Date of Award

Spring 1-1-2014

Document Type

Thesis

Degree Name

Master of Arts (MA)

Department

Ecology & Evolutionary Biology

First Advisor

Sharon K. Collinge

Second Advisor

Nichole Barger

Third Advisor

Daniel F. Doak

Abstract

Vernal pools, also termed temporary wetlands, promote key ecosystem services such as floodwater retention and provide unique habitat for many organisms. Despite their ecological value, vernal pools are declining worldwide because of habitat loss and encroachment of non-native species. Because vernal pool obligate plant species are strongly influenced by variation in annual precipitation that fills the pools, climate change and alterations in precipitation regimes can drastically alter these fragile communities. To understand how annual variation in precipitation and temperature affect vernal pool plant community composition, I examined long-term vegetation data for constructed vernal pools on Travis Air Force Base in Solano Co. CA. I used native and non-native plant frequencies collected over a 10 year period to explore the dynamics between species frequency and climate variability. I further analyzed fine-scale site topography to explore the effects spatial variability on ponding. I identified key differences between native and non-native plant species' responses to climate variability and ponding. Over all, native species tend to respond positively to winter precipitation accumulations, but non-native species do not. Inundation appears to act as an ecological filter, preventing the establishment of non-native species. In addition, elevation seems to be a predictor of ponding--lower elevation pools tend to have greater pool depths, which can enhance the effects of the inundation filter. Together, these findings will assist management efforts in understanding the climatic and spatial factors that influence vernal pool restoration practices.

Share

COinS