14.2: Procedure

Part I: Prairie Population Ecology

Examine the following data tables to investigate population and community ecology in Illinois prairie grasslands. Use this data to plot the relative population densities of each species: white-tailed deer, prairie voles and big bluestem grass.

We will be using the same unit for measuring dimension for each of the different species being examined here (km²) to provide accurate and consistent comparisons (note that the bluegrass is measured in kg rather than # of individuals). Due to the vast differences in relative population densities of these species, you will be using logarithmic graph paper for these populations’ growth curves. When such vast differences in population density exist, the graph becomes skewed as those populations with high densities will dominate the scale, while those populations with relatively low densities will appear as very small values close to the x-axis. Applying a log transformation to the density axis (y-axis) you will compress the large values and expand the small values, allowing both high and low densities to be comparable on the same graph.

Part II: Community Ecology & Diversity

A survey of three 1-ha prairie plots with differing management histories (e.g. burning and woody removal) can help us to better understand the community dynamics at play in this ecosystem. The table below provides information on the prevalence of Juniperus encroachment and the varying presence of white-tailed deer, prairie voles and overall plant species richness as an outcome of different management strategies. Use the information provided to evaluate the impacts on community ecology and biodiversity.