Hydrophytes in the Mid-Atlantic region: Ecology, communities, assessment, and diversity

Hydrophytes, or wetland plants, are the most conspicuous and perhaps most colorful element of wetland systems. In the mid-Atlantic region, hydrophytes have been the focus of many studies, resulting in a wealth of information on wetland classification, vegetation stressors, and plant-based assessment tools. For example, exploration of the relationship between hydrophytes and the physical aspects of wetlands has led to a new hydrogeomorphic classification of headwater systems that combines three previously distinct classes. Studies of stressors have shown that plants respond differentially to human-mediated disturbances in the surrounding landscape. Reed canary grass (Phalaris arundinacea), a native but highly invasive wetland grass in regional wetlands, exhibits increased establishment, growth, and biomass in response to nutrient additions, and surprisingly, in some instances, to increased sedimentation, while blue vervain (Verbena hastata), a denizen of freshwater wetland habitats, is intolerant of increased sediment loading. Hydrophtyes have also served as the foundation for some of the most powerful wetland assessment tools in the region. Floristic Quality Assessment (FQA) and biotic indices have been developed by a number of states within the region and in the case of FQA, for the region as a whole. This chapter examines the role of hydrophytes in these studies, as well as spotlights invasive and special status wetland species found in wetland habitats in the region.