Biodiversity of riparian communities along an urbanization gradient

Most of central Indiana’s wooded habitats have been converted to farmlands or centers of urbanization, but large areas of wooded habitat are found along the numerous waterways in this region. William’s Creek, located within the Indianapolis Metropolitan area, intersects several types of habitats: conservation areas, golf courses, and urban areas. By examining the William’s Creek corridor, it will be possible to determine the effects of land usage on riparian plant community diversity. We suspect that the main factors limiting plant diversity within the corridor are high amounts of disturbance and decreased habitat heterogeneity. Therefore, diversity is expected to be highest in the conservation area, lowest in the golf course, and intermediate in the urban area. We also hypothesize that invasive plant species will be more prevalent in the golf course and urban areas because of the high amount of disturbance at these locations. At each site, a nested-intensity design was used to determine biodiversity characteristics of the plant communities. Results from Shannon-Wiener diversity index were 2.6927, 1.9862, and 1.9316 for the conservation area, urban area, and golf course, respectively. In addition, there was one invasive species found in the conservation area, two in the urban area, and three at the golf course. From these results, we conclude that disturbance and habitat heterogeneity are impacting biodiversity. However, diversity indices are approximately the same at the urban area and golf course, therefore, disturbance appears to be more detrimental to diversity than low heterogeneity.