Ullah, Sami and Faulkner, Stepehn (2006) Functional assessment of urban forested wetlands. Proceedings of the Pakistan Academy of Sciences, 43 (1). pp. 15-28.
Wetlands perform various functions of vital socio-ecological significance. To avoid further loss of functions, functional assessment techniques for management purposes are important to develop for different wetland classes. Our aim was to assess the biotic functions of urban-forested wetlands, and to evaluate specific functional assessment models in an urban setting. The models were adopted from the low gradient riverine wetlands hydrogeomorphic (HGM) functional assessment guidebook of Western Kentucky of the US Army Corps of Engineers. Three bottomland hardwood wetlands were chosen for assessment and models evaluation in East Baton Rouge Parish (EBRP), Louisiana. Fourteen out of 17 variables for nutrient cycling, maintenance of native plant community and provision of habitat for wildlife functions were applicable to the selected wetlands. Three surrogate variables were developed to fill identified gaps in the existing models and provide more accurate assessment of urban forested wetlands. Litter layer depth was found to be a more reliable assessment variable for quantifying Ohorizon biomass production than the presence/absence of an O-horizon. Dominant wetlands plant species list was adjusted to accurately reflect the flora of the urban forested wetlands of EBRP. An additional variable for characterization of forest strata as a factor of wildlife habitat provision was developed, and added to the model. Overbank flood frequency variable was not applicable to the fragmented urban wetlands and was removed from the models. The amended assessment models accurately captured existing wetland conditions and the effects of site alterations due to urbanization. These alterations caused significant differences (p <0.05) in wildlife habitat provision, maintenance of characteristic plants community and nutrient cycling functions among the three sites. Further work on the application of these models in similar urban forested settings in the southeastern US is recommended.
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