PARENT SESSION
Wednesday, August 9, 8:00-11:30 am
COS 47 - Invasive species III: impacts on native species, communities, and ecosystems
Ballroom A, Ballroom Level, Cook Convention Center
Presiders: D Blumenthal and J Martin
Trade in vertebrates: The potential for biological homogenization.
Romagosa, Christina*,1, Guyer, Craig1, 1 Auburn University, Auburn, AL
ABSTRACT- Biological homogenization decreases global species diversity through species extinctions and introductions. The live vertebrate trade contributes to homogenization as the primary pathway for vertebrate introductions. Successful establishment of vertebrates is determined primarily by the number of individuals released or release events, known as propagule pressure. Based on this concept, potential propagules and subsequent homogenization through introductions should be related to the number of individuals imported and species richness per vertebrate taxon in trade. We utilized a subset of the international vertebrate trade, United States importation/exportation data from 1970–2002, to estimate how many individuals and species for 5 taxa (amphibians, turtles, squamates, crocodilians, and birds) were moved through this pathway. For each taxon, we plotted the cumulative number of species imported from 1970–2002, projected species accumulation to identify the point at which all species will have been traded, and regressed the cumulative number of established species versus the cumulative number of species imported. If the current exponential rate of species accumulation we found continues, we predict that the United States will trade all turtle, crocodilian, and squamate species in less than 75 years. The potential for homogenization through introductions is greatest for taxa with the highest proportion of their global species traded. We found an increasing relationship between the cumulative number of established species versus the cumulative number of species imported per taxon. Our results indicate that data from the live vertebrate trade can provide an informative and predictive framework for discussion of the relationship between trade and vertebrate introductions.
Key words: Biological invasions, vertebrates, homogenization