Application of a three-tier framework to assess ecological condition of Gulf of Mexico coastal wetlands.
A multi-level coastal wetland assessment strategy was applied to wetlands in the northern Gulf of Mexico (GOM) to evaluate the feasibility of this approach for a broad national scale wetland condition assessment (US Environmental Protection Agency's National Wetlands Condition Assessment). Landscape-scale assessment indicators (tier 1) were developed and applied at the sub-watershed (12-digit hydrologic unit code (HUC)) level within the GOM coastal wetland sample frame with scores calculated using land-use maps and geographic information system. Rapid assessment protocols (tier 2), using a combination of data analysis and field work, evaluated metrics associated with landscape context, hydrology, physical structure, and biological structure. Intensive site monitoring (tier 3) included measures of soil chemistry and composition, water column and pore-water chemistry, and dominant macrophyte community composition and tissue chemistry. Relationships within and among assessment levels were evaluated using multivariate analyses with few significant correlations found. More detailed measures of hydrology, soils, and macrophyte species composition from sites across a known condition gradient, in conjunction with validation of standardized rapid assessment method, may be necessary to fully characterize coastal wetlands across the region.
Gulf Ecology Division, U.S. Environmental Protection Agency, 1 Sabine Island Dr., Gulf Breeze, FL, 32561, USA, nestlerode.janet@epa.gov.
Janet A
JA
Nestlerode
Virginia D
VD
Hansen
Aarin
A
Teague
Matthew C
MC
Harwell
D003247:Conservation of Natural Resources / Q000331:legislation & jurisprudence; D004463:Ecology; D004784:Environmental Monitoring / Q000331:legislation & jurisprudence / Q000379:methods*; D040362:Geographic Information Systems; D060851:Gulf of America; D062070:Hydrology; D012623:Seawater / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D014481:United States; D014484:United States Environmental Protection Agency; D053833:Wetlands
D012987:Soil