A Stream–Wetland–Riparian (SWR) index for assessing condition of aquatic ecosystems in small watersheds along the Atlantic slope of the eastern U.S.

Abstract

As part of a regional study by the Atlantic Slope Consortium (ASC) to develop ecological and socioeconomic indicators of aquatic ecosystem condition, we developed and tested a protocol for rapidly assessing condition of the stream, wetland, and riparian components of freshwater aquatic ecosystems. Aspects of hydrology, vegetation, in-stream and wetland characteristics, and on-site stressors were measured in the field. The resulting metrics were used to develop an index of overall condition, termed the Stream-Wetland-Riparian (SWR) Index. Values of this Index were compared to existing biotic indices and chemical measures, and to a Landscape Index created using satellite-based land cover data and a geographic information system (GIS). Comparisons were made at several levels of spatial aggregation and resolution, from site to small watershed. The SWR Index and associated Landscape Indices were shown to correlate highly with biological indicators of stream condition at the site level and for small contributing areas. The landscape patterns prevalent throughout the entire watershed do not necessarily match the patterns found adjacent to the stream network. We suggest a top-down approach that managers can use to sequentially apply these methods, to first prioritize watersheds based on a relative condition measure provided by the Landscape Index, and then assess condition and diagnose stressors of aquatic resources at the subwatershed and site level.

Monitoring restored riparian vegetation: how can recent developments in remote sensing sciences help?

“…However image analysis is not a way to replace field work. We believe it provides some complementary sets of data (i) to combine with field information and (ii) to enlarge studied area (Rheinhardt et al, 2007;Brooks et al, 2009;Dufour et al, 2012). Indeed, although we provide illustrations that recent improvements in remote sensing science can provide 3D information for narrow strips of riparian vegetation with high temporal resolution, some variables (e.g.…”

“…Indeed, both scientists and managers need appropriate tools to monitor riparian vegetation: the latter for a quantitative evaluation of funded action efficiencies and the former for a detailed understanding of vegetation pattern and dynamic follow-up of restoration. Site or reach scale projects have numerous tools to assess riparian vegetation response to restoration practices (Munné et al, 2003;Coroi, 2006;Brooks et al, 2009). However, large scale projects need specific tools, capable of generating continuous and detailed data set along several river segments or at network scale (Tormos et al, 2011).…”

Image Utilisation for the Study and Management of Riparian Vegetation: Overview and Applications

“…For this purpose, images have good potential. In conclusion, image analysis can provide some complementary sets of data to combine with field information (Brooks et al, 2009) and objectives should be clearly identified before application.…”

Proposed Hydrogeomorphic Classification for Wetlands of the Mid-Atlantic Region, USA

“…During that project, we sought ways to blend similar research approaches being conducted between estuarine segments of coastal systems and the freshwater wetlands of small watersheds ). In addition, during development of a Stream-Wetland-Riparian Rapid Assessment Index (Brooks et al 2009), we needed a way to consistently describe components of aquatic ecosystems among ecoregions. Based on these experiences, we developed this regional classification system for the following reasons:…”