Plant-herbivore interactions : consequences for the structure of freshwater communities and exotic plant invasions

Parker, John D.

Title:

Plant-herbivore interactions : consequences for the structure of freshwater communities and exotic plant invasions

dc.contributor.advisor	Hay, Mark E.
dc.contributor.author	Parker, John D.
dc.contributor.committeeMember	Kubanek, Julia
dc.contributor.committeeMember	Montoya, Joseph
dc.contributor.committeeMember	Streelman, J. Todd
dc.contributor.committeeMember	David M. Lodge
dc.contributor.department	Biology
dc.date.accessioned	2006-04-25T15:07:49Z
dc.date.available	2006-04-25T15:07:49Z
dc.date.issued	2005-12
dc.description.abstract	Invasive exotic species threaten native biodiversity, alter ecosystem structure and function, and annually cost over $100 billion in the US alone. Determining the ecological traits and interactions that affect invasion success are thus critical for predicting, preventing, and mitigating the negative effects of biological invasions. Native herbivores are widely assumed to facilitate exotic plant invasions by preferentially consuming native plants and avoiding exotic plants. Here, I use freshwater plant communities scattered broadly across the Southeastern U.S. to show that herbivory is an important force driving the ecology and evolution of freshwater systems. However, native consumers often preferentially consume rather than avoid exotic over native plants. Analyses of 3 terrestrial datasets showed similar patterns, with native herbivores generally preferring exotic plants. Thus, exotic plants appear defensively nave against these evolutionarily novel consumers, and exotic plants may escape their coevolved, specialist herbivores only to be preferentially consumed by the native generalist herbivores in their new ranges. In further support of this hypothesis, a meta-analysis of 71 manipulative field studies including over 100 exotic plant species and 400 native plant species from terrestrial, aquatic, and marine systems revealed that native herbivores strongly suppressed exotic plants, while exotic herbivores enhanced the abundance and species richness of exotic plants by suppressing native plants. Both outcomes are consistent with the hypothesis that prey are susceptible to evolutionarily novel consumers. Thus, native herbivores provide biotic resistance to plant invasions, but the widespread replacement of native with exotic herbivores eliminates this ecosystem service, facilitates plant invasions, and triggers an invasional meltdown. Consequently, rather than thriving because they escape their co-evolved specialist herbivores, exotic plants may thrive because their co-evolved generalist herbivores have stronger negative effects on evolutionarily nave, native plants.	en
dc.description.degree	Ph.D.
dc.format.extent	3043982 bytes
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/9460
dc.language.iso	en_US	en
dc.publisher	Georgia Institute of Technology	en
dc.subject	Biotic resistance
dc.subject	Crayfish
dc.subject	Exotic plant invasions
dc.subject	Freshwater biology
dc.subject	Grass carp
dc.subject	Herbivores
dc.subject	Invasive plants Ecology
dc.subject	Marine ecology
dc.subject	Plant chemical defenses
dc.subject	Enemy release
dc.subject	Invasional meltdown
dc.subject	Natural enemies
dc.subject.lcsh	Invasive plants Ecology	en_US
dc.subject.lcsh	Marine ecology	en_US
dc.subject.lcsh	Freshwater biology	en_US
dc.subject.lcsh	Herbivores	en_US
dc.title	Plant-herbivore interactions : consequences for the structure of freshwater communities and exotic plant invasions	en
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Hay, Mark E.
local.contributor.corporatename	College of Sciences
local.contributor.corporatename	School of Biological Sciences
relation.isAdvisorOfPublication	f3c1eedd-ee9e-4723-b2d5-c793a79b0bbf
relation.isOrgUnitOfPublication	85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication	c8b3bd08-9989-40d3-afe3-e0ad8d5c72b5