Outcomes of stream invertebrate mesopredator interactions to benthic food webs and ecosystem functions
department or school: Forestry, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Tikka, Kelsey
issued: 2022-10-11T22:15:43Z
issued: 2022
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Within the predator guild of ecological communities are smaller-bodied mesopredators that have the ability to directly impact community structure and indirectly alter ecosystem processes. Interactions between predators can result in combined predator outcomes to their prey, termed Multiple Predator Effects (MPEs), that can be additive, antagonistic, or synergistic with the strength and direction contingent on predator identity and guild diversity. In streams on the west coast of North America, there are two co-occurring predatory stonefly larvae, Calineuria californica and Hesperoperla pacifica, both of which can cause direct depletion of the prey community which can cascade to indirectly alter leaf litter decomposition and periphyton standing stock. My objective was to quantify the role and outcome of intra- and interspecific interactions of C. californica and H. pacifica on stream food webs. I manipulated stonefly larvae identity and density, as well as richness of the predator guild, then compared larval growth and survival, prey community composition, and measures of basal resources to determine the MPE outcomes. I hypothesized that due to the high degree of niche overlap that competition would lead to antagonistic MPEs. I also hypothesized that increasing density and the presence of the more aggressive H. pacifica would lead to higher competition and stronger antagonistic MPEs. I found that stonefly larvae presence caused a 46% reduction in the prey community, and that increasing biomass of either species significantly caused this decline. For interspecific and intraspecific C. californica pairings there was density-dependent competition resulting in a switch from additive to antagonistic MPEs, while intraspecific H. pacifica pairings had antagonistic MPEs at all densities. I also found that the mechanism of predator impacts varied between the two species, with H. pacifica decreasing the prey community through consumption and C. californica through non-consumpt…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/82848
note: OUTCOMES OF STREAM INVERTEBRATE MESOPREDATOR INTERACTIONS TO BENTHIC FOOD WEBS AND ECOSYSTEM FUNCTIONS by Kelsey Tikka B.Sc. (Hons), University of British Columbia, 2020 B.Sc. (Hons), Wilfrid Laurier University, 2015 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) October 2022 © Kelsey Tikka, 2022 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Outcomes of stream invertebrate mesopredator interactions to benthic food webs and ecosystem functions submitted by Kelsey Tikka in partial fulfillment of the requirements for the degree of Master of Science in Forestry Examining Committee: John Richardson, Professor, Forestry, UBC Supervisor Katie Marshall, Assistant Professor, Zoology, UBC Supervisory Committee Member Christopher Harley, Professor, Zoology, UBC Supervisory Committee Member Juli Carrillo, Assistant Professor, Land and Food Systems, UBC Additional Examiner iii Abstract Within the predator guild of ecological communities are smaller-bodied mesopredators that have the ability to directly impact community structure and indirectly alter ecosystem processes. Interactions between predators can result in combined predator outcomes to their prey, termed Multiple Predator Effects (MPEs), that can be additive, antagonistic, or synergistic with the strength and direction contingent on predator identity and guild diversity. In streams on the west coast of North America, there are two co-occurring predatory stonefly larvae, Calineuria californica and Hesperoperla pacifica, both of which can cause direct depletion of the prey community which can cascade to indirectly alter leaf litter decomposition and periphyton standing stock. My objective was to quantify the role and outcome of intra- and interspecific…
has type: Thesis/Dissertation
date issued: 2022-11
is shown at: 10.14288/1.0421259
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
contributor: Richardson, John Stuart
type: Text
identifier URI: http://hdl.handle.net/2429/82848