Thesis
Invasive range expansion: environmental tolerance of widespread and restricted clonal lineages
Washington State University
Master of Science (MS), Washington State University
2018
Handle:
https://hdl.handle.net/2376/102994
Abstract
Widespread invaders must possess some capacity to disperse--either naturally or mediated by human activities, and dispersing genotypes need to tolerate novel environments for aggressive range expansion to occur once arriving. In this study, we tested the importance of environmental tolerance during invasive range expansion of the New Zealand freshwater snail (Potamopyrgus antipodarum). In North America, populations of P. antipodarum exist solely of one of two clonal genotypes: US1, a widespread genotype that dominates the western US, or US2, which is currently known only from the Great Lakes. We asked whether ten newly identified invasive populations near several Great Lakes states--WI, MD, MI, PA, and NY--were colonized by the US2 clone (with a shorter dispersal distance), or by US1 (the clone with a broader and more distant range but is an aggressive disperser). To do so, we constructed a MAXENT niche model based on the current range of each clone to predict habitat suitability of the newly occupied range. Our model predicted higher habitat suitability for US2 than US1 at all ten sites--with much higher habitat suitability for US2 at two sites (NY). We then surveyed the clonal composition of each of the ten new populations. Our survey showed that eight of the new populations (from WI, MD MI, and PA) were comprised entirely of US1, and that the two NY populations were comprised entirely of US2. Thus, colonization of the NY sites by US2 is consistent with both habitat suitability and short dispersal distance. Colonization of the WI, MI and PA populations by US 1 suggests that human-mediated dispersal might be more important than dispersal distance and habitat suitability. Long-distance colonization by US1 might best be explained by human vectors of dispersal, which are perhaps more likely to move snails from distant streams than from deeper waters of the Great Lakes.
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Details
- Title
- Invasive range expansion
- Creators
- Jonathan Arthur Finger
- Contributors
- Mark F. Dybdahl (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Sciences, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900524862701842
- Language
- English
- Resource Type
- Thesis