Biology ETDs

Publication Date

Fall 11-15-2022


Quantifying the flow of energy and nutrients through food webs is foundational to understanding the structure and function of ecosystems. Here, I utilize the stable carbon and nitrogen isotope analysis of individual amino acids to trace the movement of essential amino acids through terrestrial and freshwater food webs in New Mexico, USA. I first explore isotopic patterns among co-occurring terrestrial plants and aquatic algae. I then combine this molecular isotopic approach with 16S and 18S rRNA sequencing to demonstrate the importance of gut microbiota as sources of essential amino acids to wild mammalian hosts. Next, I explore the roles of microbial biofilms in facilitating terrestrial resource use by aquatic macroinvertebrates. I find that terrestrial riparian plant species greatly influences microbial biofilm diversity and composition and macroinvertebrate feeding habits. My work emphasizes the importance of microbes in facilitating the consumption and decomposition of recalcitrant terrestrial plants.

Project Sponsors

National Science Foundation Graduate Research Fellowship Program (Grant No. 1939267)




carbon, stable isotopes, amino acids, food webs, gut microbiome, aquatic microbial biofilms

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Seth D. Newsome

Second Committee Member

Cristina D. Takacs-Vesbach

Third Committee Member

Thomas F. Turner

Fourth Committee Member

Jane C. Marks