PARENT SESSION
Oral Session 7: GIS / Remote Sensing I.
Presiding: E Ellis and P Valko
Monday, August 2, 8:00 AM to 11:30 AM, Meeting Room B 116.
Landscape indicators of plant invasion in 1,215 wetlands in Ohio, USA.
Feinstein, Larry1, Lauchlan, Fraser*,1, 1 Department of Biology, Akron, Ohio, USA
ABSTRACT- Non-native plant invasives are a worldwide concern. Invasive plants are often competitive dominants that can exclude native plants, which can result in a reduction in biodiversity and a change in ecosystem function. At small scales it has been experimentally demonstrated that disturbance and nutrient enrichment can affect invasion. The purpose here was to conduct a landscape-scale investigation relating relative plant invasion with respect to wetland type (marsh, wetmeadow, scrub/shrub, forested), wetland size, and proximity to potential landscape indicators of disturbance (e.g. roads, agriculture). Twelve hundred and fifteen wetlands ranging in size from less than one tenth to over forty-five hectares located within the 13,350 hectare Cuyahoga Valley National Park (Ohio, USA) were visited; plant invasive species and abundance were scored, and the wetland size was mapped in GIS. Raster and vector GIS database analysis was conducted to determine to the degree of correlation between wetland size, proximity to disturbance, and invasive species abundance. The results show little evidence for a strong correlation of any landscape indicators with the susceptibility of a wetland to invasion. It is suggested that the stochastic complexity of real landscapes make it difficult to predict invasive patterns at the landscape scale. Landscape-scale analysis may not be an effective means to determine potential points of negative impact on wetland ecosystems. Important vectors of dispersal such as wind, drainage, and physical disturbance within a wetland may not show up on landscape-scale analysis. These results have important implications for regulatory agencies charged with protecting natural resources. This analysis suggests that the most effective means of determining negative impact is a small-scale wetland examination rather than a landscape-scale analysis.
Key words: Disturbance, Invasive Species, Wetlands, Landscape-scale analysis