The Invaders vs. The Carnivores: Invasive Species and Carnivorous Plants

Barry Rice

Wildland Invasive Species Program • The Nature Conservancy • University of California • Davis, CA 95616 • USA

The second most important cause for species extinction (after habitat destruction) is the introduction of exotic species. The most well-known are exotic animals---horror stories of brown tree snakes, zebra mussels, and arthropod-related tree diseases abound. Less well known are the dangers from exotic plant species. In national surveys in 1995 and 1998, land managers for The Nature Conservancy listed the issue of exotic species as being one the their main concerns. Exotic species degrade habitat, displace natives, and can leach a wildland of its natural value. A large number of preserves stewarded by The Nature Conservancy are freshwater wetland sites and harbor carnivorous plant species, including Sarracenia alabamensis and Sarracenia rubra subsp. jonesii. Wildland weeds are significant issues at these, and other preserves.

In the last few decades, The Nature Conservancy has changed its strategy in land protection. Instead of selecting key sites to protect specific organisms, the perspective is now on saving entire "functional landscapes," where the natural processes of fire, flooding, grazing, etc., are intact. Yet even on these scales, wildland weeds are significant threats to ecosystems.

Sarracenia oreophila

This talk will review some of The Nature Conservancy’s carnivorous plant reserves (and especially how they are being affected by exotic species). Efforts to control the exotic species will be discussed. Finally, a few aspects of carnivorous plants as exotic species themselves will be mentioned.