Back to GIS Laboratory PageJeremy Fried , Assistant Professor
Lisa Pilato , Graduate Research Assistant
The Karner blue butterfly, (Lycaeides melissa samulis), a federally listed endangered species that depends on Lupinus perennis as its sole larval food source, can be found in early successional habitat in the oak savanna/oak forest matrix of southwest Michigan. The lack of information on habitat requirements of both the Karner Blue and the L. perennis plant upon which it depends has been an obstacle for land managers seeking to create and sustain suitable habitat. The design of a successful recovery program for the Karner Blue necessitates an ecosystem management approach for identifying both butterfly habitat requirements and metapopulation dynamics. This approach entails investigation of the specific ecological requirements of L. perennis and a landscape level assessment of the relationship between indices of spatial pattern of L. perennis patches and utilization of patches by Karner Blue. This research will identify factors which control L. perennis growth and development via three studies: 1.) a landscape level study of the occurrence and co-occurence of L. perennis and Karner Blue populations, 2.) a censusing of environmental variables and L. perennis population densities in and around a representative sample of forest openings, and 3.) a greenhouse experiment designed to assess the linkage between L. perennis growth and selected environmental variables.
Utilizing the analytical capabilities of a geographical information system (GIS), spatial patterns of overstory and understory vegetation at the landscape level will be assessed and related to both L. perennis patch densities and Karner Blue observations. Metrics such as area/perimeter ratios, distance to nearest patch, patch distribution patterns within the forested landscape, patch size, and shape indices will be calculated. Many of the ecological conditions at the landscape level that may influence L. perennis density in southwest Michigan appear to be associated with the attributes of the Oakville fine sand soil series. L. perennis, as a primary successional species, may have evolved adaptive traits for surviving under poor soil conditions (e.g., high leaching, low nutrients). Existing soil maps will be geo-rectified, digitized and combined with soil series attributes to create a GIS coverage. Overlay operations on soil and L. perennis coverages will be used to assess the linkage between L. perennis growth and survival and ecological factors at the landscape level.
Information about ecological factors that affect L. perennis growth and density at the population level is needed to develop management plans that perpetuate Karner Blue habitat, and ultimately ensure its survival. Two factors addressed in this study are light availability and soil pH. Their relationship with L. perennis density will be assessed in a field study involving measurements of light, soil pH and L. perennis density. Their effect on growth and development will be determined through a replicated factorial greenhouse study using plants grown from seed in controlled environments.
This research will generate information on specific environmental conditions and the spatial structure of those conditions needed for Karner Blue habitat. Using GIS modeling, land managers responsible for Karner Blue conservation can combine this information with forest inventory data to integrate the conservation management requirements of the Karner Blue with other forest management objectives.
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