A biologist at Washington University in St. Louis has studied the ecosystem of the tree hole and the impact that three factors predation, resources and disturbance - have on species diversity.

Jamie Kneitel, Ph.D., Washington University in St. Louis post doctoral researcher in biology in Arts & Sciences, and Jonathan Chase, Ph.D.,Washington University assistant professor of biology, found that tinkering with any of those factors changes the make up of the community.

Kneitel uses the Richard the III reference "subtle, sly and bloody," Richard III's mother's description of her son as a little boy when talking about the ecosystem he studies. A tree hole can be found in nearly every forest and is an ecosystem surprisingly overlooked by ecologists. Created by a lost tree branch or deformed trunk, the tree hole collects water, which supports an aquatic community that lets an ecologist like Kneitel address fundamental ecological questions. In this small ecosystem, bugs and leaves fall into this pool of water and decompose which provides the energy for hundreds of species, including bacteria, protozoa, and mosquito larvae. It's a generally thriving community where these critters battle each other in a mini-survival-of-the-fittest.

To perform his study, Kneitel recreated the tree hole ecosystem in the laboratory, which allowed him to change the parameters to create different ecological situations. The most common disturbance for a tree hole is lack of water. Resources equate to the food supply, and predation among the three basic organisms protozoans, rotifers and mosquito larvae is rampant, and varies depending on resources and disturbance.

"Predators, resources, and disturbances are the
'"/>

Contact: Tony Fitzpatrick
tony_fitzpatrick@wustl.edu
314-935-5272
Washington University in St. Louis
15-Jun-2004