Geographia Technica, No. 1/2010, pp. 76 - 90

RELATING LAND COVER AND URBAN PATTERNS TO AQUATIC ECOLOGICAL INTEGRITY: A SPATIAL ANALYSIS

 R. R. Shaker, A. I. Crăciun , Ionela Grădinaru

ABSTRACT: Landscape change affects natural ecosystems and poses major challenges to natural resource managers and planners. Studies have shown that streams and rivers are often the ecosystems most affected by stressors associated with urbanization, and composition within a watershed has been found to account for much of the variability in aquatic ecological integrity. While studies have shown that type and quantity of land cover within a watershed can account for much of the ecological conditions in streams, few have investigated how the land mosaic influences stream ecological integrity. In ecological research there remains debate on how spatial structure and spatial dependence affects spatial statistics and statistical modeling of the species-environment interaction. In this paper, we study the relationships of seven landscape variables on an averaged Fish Index of Biological Integrity (F-IBI) in 49 watersheds in Southeastern Wisconsin, USA. Spatial clustering statistics: local Moran’s I, local Geary’s C, local Anselin Moran’s I, and local Getis-Ord Gi* were used for variable and overall comparison. Standard least squares regression and geographically weighted regression (GWR) were used for ranking landscape variables and comparison. Local Anselin Moran’s I statistic was found to best capture the association between average F-IBI and landscape variables. The standard least squares regression and GWR analyses identified percent urban and landscape shape index (LSI) as the most important predictors of aquatic environmental integrity, respectively.
Keywords: landscape pattern; fish index of biotic integrity; spatial statistics; spatial autocorrelation; spatial analysis

Full article: shaker_relating_land_cover_and_urban_patterns_to_aquatic_ecological.pdf