Wetland landscape dynamics and its socio-ecological implications

Abstract

The dynamics on the earth landscape impact both the biotic and abiotic components. One of the abiotic components of the landscape are wetlands, whose terrestrial part is also serving as a habitat for many biotic components. Many species cannot survive without wetlands, which have benefits that serve ecological values for both plants and animals. Wetlands have been loosely defined as a transitional habitat between aquatic systems and highlands; they may be a part of coasts, estuaries, floodplains, or watersheds of surface waters. As a relatively fragile part of the Earth ecosystem, wetlands are often regarded as a socio-ecological system (SES). Wetland SES functions and services include habitats for fish, wildlife, and plants, natural water quality improvement and biochemical cycling, atmospheric maintenance, hydrologic cycling, food storage, shoreline erosion protection, education research, and aesthetics. As such, it is critical to fully understand wetlands’ responses to the surrounding landscape changes in relation to the change impact on wetlands’ SES benefits. However, the research issue was less addressed by previous studies, especially in identifying resultant terrestrial habitat loss and fragmented edges mostly caused by urban development. This landscape change process was found to be one of the primary drivers of species endangerment and extinction. The social and natural components of wetlands that were affected by fragmentation in terrestrial habitats are the major focus of this study. The study selected ten wetlands situated in the three major watersheds in the Kansas City area. The physical boundaries and changes of these study wetlands were adequately captured using remote sensing and GIS techniques. The study is divided into four parts. The first part employed an object-based image analysis (OBIA) approach for image classification performed in ENVI software. This approach involves segmentation and grouping imagery into objects to preserve the spatial, spectral, and temporal scale. Two classification algorithms support vector machine (SVM) and K-Nearest Neighbor (K-NN) were used. The second part involved deriving secondary terrain attributes using the compound topographic index (CTI) and the stream power index (SPI) generated from the United States Geological Survey (USGS) digital elevation model (DEM). The third part involved metric calculations, which were implemented based on the spatial patterning of the structure of landscape heterogeneity in relation to some aspect of ecological function. The fourth part is the wetland landscape dynamic (WELD) modeling performed to estimate the changes impacted on ecological services indicators between 1992 and 2017, as it relates to wetland terrestrial habitat. In addition, demographic data were used to analyze the socio-spatial interaction of terrestrial habitat surrounding wetlands. The result of the study at the landscape level (watershed) revealed a general swell in the wetland coverage of the three major watersheds in the Kansas City area. At the patch level (wetland), the study showed modified wetland terrestrial areas, with more impacts on the smaller wetlands. The resulting indices for terrain analysis showed an increase in potential wetness for nine out of ten wetlands studied and relatively no change for the stream power. American Community Survey (ACS 2010) and major connecting roads data were used in socio-spatial interaction. The result for ACS revealed an increase in the total sum population per 100 people (sum_POP100), followed by the sum of households per 100 people (sum_HU100), the least increase revealed by census block count. The major connecting roads interaction revealed 84 locally connected roads intersecting the terrestrial portion of nine out of the ten wetlands. This may imply a limited impact on the terrestrial wetland habitats for amphibians and reptiles since they are all local roads. Overall analysis for the socio-spatial interaction showed smaller wetlands had greater changes within the 25-year study period.