Notice: The views expressed here are those of the individual authors and may not necessarily reflect the views and policies of the United States Environmental Protection Agency (EPA). Scientists in EPA have prepared the EPA sections, and those sections have been reviewed in accordance with EPA’s peer and administrative review policies and approved for presentation and publication. The EPA contributed funding to the construction of this website but is not responsible for it's contents. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Identification of forests and wetlands of highest value for protecting watershed integrity and water quality Chesapeake Bay Program Annapolis, MD Chesapeake Bay Resource Lands Assessment

Forests - linking land and water In 1753, a Pennsylvania settler wrote, “... our runs dry up apace, several which formerly would turn a fulling mill are now scarce sufficient for the farm. The reason is this, when the country was covered with woods and the swamp with brush, rain that fell was detained by these interuptions and so had time to insinuate into the earth and contribute to our springs and runs. But now the country is clear’d and the rain is hurried into our creeks, washes away the soil...and makes shoals and sandbanks in them, and hence several creeks mentioned by Mr. Penn to be navigable are no longer so” From “Pennsylvania Agriculture and County Life,

Introduction The Chesapeake 2000 Agreement charged the Chesapeake Bay Program with conducting an assessment of its resource lands in order to identify the most important to conserve. Commitment # Throughout the Chesapeake Bay watershed, valuable forests, farms, and wetlands (i.e., resource lands are under pressure from land use change and other environmental stresses.

Resource Lands Assessment (RLA) Purpose: To identify the resource lands (i.e., forests, farms and wetlands) that have the highest water quality, habitat, cultural and economic value and are the most vulnerable to loss.

RLA Objectives I. Habitat Value Assessment IIWater Quality/Watershed Integrity Value Assessment III. Cultural Value Assessment IV. Economic Value (i.e., forest and farm production) Assessment V. Vulnerability Assessment

Watershed integrity relates to physical and biological watershed functions that store precipitation, retain and assimilate nutrients, moderate runoff, protect soils and critical riparian areas, and sustain aquatic ecosystems. These functions, when present, serve to protect water quality. In general, forests and wetlands are the best land cover for providing these watershed functions. Water Quality/Watershed Integrity Value Assessment

This analysis attempts to identify the nexus between a forest or wetland and the parameters that would effect its ability to provide these functions. This analysis also attempts to place value on forests and wetlands that if lost would have significant potential to compromise or degrade watershed and water quality. The most effective scientific analysis of this landscape feature is limited by the availability of specific and consistent data sets for the Bay watershed.

Assumptions: The characteristics of soil and vegetation at a particular site, and for the watershed within which they occur, have significant bearing on this assessment of value. (i.e., parameters chosen and weights and ranks assigned) The GIS data layers used to represent the parameters are accurate enough for this coarse scale assessment.

GIS data layers were collected for terrestrial parameters known to affect water quality and watershed integrity (total of 12 parameters) Methods To identify the forests and wetlands most important for protecting water quality and maintaining watershed integrity…. Data within every parameter was classified into 4 ranges based on their influence on water quality (0 = no influence, 4 = highest) Every parameter was given a weight from 0 to 5 to emphasize variables with a greater influence on water quality

Data Types and Sources Local Parameters 1.) Proximity to water USGS NED 2.) Erodible Soils STATSGO 3.) Slope USGS DEM 4.) Wetland Function NWI 5.) Forest Fragmentation CBP 6.) 100 Year Floodplains FEMA 7.) Hydrogeomorphic USGS regions

Regional Parameters (summarized by HUC 11 watershed) 8.) Stream Density (m/sq km) USGS NHD 9.) Percent Forested MRLC ) Percent Impervious RESAC ) Atmospheric Deposition/ ReVA Indicators Acid Neutralizing Capacity 12.) Water Quality Rank USGS Sparrow/DU Data Types and Sources

Ranks and Weights

Results - Weighted

Results – Unweighted

Comparison Un-weightedWeighted

How much is enough?

Additional Data Layers Forest Productivity – based on species, geography, elevation, climate, soils, and atmospheric deposition. (FIA/USFS-PNet Model) Municipal Water supplies – small-medium size systems, proximity to major river withdrawals (compile from States)

How information will be used? Combined with other analysis – especially economic and vulnerability Guide local targeting – need ground proofing with local governments and land conservancies Identify priority landscapes for different management program needs Provide interpretive information for “State of the Forests” Report