APPLYING WETLAND REFERENCE DATA TO FUNCTIONAL ASSESSMENT, MITIGATION,AND RESTORATION

This study demonstrates an approach for rapidly collecting quantitativ e field data on reference wetland sites and using those data to assess functions (ecological processes) in wetlands. We demonstrate the hydr ogeomorphic (HGM) assessment procedure by identifying ecological funct ions performed by mineral soil wet flats, obtaining quantitative field data from 19 wet Bats (reference sites) in southeastern North Carolin a, and modeling wetland functions using variables derived from those f ield data. We chose a subset of the 19 reference sites to demonstrate how HGM assessment can be used to measure ecosystem functions before a nd after a project site is altered and the degree to which ecosystem r estoration can compensate for a reduction in functions caused by a pro ject's impact. We also illustrate how HGM assessment can be used to de termine the minimum area over which restoration should be applied to a chieve a no-net-loss in function objective. This minimum area can be d etermined by dividing the degree to which a function is reduced throug h project alteration by the degree to which a function is increased th rough restoration. The ratio of wetland area restored to wetland area altered by a project impact (compensatory mitigation ratio) varies amo ng functions and is influenced by (1) the magnitude to which any given function occurs at a project site both before and after the site is a ltered, (2) the magnitude to which any given function occurs at a comp ensatory mitigation site both before and after restoration is applied, and (3) the rate at which any given function is restored.