Date of Award
8-14-2020
Document Type
Dissertation
Degree Name
Environmental Sciences, Ph.D.
First Advisor
Travis Marsico
Committee Members
Hans Hacker; Rima Lucardi; Tanja McKay; Virginie Rolland
Call Number
LD 251 .A566d 2020 S39
Abstract
The fundamental goal in invasion ecology is to understand what drives the success of nonnative species. To assess mechanisms of invasion, invasion ecologists traditionally study populations of nonnative species that have already established and spread within an environment. A less common method is to use data from classical biocontrol agents, which are also nonnative and have variable impacts with respect to efficacy and non-target effects. Further elucidation of mechanisms of invasion can help researchers develop better methods for detection, prevention, and control of nonnative species. To make progress in the battle against nonnative species, focus should be placed on both the ecological and socio-political dimensions of invasion ecology. As such, my objectives were to: (1) employ scientometrics to assess interdisciplinary communication between invasion ecology and biocontrol; (2) analyze data from biocontrol databases to elucidate mechanisms that contribute to successful establishment and impact of insect invaders; (3) evaluate inter-rater agreement among experts who assess nonnative insect impacts; and (4) reflect on nonnative species policies in the context of results from this dissertation and other closely-linked studies. Invasion ecologists and biocontrol professionals primarily cited other research within their respective field, though biocontrol professionals also cited invasion research and invasion ecologists rarely cited biocontrol research. The analysis of biocontrol data concluded that successful phytophagous insects are coevolved with their hosts, introduced into a region with a climate similar to their native range, and/or feed on plant structures that are not easily restored, whereas the most successful entomophagous insects are host specialists and/or coevolved with their host. For the impact assessment, there was a high level of consensus among assessors, which was enhanced with implementation of joint fact-finding to resolve discordant impact scores. Considerable progress has been achieved over the past century regarding nonnative species policymaking; however, further actions (e.g., incorporation of expert assessment in decision-making, cooperation among jurisdictional units, prevention programs) should be taken to improve future prevention and control efforts. These results not only further ecological understanding of invasive species and consider socio-political improvements, but also drive the field of invasion ecology in a new direction using unconventional research approaches.
Rights Management
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Schulz, Ashley N., "Nonnative insect invasions in natural ecosystems: Impacts, policy, and evaluation of drivers using underutilized biocontrol datasets" (2020). Student Theses and Dissertations. 385.
https://arch.astate.edu/all-etd/385
