Faculty Collaboration Database

Rapid assessment of urban wetlands: do hydrogeomorphic classification and reference criteria work? Environ Manage 2009 Apr;43(4):725-42

Date

10/14/2008

Pubmed ID

18850244

DOI

10.1007/s00267-008-9211-6

Scopus ID

2-s2.0-62549104228 (requires institutional sign-in at Scopus site)   27 Citations

Abstract

The Hydrogeomorphic (HGM) functional assessment method is predicated on the ability of hydrogeomorphic wetland classification and visual assessment of alteration to provide reference standards against which functions in individual wetlands can be evaluated. The effectiveness of this approach was tested by measuring nitrogen cycling functions in forested wetlands in an urbanized region in New Jersey, USA. Fourteen sites represented three HGM classes and were characterized as "least disturbed reference" or "non-reference" based on initial visual assessment. Water table levels and in situ rates of net nitrogen mineralization, net nitrification, and denitrification were measured over one year in each site. Hydrological alterations, resulting in consistently low or flashy water table levels, were not correlated with a priori designations as reference and non-reference. Although the flat-riverine wetland class had lower net nitrification and higher denitrification rates than riverine or mineral flat wetland classes, this difference was attributable to the lack of hydrologically-altered wetlands in the flat-riverine class, and thus more consistently wet conditions. Within all HGM classes, a classification based on the long-term hydrological record that separated sites with "normal," saturated hydrology from those with "altered," drier hydrology, clearly distinguished sites with different nitrogen cycling function. Based on these findings, current practices for designating reference standard sites to judge wetland functions, at least in urbanized regions, are ineffective and potentially misleading. At least one year of hydrological monitoring data is suggested to classify wetlands into groups that have different nutrient cycling functions, particularly in urban landscapes.

Author List

Stander EK, Ehrenfeld JG

Author

Jesse Ehrenfeld MD, MPH Sr Associate Dean, Director, Professor in the Advancing a Healthier Wisconsin Endowment department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Conservation of Natural Resources
Environmental Monitoring
New Jersey
United States
Wetlands