assessment of sustainability of our forests

Southern Forest Resource Assessment

led by the USDA Forest Service's Southern Region and Southern Research Station in collaboration with the USEPA, US Fish & Wildlife, TVA, and state forestry agencies of the Southern United States

Broad Category: Watersheds, Aquatic/Riparian Ecosystems, and Forested Wetlands

Question Manager: William Ainsley, USEPA Region 4 (replacing Eva Long October 2000)

Question AQUA-2: What are the history, status, and likely future of forested wetlands in the South?

Specific points to be addressed in answering the question:

  1. Document the extent and effects of wetland restoration efforts.
  2. Evaluate the impacts of incentive programs used to restore wetlands.
  3. Evaluate the fate of wetlands that have been converted to other uses in the past.
  4. Define wetlands and describe which wetland types are especially at risk.
  5. Measure the distribution as well as the extent of all wetland types.
  6. Evaluate the quality of current forested wetlands and how quality changes when converted to non-forest cover.
  7. Disclose the limitations and degree of accuracy of data sources.
  8. Address the effects of exotic species (plant and animal) on the structure and function of wetlands.
  9. Evaluate the land ownership patterns of forested wetlands.
  10. Describe past and potential shifts among forested wetland types, i.e. mixed pine/hardwood to pine or hardwood.


Methods of Analysis:

For the purposes of this inventory, the USFWS definition and the Cowardin classification system will be applied to identify and describe wetlands of the South.  Vegetative community descriptions as used by the USFS in their Forest Inventory and Analysis (FIA) will be used to differentiate forest types.  Wetlands as defined in 1987 by the USACE are legally under the jurisdiction of Section 404 of the Clean Water Act, and delineations of jurisdictional wetlands will differ somewhat from USFWS‑defined wetlands. Section 404 policy and jurisdictional issues are relevant to this study in that they affect the "likely future" of wetlands of the South. 

Numerous estimates of the historical extent of wetlands in the United States have been published; a review of the literature would provide an approximation of extent of forested wetlands in the South.  Regarding current status and trends assessments, literature reviews are the recommended means to compile general information relevant to the different forested wetland ecosystems of the South, the functional values of these wetland systems by type, the effects of conversions/exotic species on structure and function, and the evaluation of wetland restoration efforts (note:  agencies with wetland restoration programs would additionally need to be surveyed to determine participation rates and success).

The current distribution and extent of forested wetlands in the South, as well as land-ownership patterns, recent shifts among forested wetland types, and the fate of converted wetlands (i.e. those areas which are considered restorable vs. non-restorable) can be described geographically where digitized information is available.  This would entail development of a base map of forested wetland extent from USFWS NWI maps overlain (note:  USEPA MRLC data can be utilized where NWI information is not available) with FIA forest cover data and unphased and wet-phase hydric soils data.  Data layers relevant to land-ownership (in FIA database), forest shift (in latest two FIA surveys), land-use information (in MRLC, SEAC sprawl analysis, NWI high change areas and FIA databases) would then be added to this base map.  

Data Sources:

·  USEPA GIS land-cover analysis (MRLC data)

·  USEPA GIS SEAC sprawl analysis

·  USFS FIA forest composition data

·  USFS FIA land ownership data

·  USFS FIA forest shift data (digitized only)

·  USFS Forest Health Monitoring database

·  USFWS NWI maps of wetlands by Cowardin classification

·  USFWS NWI map of ‘red flag’ areas (i.e. high change areas)

·  USFWS, State Natural Heritage Programs, State Wildlife Agencies, State Universities, and NGOs information on wetland types, special ecosystems at risk, and exotic species.

·  NRCS hydric soils data (unphased and wet phases)

·  NRCS NRI data

·  USACE Waterways HGM reference sites

·  USACE RAMS (Section 404 permit) data

·  USDOT/FHW information on mitigation bank sites

·  State Natural Heritage Programs, State Wildlife Agencies, and NGOs information on wetland restoration sites (e.g. Ducks Unlimited, The Nature Conservancy, and Land Trusts)


·  Map presentation of the type and distribution of forested wetlands for the South

·  Tabular description of ‘at risk’ wetland types

·  Map of ‘threatened’ forested wetlands near urban sprawl areas

·  Map presentation of the evaluation of fate of forested wetlands for the South

·  Tabular list of percentages of completely converted wetlands (e.g. converted to urban land use) and forest recoverable (e.g. converted to an agricultural land use)

·  Tabular description of percent shift among forested wetland types

·  Map presentation of percent shift among forested wetland types in the South

·  Qualitative description of the general functional values of wetlands by type

·  Tabular list of percent ownership of forested wetlands by category (e.g. public, industry)

·  Narrative description of exotic species and effects on structure and function of forested wetlands

·  Tabular list of acres of restored forested wetlands by State

·  Tabular list of forested wetland restoration programs

·  Results from surveys concerning the success of forested wetland restoration incentive programs

Collaborators and Sources:

USFS FIA office

USFS Center for Bottomland Hardwood Research

USFS Center for Forested Wetlands Research

USGS–studies on wetlands restoration efforts

NRCS Regional offices–NRI data

NRCS State offices–EQIP, WRP, CRP, CREP program information, soil surveys

USEPA MRLC inventories

USFWS NWI and “hotspot” information for fate analysis

USACE Waterways Experiment Station for hydrogeomorphic functional assessment information

State Natural Heritage Programs for ecosystem descriptions and exotics information

State Universities

NGO’s for restoration efforts and ecosystem descriptions

Wetland Research Center in Lafayette, LA


Exotics Pest Plant Council

Links to Other Questions:

Terrestrial for determination of forest types and distribution; forest conversion, impacts, and quality; restoration success; exotic species effects

Socioeconomic for analysis of incentive program effectiveness; land ownership patterns; and effectiveness of wetlands regulatory program


Unresolved Issues:

·  Data quality will affect the accuracy of this assessment.

·  Terms such as “conversion,” “fate,” “restore,” “history,” “forested,” “forest type,” “exotics” and “quality” need to be consistently defined throughout the assessment.

·  USFWS NWI provides information on the distribution of wetlands, but it is not by wetland type.  USFS FIA data is available for forest cover; however, extrapolation of this data over NWI information is necessary to define wetland types.  In literature reviews, it may be difficult to reconcile descriptions of different wetland types.

·  It may be difficult to compare changes in quality due to forested wetland conversions.  Functional “quality” is often not defined in a single, absolute sense, but across a set of different functional parameters.

·  Locations of wetland restoration projects implemented by NRCS is not available to the public. 

·  “Effects” cannot be easily determined for all States (e.g. of conversions or of incentive programs), unless sporadic and anecdotal.  “Effects” are not directly assessed, tracked, or reported. 

·  Regarding the analysis of effects of exotic species on forested wetlands, some forestry operations will plant non-native plant species.  The intended focus of this aspect of the study needs to be explained, e.g. to determine the effects of invasive or nuisance species.

·  Time trends (e.g. land ownership, potential shifts among forest types) may be difficult to evaluate, considering that older data is not digitally available and changes may not be readily predictable. 

·  Schedules will be affected by availability of data, availability of personnel resources, ability to manipulate available databases, and participation of agencies in surveys.

·  A small area study may provide more direct insight of changes which occur to forested wetlands when converted to non-forested cover.

Cited and Other Relevant Literature:

King, S. and B. Keeland.  Evaluation of Reforestation in the Lower Mississippi River Alluvial Valley.  December, 1999.

Shepard, J.P.  An Assessment of National Wetlands Inventory Recognition of Wetlands with Hydrophytic Vegetation. Proceedings Society of Wetlands Scientists.

US Army Corps of Engineers, Waterways Experiment Station.  HGM Guidebooks.


For referenced literature reviews:

Initiation: 4 mo. Analysis: 0 mo. Synthesis: 2 mo.

For referenced mapping products:

To develop base forested wetlands distribution map:  Initiation+Analysis+Synthesis: 9 mo to 1 yr. 

To add and analyze data layers: + 3 mo.



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 modified: 28-OCT-2000