Bernd Blossey
Friday, October 17, 2008 - 4:00-4:30
Plant invasions are suspected to alter community structure, food webs, and ecosystem function. However, quantitative evidence for unique risks to recipient communities associated with nonnative plant invasions is usually lacking. And even less is known about traits that may make certain species strong invaders that are able to transform entire communities. Recent evidence from forest communities appears to suggest that invasive plants are often the passengers, not the drivers of ecosystem change. Overabundant native deer and introduced earthworms appear to be the ecosystem engineers in forests responsible for allowing introduced plants to invade. In contrast, in littoral aquatic communities, it appears that emergent plants, as the major producers of energy and biomass, drive aquatic communities. It is less clear that there is a fundamental difference between plants based on their origin (native or not). It appears that differences in plant chemistry, not necessarily origin, have large extended effects on aquatic ecosystem processes, food webs, and trophic structure. I will explore potential underlying principles of these fundamentally different results obtained from terrestrial and aquatic environments.
Keywords: COMMUNITY STRUCTURE, LITTORAL, AQUATIC, EMERGENT, TROPHIC STRUCTURE