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Thesis Abstract – Litle (2018)

Title:

Population structure of suburban coyotes (Canis latrans) across a fragmented landscape in Southern California

Author and college:

John Litle, Pomona College

Date:

April 2018

Degree:

Bachelor of Arts in Biology

Advisor:

Wallace Meyer, Department of Biology, Pomona College

Abstract:

Herbivory is an important but understudied driver of plant community dynamics. As such, it is often difficult develop effective management and restoration strategies in systems where herbivory is not well characterized. To preliminarily assess the influence of herbivory on shrub communities in the California Sage Scrub (CSS) ecosystem, we conducted a series of experiments that addressed the following: (1) the effect of herbivory on Artemisia californica seedling survivorship, the most abundant shrub species in CSS, (2) herbivore preference of common CSS shrub species, (3) which vertebrate species are impactful herbivores in CSS fragments, and (4) to what extent herbivores alter fine fuel loads. We found that mortality was 70% higher for uncaged A. californica seedlings stage than caged seedlings. Moreover, herbivory of native shrubs in CSS is highly seasonal, occurring primarily in the late summer and early fall months. Artemisia californica and Eriogonum fasciculatum are the more susceptible than other native shrub species, however, relative shrub susceptibility to herbivory depends on the identity of the herbivore. Herbivores also significantly reduce above ground fuel loads, which may increase the periodicity of fire cycles and promote native shrub survivorship in the long term. Our results highlight that restoration of CSS plant communities must consider the impacts of vertebrate herbivores, particularly at the seedling stage. However, vertebrate herbivores are potentially beneficial to the long-term preservation of the CSS ecosystem by reducing fine fuel loads and ignition probabilities, and increasing fire return intervals.

For more information:

Contact Wallace Meyer – Wallace.Meyer@Pomona.edu