Earthworm invasion : consequences and conservation implications for the endangered Garry Oak (Quercus garryana) and maritime meadow ecosystems
department or school: Forestry, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Fleri, Jesse R.
issued: 2020-07-02T17:01:33Z
issued: 2020
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Biological invasions by non-native ‘ecosystem engineers’ can radically alter the ecological and socio-economic values of ecosystems in ways that may require decades to detect. The invasion of North American glacial refuges by non-native earthworms is a prominent but understudied example of a cryptic invasion by an ecosystem engineer. Non-native earthworms are known to reduce soil carbon, disrupt mycorrhizal networks, and homogenize plant communities in their role as seed predators, root foragers, and in nutrient cycling and redistribution. However, natural resource managers have struggled to discern the scale at which non-native earthworms influence plant species diversity across invaded biomes. With no effective methods to eradicate or control established earthworm populations, there is great need for preemptive strategies to identify high-value conservation areas at risk of invasion. Herein, I address two main questions with implications for forest management: 1) Can the influence of non-native earthworms on plant community assembly be reliably predicted using plant traits? 2) Can abiotic factors be used to identify and predict natural refuges from earthworms in heterogenous habitats? I found that the presence of earthworms contributed to the simplification of plant communities in experimental mesocosms and observational surveys of in-situ forest and meadow habitat. In general, earthworms were associated with plant communities dominated by species with large seeds and fibrous roots, whereas species with small seeds and taproots only persisted in multi-species mesocosms without earthworms. These findings suggest that earthworms shape community composition in the early stages of invasion by acting as ecological filters on morphological plant traits. Last, I constructed an ensemble species distribution model for non-native earthworms using data from 300 survey plots to identify the suite of environmental conditions needed to limit the dispersal and persistence of inv…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/74832
note: EARTHWORM INVASION: CONSEQUENCES AND CONSERVATION IMPLICATIONS FOR THE ENDANGERED GARRY OAK (Quercus garryana) AND MARITIME MEADOW ECOSYSTEMS by Jesse R. Fleri B.S., Utah State University, 2018 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Forestry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) June 2020 © Jesse R. Fleri, 2020 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Earthworm Invasion: Consequences and Conservation Implications for the Endangered Garry Oak (Quercus garryana) and Maritime Meadow Ecosystems submitted by Jesse R. Fleri in partial fulfillment of the requirements for the degree of Master of Science in Forestry Examining Committee: Dr. Peter Arcese, Forestry Supervisor Dr. Tara G. Martin, Forestry Supervisory Committee Member Dr. Amanda Rodewald, Department of Natural Resources, Cornell University Supervisory Committee Member Dr. Cindy Prescott, Forestry Additional Examiner iii Abstract Biological invasions by non-native ‘ecosystem engineers’ can radically alter the ecological and socio-economic values of ecosystems in ways that may require decades to detect. The invasion of North American glacial refuges by non-native earthworms is a prominent but understudied example of a cryptic invasion by an ecosystem engineer. Non-native earthworms are known to reduce soil carbon, disrupt mycorrhizal networks, and homogenize plant communities in their role as seed predators, root foragers, and in nutrient cycling and redistribution. However, natural resource managers have struggled to discern the scale at which non-native earthworms influence plant species diversity across invaded biomes. With no effective methods to eradicate or control established earthworm populations, there is great need for preemptive strategies to identify high-value con…
has type: Thesis/Dissertation
date issued: 2020-11
is shown at: 10.14288/1.0392040
language: eng
degree discipline: Forestry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/74832