Graduation Date

Spring 2026

Document Type

Thesis

Program

Master of Science degree with a major in Biology

Committee Chair Name

Dr. Catalina Cuellar-Gempeler

Committee Chair Affiliation

Cal Poly Humboldt Faculty or Staff

Second Committee Member Name

Dr. Paul Bourdeau

Second Committee Member Affiliation

Cal Poly Humboldt Faculty or Staff

Third Committee Member Name

Dr. Jianmin Zhong

Third Committee Member Affiliation

Cal Poly Humboldt Faculty or Staff

Fourth Committee Member Name

Dr. Christopher Dugaw

Fourth Committee Member Affiliation

Cal Poly Humboldt Faculty or Staff

Keywords

Biodiversity–ecosystem functioning, Microbial ecology, Stress gradient hypothesis, Darlingtonia californica, Microbiome, Modeling, Pitcher plants, Exyra moths, Lotka-Volterra, Host-antagonist interactions

Subject Categories

Biology

Abstract

This work looks at two different sites with differing abiotic factors in measures of altitude, temperature and precipitation. The site with higher altitude, larger temperature range, and lower precipitation, located in Plumas National Forest (Quincy, CA), had a flat BEF trend that suggests functional redundancy The site with lower altitude, more moderate temperatures, and higher precipitation located in Six Rivers National Forest (Gasquet, CA), also had a flat BEF trend. These abiotic factors could correlate to the significantly different bacterial compositions between sites. The second portion of this work is modeling the host antagonist relationship between Eyxra moths and their obligate host Sarracencia pitcher plants. I modeled this relationship between moths, leaves, and available nitrogen in their inquiline communities using Lotka-Volterra models. Through non-dimensionalization and by graphing all three steady-state functions as the parameters increase, I found that the growth rate of moths at carrying capacity is the most influential parameter. These results are consistent with the literature that Exyra moths have an impact on the system. My thesis contributes to our understanding of links between community dynamics and function, in the context of pitcher plant associated microbial communities. In the first portion, I found evidence of the effects of abiotic factors on assembly processes, with no direct significant impact on function. In the second portion, I found that the antagonist is driving changes to all levels of this trophic interaction. Broadly, this work advances our ability to consider the ecological complexity that drives community level responses to biotic and abiotic factors, with emphasis on the functional consequences that can impact natural ecosystems.

Citation Style

APA

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