Thursday, May 29, 2008 - 2:45 PM
575

How resources mediate invasiveness: The case for phosphorus

Teresa M. Tibbets and Amy C. Krist. Zoology and Physiology, University of Wyoming, 1000 E. University Ave, Dept 3166, Laramie, WY 82071

In order to predict and control the extent of invasive species impacts, it is vitally important to understand the mechanisms by which invasive species succeed in new environments. Food quality is important to understanding whether or not introduced species become invasive because it can affect population dynamics through its effects on life-history traits.  Potamopyrgus antipodarum (New Zealand mudsnail), a gastropod native to New Zealand, has spread throughout Europe, Australia, and North America. We examined how mudsnail growth rates, fecundity, and population dynamics respond to changing phosphorus (P) content of food. Mudsnails reared under low phosphorous conditions (high algal C:P ratio) grew more slowly, produced smaller offspring, and grew to a smaller adult size than snails grown on intermediate and high levels of P. P-limitation had demographic consequences;  the potential population growth rate of these snails was higher at low algal C:P ratios than under conditions of P-limitation. Because population growth rate affects whether or not an introduced species becomes invasive, the connection between P availability and population growth may help us to understand P. antipodarum introductions and to better predict where the snail is likely to become invasive.


Web Page: New Zealand mudsnail, C:N:P stoichiometry, invasive species