Invasive species can alter the structure and function of ecosystems, reduce biological diversity, and directly change communities through predation, facilitation and competition. The invasive New Zealand mud snail ( Potamopyrgus antipodarum) has varying effects on native species in ecosystems where it has been introduced. We used two different experimental designs to study the interactions between P. antipodarum and the native snail, Fossaria (Bakerilymnaea) bulimoides group in Polecat Creek, Wyoming. We predicted that P. antipodarum would compete with Fossaria because they co-occur and consume similar resources. In the first experiment, we investigated growth at low ambient levels of biomass of each species. We found that growth of Fossaria and P. antipodarum was reduced by the presence of all competitors and that Fossaria grew more in intraspecific than interspecific interactions. This result was probably caused by much higher ambient biomass of the invasive P. antipodarum in the interspecific interaction treatment. Therefore, in our second experiment, we investigated how the snails interacted at an equal, higher biomass. Although growth of Fossaria was nearly halted at this high biomass of competitors, P. antipodarum grew fourteen times faster than the native despite removing less algae. In the high biomass treatment, growth of P. antipodarum was facilitated by the presence of Fossaria. Overall, although growth of both snail species was reduced by the biomass of competitors, for Fossaria, growth was reduced at a rate that was four times higher than P. antipodarum. We concluded that any negative effects on Fossaria do not appear to be caused by traits of P. antipodarum, per se, but rather by a high biomass of snails that occurs when they are highly abundant.
|Advisor:||Krist, Amy C., Hall, Robert O., Jr.|
|Commitee:||Hall, Robert O., Legg, David|
|School:||University of Wyoming|
|Department:||Zoology & Physiology|
|School Location:||United States -- Wyoming|
|Source:||MAI 50/03M, Masters Abstracts International|
|Keywords:||Competition, Growth, Invasive, Potamopyrgus antipodarum, Wyoming, Yellowstone|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be