

Melzo~ttzu herl?ertrr Rolfe 

Morltez~ttna specrosslina SessC & Moc. 

Mc~mnzea urrzertcann L. 

- - - Thousand cubic meters - 

82.7 35.3 

9 1.9 48.7 

58.7 17.6 

33.7 11.2 

33.8 30.0 

13.4 24.6 

9.1 9.2 

3.3 21.0 

29.6 8.5 

9.6 20.0 

4.9 0 

5.8 17.7 

0 6.6 

4.8 2.1 

14.0 9.3 

0 9.9 

10.8 10.3 

0 14.1 

0 4.6 

15.4 12.2 

0 15.8 

6.1 2.0 

1.7 0 

11.0 3.8 

0 0 

1.3 0 

3.1 9.1 

0 7.2 

0 0 

0 0 

8.4 0 

0 7.5 

7.6 0 

8.1 4.6 

0 0 

0 6.7 

0 0 

3.5 0 

3.4 0 

7.8 0 

0 0 

2.1 0 

0 3.4 
Diameter class (centimeters) 

Species 

code Species name 

All 

classes 30 3 5 40 45 50 55-1- 

Nectundra antillana Meisn. 

Micropholis chrysophylloides Pierre 

Unidentified species 

Rapaneu ferruginea (Ruiz & Pav.) Mez 

Magnolia portoricensis Bello 

Albizia procem (Roxb.) Benth. 

Quararib~a turbinata (Sw.) Poir. 

Clusia rosea Jacq. 

Cupanicr umericana L. 

Vitex divaricatu Sw. 

Persea americuna Mill. 

Tetrugustris balsamifera (Sw.) Kuntze 

Citharexylwn fruticasurn L. 

Hura crepitans L. 

Bur~era imaruba (L.) Sarg. 

Eugenia aeruginea DC. 

Ochroma pyramidale (Cav.) Urban 

Casearia decandra Jacq. 

Turpinia paniculuta Vent. 

Miconia subcorymbosa Britton 

Cczssia siamea Lam. 

Caljptranthes pallens Griseb. 

Total 

- - Thousand cubic meters - - 

aColurnns may not add up to totals as a result of rounding numbers. 
Table 24-Volume of sawtimber on timberland by species and butt log grade, Puerto Rico, 1990" 

Species 

code Species name 

Volume in 

All Butt log gradeb ungraded 

classes 1 2 3 portion 

Spathodea campanulata Beauv. 

Cecropia peltata L. 

Guarea guidonia (L.) Sleumer 

Erythrina poeppigiana (Walp.) 0. F. Cook 

Inga Vera Willd. 

Inga fagqolia (L.) Willd. 

Didymopanax morototoni (Aubl.) Decne. & Planch. 

Calophyllum brasiliense Camb. 

Tabebuia heterophylla (DC.) Britton 

Dacryodes excelsea Vahl 

Andira inermis (W. Wright) H.B.K. 

Terminalia catappa L. 

Spondias mombin L. 

Nectandra sintenisii Mez (E) 

Other species 

----- Thousand cubic meters - - - - - 

Total 2647.2 186.3 928.7 1128.2 404.0 

"Columns may not add up to totals as a result of rounding numbers. 

b~raded by hardwood log grade standards used in the Southern United States. 

Table 25-Volume of timber, growing stock, and sawtimber on timberland by 

stand-size class, Puerto Rico, 1990 

Volume of Volume of Volume of 

Stand-size class timber growing stock sawtimber 

Thousand cubic meters - - - - - - - - - - - 

Sawtimber 7 031.2 

Poletimber 4 244.5 

Sapling-seedling 248.9 

Total 11 524.6 7636.9 2647.4 
Table 26-Volume of timber on timberland by Life Zone, soil group, and slope class, Puerto Rico, 1990 

Percent slope class 

Life Zone 

and soil group 

All 

groups 0 to 10 11 to 25 26 to 45 > 45 

Subtropical Moist Forest 

Deep volcanic soils 

Shallow volcanic soils 

Granitic soils 

Limestone soils 

Total 

Subtropical Wet Forest 

Deep volcanic soils 

Shallow volcanic soils 

Granitic soils 

Limestone soils 

Total 

Total, all Life Zones 

Franco, Peter A.; Weaver, Peter L.; Eggen-McIntosh, Susan. 1997. Forest resources of Puerto Rico, 

1990. Resour. Bull. SRS-22. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern 

Research Station. 45 p. 

The principal findings of the second forest survey of Puerto Rico (1990) and changes that have occurred 

since the survey was established in 1980 are presented. The forest inventory estimates describe the timber 

resource found within the potential commercial region designated in the first survey. The timber resource 

addressed consists primarily of regrown areas on abandoned pastures and cropland, including coffee 

production areas. The status and trends of the timber resource are presented for the two Life Zones 

occurring in the commercial region, as well as for various forest classes, which are based on stand history 

and origin. Topics discussed include forest area, timberland area, basal area, species composition, timber 

volume, growing-stock volume, and sawtimber volume. Results of the 1990 survey are promising, 

showing increases in numbers of trees across all diameter classes and substantial increases in volume. 

These trends offer evidence that Puerto Rico's forests are continuing to recover following a dramatic 

decline of the late 19'h and early 20th centuries. 

Keywords: Coffee shade forests, forest area, forest inventory, secondary forests, timber volume, tropical 

forest management. 
esT ~v/cc @ The Forest Service, U.S. Department of 

Agriculture, is dedicated to the principle of multiple 

use management of the Nation's forest resources for 

sustained yields of wood, water, forage, wildlife, and recreation. 

Through forestry research, cooperation with the States and private 

forest owners, and management of the National Forests and 

National Grasslands, it strives-as directed by Congress-to 

provide increasingly greater service to a growing Nation. 

The United States Department of Agriculture (USDA) prohibits 

discrimination in its programs on the basis of race, color, national 

origin, sex, religion, age, disability, political beliefs, and rnarital or 

familial status. (Not all prohibited bases apply to all programs). 

Persons with disabilities who require alternative means for 

communication of program information (braille, large print, 

audiotape, etc.) should contact the USDA's TARGET Center at 

202-720-2600 (voice and TDD). To file a complaint, write the 

Secretary of Agriculture, U. S . Department of Agriculture, 

Washington, DC 20250, or call 1-800-245-6340 (voice) or 202- 

720-1 127 (TDD). USDA is an equal employment opportunity 

employer.