Effects of the manipulation of aboveground plant diversity in restoration management on the diversity of belowground arthropod assemblage
Gilmore, C. E.. 2012. M.S. Thesis, DePaul University°, Chigaco, Illinois
Abstract
A missing element in restoring belowground soil systems to a relatively healthy state may lie in promoting microarthropod diversity. By contributing to healthy nutrient cycling and assisting in the breakdown of leaf litter a diverse microarthropod population helps improve the overall soil quality. My study evaluated how current restoration practices aimed at maintaining aboveground
diversity affects belowground microarthropod populations. I examined how the aboveground manipulation of plant diversity in restoration management practices affects the hyperdiverse
assemblage of belowground arthropod communities. Additionally, I examined the relationship between soil nutrient content and microarthropod diversity. This study was conducted within the
boundaries of Chicago Wilderness from sites with four different management treatments, ranging from unmanaged (W0) to highly managed (W3). 3 soil cores measuring 5 x 5 centimeters were
taken from each site and microarthropods were extracted in a Berlese funnel. Abundance and species diversity were assessed. The microarthropod species data showed that while 12 common
species were found at over 70% of the sites, 32 species were present at less than 30% of the sites. Of these 32 rare species, 15 were unique to only 1 site. Further analysis of the common mites revealed specific associations between those 12 common species. My results showed that restoration management had no significant effect on microarthropod diversity. Plant root
simulator (PRS™) probes were used on each site providing data on fifteen soil nutrients. There was significant explanatory value to the soil nutrient data, especially nitrogen, phosphorus, and zinc.
As these nutrients increased in the soil, microarthropod diversity also increased. Knowledge of these nutrients offers a simple set of tools for evaluating the relationship between soil quality of a
specific site and belowground diversity. I concluded that restoration management aimed at plant diversity was largely ineffective in determining microarthropod diversity; nevertheless, the relationship between soil nutrients available and microarthropod diversity may have implications for management. Understanding relationships such as these are instrumental in the development of new restoration management tools.
