Browsing by Author "Dexter, Sarah"

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    Diversity Within Small Mammal Communities of Forested Sites Around Itasca State Park and Nearby Prairie Sites
    (2010-11-30) Dexter, Sarah; Gasteiger, Autumn
    Different habitats provide a variety of niches in which organisms can live. These habitats have an influence on what types of animals can be found in certain areas. The objective here is to study mammal diversity in differing habitats in and around Itasca State Park, but concentrating on differences between forest and prairie environments. Six groups of students set up a grid in one of six areas, a bog, an aspen forest, burned and unburned deciduous forest, and burned and unburned red pine forest. Fifty-five traps were set, and all mammals caught were marked and recorded. Sixty-nine mammals were caught in the prairie locations, and 114 mammals were caught in the forest locations. The prairie locations captured eight different species, while the forest locations captured six different species. Three species were common to both locations. The ‘habitat heterogeneity hypothesis’ is one of the benchmarks for ecology. It considers that complex and structurally different habitats may provide more niches and diverse ways of exploiting the environmental resources, in turn increasing species diversity. In most habitats, plant communities determine the physical structure of the location and have a considerable influence on the distributions and interactions of animal species (J. Tews et al., 2004). The objective in our study is to examine the diversity of small mammals found within various forest habitats within or near Itasca State Park and to compare and contrast those communities with various prairie sites.
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    The Effects of Geomys bursarius Mound Building on Vegetation Diversity in Prairies
    (2010-11-30) Dexter, Sarah; Kartak, Jacob; Lindsay, Erik; Sevdy, Kim
    In June of 2009, in a dry prairie approximately 2 miles north of Itasca State Park in North-central Minnesota, we found that the building of mounds by Geomys bursarius significantly alters vegetation diversity. We collected our data by setting up a total of 1,200 meters of transects, which gave us an estimation of G. bursarius mounds. Additionally, we counted the species richness on 60 randomly selected mounds in our study area; we compared these to a control that lay within approximately 5 meters from the mound counted. Our data was also compared to data from previous years taken from the same area. Along with these studies we chose areas that exhibited unique vegetation and determined if their presence is linked to a disturbance to the prairie compliments of the G. bursarius. The results we found were statistically significant, proving the Geomys bursarius has great effects on prairie ecosystems.