Food Web Dynamics of Spring Rivers

New Fall River Research from Erin Donley (UC Davis, Ph.D. Student) 

Food Web Dynamics of Spring Fed Rivers: Independent UC Davis Research

Weevils Fall River California

At FRC, we do everything we can to support independent research from talented scientists and universities interested in the Fall River.  In Erin Donley’s case, we hardly need to do a thing. She brings to the Fall River the resources, experience, and multidisciplinary approach of UC Davis to help us better understand how this complex ecological system functions.  If you see her on the river, lend her a hand or get out of her way: she’s doing great work!

Read on for a description of Donley’s research abstract:

Food Web Dynamics of Spring Fed Rivers

Food webs are important drivers of ecosystem processes and are of particular importance in aquatic ecosystems, where they represent the energetic pathway between organic matter from vegetation and often threatened or endangered apex consumer populations.


Currently, a large degree of uncertainty exists surrounding the influence of bottom-up forces (carbon and nutrients from various sources: allochthonous, autochthonous, or groundwater sources) on the structure and function of aquatic food webs.

To address this uncertainty, I propose to assess the influence of various primary production sources and substrate types on macroinvertebrate community structure in spring-fed rivers of Shasta County: Fall River, Rising River, Hat Creek.

In this study, I intend to investigate the following questions: 1) What is the current composition of the portfolio of primary production sources in spring-fed rivers in Shasta County? 2) How might shifts in the composition of the portfolio of primary production sources impact food web community structure (species richness, species composition, patterns of interactions among species)? 3) How do changes in food web community structure influence system stability and resilience?

I intend to investigate these questions using a combination of stable carbon isotope analysis, empirical field studies, simulation modeling and network analysis.  I hypothesize that diverse sources of fine particulate organic matter (FPOM) support diverse invertebrate food web communities. I also expect that diverse invertebrate communities will be more stable, resilient and able to sustain ecosystem functioning in the form of nutrition for the iconic rainbow trout (Oncorhynchus mykiss) of northern California spring-fed rivers.

Slide 5

Leave a Reply