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You searched for +publisher:"University of Notre Dame" +contributor:("Gary E. Belovsky, Committee Chair"). Showing records 1 – 3 of 3 total matches.

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University of Notre Dame

1. Matthew John Michel. Influence of multiple environments on tadpole phenotypes: plasticity, adaptation, and conservation implications</h1>.

Degree: PhD, Biological Sciences, 2009, University of Notre Dame

Phenotypic plasticity is the ability of an organism to alter its phenotype in response to changing environmental conditions. The recognition that phenotypic changes often improve the fitness of individuals (i.e., are adaptive) has expanded interest in plasticity as an important driver of many ecological and evolutionary processes. Predation risk and competition density are important environmental factors that induce adaptive phenotypic changes in many species. However, the specific impact of these factors on an individual’s phenotype depends on the foraging behavior employed by the predator, the type of competition experienced (interference vs. exploitative), and other environmental conditions. For anuran larvae (i.e., tadpoles), the presence of vertical habitat structure may affect phenotypic responses by altering: 1) capture success and foraging behavior of predators and 2) the type and level of competition experienced. Using large-scale mesocosm experiments, I found that, compared to simple environments, tadpoles were less likely to express adaptive behavioral and morphological phenotypes in habitats containing greater environmental complexity. For example, tadpole phenotypic responses to changes in habitat structure and competition density were adaptive, but only in the absence of predation risk. However, in a survey of natural ponds, predation risk and competition density, but not habitat structure, explained substantial portions of tadpole phenotypic variance. Even though tadpoles experience changes in multiple environmental variables, predation and competition seem to exert the greatest influence in shaping tadpole phenotypes. Predation risk and competition intensity also interacted to modify the development of a maladaptive tadpole malformity linked to ultraviolet-B radiation overexposure. Behavioral changes of tadpoles induced by predation and competition, such as activity levels, likely mediated this effect. Through this research, I have demonstrated that increasing environmental complexity constrains the ability of organisms to express adaptive phenotypes. Patterns of phenotypic plasticity observed in laboratory conditions do translate to natural environments, but are limited to phenotypic responses to environments that exert strong inductive and selective pressures. Furthermore, phenotypic plasticity can modify the susceptibility of organisms to the effects of environmental stressors. Advisors/Committee Members: Gary E. Belovsky, Committee Chair, Hope Hollocher, Committee Member, Rick A. Relyea, Committee Member, Jessica J. Hellmann, Committee Member.

Subjects/Keywords: trait-mediated interaction; Rana sylvatica; phenotype-environment association; scoliosis; wood frog; behavioral plasticity; trophic cascade; Dytiscus; diving water beetle

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APA (6th Edition):

Michel, M. J. (2009). Influence of multiple environments on tadpole phenotypes: plasticity, adaptation, and conservation implications</h1>. (Doctoral Dissertation). University of Notre Dame. Retrieved from https://curate.nd.edu/show/5h73pv65d1v

Chicago Manual of Style (16th Edition):

Michel, Matthew John. “Influence of multiple environments on tadpole phenotypes: plasticity, adaptation, and conservation implications</h1>.” 2009. Doctoral Dissertation, University of Notre Dame. Accessed March 20, 2019. https://curate.nd.edu/show/5h73pv65d1v.

MLA Handbook (7th Edition):

Michel, Matthew John. “Influence of multiple environments on tadpole phenotypes: plasticity, adaptation, and conservation implications</h1>.” 2009. Web. 20 Mar 2019.

Vancouver:

Michel MJ. Influence of multiple environments on tadpole phenotypes: plasticity, adaptation, and conservation implications</h1>. [Internet] [Doctoral dissertation]. University of Notre Dame; 2009. [cited 2019 Mar 20]. Available from: https://curate.nd.edu/show/5h73pv65d1v.

Council of Science Editors:

Michel MJ. Influence of multiple environments on tadpole phenotypes: plasticity, adaptation, and conservation implications</h1>. [Doctoral Dissertation]. University of Notre Dame; 2009. Available from: https://curate.nd.edu/show/5h73pv65d1v


University of Notre Dame

2. Angela Nardoni Laws. Effects of abiotic conditions and herbivore density on tritrophic interactions in an old field food chain</h1>.

Degree: PhD, Biological Sciences, 2007, University of Notre Dame

An important challenge for ecologists is to understand how variation in climatological factors caused by global warming will affect biotic communities. Climatological factors such as temperature may have important impacts on species interactions and community processes, including the occurrence of trophic cascades. This study investigated the effects of temperature on species interactions in a model plant–grasshopper–spider food chain. Three main questions were addressed: 1) How do grasshoppers behaviorally respond to temperature and predation risk? 2) How do grasshopper performance traits (survival, fecundity, body mass) respond to variation in temperature, and can grasshopper density modify these responses? 3) How does temperature and grasshopper density affect the occurrence of trophic cascades in this system? Manipulative field experiments were conducted in an old field at the University of Notre Dame Environmental Research Center (East) in northern Wisconsin from 2002 - 2005. Food chain length, grasshopper density, and temperature were manipulated in field enclosures. Temperature was varied using shade cloth or plastic greenhouses placed over enclosures. Grasshopper behavior and performance traits were measured, as well as plant biomass. Spider presence caused grasshoppers to shift feeding to warmer parts of the day, and to increase overall time spent feeding. This is surprising because most studies find that grasshoppers decrease activity in response to predator presence. It is hypothesized that increased feeding in response to spider presence may be a mechanism to compensate for increased metabolic costs of foraging in warmer parts of the day. Both temperature and grasshopper density were found to be important factors affecting predator-prey dynamics. Furthermore, spiders modified grasshopper response to temperature. For example, grasshopper survival varied with temperature when spiders were not present. This was best explained by the effects of temperature on net resource intake. In contrast, when spiders were present, climate treatment had no effect on grasshopper survival. This indicates that spiders can buffer grasshopper survival from the effects of temperature change. Furthermore, the occurrence of trophic cascades varied with both temperature and grasshopper density. This research indicates that global climate change may have profound impacts on biotic communities, affecting species performance and species interactions. Advisors/Committee Members: Gary E. Belovsky, Committee Chair, Anthony Joern, Committee Member, David Lodge, Committee Member, Jessica Hellmann, Committee Member.

Subjects/Keywords: temperature; food web; trophic cascades; global climate change; grasshopper

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Laws, A. N. (2007). Effects of abiotic conditions and herbivore density on tritrophic interactions in an old field food chain</h1>. (Doctoral Dissertation). University of Notre Dame. Retrieved from https://curate.nd.edu/show/g158bg27d49

Chicago Manual of Style (16th Edition):

Laws, Angela Nardoni. “Effects of abiotic conditions and herbivore density on tritrophic interactions in an old field food chain</h1>.” 2007. Doctoral Dissertation, University of Notre Dame. Accessed March 20, 2019. https://curate.nd.edu/show/g158bg27d49.

MLA Handbook (7th Edition):

Laws, Angela Nardoni. “Effects of abiotic conditions and herbivore density on tritrophic interactions in an old field food chain</h1>.” 2007. Web. 20 Mar 2019.

Vancouver:

Laws AN. Effects of abiotic conditions and herbivore density on tritrophic interactions in an old field food chain</h1>. [Internet] [Doctoral dissertation]. University of Notre Dame; 2007. [cited 2019 Mar 20]. Available from: https://curate.nd.edu/show/g158bg27d49.

Council of Science Editors:

Laws AN. Effects of abiotic conditions and herbivore density on tritrophic interactions in an old field food chain</h1>. [Doctoral Dissertation]. University of Notre Dame; 2007. Available from: https://curate.nd.edu/show/g158bg27d49


University of Notre Dame

3. Jennifer F Hsia. Post-dispersal sugar maple (Acer saccharum) seed predation by sciurids and other small mammals in a northern hardwood forest</h1>.

Degree: MS, Biological Sciences, 2007, University of Notre Dame

Small granivorous mammals can potentially affect forest regeneration through seed dispersal or predation. Using live-trapping efforts and track boards with tagged sugar maple (Acer saccharum) seeds in June and August of 2006 at eight mixed forest sites in Michigan’s Upper Peninsula, we asked: (1) are sugar maple seeds provided later in the summer more often cached? (2) Are small mammals seed dispersers or predators at these sites? (3) How did seed predator (i.e., all granivorous small mammals) and sciurid (chipmunks and squirrels only) biomasses affect the proportion of seeds eaten? (4) How did habitat structure affect small mammal biomasses? 5) How did sciurid biomass relate to non-sciurid biomass? Although fewer seeds were cached in August, we found that small mammals, eastern chipmunks in particular, were predators of sugar maple seeds, with an increased proportion of seeds eaten with increasing seed predator and sciurid biomasses. We also found a larger seed predator biomass and the presence of eastern chipmunks in areas with relatively more deciduous trees, and sciurid biomass increased with non-sciurid biomass, indicating their similar responses to environmental resources. Future studies should track sugar maples seed fates and eastern chipmunk biomass changes throughout the year to locate the time of highest seed survival. Advisors/Committee Members: Karen E. Francl, Committee Member, Jessica J. Hellmann, Committee Member, John G. Duman, Committee Member, Gary E. Belovsky, Committee Chair.

Subjects/Keywords: caching; sugar maple; eastern chipmunk; small mammals; red squirrel; seed predation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hsia, J. F. (2007). Post-dispersal sugar maple (Acer saccharum) seed predation by sciurids and other small mammals in a northern hardwood forest</h1>. (Masters Thesis). University of Notre Dame. Retrieved from https://curate.nd.edu/show/b8515m62s81

Chicago Manual of Style (16th Edition):

Hsia, Jennifer F. “Post-dispersal sugar maple (Acer saccharum) seed predation by sciurids and other small mammals in a northern hardwood forest</h1>.” 2007. Masters Thesis, University of Notre Dame. Accessed March 20, 2019. https://curate.nd.edu/show/b8515m62s81.

MLA Handbook (7th Edition):

Hsia, Jennifer F. “Post-dispersal sugar maple (Acer saccharum) seed predation by sciurids and other small mammals in a northern hardwood forest</h1>.” 2007. Web. 20 Mar 2019.

Vancouver:

Hsia JF. Post-dispersal sugar maple (Acer saccharum) seed predation by sciurids and other small mammals in a northern hardwood forest</h1>. [Internet] [Masters thesis]. University of Notre Dame; 2007. [cited 2019 Mar 20]. Available from: https://curate.nd.edu/show/b8515m62s81.

Council of Science Editors:

Hsia JF. Post-dispersal sugar maple (Acer saccharum) seed predation by sciurids and other small mammals in a northern hardwood forest</h1>. [Masters Thesis]. University of Notre Dame; 2007. Available from: https://curate.nd.edu/show/b8515m62s81

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