Spring 2024

Document Type

Master's Thesis (Open Access)

Degree Name

Master of Science (M.S.)


Applied Environmental Science


River ecosystems in the United States are facing significant ecological and economic impacts from invasive species. In California, along the Salinas River, Arundo donax has become a major concern, aggressively outcompeting native plant species and altering river flow and regime. The Resource Conservation District of Monterey County has been removing A. donax since 2014 using methods like mowing and applying herbicides and cleared an additional 415 acres in 2019. The study investigates the changes in invertebrate communities before and after A. donax removal, using the California Stream Condition Index (CSCI) and the Dry Stream Condition Index (DSCI) to assess ecological health. Despite removal efforts, the study finds that ecological conditions did not significantly improve, suggesting that A. donax removal alone may not be sufficient to restore ecological balance. The findings underscore the complexity of river ecosystem restoration, the need for comprehensive management strategies that address the root causes of degradation, and the importance of innovative assessment tools to evaluate ecosystem health under varying conditions.