Reproductive output--number of flowering heads: Soil Disturbance Gradient

This study is one of six experiments (E086, E103, E104, E105, E106, E107, E108) that test the influence of many factors on the diversity and abundance of prairie plant communities. Each community is a 2.25 meter square plot seeded with the same amount of seeds from 59 different species of plants. The first experiment is a nitrogen-fire-water factorial. The second experiment is a nitrogen-pH factorial. The third experiment is a nitrogen gradient and the fourth experiment is a nitrogen gradient with a diversity of seeds added each year. This experiment (E108) is a disturbance gradient and the last experiment has three levels of soil heterogeneity (variance from the mean) for both nitrogen and pH.