Habitat patch size and breeding site quality drive relative abundance of Ambystoma salamander larvae

Document
Abstract

Amphibian biodiversity is in global decline, driven primarily by habitat loss and fragmentation arising from landcover alteration. For pond-breeding amphibians, larval abundance should be governed by aquatic breeding site quality, surrounding terrestrial habitat characteristics, and proximity to neighbouring populations. If safeguarding salamander populations is a priority, conservation efforts will benefit from understanding the relative importance of each feature on salamander populations. I sought to identify the factors associated with relative abundance of Ambystoma salamander larvae across habitat patches on Pelee Island, Ontario, Canada. Larval density and a suite of environmental variables were measured at 34 breeding sites across the island. Using spatial analysis, I also determined landcover features surrounding the breeding site, including, terrestrial habitat type, terrestrial patch size, and indices of isolation (e.g., nearest neighbour distance, proximity index). The relative abundance of Ambystoma larvae was best predicted by additive effects of breeding site quality (e.g., canopy cover, submergent vegetation, and cooler water temperature) and size of surrounding terrestrial habitat patches. I did not detect any influence of agricultural land cover within 300 m of the breeding sites on larval count, implying that Ambystoma can persist within agriculture-dominated landscapes provided that high breeding habitat quality is maintained, and ponds are embedded within large forest patches. Further, I failed to detect any impact of breeding site isolation on larval numbers, indicating that local habitat quality and terrestrial patch size more strongly determine larval abundance than patch connectivity. My research highlights the critical importance of conserving high-quality aquatic breeding habitats and maintaining large contiguous patches of terrestrial habitat for amphibian

Author Keywords: Amphibian, Anthropogenic impacts, Biodiversity conservation, Habitat fragmentation, Habitat suitability, Salamanders

    Item Description
    Type
    Contributors
    Creator (cre): McDonald, Jordan
    Thesis advisor (ths): Hossie, Thomas J
    Thesis advisor (ths): Murray, Dennis
    Degree committee member (dgc): Wilson, Chris
    Degree granting institution (dgg): Trent University
    Date Issued
    2025
    Date (Unspecified)
    2025
    Place Published
    Peterborough, ON
    Language
    Extent
    61 pages
    Rights
    Copyright is held by the author, with all rights reserved, unless otherwise noted.
    Subject (Topical)
    Local Identifier
    TC-OPET-32042480
    Publisher
    Trent University
    Degree
    Master of Science (M.Sc.): Bioenvironmental Monitoring & Assessment