Hurricanes, wildfires and influxes of pollutants create disturbances that can put ecological systems under extreme stress. Ecologists had believed that at times like these, competition between species becomes less important as all struggle to survive.
But a new laboratory study of microscopic organisms subjected to varying degrees of acoustic disturbance now challenges that assumption and could lead ecologists to reconsider how organisms compete during challenging times.
"The consistent role of competition at all levels of disturbance found in our study underscores the need for ecologists to examine competitive interactions and their consequences even in highly disturbed habitats," said Lin Jiang, an assistant professor in the Georgia Tech School of Biology.
Sponsored by the National Science Foundation, the research was reported June 28, 2010, in the early online edition of the journal Proceedings of the National Academy of Sciences. The study is believed to be the first to show experimentally that competition could be a factor in regulating ecological communities regardless of the intensity or frequency of disturbance.
Jiang and his team -- Cyrille Violle, formerly a postdoctoral fellow at Georgia Tech currently at the University of Arizona, and Georgia Tech biology graduate student Zhichao Pu -- conducted experiments with freshwater bacterivorous protists in artificial, simplified ecosystems called microcosms.
"A key advantage of this microcosm system is that the rapid reproduction of the microorganisms allowed us to examine multigenerational community dynamics, including competitive exclusion and stable coexistence, in a period of a few weeks," said Jiang.
The researchers assessed the ability of different species of single-celled eukaryotes called protozoa to cope with disturbance in the absence of competition, the competitive ability of species in the absence of disturbance, and the
|Contact: Abby Vogel Robinson|
Georgia Institute of Technology Research News