1

Scientific Review of the Prescribed Fire 

 Program at 

Blackwater National Wildlife Refuge 

(Chesapeake Marshlands NWR Complex) 

and 

Fishing Bay Wildlife Management Area 

February 22, 2005 

Introduction 

 

“The goal of the wildland fire management program is to plan and make decisions that 

help accomplish the mission of the National Wildlife Refuge System (U.S. Dept. of Interior 1998; 

620 DM1)” and help achieve refuge purposes and objectives.

 When establishing protection priorities, firefighter and public safety is the first priority. 

Property and natural/cultural resources follow “If it becomes necessary to prioritize between 

property and natural/cultural resources, we prioritize based on relative values to be protected, 

commensurate with fire management costs.” In addition, the fire program is guided by 

Departmental Policy (U.S. Dept. of Interior 1998; 620 DM1) which states: 

1. every area with burnable vegetation must have an approved Fire Management Plan (FMP) 

that addresses all potential wildland fire occurrences and includes the full range of wildland fire 

management actions 

. 

2. fire will be integrated into land, natural, and cultural management plans and activities on a 

landscape scale, across bureau boundaries, and will be based on the best available science. 

3. wildland fire will be used to protect, maintain, and enhance natural and cultural resources. 

4. wildland fire management must be cost effective, consider firefighter and public safety, 

benefits, and values to be protected, and be consistent with natural and cultural resource 

objectives. 

Background 

 In 1995, staff at the Chesapeake Marshlands NWR Complex (then Blackwater NWR) and 

Maryland Department of Natural Resources, Wildlife and Heritage Services, collaborated in a 

comprehensive review of the fire management programs for Blackwater River and Fishing Bay 

marshes in Dorchester County, Maryland. Controversy regarding management objectives, the 

strategies/tools to implement them, and new Departmental and Service policies prompted this 

review. This effort was led by an independent and impartial, interdisciplinary panel of local and 
2

national experts in fire and wetlands ecology who were asked to review all relevant biological 

and cultural information related to prescribed fire in this ecosystem, and to recommend an 

appropriate fire management regime. The panel was charged to “examine the 48 issues, 

(Appendix A), related to fire management on federal and state lands within Blackwater NWR 

and Fishing Bay WMA, and following deliberations, offer findings and suggestions for 

appropriate fire management alternatives.” A list of panel members is attached in Appendix B. 

After an intensive 4 day site review and testimonies by state and refuge staff, landowners, and 

others who expressed an interest in the use of fire in this ecosystem, the panel identified 6 fire 

management alternatives for these units (Samson et al. 1996) 

1. Aggressive Fire Suppression Regime- Fire is excluded from all areas. 

2. Appropriate Fire Suppression Regime- The influence of fire is restricted to unscheduled 

wildfires. 

3. Current Annual Marsh Plus Fire Regime- Annual fire frequencies are prescribed for only half 

the marsh acreage and fire use is expanded into upland communities. 

4. Current Annual Marsh Fire Regime- Annual fire frequencies are prescribed in all community 

types at varying frequencies. 

5. Multiple-objective Prescribed Fire Regime- Fire and fire exclusion are prescribed in all 

community types at varying frequencies. 

6. More Frequent Prescribed Fire Regime- Frequent fire frequencies are prescribed in all 

community types. 

When the fire management alternatives were compared with the 2 agencies land management 

objectives, the recommended alternative was the Multiple Objective Prescribed Fire Regime 

(MOPFR). This regime supports the refuge’s programmatic approach to prescribed fire by 

allowing the refuge and state to use prescribed fire as a tool to achieve more than one 

management goal and/or objective at a time. 

 

The prescribed burn program at Blackwater is divided into 3 classifications of treatment 

objectives: 

1) Hazard Fuel Reduction-“The Service will employ prescribed fire whenever it is an appropriate 

tool for managing Service resources and to protect against unwanted wildland fire, whenever it 

threatens human life, property and natural/cultural resources.” (FMH Chapter 1.1) 

2) Retaining Ecological Health- maintain current levels of Schoenoplectus americanus and 

Spartina patens to provide habitat for wildlife. 

3) Research- “ Fire, as an ecological process, will be integrated into resource management plans 

and activities on a landscape scale, across bureau boundaries and will be based upon the best 

available science.” (FMH Chapter 1.1). 

Within a single burn unit, we might burn to reduce hazardous fuels, or to retain the ecological 

health of the marsh, or as part of our fire research plots or any combination of objectives. This 

alternative provides for the greatest management flexibility and evaluation of the ecological and 

programmatic effects of a variety of fire regimes. (Samson et al. 1996) 
3

Even though Pendleton and Stevenson (1983) found that marsh burning did not lead to marsh 

loss but rather increased marsh production the panel could only find anecdotal evidence that this 

increase in marsh production had any effect on slowing marsh loss. 

The panel also recommended that adaptive management, coupled with active monitoring and 

long-term research and assessment, be applied to guide changes in management objectives and 

actions in the future. (Samson et al.) The panel completed the review and in 1996 submitted 

their recommendations with a final report entitled, “Technical Review of Fire Management 

Alternatives in the Blackwater National Wildlife Refuge and Adjacent Wetland Management 

Areas.” (Appendix C) 

The panel’s recommendations were incorporated into the environmental assessment, written in 

1998, for Blackwater’s Fire Management Plan. The panel recommended 4 fire frequencies. The 

following 3 rotations and a control were proposed: 1) annual burn, 2) 3-5 year burn, 3) 7-10 

year burn and, 4) no burn, or fire exclusion. As noted below, substantial changes to the annual 

burning program were made as a result of the review and implementation of MOPFR. 

COMPARISON TABLES 

Pre-1995 review Post 1995 review 

Blackwater NWR and 

Fishing Bay WMA 

Acres treated Multiple Objective 

Prescribed Fire 

Regime BWR & 

FBWMA 

Acres treated 

Annual 30,700 Annual 9,300 

3-5 300 3-5 6,300 

7-10 0 7-10 5,700 

No burn 300 No burn 10,000 

Total 31,300 Total 31,300 

Multiple Objective Prescribed Fire Regime by agency 

Blackwater NWR Acres treated Fishing Bay WMA Acres treated 

Annual 3600 Annual 5700 

3-5 200 3-5 6100 

7-10 200 7-10 5500 

No burn 5000 No burn 5000 

Total 9000 Total 22300 

Comparative Analysis of the Pre-1995 and MOPFR Programs 

Pre-1995 Program MOPFR program

-- All or nothing: Annual/no burn Multiple fire return frequencies in every habitat 

 community. 

-- 70/30 planned vs accomplished. 70/30 planned vs accomplished 

-- 70/30 burn mosaic 70/30 burn mosaic 

-- Not ecosystem based Ecosystem based 
4

-- Objectives based on furbearers, Clearly defined objectives (wildlife/habitat diversity) 

waterfowl, marsh health 

-- No Dept/Service policies Clear Dept./Service policies 

-- No clear priorities/mandates Clear priorities and mandates 

-- Separate programs/efforts Cooperative Agreement 

 Cross boundary, landscape effort 

The refuge and DNR staff implemented the panel’s recommendations in 2000, after complying 

with the National Environmental Protection Act (NEPA) requirements and finalizing the Fire 

Management Plan in accordance with national and regional policies. 

In 1998, the Fish and Wildlife Service entered into a collaborative agreement with the University 

of Maryland and the Maryland Cooperative Fish and Wildlife Research Unit to initiate a study 

entitled “Evaluation of vegetative response to fire exclusion and prescribed fire rotation on 

Blackwater National Wildlife Refuge and Fishing Bay Wildlife Management Area”(Flores 

2003). The study was designed to evaluate the implementation of the panel’s recommendation 

of the 4 fire frequencies. 

2003 Panel Review of Fire Management Alternatives 

Prompted by a change in personnel and more recent studies on fire effects in marsh ecosystems, 

4 of the original 5 members (one was unable to attend due to illness), reconvened on November 

13 and 14, 2003, for a symposium at the Horn Point Laboratory of the University of Maryland 

Center for Environmental Science in Cambridge, Maryland. 

The purpose of the 2003 symposium was to review the most current research findings related to 

the use of prescribed fire in marsh ecosystems. Eleven scientists from federal, state, and private 

institutions presented their scientific results at the conference (Appendix D). The fire review 

panel and 40 additional researchers participated in the conference. Each presenter was given 30 

minutes to present their research projects, followed by a question and answer period from the 

panel and the audience. A brief synopsis of each of the 11 research presentations is provided in 

Appendix E. 

At the conclusion of the 2-day conference, the fire review panel met to discuss whether the 

Multiple Objective Prescribed Fire Regime was still the most effective management alternative. 

The panel issued a report in April 2004 entitled “Review of fire management programs for 

Fishing Bay Wildlife Management Area and Blackwater National Wildlife Refuge” (Appendix 

F). 

The 2004 Fire Review Panel Report found the was “no basis” for recommending changes in the 

management regime, and acknowledged that the research issues are extremely complex. The 

Panel also expressed disappointment that funding had not been made available to conduct the 

recommendations the Panel made in 1995. To address the complex issues regarding the 
5

dynamics of the marsh ecosystem and the effects of prescribed fire, additional multi-disciplinary 

research is needed and recommended. 

Expansion of Scientific Research Activities 

In 2004, the Refuge began a collaborative research project with George Mason University and 

U.S. Geological Survey wetland scientists. Based on the findings of Flores (2003), 2 additional 

study areas were added to the long-term fire research monitoring program which increased the 

number of study areas from 6 to 8 areas. Each of these 8 study areas has 3 treatment sites 

including an annual burn, a 3-5 year, a 7-10 year, and a control or no burn area. 

A second graduate student, Ms. Cheryl Leonard, began conducting a research project entitled 

“Above- and below-ground vegetative response to prescribed fire rotations at Blackwater 

National Wildlife Refuge” in 2004. Ms. Leonard is comparing the vegetative response of aboveground and below-ground biomass among the various fire rotations and fire exclusion. 

In addition, refuge staff established permanent photographic stations within each of the treatment 

and control sites within the 8 study areas. Photographs are taken 2-3 times per year to visually 

document the effects of fire on changes in the above-ground vegetation and in the marsh 

ecosystem. In 2006, refuge staff will also collect fire behavior and post-burn severity data. 

A collaborative research project with the U.S. Geological Survey and the National Aquarium in 

Baltimore was initiated in 2005. A study entitled “Marsh elevation dynamics at Blackwater 

National Wildlife Refuge Using Surface Elevation Tables (SETs)” was funded through the Quick 

Response Program of the U.S. Geological Survey and the U.S. Fish and Wildlife Service. The 

objectives of this project are to investigate and document changes in elevation at 3-year old and 

25-year old restored marshes with high precision and to partition the changes into surface (i.e., 

erosional and depositional) and below-ground processes. The results of this study will assist 

scientists in understanding the processes of marsh soil development as restored marshes mature. 

This information will be used to facilitate the design of future marsh restoration projects at the 

refuge. 

The National Geodetic Survey (NOAA), USGS, and the refuge initiated terrestrial and wetland 

elevational research in September 2005. This information will be used to determine the effects 

of elevational change on marsh loss over time. 

In addition, a global climate change research project was initiated in 2005 at Blackwater 

National Wildlife Refuge entitled “Predicting the vulnerability of coastal wetlands to sea level 

rises and other stressors”. This project will address several factors relating to global climate 

change and the effects on marsh loss and marsh accretion. 

Wetland Restoration and the Use of Prescribed Fire 

In 2005, the U.S. Army Corps of Engineers (ACE) issued a report entitled “Draft Baltimore 

Harbor and Channels Dredged Material Management Plan and Tiered Environmental Impact 
6

Statement”. In this report, Blackwater NWR is listed as 1 of 3 options for the placement of 

clean dredged material from the Port of Baltimore. The Blackwater option has the highest 

environmental benefits and also the highest cost for wetland restoration. 

Blackwater staff are working closely with the ACE and the Port of Baltimore to develop 

technical working groups in the following disciplines: wetland processes, geology, hydrology, 

biology, fire effects, and engineering. Scientific experts from over 20 federal, state, and private 

organizations will be working collaboratively to investigate factors related to restoring the 

Blackwater watershed over the next 50 years. This large-scale initiative will be the most 

comprehensive scientific project undertaken to restore the marsh ecosystem at Blackwater 

refuge. The effects of fire on marsh processes will continue to be closely examined throughout 

this project. 

Literature Cited

Flores, C. 2003. Evaluation of vegetative response to fire exclusion and prescribed fire rotation 

on Blackwater National Wildlife Refuge and Fishing Bay Wildlife Management Area. 

Unpublished thesis. University of Maryland Eastern Shore, Princess Anne, Maryland. 326 pp. 

Pendleton, E.C. and J.C. Stevenson. 1983. Investigations of marsh losses at Blackwater Refuge, 

Horn Point Environmental Laboratories, Center for Environmental and Estuarine Studies, 

University of Maryland, Cambridge, MD. 151p. 

Samson, D.A., W.P. Leenhouts., E.C. Soutiere, D. Boesch and F. Cole. 1996. Technical Review 

of Fire Management Alternatives in the Blackwater National Wildlife Refuge and Adjacent 

Wetland Management Areas. 

U.S. Dept. of the Interior, Departmental Manual 620, Chapter 1. 

U.S. Dept. of the Interior, Departmental Manual 620, Chapter 1. 

U.S. Fish and Wildlife Service 2004. Fire Management Handbook. 
7

Appendix A: Forty Eight Issues Related to Fire Management on Federal 

and State Land.

1. Effects of Rx fire on improving/maintaining habitats to achieve purposes/objectives. 

2. Effects of Rx fire in maintaining fire maintained ecosystems and perpetuating 

historical vegetation communities representative of those for which these areas were 

acquired and established. 

3. Effects of Rx fire on maintaining vegetative productivity and vigor (above and below 

ground). 

4. Effects of Rx fire on marsh succession. 

5. Effects on marsh loss. 

6. Effects on habitat suitability for and abundance of marsh herbivores. 

7. Effects on providing browse for wintering waterfowl. 

8. Effects on plant biomass and NAPP and contributions to marsh accretion. 

9. Effects on structural habitat diversity due to incomplete burns. 

10. Effects on trapping and control of herbivores. 

11. Effects on socioeconomic/cultural factors. 

12. Effects of methods, timing, and frequency of fire. 

13. Are past scientific management recommendations used. 

14. Effects of mash herbivores on marsh loss and succession. 

15. Are the marshes fire-maintained or fire-adapted? 

16. Declines of 3-square and resultant effects on biodiversity (landscape context). 

17. Effects on overall species diversity and abundance. 

18. Effects on T&E species and species of special concern. 

19. Effects on non-game species. 

20. Effects on waterfowl species. 

21. Effects on predator-prey relationships. 

22. Effects on residual vegetation. 

23. Effects on invertebrates. 

24. Effects on spatial reorganization of habitats. 

25. Effects on adjacent forest lands. 

26. Effects on nutrient recycling. 

27. Effects on sediment transport. 

28. Effects on air quality. 

29. Effects on soils and soil organisms. 

30. Effect on water quality. 

31. Effects on fishery resources. 

32. Effects on specific plant species (3-square, patens, distichlis, and phragmites). 

33. Effects on public use. 

34. Effects on adjacent landowners. 
8

35. Effects on public health and safety. 

36. Use of Rx fire as a presuppression tool and relationship to liability. 

37. Need to suppress every wildfire on or threatening refuge or the WMU. 

38. Use of LE as alternative management activity to using wildfire presuppression 

burning to prevent trespass/arson wildfires. 

39. Fire will continue to be a major process on these areas with or without Rx fire. 

40. Comparison of effects of Rx fire vs wildfire on human environment, public safety, 

and natural resources (sporadic wildfire vs. scheduled Rx fire). 

41. Comparative costs of fire management activities. 

42. Appropriate coordination with local fire companies. 

43. Impacts on local fire companies/state resources with non-Rx fire. 

44. Appropriate monitoring and assessment. 

45. Frequency and timing of Rx vs. wildfire. 

46. Recognition of and compliance with regulatory factors. 

47. Sixty years of prescribed burning has not stopped marsh loss – should we still be 

burning. 

48. Maintenance of literature pertinent to wildland fire and associate effects.
9

Appendix B: Interdisciplinary Fire Panel Members (1995 and 2003)

Willard P. Leenhouts 

Fire/ Wildlife Ecologist 

U.S. Fish and Wildlife Service 

National Interagency Fire Center 

3833 South Development Ave. 

Boise, ID 83705 

Dr. Edward C. Soutiere, 

President 

Tudor Farms, INC. 

3675 Decoursey Bridge Rd. 

Cambridge, MD 21613 

Dr. Douglas A. Samson 

Director of Science and Stewardship 

The Nature Conservancy of Maryland 

5410 Grosvenor Lane 

Bethesda, Maryland 20814 

Dr. Donald Boesch 

President 

University of Maryland 

Center of Environmental Science (UMCES) 

PO Box 775 

Cambridge, MD 21613 

Mr. Frank Cole* 

U.S. Fish and Wildlife Service- Retired 

1670 Meridian Dr. 

Thomasville, Georgia 31792 

* Mr. Cole was unable to attend the 2003 conference, due to illness. 
10

Appendix C:

Technical Review of Fire Management 

Alternatives in the Blackwater National 

Wildlife Refuge and Adjacent Wetland 

Management Areas 

April 11, 1996
11

Table of Contents 

Executive Summary 2 

Introduction 3 

Fire Management Alternatives 4 

Alternative Evaluation Matrix 6 

Objective Achievement Rationale 11 

Recommended Alternative and Justification 15 

Findings 16 

Wildfire History 16 

Causes of Marsh Loss 16 

Fire Effects on Marsh Vegetation 17 

Grazing Impacts on Marsh Vegetation 18 

Fire Effects on Animal Species 19 

Fire Effects on Human Communities 20 

Fire Program Management 22 

Literature Cited 23 
12

Executive Summary 

An independent panel of 5 individuals evaluated the fire management programs of the 

Dorchester County lands of the Maryland Department of Natural Resources (MDNR) and 

Blackwater National Wildlife Refuge (BNWR) as they relate to the established objectives of 

these units. The panel identified 6 possible fire management alternatives of these units: 

Χ Aggressive Fire Suppression Regime - Fire is excluded from all areas. 

Χ Appropriate Fire Suppression Regime - The influence of fire is restricted to unscheduled 

wildfires. 

Χ Current Annual Marsh Plus Fire Regime - Annual fire frequencies are prescribed for only 

half the marsh acreage and fire use is expanded into upland communities. 

Χ Current Annual Marsh Fire Regime - Annual fire frequencies are prescribed for only half 

the marsh acreage. 

Χ Multiple-objective Prescribed Fire Regime - Fire and fire exclusion are prescribed in all 

community types at varying frequencies. 

Χ More Frequent Prescribed Fire Regime - Frequent fire frequencies are prescribed in all 

community types. 

The panel recommends that the agencies begin comprehensive planning to implement the 

Multiple-objective Prescribed Fire Regime alternative. This alternative best achieves most of the 

23 ecological land management objectives. It provides the greatest management flexibility and a 

diversity of fire regimes. This diversity and flexibility will allow the MDNR and BNWR to 

evaluate the ecological and programmatic effects of a variety of fire regimes. This will require 

an adaptive management approach which includes adequate land-term research, monitoring and 

evaluation in order to determine whether or not management actions are achieving unit 

objectives. 

The most significant single finding of the panel was that no new or additional evidence to refute 

the findings of Pendleton and Stevenson (1983) that: "Annual marsh burning was not directly 

implicated in marsh losses and....marsh losses on the refuge appear from this study to have 

proceeded from natural causes, primarily that of rising sea levels." Although Pendleton and 

Stevenson (1983) and others also found that fire "was found to increase marsh production," the 

panel could only find anecdotal evidence that this increase in marsh production had any effect on 

slowing marsh loss. 
13

Introduction

For many years, fire has been used in wetlands of Maryland's Eastern Shore to facilitate trapping 

of fur-bearing animals, stimulate the growth of vegetation thought to be beneficial to furbearers 

or waterfowl, or to reduce the risk to life and property due to uncontrolled fires. Prescribed fire 

has also long been used in the management of wetlands of the Blackwater National Wildlife 

Refuge (BNWR) and nearby wildlife management areas operated by the Maryland Department 

of Natural Resources (MDNR). Prescribed fires have been thought to be beneficial, and even 

necessary, for favoring the growth of wetland vegetation conducive to wildlife use and to 

facilitate the trapping of introduced nutria, which overgraze these marshes. At the same time, the 

tidal wetlands of this area have undergone very rapid deterioration and loss as a result of 

geologic and hydrodynamic phenomena, human alterations and populations of animal grazers. 

To meet this challenge of habitat loss, prescribed fires have also sought to promote the growth of 

wetland vegetation which may enhance the long-term viability of the wetlands. 

The effectiveness of fire in achieving multiple management objectives, including sustaining 

these important wetland ecosystems and enhancing wildlife, have come into question. To help 

address the role of fire in the stewardship of these public wetlands and adjacent wetlands, the 

Maryland Department of Natural Resources (MDNR) and the Blackwater National Wildlife 

Refuge (BNWR) convened an independent panel of experts to examine the issues related to fire 

management on these lands by reviewing the literature, visiting the environments in question, 

and obtaining public input on the issues. The Panel was asked to deliberate, offer its findings 

and suggest appropriate fire management alternatives. The Panel is composed of: 

Χ Edward C. Soutiere, President, Tudor Farms, Cambridge, MD. 

Χ Frank T. Cole, Project Leader/Fire Ecologist, U.S. Fish and Wildlife Service, Tall 

Timbers Research Station, Tallahassee, FL. 

Χ Donald F. Boesch, Ph.D., President, Center for Environmental and Estuarine Studies, 

University of Maryland System, Cambridge, MD. 

Χ Douglas A. Samson, Ph.D., Director of Science and Stewardship, The Nature 

Conservancy of Maryland, Chevy Chase, MD. 

Χ Willard P. Leenhouts, Fire/Wildlife Ecologist, U.S. Fish and Wildlife Service, National 

Interagency Fire Center, Boise, ID. 

This is the final report of the panel. In it, we describe an array of Fire Management Alternatives, 

from the most limited to the most extensive; evaluate the potential of these Alternatives to meet 

23 specific objectives in an Alternative Evaluation Matrix; present the Panel's Findings; and 

develop Recommendations for the preferred alternative and comprehensive planning. 
14

Fire Management Alternatives 

After reviewing the literature, conducting a site visit, obtaining public input on the issues, and 

discussing the issues, the panel developed 6 fire management alternatives for the Maryland 

Department of Natural Resources and the U. S. Fish and Wildlife Service. The panel feels that 

these 6 fire management alternatives represent a broad spectrum of possible alternatives. The 

panel also feels that it would be irresponsible for any alternative to advocate no fire management 

action, even suppression. This would risk public safety, be irresponsible ecological stewardship, 

and be contrary to agency policies. Each alternative is evaluated against 23 land management 

objectives. 

- Aggressive Fire Suppression Regime: A fire management plan will be developed to 

ensure that all wildfires will be controlled at a minimum size irrespective of values at risk 

or suppression cost, and no prescribed fires will be used. Under this alternative 

aggressive wildfire suppression will be taken on all fires regardless of the values at risk to 

ensure that a minimum of public land burns. No prescribed fires will be used on any 

lands. It is anticipated that there will be less average annual acreage burned compared to 

the current situation. Fire management costs will significantly increase due to the 

aggressive wildfire suppression strategy. 

- Appropriate Suppression Fire Regime: A fire management plan will be developed to 

ensure that all wildfires will be suppressed according to policies of each land 

management agency, and no prescribed fires will be used. Under this alternative the 

current fire management strategy will continue, less any prescribed fires. Wildfire 

suppression actions will be taken on all lightning and human caused fires appropriate to 

the values at risk and cost of suppression. It is anticipated that aggressive suppression 

will be taken where public safety and property are at risk, but less aggressive actions may 

be used where the fire is causing little human threat or ecological impact (e.g., remote 

marsh areas). No prescribed fires will be used on any lands. It is anticipated that there 

will a decrease in the average annual acreage burned from the current situation, but much 

of the 13,000 acres currently prescribed burned will be burned by wildfires. Fire 

management costs should significantly increase with the increased wildland fire 

suppression activities. 

- Current Annual Marsh Fire Regime: The current fire management plan will continue 

to ensure that all wildfires will be suppressed according to policies of each land 

management agency. This is the "no action" alternative because there will be no change 

in the current fire management plan. Wildfire suppression actions will be taken on all 

lightning and human caused fires appropriate to the values at risk and cost of suppression. 

Annual prescribed fires will be applied to approximately 3,000 acres of U.S. Fish and 

Wildlife Service and 10,000 acres of Maryland Department of Natural Resources marsh 

lands. Under this alternative the current fire management strategy will continue. This is 

probably the least costly wildland fire management alternative. 

- Current Annual Marsh Fire Regime Plus Woodland Prescribed Fires: A fire 

management plan will be developed to ensure that all wildfires will be suppressed 
15

according to policies of each land management agency. Wildfire suppression actions will 

be taken on all lightning and human caused fires appropriate to the values at risk and cost 

of suppression. Annual prescribed fires will be applied to approximately 3,000 acres of 

U.S. Fish and Wildlife Service and 10,000 acres of Maryland Department of Natural 

Resources marsh lands. The U. S. Fish and Wildlife Service will also begin using 

prescribed fire on 500 acres of woodlands on approximately a 5-year fire rotation 

interval. Under this alternative the current fire management strategy will continue, with 

the addition of woodland prescribed fire by the U. S. Fish and Wildlife Service. Fire 

management costs should increase proportional to the increased woodland prescribed 

fires. 

 

- Multiple-objective Prescribed Fire Regime: A fire management plan will be 

developed to ensure that there are significant areas of all vegetative community types 

representative in varying fire regimes. Under this alternative wildfire suppression and 

prescribed fire activities will be planned to ensure that all major public land vegetative 

community types have representative areas of approximately 1-, 5-, and 20-year fire 

rotation intervals, and total fire exclusion. It is anticipated that there will be little change 

in the average annual acreage burned compared to the current situation. Fire 

management costs should significantly increase with the increased wildland fire 

suppression and prescribed fire activities needed to implement this alternative. 

- More Frequent Prescribed Fire Regime: A fire management plan will be developed to 

ensure that frequent fire regimes are maintained in all vegetative community types. 

Under this alternative wildfire suppression and prescribed fire activities will be planned 

to ensure that all major public land vegetative community types have representative areas 

of approximately 1- and 5-year fire rotation intervals. It is anticipated that there will 

more annual acreage burned compared to the current situation. Fire management costs 

should significantly increase with the increased prescribed fire activities, but wildland 

fire suppression cost decreases may mitigate some of the increased prescribed fire costs 

for this alternative. 

Alternative Evaluation Matrix 

The 6 alternatives were evaluated against 23 land management objectives provided by MDNR 

and BNWR. The first 21 land management objectives were provided to the panel by the 

Maryland Department of Natural Resources and U.S. Fish and Wildlife Service as evaluation 

criteria of the fire management alternatives. The panel added the objectives 22 and 23 to 

evaluate the probability an alternative could be implemented. 

The probability an alternative could achieve any particular objective is indicated as: ++ Highly 

probable; + Possible; +- Uncertain; - Unlikely; -- Highly improbable. 
16

Objective 

Aggressive 

Fire 

Suppression 

Regime 

Appropriate 

Fire 

Suppression 

Regime 

Current 

Annual 

Marsh Fire 

Regime 

Current 

Annual 

Marsh Fire 

Regime 

Plus 

Woodland 

Rx Fires 

Multiple 

Objective 

Prescribed 

Fire 

Regime 

More 

Frequent 

Prescribed 

Fire 

Regime 

1. Provide a level of wildland fire protection that 

will result in the least cost plus net value change 

(cost efficient level) commensurate with resource 

management objectives and constraints. 

_ + ++ ++ ++ + 

2. Reduce adverse impacts of all resource mgt. 

activities and the threats of wildfires associated 

with trespass and arson fires in the intermingled 

Federal/State/Private lands and along the WUI. 

_ _ ++ ++ ++ ++ 

3. Maintain optimum nesting and brood habitat 

for State and Federal endangered and threatened 

species and species of special concern. 

_ 

_ + ++ ++ + 

4. Provide feeding & resting habitat for mtce. 

requirements of migratory waterfowl during 

migration and wintering periods. 

_ 

_ + + + + 

5. Promote the control of resident and alien 

furbearers. _ _ ++ ++ + ++ 

6. Provide nesting and brood habitat for duck 

production 

+- + ++ ++ ++ +- 

7. Maintain health and vigor of marsh vegetation - - ++ ++ + ++ 

8. Maintain current marshland acreage and 

species mixture. Reduce brush invasion into 

marshlands. 

_ _ 

+- +- +- +- 

9. Control phragmites, an alien species - - - - +- +- 

10. Reduce brush species dominance and 

encourage native herbaceous growth on 

abandoned cropland areas. 

_ + _ _ + ++ 

11. Reduce the encroachment of tree species that 

are not part of the desired community _ _ _ ++ ++ + 

12. Prepare sites for seeding and planting and 

dispose of logging slash. _ _ _ + ++ ++ 

13. Utilize mgt. practices to produce traditional 

forest habitat values: wood, water, wildlife, rec. _ _ _ + ++ + 

14. Provide compatible public hunting, trapping 

and outdoor recreational opportunities _ +- + ++ ++ + 

15. Provide opportunities for the public to understand & appreciate the need for wildland fire 

activities 

_ _ + ++ ++ ++ 

16. Comply with state air quality implementation 

plans to protect public health 

++ ++ + + + + 

17. Assure no disruption or adverse impact on 

transportation/utility corridors occurs from 

wildland fires. 

+ + ++ + ++ + 

18. Prepare sites for seeding and planting - - - + ++ ++ 

19. Maintain current ecosystem diversity w/in the 

landscape context. - - ++ + + +- 

20. Contribute to the recovery and restoration of 

Chesapeake Bay ecosystem diversity & function - - + + ++ - 

21. Protect valuable resources of international, 

regional and local significance. - +- + + ++ - 

22. Achievable w/in current funding levels. - ++ + + + - 23. Achievable under current social/political 

constraints. - ++ + + + - 
17

Objective Achievement Rationale

The following is a discussion of the wildland fire use rationale behind the rating given in 

the Alternative Evaluation Matrix. The rationale provided are generalizations. As with 

all generalizations, specific exceptions always exist, but on average the generalization 

applies most often across a broad spectrum of circumstances. See the Findings section of 

the report for a detailed explanation of these issues. 

1. Provide a level of wildland fire protection that will result in the least cost plus net 

value change (cost efficient level) commensurate with resource management 

objectives and constraints. A combination of presuppression hazard reduction 

prescribed fire and appropriate suppression strategies has been shown to be the 

most efficient level of wildfire protection. Only the alternatives that use 

prescribed fire can implement a presuppression hazard reduction program. Since 

most of the wildfires occur in the marshes, the alternatives that implement marsh 

prescribed fires are rated the highest. 

2. Reduce adverse impacts of all resource management activities and the threats of 

wildfires associated with trespass and arson fires in the intermingled 

Federal/State/private lands and along the wildland/rural interface. Same logic as 

1. 

3. Maintain optimum nesting and brood habitat for State and Federal endangered 

and threatened species and species of special concern. The more habitat diversity, 

the greater probability of addressing endangered and threatened species needs. 

The extirpation of the red-cockaded woodpecker demonstrates that uplands 

require some fire treatment. The alternatives that utilize prescribed fire in both 

the marsh and uplands rate higher than those that only address the marsh. The 

More Frequent Prescribed Fire Regime lacks the long rotation and complete 

exclusion options and is rated lower. 

4. Provide feeding and resting habitat for maintenance requirements of migratory 

waterfowl during migration and wintering periods. Frequent fires in wetlands 

subsidized vegetation species (i.e., Scirpus spp.) that are favored by waterfowl. 

All alternative that utilize prescribed fire in the marsh achieve this objective, but 

the panel felt that marsh fire was only one of many factors needed to achieve this 

objective, and by itself would not assure optimal feeding and resting habitat. 

5. Promote the control of resident and alien furbearers. Winter prescribed fire fuel 

reduction facilitates trapping, which is the most efficient furbearer control 

technique. The most aggressive marsh prescribed fire programs makes objective 

achievement greater. Because the Multiple-objective Prescribed Fire Regime sets 

aside significant marsh acreage in long rotation and fire exclusion zones, this 

reduces the chances of this alternative achieving this objective. 

6. Provide nesting and brood habitat for duck production. Black ducks require dense 

ground nesting cover which is in ample supply unless fire is completely excluded 

or applied across all habitat types. Wood ducks require nesting cavities which are 

provided by artificial nesting cavities or trees with cavities that are facilitated by 

fire damage. Prescribed fire has been used successfully in the management of 
18

waterfowl habitat (Kirby et al. 1988) and silvicultural treatments (Wright and 

Bailey 1982). Therefore, the alternative to utilize prescribed fire and maintain a 

diversity of marsh and upland habitats is rated the highest. 

7. Maintain health and vigor of marsh vegetation. Much of the existing marsh 

vegetation has evolved with periodic fire (Kirby et al. 1988). The Scirpus

marshes require annual or biennial burning. Attempting to convert water stressed 

marshes that have adapted to fire may result in complete marsh vegetation loss 

from the rise in the relative sea level. Alternatives that maintain significant 

acreage of frequent fire regime vegetation are more likely to achieve this 

objective. 

8. Maintain current marshland acreage and species mixture. Reduce brush invasion 

into marshlands. Unless the past century of relative sea level rise is reversed 

which appears unlikely, marsh loss will continue, and achievement of this 

objective is unlikely. In order to maintain the current marsh condition, all 

ecological processes must continue as in the past; this includes frequent (annual) 

marsh burning. Frequent marsh burning, especially growing season burning, also 

favors herbaceous species over woody species. Only those alternatives that 

continue the current marsh fire regimes can fully achieve this objective. Because 

the Multiple-objective Prescribed Fire Regime sets aside significant marsh 

acreage in long rotation and fire exclusion zones, this reduces the chances of this 

alternative achieving this objective. 

9. Control phragmites, an alien species. Surface fire alone reduces phragmites 

biomass, but is not an acceptable control technique. Surface fire in combination 

with herbicides or flooding has been effective. Severe root burns can kill 

phragmites plants (Cross, D. H. 1983). But fire alone cannot significantly control 

Phragmites and it is unlikely that any of the alternatives can achieve this 

objective. 

10. Reduce brush species dominance and encourage native herbaceous growth on 

abandoned cropland areas. Frequent growing season fire favors herbaceous over 

woody species. The more frequent fires in upland communities, the greater 

likelihood of brush control. 

11. Reduce the encroachment of tree species that are not part of the desired 

community. Frequent growing season fire favors herbaceous over woody species. 

Tree control through fire is more successful on small, non-fire adapted tree 

species (Robbins and Myers 1992). The alternatives that utilize fire in the upland 

communities and maintain a diversity of fire regimes are most likely to achieve 

this objective. 

12. Prepare sites for seeding and planting, and dispose of logging slash. Fire can be 

used as an effective site preparation and slash disposal technique, but other 

alternatives to site preparation and slash disposal are available. The alternatives 

that utilize fire in the upland communities and maintain a diversity of fire regimes 

are more likely to achieve this objective. The alternatives that are targeted at 

specific areas (Multiple-objective) or have the greatest fire frequency are most 

likely to achieve this objective. 

13. Utilize management practices to produce traditional forest habitat values: wood, 

water, wildlife, recreation. Fire is an ecological process in the forest community 
19

of Maryland. Applied appropriately, traditional forest habitat values can be 

improved. The alternative that provided the greatest diversity of upland 

communities has the best probability of achieving this objective. 

14. Provide compatible public hunting, trapping, and outdoor recreational 

opportunities. Fire is an ecological process in Maryland ecosystems. Applied 

appropriately, wildlife oriented outdoor recreational values can be improved. 

The alternative that provided the greatest diversity of marsh and upland 

communities has the best probability of achieving this objective. 

15. Provide opportunities for the public to understand and appreciate the need for 

wildland fire activities. A diversity of wildland fire management options will 

provide more educational opportunities. The alternative that provided the 

greatest diversity of marsh and upland communities has the best probability of 

achieving this objective. 

16. Comply with State Air Quality Implementation Plans to protect public health. 

Prescribed fire emissions are defined as anthropogenic pollution. The more 

smoke produced, the more likelihood of noncompliance with State Air Quality 

Implementation Plans. Alternatives that minimize prescribed fire use are most 

likely to achieve this objective. 

17. Assure no disruption or adverse impact on transportation/utility corridors occurs 

from wildland fires. Transportation/utility corridors can be disrupted by both 

wildfire and prescribed fire management activities and smoke emissions. The 

more activity, the more likelihood of disruptions. The alternatives that only burn 

marsh or optimize the area burned have the greatest probability of achieving this 

objective. 

18. Prepare sites for seeding and planting. Fire can be used as an effective site 

preparation, but other alternatives to site preparation are available. The 

alternatives that target the use of prescribed fire in the uplands or frequently use 

fire in the uplands have the greatest probability of objective achievement. 

19. Maintain current ecosystem diversity within the landscape context. In order to 

maintain the current ecosystem diversity, all ecological processes must continue 

as in the past, which include frequent (annual) marsh burning and fire exclusion in 

the uplands. However, ecological processes diversity affords the greatest 

likelihood of ecosystem diversity. Only those alternatives that continue the 

current fire regimes can fully achieve this objective. Because the Multipleobjective Prescribed Fire Regime sets aside significant marsh acreage in long 

rotation and fire exclusion zones, this reduces the chances of this alternative 

achieving this objective. However, the Multiple-objective Prescribed Fire 

Regime may provide better ecosystem diversity within the landscape context that 

the current regime. 

20. Contribute to the recovery and restoration of the Chesapeake Bay ecosystem 

diversity and function. Compared to flooding due to sea level rise, fire is an 

insignificant ecological process in the Chesapeake Bay. However, ecological 

processes diversity affords the greatest potential for recovery and restoration of 

ecosystem diversity and function. Only the Multiple-objective Prescribed Fire 

Regime provides the diversity and flexibility of fully achieving this objective. 
20

21. Protect valuable resources of international, regional, and local significance. 

Ecological processes diversity affords the greatest potential for resource 

protection. The Multiple-objective Prescribed Fire Regime provides the diversity 

and flexibility of fully achieving this objective. 

22. Achievable within current funding levels. Program cost increases are directly 

proportional to the increase in the amount and complexity of the program. 

Basically, funding is only available to address the current situation and take 

appropriate suppression actions. More aggressive suppression or increased 

prescribed fire activity will require additional funds. 

23. Achievable under current social and political constraints. Stakeholder informed 

consent decreases proportional to the amount of program change. The greatest 

change in the current program would be aggressive suppression and frequent fire 

regime prescribed fire activity. There is some stakeholder concern over the 

current situation. Initiating prescribed fire activities in the uplands will generate 

concern from local citizens, but this can be mitigated by planning that involves 

the public and performing professionally. 
21

Recommended Alternative and Justification 

The panel recommends that MDNR and BNWR begin comprehensive planning to 

implement the Multiple-objective Prescribed Fire Regime alternative. This alternative 

best achieves most of the ecological land management objectives (see Matrix above). It 

also provides the greatest management flexibility and a diversity of fire regimes. This 

diversity and flexibility will allow the MDNR and BNWR to evaluate the ecological and 

programmatic effects of a variety of fire regimes. This will require an adaptive 

management approach which includes adequate land-term research, monitoring and 

evaluation in order to determine whether or not management actions are achieving unit 

objectives. Wildland fire management must be fully integrated into the overall unit 

management plans of these public lands. Building partnerships and fully engaging local 

residents and the public in this process will also be critical for obtaining stakeholder 

informed consent. 

The panel recognizes that the implementation cost of the Multiple-objective Prescribed 

Fire Regime alternative may exceed the current fire management budgets of both the 

MDNR and BNWR. However, no fire management alternative should be implemented if 

it does not provide confidence to stakeholders and include a process to validate whether 

or not management objectives are being achieved. Additional research and monitoring 

effort is needed to evaluate fire impacts on these marshes and their resident and migratory 

species, regardless of the fire management alternative adopted. Estimating future 

program costs under any of the management alternatives, even within a large margin of 

error, is beyond the scope of the panel, and can best be addressed by the agencies' 

comprehensive planning process. However, this report provides considerable support and 

justification for increased allocation of resources to fire management programs on these 

public lands. 

The panel feels that this report should assist the agencies to continue ongoing efforts to 

jointly develop compatible, ecosystem-based, multiple-scale, interagency land 

management plans that involve all interested parties and facilitate adaptive management. 

This process should: 

Χ fully integrate ecological concepts that consider long-term dynamics and cross 

agency boundaries. 

Χ effectively incorporate current fire-related information, including scientific 

knowledge, risk assessment, social and economic concerns, and public health 

considerations. 

Χ identify important research/information needs that relate directly or indirectly to 

marsh vegetation health and sustainability, and fire impacts on component species 

and communities. 
22

Findings

Wildfire History 

Wildland fire is an ecological process and has been a historic part of Dorchester County. 

The presettlement fire regime may have been relatively frequent, primarily from 

anthropogenic ignitions (Pyne 1995). European values and land use changes have 

significantly impacted the historical fire regime. Agriculture and timber production have 

removed and fragmented almost all the presettlement upland communities. For centuries 

wildland fire in the upland communities has been suppressed, and little or no prescribed 

fire has been used. The open marsh community has been dominated by furbearer 

management practices (Dozier et. al. 1948). Since early settlement the marshes have 

been prescribed burned almost annually to improve wildlife food production (Scirpus 

olneyi) and facilitate furbearer harvest (Pendleton and Stevenson 1983). For two centuries 

the application of fire and fire exclusion has significantly affected the ecological 

characteristics of Dorchester County. The current ecological composition, structure and 

species populations reflect these fire regimes. 

Causes of Marsh Loss 

Marshes in the Blackwater area are changing and being rapidly lost as a result of 

increased relative sea level rise during this century (Kearney and Stevenson 1991). 

Changes in the rate of sea level rise in the Chesapeake bay area have three components: 

(1) decidual scale variation of coastal water level, which results from Gulf Stream flow; 

(2) increases in global sea level, potentially as a result of global warming: and (3) 

localized increases in the regional land subsidence rate resulting from groundwater 

withdrawals. Particularly important in the Blackwater area is the significant decline in 

aquifer pressures, which result from water withdrawals at Cambridge during the 1950s 

and 1960s. Models predict that this resulted in 14 cm of compaction at nearby Church 

Creek, mostly due to compaction of the Nanjemoy formation (Tim Rule, personal 

communication). 

The increased flooding resulting from accelerated sea level outpaces the ability of the 

marsh to accrete soil, which in the Blackwater area is mainly composed of organic peat, 

leading to conversion of marsh to open water (Stevenson et al. 1985). This may occur 

because of insufficient periodic drainage of the soil, which stresses and ultimately kills 

marsh plants. Also, increased inundation, compounded by marsh breakup, has allowed 

greater intrusion of saline waters into the upper reaches of the Blackwater wetland 

system. This has not only increased physiological stress of freshwater or otherwise salttolerant plants, but also introduced more sulfate, a significant anion in marine and 

estuarine waters. The availability of sulfate increased the anaerobic decomposition of 

organic soils and, under anaerobic conditions in the soil, resulted in higher soil sulfide 

concentrations and additional physiological stress on plants. 
23

Increased relative sea level has, of course, caused increased flooding of low-lying 

uplands and their conversion to marshes (Nixon 1982), but the gains in marsh area have 

been relatively small compared to the losses due to the processes described above. The 

marshes of the Blackwater have, in fact, resulted from slow submergence of upland areas 

(Kearney and Stevenson 1991). As a consequence, these marshes lack a well-integrated 

tidal creek network, are relatively isolated from mineral sediment influx, and are drained 

by a limited number of long first-order tidal creeks in which ebb velocities are stronger 

than flood tidal velocities. The effect of this physiography is to make such marshes 

particularly vulnerable to relative sea level rise. 

The marsh soils accrete by upward and lateral extension of below-ground rhizome and 

root networks (Stevenson et al. 1985). Not all of the above-ground and below-ground 

organic material produced in a marsh is accumulated in peat. In Louisiana 50 percent is 

lost in 5 months (White et al. 1978). Emergent macrophyte stem and leaf litter subjected 

to above-ground inundation treatments increase the rate of decay, and inundation retards 

decay below-ground. Almost half of the flooded above-ground litter was decomposed 

within 100 days, but half of the flooded below-ground litter remained after 438 days 

(Neckless and Neill 1994). Less than a third of the below-ground production is buried, 

and only about 5 percent of the total Spartina alterniflora biomass produced in the 

Sippewissett Marsh on Cape Cod was accumulated in peat (Valiela et. al. 1976). 

Blackwater marsh soils are almost entirely composed of plant matter and consist of a 

thick vegetative mat capping a finely divided, highly organic ooze remnant from organic 

peat deposition. Ebb-tidal dominance continually erodes these soil materials, which are 

made even more erodible by marsh die-off and salinity intrusion. 

Fire Effects on Marsh Vegetation 

Dorchester County marsh wildland fires are surface fires. They consume only dead and 

living plant components and seldom, if ever, consume organic material in the soil. This 

is because the soils remain saturated. Exactly what effect fire has had on marsh loss is 

debatable. Fire directly removes organic matter, which could be used in marsh 

maintenance. Marsh fires in Dorchester County directly consume 0.46 kg m-2 of organic 

material per fire that would be available for sedimentation (Pendleton and Stevenson 

1983). Fire increases primary production (Christensen and Wilbur 1993, Hackney and de 

la Cruz 1992) and metabolism in wetlands (Johnson and Knapp 1993). Fires every 4-5 

years maintain the vigor of marshes (Hackney and de la Cruz 1992). This may explain 

why total standing Scirpus olneyi biomass and live biomass were significantly larger in 

the burned than unburned plots and live below-ground biomass on burned sites exceeded 

unburned sites by 3.7 kg m-2 (Pendleton and Stevenson 1983). The increase in Scirpus 

olneyi production and deposition, especially in below-ground roots and rhizomes, may be 

equal to or greater than the potential deposition of organic matter lost due to combustion. 

Pendleton and Stevenson (1983) concluded: "Annual marsh burning was not directly 

implicated in marsh losses and, indeed, was found to increase marsh production. In 

summary marsh losses on the refuge appear from this study to have proceeded from 

natural causes, primarily that of rising sea levels." This conclusion is supported by 

observations of moderate to complete deterioration of portions of the Nanticoke estuary 
24

marshes (Kearney et al. 1988) that have experienced an infrequent fire regime (Wade 

Henry, pers. comm.). 

The amount of organic matter consumed by fire (0.46 kg m-2) or the increase in live 

below-ground biomass by fire (3.7 kg m-2) may be insignificant to the 13.8 kg m-2 yr-1 of 

net sediment exported from the marsh (Stevenson et. al. 1985). The effect of fire on 

marsh loss, whether positive or negative, is probably insignificant to the effects of sea 

level rise. Although the historic open marsh is being lost, fire can hasten the conversion 

of the upland fringe to open marsh by killing trees and brush, and selecting for marsh 

plants adapted to fire (e.g., Scirpus olneyi). 

In addition to the lack to evidence that fire has contributed significantly to marsh loss, it 

seems also clear that the effects of burning on the ecological components of the marsh 

and adjacent estuary are small in comparison to the effects of marsh loss itself. The main 

threat to the biotic integrity of the wetland ecosystem is the rapid conversion of the marsh 

to open water as a result of the combination of relative sea level rise, hydrologic 

alteration and salinity intrusion, rather than fire. Marsh deterioration, in combination 

with ditching and channelization, is allowing salt water to penetrate farther into the 

Blackwater marshes. Not only are brackish and fresh marshes being lost, but other biota, 

including fishes (Leon Fewless, personal communication), is shifting to more salt tolerant 

forms. With the increased salinity comes increased dissolved sulfate concentrations, 

which in turn allow sulfate reducing bacteria to degrade the peat in anaerobic marsh soils, 

resulting in a breakup of the highly organic marsh substrate. The release of soil organic 

matter also results in depleted oxygen concentrations in adjacent water bodies. While 

breakup of extensive marshes may in the short term facilitate secondary production of 

fish and shellfish by increasing the marsh-water interface, as marsh deterioration 

continues the secondary production which depends on this habitat may be expected to 

decline precipitously (Brower, et al., 1989). 

Grazing Impacts on Marsh Vegetation 

Another contributing factor to marsh loss is herbivore grazing - muskrats, nutria, and 

geese. Nutria create openings in the marsh by concentrating their feeding activities 

(Hilbricht and Ryszkowski 1961, Wentz 1971). These openings are the nucleus (catalyst) 

for the interior ponding that is accelerating the BNWR and Nanticoke marsh losses. 

Grazing damage to marsh substrates in most cases is reversible, except in marshes where 

periodic anoxic water conditions result in adverse physiological effects in the rhizophere 

of the remaining plants (Mendelssohn et al. 1981). 

Grazers (muskrats, nutria, and geese) may have accelerated marsh loss (Pendleton and 

Stevenson 1983). Unfortunately, the same plants favored by marsh grazers are 

stimulated by burning (Chabreck 19__), but burning facilitates furbearer trapping - the 

primary harvest technique for muskrats and nutria. Under historic conditions plant 

production, either burned or unburned, and grazing impacts reach some dynamic 

equilibrium. The Dorchester County marshes have two additional stressors that were not 

present historically: an acceleration in relative sea level rise and nutria. Relative sea 

level rise is a stressor to marsh vegetation production, and nutria have increased grazing 
25

above historic muskrat levels. Geese also have to a lesser extent increased grazing above 

historic muskrat levels. There may also be some compensatory effects among the three 

primary grazers. BNWR (1994) estimates the muskrat population has dropped from 7.9 

to 3.0, while the nutria population has increased from 0.7 to 2.5 animals per acre from 

1987 to 1993. Exclosure data indicates that total exclusion of grazing could significantly 

subsidize marsh vegetation (Pendleton and Stevenson 1983). Whether this subsidy 

offsets the stress of relative sea level rise, or if total exclusion is practical, is unknown. 

Total elimination of marsh grazing on either State or Federal lands is contrary to the 

mandate of those lands, whether recreational (hunting, trapping) or ecological (biological 

diversity, ecosystem function). The historic components of the marsh (muskrats and 

geese) must remain part of the future marsh. State law (Nutria Eradication Bill) and 

Federal mandates encourage the complete extirpation of nutria (a noxious introduction), 

however. The practicality of complete extirpation of nutria is questionable. An 

estimated cost of $5 million was provided by a leading nutria expert to extirpate the 

species from Maryland. The State of Maryland has authorized extirpation of nutria 

(Nutria Eradication Bill), but failed to appropriate any funds for the activity. 

Recreational, commercial, and professional harvest of nutria at BNWR has steadily 

increased for the past 10 years from 65 to over 5,000 per year, but the nutria population 

has also increased from 100 to 15,000. Both State and Federal land management 

agencies have been using a rebate program to encourage increased harvest since 1990. 

This effort has led to a harvest rate of 0.9 animals per acre in 1994 (BNWR 1994). An 

enhanced harvest effort, as part of the MDNR comprehensive nutria eradication 

assessment at Tudor Farms, indicated that harvest rates of between 6 - 8 animals per acre 

are possible. The important - yet unanswered - question is, at what level does harvest 

mortality become additive to natural mortality? Only at that level is management 

effective. 

At best, the current bounty system is of little ecological value, although it does have some 

political value: "While the numbers of nutria which can be removed as part of this 

program is not adequate to keep nutria populations in check, the refuge program has 

been praised by the local community and Maryland elected officials because the refuge, 

at least under this program, is attempting to remove nutria and prevent marsh loss" 

(BNWR 1994:2). "Unfortunately the bounty is well adapted to the needs of the poor 

informed, politically minded administrator or the table-pounding fireball in the 

sportsman's club. It is likely to be used, and once it is entrenched, the profits enlist loyal 

supporters" (Allen 1962:267). 

The MDNR comprehensive nutria eradication assessment currently underway should 

provide some insight into the level and cost of management activity necessary to manage 

the nutria population at a level that provides an ecological subsidy to marsh vegetation. 

Additional insight into the compensatory effect nutria harvest has on other marsh grazers, 

and whether the ecological subsidy provided is worth the cost, will also be helpful. 
26

Fire Effects on Animal Species 

All ecological processes such as fire are both an ecological subsidy and a stressor (Lugo 

1993). The effects of fire on any specific ecological component (e.g., endangered 

species, non-game species, waterfowl species, predator-prey relationships, etc.) are 

dependent on the evolutionary relationship that ecological component has had with the 

ecological process. For species adapted to fire, fire is a subsidy; but for those same 

species, fire exclusion is a stressor. The sustainability of these ecological components is 

ecologically important. Population levels are more politically and socially important. 

Maintaining biotic integrity is accomplished through an understanding and management 

of ecological processes (Samson and Knoff 1993). Hydrology (relative sea level rise) 

and fire are the two most critical ecological processes influencing the Dorchester County 

marshes. Unfortunately, only limited fire effects research has been conducted to date on 

Dorchester County rare marsh animals. 

Species such as marsh wrens do not nest in the burned portion of the marsh the first year 

after a fire, but will in the second. Studies indicate that American bittern, black rail, least 

bittern, and king rail populations may be subsidized by fire exclusion; common moorhen, 

clapper rail, and Virginia rail populations may be subsidized by fire; and fire or fire 

exclusion may have no effects on sora rail populations (Dave Brinker, pers. comm.). The 

frequent fire regime may have contributed to the extirpation of the Eastern Henslow's 

sparrow from the Dorchester marshes because "thick vegetation seems a basic 

requirement of its habitat" (Smith 1968:776). Except for the Eastern Henslow sparrow, 

no other species has been documented as being extirpated over almost 2 centuries of 

marsh burning. Possibly significantly altering the 2-century subsidy - stressor relation of 

fire on the marsh, may significantly alter the biological relationship of the marsh. 

Forest fragmentation and fire exclusion of upland habitat of Dorchester County has been 

significant over the past 50 years (Alan Zentz pres comm.). Not surprisingly, fire 

adapted species have been significantly impacted (e.g., red-cockaded woodpecker, 

extirpated in the 1970s, and the Delmarva fox squirrel, Federally listed as endangered). 

A discussion of the specific fire effects on other species and ecological communities is 

beyond the scope of this report. The reader can access much of this information through 

the Fire Effects Information System (FEIS) (Fisher 1989). The computerized FEIS 

presents concise, easy-to-understand summaries of technical information. The system 

has information on about 900 plant species, 90 animal species and 25 plant communities. 

Hessl and Spackman (1995) provide an up-to-date literature synthesis of the effects of 

fire on threatened and endangered plants. Kirby et al. (1988) provide a literature 

synthesis on the effects of fire on wetland ecosystems and fire-wildlife relations. The 

BNWR is also maintaining a comprehensive library of literature and other information to 

address this issue. 
27

Fire Effects on Human Communities 

The social and economic effects of fire on the human environment adjacent to these 

public lands must also be considered. People live, work, recreate, and have a personal 

interest in the public wildlands of Dorchester County. Winter marsh wildfires have been 

a historical occurrence in Dorchester County for decades, and will continue to be a 

feature of the regional landscape in the future. Since 1990, 12,345 and 53,470 acres have 

been burned by wildfires and prescribed fires, respectively. Most wildfires were humancaused (arson) fires in the winter, although wildfires (human- and lightning-caused) occur 

during all seasons (Gerald Vickers, pers. comm.). Many arson fires set in the marsh in 

the winter are deliberate attempts to improve furbearer trapping efficiency, but others 

appear to be simple arson, without motive. 

The harmful effects of fire on the human environment are many and varied, and include: 

direct (fire) and indirect (smoke) health and safety effects, personal property damages, 

and public use and recreation inconveniences. Citizens and firefighters are far too 

frequently killed or injured by wildfires. Wildland fire smoke has been attributed to 

highway accidents, and is a recognized human health risk. Personal property damage 

from wildfires is millions of dollars annually. Wildfires inconvenience thousands of 

people using public lands each year. 

Public policies are not only to manage fire to achieve land management objectives, but 

also to protect human life and property. This requires Federal and state agencies to 

address appropriate suppression actions for wildfires on or near agency lands. 

Appropriate suppression actions may include pressuppression activities (fuel reduction, 

education, law enforcement, etc.), as well as suppression strategies (contain, confine, and 

control). All of these actions are currently being used to some degree in Dorchester 

County. 

Despite the lack of good objective assessments as to the cost effectiveness of any of the 

presuppression actions, public land managers, fire control specialists, and law 

enforcement specialists have agreed that pre-season prescribed fire fuel reduction is 

probably the most cost effective technique for preventing wildfires. Comparative 

wildfire and prescribed fire costs for Region 5 of the U. S. Fish and Wildlife Service were 

$909 vs. $15 per acre per incident, respectively (Omi et al. 1995). The relationship 

between decreasing wildfires by increasing prescribed fire seems intuitively to exist, but 

analysis of existing data has not been able to demonstrate this link (Omi et al. 1995). 

Hazard fuel reduction prescribed fires can minimize adverse social effects (smoke and 

inconvenience) through proper scheduling and prescriptions. 

Alternatives to hazard fuel reduction prescribed fires, such as education and law 

enforcement, are far less effective. The public's values and attitudes concerning wildland 

fire policy are strong and not easily changed (Manfredo 1993). This is particularly true in 

an area where wildfires have been a common feature for many generations. The 

application of fire prevention campaigns such as Smokey Bear can be successful, but it 

has taken Smokey 50 years of work to achieve today's success. Law enforcement may be 
28

even less effective. Arson is one of the most difficult crimes to prove, and penalties for 

wildland arson crimes have little deterrent effect (Vernon Ricker, pers. comm.). 

Land management agencies and their cooperators currently are using a combination of all 

three suppression strategies to suppress wildfires. The suppression objective "... is to 

suppress wildfires at minimum cost consistent with values at risk while minimizing the 

impacts for the suppression activities" (U. S. Fish and Wildlife Service 1994:3.2-1). 

Which strategy is used where and under what conditions is determined through planning 

and public involvement. Through the sharing of resources, suppression costs can be 

minimized. The establishment of the Delmarva Fire Management Group has facilitated 

interagency planning and the sharing of resources (Carowan 1992). The interagency fire 

program infrastructure currently established in Dorchester County is the model currently 

being advocated by the wildland fire management community. 

Burning under exactly the same conditions, the ecological, social and economic effects of 

a wildfire or prescribed fire are indistinguishable. But because wildfires are unplanned, 

unscheduled and more poorly controlled events, the effects may or may not be desirable. 

However, prescribed fire - a managed event - can be planned and scheduled in order to 

produce specific effects. Through prescriptions and firing patterns, prescribed fire can be 

used to develop vertical and horizontal habitat structure and vegetation species 

composition targeted toward the habitat requirements of specific species. Undesirable 

effects can also be mitigated through scheduling and prescriptions. 

Fire Program Management 

A fire program of the MDNR and BNWR is no different than any other management 

program. It requires a good plan that is followed. The plan, in order to be effective, must 

be integrated into the general management plan for each agency, address cross boundary 

interests and have the informed consent of the public. The fire program must evolve with 

changing conditions and that requires an adaptive management structure where fire 

objectives are established, management actions taken, and outputs obtained and evaluated 

to determine if they achieved the objectives. If they do not, either the management action 

or the objective needs to be modified. Such a program requires sufficient resources 

(funding and qualified personnel) to do the planning, execute the management action, 

conduct the appropriate monitoring, and perform the evaluation. 
29

Literature Cited

Allen, D. L. 1962. Our Wildlife Legacy. Funk and Wagnalls, New York. 422p. 

BNWR. 1994. Annual trapping program 1994-95 - Blackwater NWR. U.S. Fish and 

Wildlife Service. Cambridge, Md. 6p. mimeo. 

Brower, J.A., L.N. May, Jr., A. Rosenthal, J.G. Gosselink, and R.H. Baumann. 1989. 

Modeling future trends in wetland loss and brown shrimp production in Louisiana using 

thematic mapper imagery. Remote Sensing of the Environment 28: 45-59. 

Carowan, G. A. Jr. 1993. Partnerships - making them work in times of limited resources, 

Fire Manage. Notes 53-54(2):23-24. 

Chabreck, R. H. 19__. Effects of burn date on regrowth rate of Scirpus Olney and 

Spartina Patens. 

Christensen, N. L. and R. B. Wilber. 1993. Short- and long-term effects of fire on 

vegetation and biogeochemical processes in Southeastern evergreen shrub bogs 

(Pocosins). Page 30, In Cerulean, S. I. and R. T. Engstrom eds., Proceedings 19th Tall 

Timbers Fire Ecology Conference, Tallahassee, FL. 175p. 

Cross, D. H. Wildlife habitat improvement by control of Phragmites communis with fire 

and herbicices. M.S. Thesis. Colorado State University, Fort Collins. 81p. 

Dozier, H. L., M. H. Mackley, and L. M. Llewellyn. 1948. Muskrat investigations on the 

Blackwater National Wildlife Refuge, Maryland, 1941-1945. J. Wildl. Manage. 

12(2):177-190. 

Fisher, W. C. 1989. The fire effects information system: a computerized encyclopedia of 

fire ecology. Pager 133-142. In 17th Tall Timbers Fire Ecology Conference. Tallahassee, 

Fl. 435p. 

Hackney, C. T. and A. A. de la Cruz. 1992. Effects of fire on brackish marsh 

communities: management implications. Pages 75-86. In Wetlands, M. C. Landin, ed. 

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31

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32

Appendix D: Presenters and Research Projects

Presenter Research Topic

Dr. Cecil Frost Pre-settlement vegetation 

N.C. Dept. of Agriculture and Consumer Services and fire frequency. 

Plant Industry Division 

P.O. Box 27647 

Raleigh, North Carolina 27611 

Dr. Glenn Guntenspergen Elevation monitoring and 

Natural Resources Research Institute wetland loss at Blackwater. 

5013 Miller Trunk Highway 

Duluth, Minnesota 55811 

Connie Flores Evaluation of vegetative 

Rocky Mtn. Research Station- response to fire exclusion 

Fire Sciences Laboratory and prescribed fire. 

5775 W. U.S. Hwy 10 

Missoula, Montana 59808 

Dr. Jill Rooth Effects of prescribed fire 

Horn Pt. Laboratory, UMCES on marsh elevation change. 

Box 775 

Cambridge, Maryland 21613 

Dr. Don Cahoon Prescribed marsh burning 

USGS/ Patuxent Wildlife Research Center enhances recovery of sedi11510 American Holly Dr. ment elevation from floodLaurel, Maryland 20708 induced peat collapse 

Dr. J. Court Stevenson Health and long term 

Horn Pt. Laboratory, UMCES stability of natural and 

Box 775 restored marshes in 

Cambridge, Maryland 21613 Chesapeake Bay 

Dr. Steve Gabrey Effects of winter burning 

N.W. State University of Louisiana on plant and bird comm.- 

Biology Dept. N.W. State Univ. unities. 

Natchitoches, Louisiana 71497 

Dr. Pete Marra Effects of prescribed burning 

SERC, P.O. Box 28 on secretive marsh birds. 

647 Contee Whart 

Edgewater, Maryland 21037 
33

Mike Legare Marsh bird response during 

Mattamuskeet NWR two prescribed burns. 

38 Mattamuskeet Rd. 

Swan Quarter, North Carolina 27885 

Dr. Curt Larson A LIDAR Inundation 

USGS/ Patuxent Wildlife Research Center Model for the Blackwater 

11510 American Holly Dr. National Wildlife Refuge. 

Laurel, Maryland 20708 

Dr. Stephen Ailstock Phragmites response to 

Ann Arundel C.C. Biology Dept. burning. 

101 College Parkway 

Arnold, Maryland 21012 
34

Appendix E: Summaries of Fire Science Conference on

November 13 and 14, 2003.

Author: Dr. Cecil Frost 

Title: Pre-settlement vegetation and fire frequency 

Summary: 

 Dr. Frost’s expertise is in mapping original fire regimes and pre-settlement 

vegetation. His talk focused on pre-settlement vegetation and landscape fire ecology. 

Dr. Frost examined 75 marsh communities from Back Bay, south to the Croatan National 

Forest in North Carolina, and he mapped pre-settlement fire regimes for several agencies. 

He studied species diversity as it relates to salinity and fire frequency. Dr. Frost stated 

that species diversity in marshes increases as salinity decreases and as fire frequency 

increases. 

 Dr. Frost stated that fire frequency in marsh habitat was related to fire 

compartment size on the adjacent uplands and to pathways for fire flow. Most marsh 

fires are ignited from fires in the adjacent uplands. He used the Venus flytrap to illustrate 

the relationship between fire compartment size and fire frequency. This plant, which dies 

out if mean fire frequency drops below four years, is found only in the largest fire 

compartments. This is an ancient species, long preceding the appearance of Native 

Americans on the scene, and is one of a number of fire frequency indicator species that 

help us map presettlement fire regimes. Dr. Frost examined lightning strike density on 

the Delmarva peninsula and determined that this area receives approximately 4 lightning 

strikes per square kilometer per year. Dr. Frost stated that it is highly unlikely that an 

annual fire regime existed in Dorchester County based on lightning ignition. 

Author: Dr. Glenn Guntenspurgen 

Title: Elevation monitoring and wetland loss at Blackwater 

Summary: 

 Dr. Guntenspergen’s presentation focused on elevation monitoring and wetland 

loss at Blackwater National Wildlife Refuge. He stated that the current rate of sea level 

rise at rates of 3-4 mm/ year is exceeding the sediment deposit rates of 1-2 mm/ year. He 

presented a flow chart depicting multiple variables that affect marsh elevation and 

dynamics, including rising sea level, tidal flooding, sedimentation, vertical accretion, soil 

volume, compaction/decomposition, changes in ground water, subsidence and plant 

processes. 

 Dr. Guntenspergen also displayed the Sediment Elevation Table (SET) that 

measures both surface and subsurface processes that may affect elevation. Dr. 

Guntenspurgen and others established this SET at 3 sites throughout Blackwater along an 

elevation gradient, not taking into consideration fire frequency. He suggested that local 

processes such as groundwater flux issues may be more of a contributing factor in land 

subsidence. Blackwater is a rapidly deteriorating system in which marsh surface 

elevation is not keeping pace with sea-level rise. The marsh is expanding up-slope, but 

breaking up as well. 
35

Author: Conception Flores 

Title: Evaluation of vegetative response to fire exclusion and prescribed 

 fire rotation on Blackwater National Wildlife Refuge and Fishing 

 Bay Wildlife Management Area. 

Summary: 

In 1998, Ms. Flores initiated a fire evaluation study on Blackwater National 

Wildlife Refuge (NWR) and Fishing Bay Wildlife Management Area (WMA) to compare 

the vegetative response of 2 fire rotations and fire exclusion at 6 tidal marsh areas. The 6 

marsh areas were divided into 2 treatment sites (annual burn and 3-year burn) and 2 

control sites (no burn). To provide an equal basis for comparisons, all sites (N=24) were 

initially burned in 1998. Ms. Flores collected vegetation data for percent cover, average 

height, biomass, and stem density at all sites, just after the growing season from 

September-December 1998-2001. Prescribed burns were conducted on the annual burn 

treatment areas from January-March 1998-2002. The 3-year treatment sites were burned 

once from January-March 2001. Ms. Flores conducted a macro-analysis of the overall 

cover, average height, total biomass, live biomass, litter and stem density data for all 

species and conducted species specific analysis for: Distichlis spicata, Juncus 

roemerianus, Schoenoplectus americanus, Spartina alterniflora, and Spartina patens. 

She found no significant difference for cover among the 2 treatment and the 2 control 

sites. However, she did find a difference among the years, with 2001 having the greatest 

cover and 2000 having the least cover. In 1999, a drought may have negatively affected 

the vegetation. Ms. Flores found significantly greater live biomass ( biomass without 

litter) in annual burn sites than the other sites. She analyzed litter separately and found 

significantly less litter among annual burn sites. For stem density, Ms. Flores found that 

the annual burn sites had significantly higher stem densities than the 3-year treatment or 

control sites. In addition, 1998 had significantly greater stem densities than the other 

years. In her macro-analysis (all species), Ms. Flores found that fire had a positive effect 

(increase) on cover biomass and stem density for Distichlis spicata, Spartina alterniflora

and Spartina patens and a negative effect (decrease) on litter. In her micro-analysis (only 

sites with ≥ 25% of the dominant species), Ms. Flores found that fire had a positive effect 

for Distichlis spicata and Spartina alterniflora biomass and stem density. Fire also 

increased Spartina patens stem densities. 

Author: Dr. Jill Rooth 

Title: Effects of prescribed fire on marsh elevation change 

Summary: 

 Dr. Rooth stated there are contradictory scientific findings relating the effect of 

prescribed fire on marsh vegetation. Therefore, it makes it difficult to determine how it 

would impact marshes under stress from a myriad of negative forcing functions such as 

sea-level rise. Within Chesapeake Bay, tidal marshes were historically burned for 

“renewal of vegetation”, to manage unwanted marsh plants (those perceived as not 

providing wildlife fodder or protection) and to promote trapper access during colder 

months. Marsh burning removes a considerable amount of accumulated litter that 

collects on the marsh surface during senescence each fall and winter. Subsequently, a 

reduction in total organic material near to or on top of the sediment surface reduces 

overall structural complexity of the wintering marsh community. It is that structural 
36

complexity that can reduce the velocity of the incoming tidal water, consequently causing 

sediment to deposit on top of the marsh. Mineral sediment deposition is critical to the 

survival of these highly organic systems that are undergoing rapid subsidence. Other 

forcing functions that are contributing to wetland loss of the NWR/WMA complex are 

regional sea-level rise, rodent herbivory, historic groundwater withdrawal, and salinity 

intrusion. 

Study results indicate that over three growing seasons, subsidence prevails at all sites, 

regardless of the annual burn or no burn treatment. The only significant contribution of 

accretion to the marshes during monitoring was from Hurricane Isabel in 2003. The 

fire’s removal of organic material both, in terms of lowering organic deposition and 

marsh surface complexity, appears not to be a factor controlling accretion in those areas 

annually burned. Rate of elevation change and accretion were more likely to vary with 

location then paired sites (annual burn versus no burn). This suggests the role of 

prescribed fire in short-term applications is not playing a decisive factor in the 

sustainability of marshes. Localized factors such as distance to sediment source and 

amount of inundation were immediately controlling the elevation of the study marshes. 

Although cause and effect would predicate that fire would have a role in elevation change 

there was no consistent evidence to suggest this was occurring. 

Author: Dr. Donald Cahoon 

Title: Prescribed marsh burning enhances recovery of sediment elevation 

 from flood induced peat collapse. 

Summary: 

 Summary findings of the presentation are excerpted from: 

Cahoon, D. R., M. A. Ford, and P. F. Hensel (2004), Ecogeomorphology of 

Spartina patens-Dominated Tidal Marshes: Soil Organic Matter Accumulation, 

Marsh Elevation Dynamics, and Disturbance, in The Ecogeomorphology of Tidal 

Marshes, Coastal Estuarine Stud., vol. 59, edited by S. Fagherazzi, M. Marani, 

and L. K. Blum, pp. 247–266, AGU, Washington, D. C. 

“Surface erosion and accretion processes contributed little if any to soil elevation 

changes during the death and subsequent recovery of the Spartina patens-dominated 

marsh. Instead, marsh elevation was controlled by soil (i.e., subsurface) organic matter 

accumulation dynamics, which were affected by plant mortality and prescribed burning. 

Elevation of the underlying marsh peat collapsed as a result of flood-induced mass plant 

mortality. Following the peat collapse, recovery of elevation was related to increases in 

the volume of organic material in the root zone, and burning enhanced the volume of 

organic material and the rate of elevation recovery. How burning affected soil organic 

matter volume is not clear. Burning of the dead marsh substrate may have increased root 

production through enhanced plant colonization of the highly disturbed substrate, which 

is in direct contrast to findings by Gabrey and Afton [2001] and Schmitz [2000] where 

burning of healthy marshes did not affect belowground production. On the other hand, 

the effects of burning on soil decomposition processes cannot be overlooked. Burning 

may have limited the colonization of the substrate by soil fungi by removing the plant 

canopy.” 
37

“From a management perspective, it is important to understand how disturbance affects 

soil organic matter accumulation and marsh elevation so that appropriate management 

practices can be developed. We know that lethal stresses on S. patens can lead to peat 

collapse. But we need to better understand the effect of sub-lethal stress from chronic 

low levels of disturbance (e.g., flooding, grazing, and burning), and the interactive effect 

of multiple stressors (e.g., sea-level rise and burning), on soil organic matter 

accumulation and marsh soil elevation change. For individual sub-lethal stresses, such as 

prescribed burning, we need to understand the extent and intensity of its impact on the 

relationship between soil organic matter accumulation and soil elevation. For example, 

does the rapid re-mineralization of plant matter caused by burning act like a fertilizer and 

enhance soil organic matter? Data from healthy marshes suggests it does not [Gabrey 

and Afton, 2001; Schmitz, 2000], but our data from an acutely stressed marsh suggests it 

does. If re-mineralization by burning enhances soil organic matter, will the soil nutrient 

supply become depleted and limit soil organic matter accumulation if the marsh is burned 

every year? The typical burning frequency for S. patens marshes in Louisiana and Texas 

is approximately every 3 years [Nyman and Chabreck, 1995], compared to an annual 

burning frequency at Blackwater National Wildlife Refuge in Chesapeake Bay [Flores, 

2003]. What is the fire frequency that will maximize soil organic matter accumulation 

and marsh soil elevation?” 

Author: Dr. J. Court Stevenson 

Title: Health and long term stability of natural and restored 

 Marshes in Chesapeake Bay. 

Summary: 

 The health and long term stability of natural and restored marshes in Chesapeake 

Bay. Relative sea level is rising in the Chesapeake Bay. This can be balanced by 

sediment/organic accretion in healthy marshes. Blackwater NWR is a low productivity 

marsh. Dr. Stevenson adds that marsh burning promotes S. americanus which promotes 

grazing. “Burning should be done on a more limited and experimental basis” 

The sediment budget for the Blackwater river has output exceeding input. Dr. Stevenson 

created cosms for conducting various marsh experiments, including burning. He 

emphasized that we should not conduct spring burns. (note: The refuge does not conduct 

spring burns in the marsh) His burning in the cosms showed that S. americanus

responded with enhanced productivity. Dr. Stevenson also emphasized the need to 

measure below ground biomass as well as above ground. He determined there was not 

much difference in nitrogen amounts in the burn vs no burn areas. A big problem with 

BWR marshes is that they suffer from anoxia. Blackwater embayments go completely 

anoxic in the water column in the summer. He also added that phragmites can double 

sediment accretion. Dr. Stevenson also said that the problem with winter fire is that it 

encourages S. americanus at the expense of other non-fire adapted plant species (which 

can aerate and hold sediment in place). 
38

Author: Dr. Steve Gabrey 

Title: Effects of winter burning on plant and bird communities. 

Summary: 

 Burning in Louisiana marshes, managing for snow geese habitat. The goal at 

Rockefeller NWR was to remove Spartina patens and replace with Schoenoplectus 

americanus. The experiment looked at whether or not snow geese prefer burned or 

unburned marsh. 

Dr. Gabrey discovered that burning only plays a part in determining vegetation 

communities. Salinity and flooding regime were equally as important. S. patens perks 

up 1.5 years after burning, however, there was no change in species or composition. 

There was a decrease in biomass for the first 2 years. 

The study also looked at smaller birds, such as blackbirds and grackles, marsh 

wrens and sparrows. It was discovered that during the winter period 2 months post burn, 

blackbirds and grackles liked burned areas and marshwrens and sparrows did not. 

However, 1 year post burn wrens and sparrows densities were the same as pre-burn. 

During a post summer burn 6 month survey, densities decreased. One and a half years 

later though, the densities more than doubled. It appears that the impacts to the wrens 

and sparrows last about 1 year. 

Author: Dr. Pete Marra 

Title: Effects of prescribed burning on secretive marsh birds. 

Summary: 

 Effects of prescribed burning on secretive marsh birds. Seaside sparrows and 

coastal plain swamp sparrows. Does prescribed burning impact non-breeding season bird 

density? Does prescribed burning impact breeding season bird density? Dr. Marra 

looked at nest predation rates in natural and artificial nests, reproductive success and 

annual return rates. Dr. Marra felt it was unfortunate how the sites were selected, as they 

were not replicate of each other. He looked at annual and no burn sites on Fishing Bay 

Wildlife Management Area. He asked the question, “does prescribed burning influence 

wintering bird communities?” There is no evidence of depauperate communities. 

”This is the time to burn”. Dr. Marra also examined whether or not there is an impact 

from prescribed burning on breeding marsh bird density. He concluded there was not 

much difference in species richness and diversity. 

Dr. Marra also examined the influences that prescribed burning has on 

reproductive success and annual survival. He studied the seaside sparrow because there 

are plenty available to study. Some of the causes of failure include predation and 

flooding. He also asked the question, “does burning influence nest predation?”. He 

found that in 2002 burning had a significant effect on predation of nests. He also 

reminded everyone of the extreme drought throughout the state in 2002. In 2003, there 

was no effect on the nests from predation, possibly as a result of an extremely wet year. 

Dr. Marra found that the greatest number of predators were small mammals, and artificial 

nests results were similar to natural nests. He felt that before we draw any conclusions, 

we need more years of data. Based upon what data he has examined, there does not 

appear to be a difference between burned and unburned areas. The clutch size and fledge 

rates were equal. The nest predation was higher on burn sites during incubation, but the 

total number of young fledged was higher on burn sites. He feels that more years on 
39

reproductive success and annual survival are needed. Along with small mammal 

surveys, food sampling and consistent monitoring. 

Author: Mike Legare 

Title: Marsh bird response during two prescribed burns. 

Summary: 

 Mr. LeGare’s presentation was from an operational experience of how prescribed 

burns are conducted in Florida. Mike’s interest is in Black Rails, which has adapted to a 

fire-dependent species. The three main reasons burns are conducted in Florida are hazard 

fuel reduction, ecological burning and ecosystem management. Firefighters want to see 

“clean burns”, with no unburned patches of fuel. Mr. LeGare is saying it’s important to 

leave even small, unburned patches that the black rails could hide in. Contrary to popular 

belief, these birds do not just fly away when the fire approaches. They tend to stay close 

to the ground and hide and let the fire pass. This struggle between burning for resource 

value, i.e. birds, etc. conflicts with the firefighters goal to burn quickly, cleanly and 

operationally safely to manage for smoke issues is where the challenge lies. (note: 

Blackwater and Fishing Bay prescribed fire goals are to produce a mosaic of burned vs. 

unburned) 

Author: Dr. Curt Larson 

Title: A LIDAR Inundation Model for the Blackwater NWR 

Summary: 

 LIDAR sea inundation model for Blackwater. Dr. Larson produced a photo of a 

map from 1877 that showed the area that is now BWR, mostly forested. 

Blackwater has no source of incoming sediment other than adjacent uplands which 

provide little sediment, thus the refuge is being drowned. 

Inundation of a preexisting land surface is the dominant natural process affecting 

the refuge. Blackwater did not become a marsh until the 20th century. Dr. Larson 

presented several scenarios projecting sea level rise. In his “business as usual” scenario, 

the long term trend of sea level rise will continue at a current rate of 3.1 mm/yr. The 

lidar shows an increase in the area of open water that is relatively constant until about 

2050 when open water shows a marked increase. This is due to topographic influences. 

The intertidal marsh area increases continually in keeping with the open water. It 

expands after 2050. Sea level overruns the existing landforms after 2050 and high marsh 

begins a major decline. Dr. Larson also presented a “global warming” scenario. With 

sea level rise, the rate of inundation will be much more rapid. Much of the refuge will be 

covered by open water by 2100. 

Author: Dr. Stephen Ailstock 

Title: Phragmites response to burning 

Summary: 

 Dr. Ailstock examined fire as an element of phragmites control program, and fire 

as a promoter of phragmites recruitment. Dr. Ailstock manages phragmites for national 

security. He keeps it in check in areas where line of sight to potential targets is an issue. 

Dr. Ailstock stated that litter is a very important thing for plants, and that phragmites is a 

self mulching plant. It creates a lot of micro-climates which encourages diversity. To 
40

treat phragmites, we need to combine spraying (rodeo) with burning. Phragmites 

produces abundant seeds and also spreads through rhizomes. Seeds that land on bare soil 

do very well. Seeds that land on plants, or water, do not. He asked the question, “are we 

creating a good host by burning the phragmites?” 
41

Appendix E: 

Review of Fire Management Programs for 

Fishing Bay Wildlife Management Area 

and 

Blackwater National Wildlife Refuge 

conducted for 

U.S. Fish and Wildlife Service and Maryland Department of Natural 

Resources

by 

Dr. Donald F. Boesch, Mr. Willard P. Leenhouts, Dr. Douglas A. Samson, 

and Dr. Edward C. Soutiere 

April 2004 

Introduction 

In April 1996 a Panel of five scientific experts was convened to review fire 

management practices at the Blackwater National Wildlife Refuge (BNWR) and adjacent 

wetland areas managed by the Maryland Department of Natural Resources, particularly 

the Fishing Bay Wildlife Management Area (FBWMA). These areas are located along 

the Eastern Shore of the Chesapeake Bay. The Panel’s report1

 evaluated existing 

practices at the Refuge and nearby management areas and specifically considered six 

possible fire management alternatives. The Panel concluded that the technical basis to 

support fire management and prescribed burns then practiced was inadequate and 

recommended the Multiple-Objective Prescribed Fire Regime as preferred among the 

possible management alternatives in order to best achieve the agencies’ ecological land 

management objectives while meeting their social responsibilities. Because of the 

general lack of technical evidence concerning the efficacy of fire management, the Panel 

further recommended that adaptive management, coupled with active monitoring and 

long-term research and assessment, be applied to guide changes in management 

objectives and actions in the future. 

While the agencies indicate they have followed the Multiple-Objective Prescribed 

Fire Regime “exceptionally well,” they felt it was necessary to reconvene the Panel to 

review whether the results of monitoring and research efforts demonstrate that this 

management plan is achieving the desired results. Accordingly, four of the original 

members of the Panel (one member was prevented from attending by illness) reconvened 

 

1 Technical Review of Fire Management Alternatives in the Blackwater National Wildlife Refuge and 

Adjacent Wetland Management Areas, April 1996, U.S. Fish and Wildlife Service. 
42

on November 13 and 14, 2003, at the Horn Point Laboratory of the University of 

Maryland Center for Environmental Science near Cambridge to review new information 

related to the use of prescribed fire in this and similar ecosystems. The members and 

institutional affiliations of the Panel members are provided in Appendix 1. 

The Panel was asked to prepare a report that either reconfirms, modifies, or 

replaces the original recommendations and identifies and prioritizes future research 

needs. The Panel was also given a long list of questions to consider, which were grouped 

under five technical issues: 

A. The current prescribed fire program does/does not consider natural burn 

cycles in achieving management objectives. 

B. The current prescribed fire program is/is not adversely affecting vertical 

accretion, above and below ground biomass, and species of conservation 

concern. 

C. The current prescribed fire program does/does not consider differing fire 

frequencies by community type. 

D. The multiple-objective prescribed fire management regimes do/do not 

contribute to invasion of exotic species (nutria, Phragmites, etc.). 

E. Conversion of marsh to open water will/will not continue irrespective of 

the use of fire. 

The overarching conclusions and recommendations are first presented and the 

specific consideration of these five technical issues evaluated in greater detail. 

Overarching Conclusions and Recommendations 

 The Panel was specifically asked to make recommendations either to reconfirm, 

modify, or replace the originally recommended Multiple-Objective Prescribed Fire 

Regime. After considering the above specific consideration of the five issues, we found 

that: 

a. The current program was designed to address 22 specific management objectives, 

not to mimic natural burn cycles. To do this would require a very different 

prescribed fire program2

. However, marsh vegetation community types and their 

natural fire regimes should be considered when establishing burning frequencies 

under the multiple-objective fire regime approach. 

b. Based on the existing evidence it cannot be confidently concluded that the 

prescribed fire programs at BNWR and FBWMA are having either a positive or 

negative effect on soil accretion or loss and the rate of conversion of marsh to 

open water. A definitive understanding of the role of fire in marsh soil accretion 

 

2

 Robbins, L. E. and R. L. Myers. 1992. Seasonal effects of prescribed burning in Florida: a review. Tall 

Timbers Research, Inc. Misc. Publ. No. 8. 96pp. 
43

will probably require a comprehensive, long-term, well-funded research and 

assessment commitment. 

c. The management agencies have only modestly quantified the effects of the fire 

management program on species of conservation concern or invasion of exotic 

species. 

Having said that, we have no basis for recommending changes in the management 

regime at this time. Quite honestly, though, we are less confident in supporting this 

regime than we were in 1996 because we have learned relatively little over the past eight 

years other than that the issues are much more complex, questions much more difficult to 

answer, and management implications much more diverse then originally thought. 

Consequently, it is impossible to judge whether the multiple, complexly related 

objectives of the regime are being achieved. We are disappointed that the agencies have 

failed—or been unable—to obtain sufficient funding and support to implement the 

Panel’s additional recommendation to institute an effective adaptive management 

program, one which integrates active monitoring, and long-term research and assessment, 

in order to guide changes in management objectives and actions in the future. 

The refuges encompass the most extensive tidal wetlands in the heart of the 

Chesapeake Bay, the largest estuary in the United States, which is itself the subject of an 

expensive and internationally prominent restoration and management program. The 

Panel believes that this justifies a much greater investment in strategic research, 

monitoring and assessment, which should focus on two priority issues: 

1. The effects of fire frequency and other processes subject to management 

intervention on the sustainability of this valuable wetland ecosystem, particularly 

plant community dynamics and their effects on marsh accretion in the face of 

rising sea level. 

2. The consequences of fire frequency on species of special conservation concern, 

including seaside sparrows, wintering waterfowl, forest interior-dwelling species, 

and the endangered Delmarva fox squirrel. 

The Panel believes that research related to plant communities (species composition, 

community structure, above and below-ground production, detrital exchange, and nutrient 

cycling) is important only in so far as it helps resolve the central questions of wetland 

sustainability and habitat suitability for species of special concern. Furthermore, research 

related to animal populations other than those of special concern is of much lower 

priority. 

Evaluation of Specific Issues 

Issue A: The current prescribed fire does/does not consider natural burn cycles in 

achieving management objectives.
44

The original charge of the panel in 1995 was to provide fire management 

recommendations to BNWR and FBWMA to incorporate 22 management objectives, 

none of which were to mimic natural burn cycles. Implementing a natural fire regime 

was not one of the six alternatives evaluated by the panel. The multiple-objective 

prescribed fire regime alternative provided BNWR and FBWMA the opportunity to 

accomplish many if not most of its 22 management objectives. Burning to reduce 

hazardous fuel conditions (to protect private property, sensitive species, or both), to 

promote rare, threatened and endangered species, and to enhance habitat for wildlife 

species, all represent legitimate and/or mandatory management objectives that may be 

mutually exclusive of the application of natural burn cycles (or our best approximation 

thereof), over large portions of the managed landscape. Said differently, even if our 

knowledge of pre-settlement fire frequencies, seasonality and average magnitude was 

perfect and complete, mimicking those patterns with prescribed burning would only be 

appropriate in those portions of the marsh not subject to management for other objectives. 

Having acknowledged that, it was observed that the current prescribed fire 

program at BNWR and FBWMA does not mimic natural burn cycles, for several reasons. 

First, “natural” burn cycles—that is, long-term average fire frequencies (or firereturn intervals) for both upland and marsh habitats in southern Dorchester County prior 

to European colonization (including both wildfires and fires set by Native Americans), 

are unknown. Frost3 suggested that pre-settlement fire frequencies in this part of 

Maryland were 4 to 6 years, based on his review of fire history studies and analysis of 

fire compartment size, as interpreted from land surface form maps. But the scale of his 

analysis fails to discriminate between upland and marsh habitats, much less between 

different vegetative communities in the marsh. Work done by Frost in marshes farther 

south along the Atlantic (Virginia, North and South Carolina) suggests that pre-settlement 

fire frequencies for oligohaline and brackish marshes were 1 to 5 and 4 to 6 years, 

respectively4. But no similar analyses have been done for marshes on the Eastern Shore 

of Maryland, so the effects that local compartment size, prevailing winds, nearby water 

bodies (e.g., Chesapeake Bay), etc., might have had on natural fire frequencies have not 

been examined. Further, the history of Native American use of tidal habitats in 

Dorchester County, and whether or not fire was used to manage marsh communities, is 

unknown. The limited anecdotal information available on the frequency of “natural” 

(i.e., lightning-caused) wildfires in Dorchester County marshes today suggests a much 

longer fire return interval, but because vegetative cover is likely to be significantly 

different now than in pre-settlement times, such observations are difficult to interpret. 

 Second, the location of treatment areas where current burn regimes (annual, 3 to 5 

years, 7 to10 years and no-burn) are being applied to marsh habitats at BNWR and 

 

3

 Frost, C.C. 1998. Presettlement fire frequency regimes of the United States: a first approximation. Tall 

Timbers Fire Ecology Conference Proceedings 20: 70-81. 4

 Frost, C.C. 1995. Presettlement fire regimes in southeastern marshes, peatlands and swamps. Tall 

Timbers Fire Ecology Conference Proceedings 19: 39-60. 

Frost. C.C. 1996. Presettlement Vegetation of the Croatan National Forest, North Carolina. Report to 

the U.S. Department of Agriculture Forest Service, Croatan Ranger District, New Bern, NC. 
45

FBWMA were apparently selected for reasons of accessibility, logistics (e.g., 

arrangement of natural fire breaks), and other considerations (e.g., presence/absence of 

sensitive species), rather than because it was determined that those areas were subjected 

to particular fire-return intervals pre-settlement. Thus, there is no deliberate 

correspondence between different marsh community types and prescribed burn 

frequencies (see also separate discussion of Issue C), and a given marsh community type 

is subjected to different burn regimes in different areas of BNWR and FBWMA. 

 Third, even with a management approach that includes multiple burn treatments, 

this burn regime is unlikely to closely mimic pre-settlement natural cycles, because: 

1. The seasonality of burning is likely to be different now than under pre-settlement 

conditions. Local climate patterns are such that lightning-ignited wildfires were 

probably most frequent in summer and fall, rather than winter, when most of the 

current prescribed burning is done. Nothing is known about the seasonality of 

Native American marsh burning, if it happened at all. 

2. Under pre-settlement conditions, we would expect a frequency distribution of 

return intervals for wildfires started by natural ignition events. That is, while a 

given section of marsh might have burned on average, say, every six years, some 

areas would have burned annually and some only once every 15 to 20 years. 

Applying fire repeatedly to a treatment area at a set interval, even when it 

approximates what we think the average pre-settlement fire-return interval might 

have been, minimizes the temporal variation in the occurrence of fire that likely 

characterized the region pre-colonization. 

3. Similarly, the amount (acreage) of marsh burned during any one fire under presettlement conditions likely varied dramatically within and among years and 

across the local landscape. This variation—from a few acres to thousands of 

acres, depending on circumstances—is presumed to have had significant effects 

on the population dynamics of both resident and migratory animal species—at all 

trophic levels—using the marsh. Ironically, deliberately not burning sections of 

the marsh at all, and/or suppressing any wildfires that might get started in 

designated “no-burn” zones, likely creates “artificial” conditions relative to what 

would have prevailed in pre-settlement times, when presumably most or all of the 

marsh would have burned at some frequency. 

Fourth and finally, social and political restrictions (e.g., public safety and human 

property protection, air quality issues, concerns of nesting season burning killing young 

animals in nests, etc.) limit many of the extreme and ecologically important prescriptions 

necessary to mimic natural fires (e.g., a high intensity wind-driven fire during drought 

conditions which occasionally occurs could not be risked today). 

Not being able to implement a natural fire regime does not mean that the 

knowledge of historic fire regimes is not important. Studies such as those done by Frost 

and others carried out in southern Dorchester County would improve our understanding 

of pre-settlement fire regimes in this region. This information will be quite useful in 
46

understanding and identifying the fire regimes needed to achieve BNWR and FBWMA 

management objectives. 

Determining a natural fire cycle is fraught with much uncertainty. To begin to 

empirically demonstrate “natural burn cycles” for Blackwater and Fishing Bay, a large 

(5-10,000 ac?) area with no prescribed burning would need to be set aside, and the 

frequency and extent of naturally-ignited fires would need to be recorded over a time 

period (15-20 yrs?) long enough to allow vegetation communities approximating presettlement conditions to become reestablished. Unfortunately, the history of Native 

American use of the marshes, and how that use may or may not have altered natural burn 

cycles, may never be known. Thus, even if empirical data on wildfires and natural burn 

cycles were collected, they will provide an incomplete picture of the burn cycles and 

patterns that would have structured marsh communities pre-settlement. 

 The current prescribed burn program at BNWR and FBWMA is using an overall 

burn regime that represents an approximation of what average natural burn cycles might 

have been pre-settlement, based on best available knowledge. But the current knowledge 

base is minimal, especially for southern Dorchester County, and the prescribed burn 

treatments in use likely differ from pre-settlement cycles in their seasonality, their 

variation in time and space, and in the degree to which different return intervals 

correspond to different vegetative community types. Given its significance as one of the 

dominant ecological processes in these marsh communities, this means that fire is likely 

affecting native plant and animal populations quite differently now than in pre-settlement 

times. 

To make assessment of this issue even more difficult, this entire question is 

rendered moot—at least for the area currently occupied by BNWR and FBWMA—if it 

turns out that marsh communities prior to 1500 covered significantly less area than in the 

last 200 years. That is, if the vast expanses of tidal marshes in southern Dorchester 

County have developed with sea level rise and land subsidence only in the last two 

centuries or less (for which there is some evidence), there were no “natural burn cycles” 

for marsh communities pre-settlement. Or they were quite different, given that the 

vegetative landscape mosaic would have been very different. At the same time, however, 

tidal marsh communities no doubt covered thousands of acres elsewhere around the 

Chesapeake Bay pre-settlement. So if periodic wildfires are presumed to have been an 

important natural disturbance process in those communities historically, the question 

remains relevant, but on a regional rather than site level. 

Issue B: The current prescribed fire program is/is not adversely affecting vertical 

accretion, above and below ground biomass, and species of conservation concern. 

 When the Panel reviewed fire management alternatives in 1996, it was presented 

with conflicting evidence and opinions about whether periodic burning negatively or 

positively affected the longevity of tidal marshes in a rapidly subsiding environment, 

such as at the BNWR and FBWMA. On one hand, it was argued that fire consumed the 

vascular plant detritus originating from aboveground production that is essential to soil 
47

building in a subsiding wetland that is starved of mineral sediment sources. On the other, 

it was argued that burning increased belowground production through fertilization and 

other effects, thereby increasing the volume of roots and rhizomes and related organic 

detritus in the soil. 

 Several studies on the effects of burning on Blackwater marshes have been 

conducted in the intervening years. These have produced mixed and generally 

inconclusive results with regard to addressing Issue B. One study found that while 

burning increased stem density and aboveground biomass, it also reduced plant litter on 

the marsh surface.5 Another found no consistent differences in soil elevation between 

matched burned and unburned sites6. In some cases burned sites showed more or less 

elevation change and soil accretion, but this was largely attributable to differences 

between control and treatment plots, for example whether the site was affected by nutria 

disturbance. Recent USGS studies of changes in marsh elevation at Blackwater have also 

not demonstrated any effect of burning on soil volume and sediment elevation similar to 

those observed in Texas Gulf Coast marshes, where burning enhanced the recovery of 

sediment elevation from flood-induced peat collapse.7

 

 The results of the studies on marsh health and soil accretion did not fully address 

the Panel’s earlier questions regarding the long-term effects of burning on the marsh 

itself, a key issue for judging the wisdom and sustainability of prescribed burning. The 

studies thus far have been either modest in scope; limited by designs that did not 

adequately take into account small-scale variability; very late in coming, or not 

adequately funded to undertake the comprehensive (expensive) analysis needed to 

effectively answer this quite difficult and complex issue. We are left with virtually the 

same uncertainty that existed in 1996 with regard to this most important issue. 

The effects of the current prescribed fire program on species of conservation 

concern are addressed under Issue C. 

Issue C: The current prescribed fire program does/does not consider differing fire 

frequencies by community type.

The current prescribed fire program at BNWR and FBWMA does not specifically 

adjust fire frequency to individual community types. That is, as discussed under Issue A, 

there is no deliberate correspondence between different marsh community types and 

prescribed burn frequencies. Rather, the program is an accommodation to Department of 

Interior policies, practical on-the-ground limitations imposed by considerations for 

safety, accessibility, logistics, and resource management objectives, and, finally, by the 

 

5

 Flores, C. 2003. Evaluation of Vegetative Responses to Fire Exclusion and Prescribed Fire Rotation on 

Blackwater National Wildlife Refuge and Fishing Bay Wildlife Management Area. M.S. Thesis, University 

of Maryland Eastern Shore, Princess Anne, MD. 

6

 Rooth, J.E. 2003. To Burn or Not to Burn... The Effect of Prescribed Fire on Marsh Elevation Change. 

Report to Blackwater National Wildlife Refuge. 

7

 Guntenspergen, G. Presentation to the Panel, November 13, 2003. Cahoon, D.R. Presentation to the 

Panel, November 13, 2003. 
48

recommendations made by the 1996 panel regarding a multiple-objective prescribed fire 

regime. 

As dictated by Department of Interior policies, fire protection and management 

priorities require BNWR to protect life and health first, property and natural/cultural 

resources second. Should it become necessary to prioritize between property and 

natural/cultural resources, the refuge must prioritize based on relative values to be 

protected, commensurate with fire management costs. It was because BNWR integrated 

prescribed fire into its management plans on a landscape scale, and not on a community 

scale, that the 1996 panel recommended the multiple-objective regime with the goal of 

meeting the needs of the varied plant and animal communities. Before 1996 

approximately 30,700 of the 31,300 acres of marshlands within the BNWR and FBWMA 

were burned annually. The current prescribed burn rotations are as follows: 9,300 acres 

annual, of which 5,600 are for hazardous fuel reduction; 6,300 acres, 3-5 years; 5.700 

acres, 7-10 years; and 10,000 acres, no burning. 

As discussed under Issue A, the available evidence suggests that the plant and 

animal communities dominating the Maryland Eastern Shore developed under a natural 

fire regime of fires on a frequency of 4 to 6 years, although the burn frequency for tidal 

marshes is less well known. Studies on the effects of fire on bird species found that 

different species utilize different habitat niches. For example, fewer black rails and 

seaside sparrows but more grackles and Eastern meadowlarks use areas that are annually 

burned8. Since there is a special concern for black rails and seaside sparrows on the 

refuge, which seem to do best under fire frequencies of 3 to 5 years, burning on that 

frequency, which is more in line with the natural fire regime, would favor the species of 

special concern over those more adapted to annual fire regime habitats. 

BNWR has had as a goal of their fire program the promotion of the three-square 

bulrush (Schoenoplectus americanus) community. Study results are mixed. Some 

studies found that burning increased above ground live-stem density and live-biomass, 

but recent studies at Blackwater found no such effect9

. Salinity and elevation appear to 

be the dominant factors determining the presence or absence of three-square bulrush. 

Burning can potentially give three-square bulrush an early start during the growing 

season, permitting it to out compete smooth and meadow marshhay cordgrass, but 

burning alone will not maintain the species and should not be substituted for necessary 

water levels and salinities in the management of this species or any other coastal 

species10. 

 

8

 Kirby, R. E. 1988. Fire in North American wetland ecosystems and fire – wildlife relations: an annotated 

bibliography. U.S. Fish and Wildl. Serv., Biol. Rep. 88(1),. 146 pp. 9

 Flores, C. 2003. op. cit. 

10 Chabreck, R.H.. 1976. Management of wetlands for wildlife habitat improvement. Pages 226-233 in M. 

Wiley, ed. Estuarine precesses. Vol. I. Uses, stresses, and adaptation to the estuary. Academic Press, New 

York. 

Nyman, J. A. and R. H. Chabreck. 1995. Fire in coastal marshes: history and recent concerns. Pages 34-141 

in S. I. Cerulean and R. T. Engstrum, eds. Fire in wetlands: a management perspective. Proc. Of the Tall 

Timbers Fire Ecol. Conf. No. 19. Tall Timbers Research Station,Tallahassee, FL. 
49

The experimental study plots set up to determine the effects of fire frequency on 

plant and animal communities on BNWR had significant shortcomings. The plant 

communities differ too greatly between the Blackwater River plots and the Fishing Bay 

plot to effectively serve as paired plots in a research design. If feasible, the Refuge 

should lay out a second set of plots to be paired with each site. 

Issue D: The multiple-objective prescribed fire management regime does/does not 

contribute to invasion of exotic species (nutria, Phragmites, etc.).

As discussed under Issue A, fire is an important part of the ecology of Maryland’s 

Eastern Shore. And while Native Americans and early European settlers burned the 

marshes to improve wildlife food production and facilitate furbearer harvest, fire has 

been excluded from almost all upland plant communities. However, marsh burning 

continues as planned prescribed fire and/or unplanned and unwanted arson fires. 

Fire is a classic disturbance agent. It changes ecosystems, community, and 

population structure, either by selectively favoring certain species or creating conditions 

for new species to invade. It usually favors early successional species, but can sometimes 

accelerate succession in favor of late successional species. It usually increases mineral 

elements and temporarily reduces total site nitrogen while at the same time increasing 

available nitrogen. The physical environment is also altered. Such effects are specific to 

the fire, fire regime, ecosystem and individual plant and animal species.11 Since many 

exotic species are adapted to disturbance, the risk of creating a favorable environment for 

an exotic invader and exacerbating the impact of an existing exotic species increases as 

the disturbance regime becomes more frequent and/or severe (irrespective of whether the 

disturbance is a planned prescribed fire or a unplanned and unwanted arson fire). 

At Blackwater National Wildlife Refuge (NWR) two exotic species are of greatest 

interest: nutria, Myocastor coypus, and the common reed, Phragmites australis. 

However, other invasive species are also of concern, especially if fire is reintroduced 

into the upland plant communities (e.g., multiflora rose, Rosa multiflora; common 

buckthorn, Rhamnus cathartica; Asian honeysuckles, Lonicera spp.; Japanese barberry, 

Berberis thunbergii; Scotch broom, Cytisus scoparius, and Japanese stiltgrass,

Microstegium vimineum). 

Nutria. Willner et al.12 found that three-square bulrush, Schoenoplectus americanus,

roots were a preferred nutria food, comprising nearly 80 percent of its diet. While they 

found that Schoenoplectus increased in cover following burning and was out competed by 

other species without periodic fire, more recent studies have yielded no evidence that fire 

at the BNWR is maintaining or increasing the coverage of three-square bulrush (as 

discussed under Issue C, above). If frequent fire did increase Schoenoplectus cover, 

using fire to increase a preferred food source of a desired species such as muskrat, could 

 

11 Agee, J. K. 1993. Fire Ecology of Pacific Northwest Forest. Island Press. Washington, DC. 491p. 12 Willner, G. R., J. A. Chapman, D. Pursley. 1979. Reproduction, physiological responses, food habits, and 

abundance of nutria on Maryland marshes. Wildl. Monographs. 65:1-43. 
50

have the unintended effect of increasing populations of destructive nutria as well. 

Greater nutria populations increase nutria feeding and marsh disturbance and possibly 

marsh deterioration. In the 1996 Panel review, the destructive effects of nutria feeding 

activities on the marshes were a major concern. It was suggested that these effects 

overwhelmed any effects of fire management. By 2003 nutria populations have been 

considerably reduced, in large part as a result of aggressive eradication efforts. This 

experience indicates that burning is at most a secondary consideration with regard to 

management of this invasive rodent, and that direct population controls will be required 

in any case. 

Phragmites Most fires favor Phragmites. Fire removes the standing dead canes and 

accumulated litter, allowing the soil to warm up rapidly in the spring, which results in 

earlier shoot emergence. Stands burned during the spring (before shoot emergence or 

during early growth stages), late summer or fall (plants green or dormant), or winter 

recover quickly; preburn stem density and biomass are attained within one growing 

season. Although plants burned during the summer usually initiate new top-growth 

within a few days, stem density is greatly reduced, and stems regrow to only about half of 

normal height before killing frosts occur. Furthermore, early to midsummer burning 

during the peak of plant growth (when carbohydrate reserves are lowest) reduces stem 

density and aboveground biomass for two to four growing seasons.13 In addition to 

rhizomatous growth and reproduction, Phragmites reproduces successfully by seed 

especially if the seed falls on moist, bare mineral soil (i.e., a burned marsh where litter is 

removed). Since burning under high litter moisture content or a flooded marsh can 

reduce or eliminate litter consumption, prescribed fires may be preferable to wildfires in 

preventing or retarding Phragmites invasion or expansion. 

Other species. Among invasive plant species, root total non-structural carbohydrate 

(TNC) level of a plant is a key indicator of their potential proliferation.14 Both cutting 

and burning treatments impact root TNC levels, but growing season treatments had the 

greatest multiple-year impact. Multiple treatments (cutting and burning) appear to 

prevent recovery of root TNC to pre-treatment levels for at least two years. The 

implications are that the timing of disturbances may be even more important than the type 

of activity (cutting versus burning). To have the greatest success at reducing woody 

stems, a treatment should be conducted during periods of low below-ground carbohydrate 

storage (such as immediately after spring flushing and growth) and should be followed 

with a second growing season treatment before root TNC levels are replenished. The 

timing of prescribed fire and/or mechanical treatments should be planned appropriately to 

take advantage of this physiological phenomena. 

The multiple-objective prescribed fire management regime, in conjunction with 

specific management prescriptions (e.g., litter moisture levels) provides the greatest 

 

13 Uchytil, Ronald J. 1992. Phragmites australis. In: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Research Station, Fire Sciences Laboratory (2003, October). Fire Effects Information 

System, [Online]. Available: http://www.fs.fed.us/database/feis/. 

14 Richburg, J. A. and W. A. Patterson III. 2001. Fire and invasive plants in the Northeastern United States. 

http://www.fs.fed.us/ne/durham/4155/fire/dibble1_jfsp.html#top
51

flexibility to tailor a fire (disturbance) regime that can address the particular exotic 

species issue(s) of interest. The U.S. Fish and Wildlife Service requires every National 

Wildlife Refuge develop a Habitat Management Plan (HMP). It is the HMP where exotic 

species’ concerns are identified, management conflicts reconciled, habitat goals and 

objectives identified, and habitat management strategies developed, including the 

appropriate disturbance regime (location, timing, frequency, and intensity parameters). 

The HMP integrates fire management into overall refuge management and should be 

developed as soon as possible. 

Issue E: Conversion of marsh to open water will/will not continue irrespective of the 

use of fire. 

 There is every reason to believe that the trend of conversion of marsh to open 

water at BNWR and FBWMA will continue irrespective of the use of fire, but the 

important question is whether or not this conversion will be accelerated by the 

continuation of the Multiple-Objective Prescribed Fire Regime. That is a much more 

difficult question to answer. 

 Stevenson et al.15 reviewed the health and long-term stability of the marshes of 

the Chesapeake Bay, finding that marshes around the bay have been negatively affected 

by the imbalance between relative sea-level rise and marsh soil accretion. They further 

noted that even more dramatic losses of marshes have been observed around the BNWR, 

and attributed these changes to more rapid land subsidence due to groundwater 

withdrawals16, reductions of ground water inflows, hydrological modifications and the 

destructive effects of nutria. Furthermore, the eustatic component of local sea level rise 

is highly likely to accelerate during the 21st century due to global warming17, putting 

greater pressure on tidal wetlands of the BNWR and FBWMA. This was well 

demonstrated by the NOAA inundation model for the BNWR18 based on LIDAR 

elevation surveys. This model does not, however, simulate marsh responses, including 

soil accretion and marsh losses and gains. 

 The extensive tidal marshes of the Blackwater and Fishing Bay areas are 

geologically recent and dynamic environments, built after flooding of low-lying fastlands 

during a period of relatively stable sea level. They cannot be preserved forever and will 

experience losses due to inundation and shoreline erosion, as well as gains due to 

transgression across low-lying fastland. The management plans for BNWR and FBWMA 

should acknowledge that and seek to minimize wetland losses and maximize gains in this 

dynamic ecosystem. Although the consequences of fire management in this regime are 

 

15 Stevenson, J.C., J.E. Rooth, M.S. Kearney, and K.L. Sundberg. 2001. The health and long-term stability 

of natural and restored marshes in Chesapeake Bay. 

16 The effects of subsidence induced by groundwater withdrawals was disputed by Curt Larson (NOAA) 

who presented evidence to the Panel that relative sea-level rise rates were similar at Solomons and 

Cambridge. 

17 Wood, R.J., D.F. Boesch, and V.S. Kennedy. 2002. Future consequences of climate change for the 

Chesapeake Bay ecosystem and its fisheries. American Fisheries Society Symposium 32:171-184. 18 Larson, C. Presentation to the Panel, November 13, 2003. 
52

relatively small in comparison to other factors, they should be factored into this dynamic 

management regime designed to maximize wetland longevity while accommodating 

transition. At this point, there is no evidence that prescribed fire is enhancing the health 

and longevity of the marshes and only speculation that it may be having a negative effect.