95th ESA Annual Meeting (August 1 -- 6, 2010)

PS 66-16 - Effect of Megathyrsus maximus, exotic grass, on soil mites in Mona Island Reserve

Thursday, August 5, 2010
Exhibit Hall A, David L Lawrence Convention Center
Lourdes B. Lastra-Díaz, Institute for Tropical Ecosystem Studies, University of Puerto Rico, Rio Piedras Campus, San Juan, PR, Elvia Melendez-Ackerman, Environmental Sciences and Center for Applied Tropical Ecology and Conservation, University of Puerto Rico, Rio Piedras, San Juan, PR and Lorna M. Moreno, Biology, University of Puerto Rico, San Juan, PR

Tropical dry forests are considered one of the most endangered biomes in the world, and have been particularly susceptible to human-induced grass introductions as these sites are often used for agricultural practices. Biological invasions can alter the ecosystem processes severely and lead to functional and compositional changes that may become permanent. Those effects can be reflected not only in the aboveground dynamics but have a big influence in belowground fauna.  Mites are very abundant in the soils and can play a major role in the cycling of nutrients. They are represented by three major suborders: Oribatida, Mesostigmata and Prostigmata, which cover a variety of functional roles within the ecosystem: Detrivourous, Predators and Parasitoids, (Neher, 1999). Prior studies suggest that Oribatid mites tend to be highly susceptible to environmental changes. This project is studying the association between the presence and absence of an invasive African grass, Megatyrsus maximus and mite community diversity in Mona Island Reserve, a natural reserve west of Puerto Rico which exhibits a conglomerate sub tropical dry forests associations.  We are testing the hypothesis that the presence of Megathyrsus maximus influences mite biodiversity and most likely the Oribatida taxa, a detrivorous taxon


Preliminary results we have found a  reduction in mite abundance in grass invaded sites and we are currently in the process of identifying the relative distribution of mites by suborder.