Location: Hydrology and Remote Sensing Laboratory
2012 Annual Report
A total of 47 isolated depressional wetlands including prior converted croplands, restored wetlands, and wetlands with native vegetation were sampled for vegetation cover between the last week of June and middle of October (2011), with the bulk of sampling done in July and August. The 11 sites in Virginia were sampled between June and July. The 20 Maryland sites were sampled between July and the end of August with three remaining sites that required special access due to the presence of sensitive species sampled in early October. The 9 North Carolina sites were sampled in early August. The 7 Delaware sites were sampled in August. Percent cover of each vegetation species was recorded in 176 10x10-m plots across the 47 sites. Six hundred and twenty plant species samples that could not be identified in the field were collected, pressed and are currently being identified using dichotomous keys. An Anthropogenic Activity Index (AAI) worksheet was completed to assess the level of continued disturbance at each site. Once all plants are identified the data will be analyzed for floristic quality (FQAI and FAQWet), species richness and evenness, evidence of plant succession, and percentage of non-native species. These indices will used to compare the three wetland types. Various statistical tests will be used to determine if there are significant differences in plant communities, which will suggest whether the restored wetlands are functioning similar to the natural reference sites. We looked for correlations between vegetation indices and AAI. Preliminary results indicate that there is very little overlap in the species composition across the three wetland classes. Natural sites were predominantly wooded with little herbaceous vegetation, where as the restored sites had little to no woody plants. Many restored sites continue to experience human alteration (i.e. typically mowing and sometime digging), which may prevent woody vegetation from establishing.