Abstract Detail

Ecology

Tang, Joanna [1], Nolan, Maddie [2].

Exotic Species Invasion in Restored Vernal Pools.

95% of California’s vernal pool ecosystems have been lost, resulting in a growing effort to restore these ecosystems and their associated endemic flora and fauna. However, because restored vernal pools often exist within a grassland matrix, they are prone to invasion by exotic annual grasses. We hypothesize that restored vernal pools are particularly susceptible to exotic invasion because restoration projects often have frontloaded short-term invasive species management. Long-term budget constraints often result in intensive exotic species weeding effort only 1-3 years after restoration. Even if these restored ecosystems show low exotic species abundance in the short term, they may not be resistant to exotic invasion in the long run.
We assessed exotic species abundance and diversity after intensive weeding had ceased in a set of restored vernal pools in Southern California. We found that exotic species cover and richness increased, particularly around the edges of the pools. We hypothesize that this increase in exotics around the pools’ edges indicates encroachment of exotic grasses from the upland grassland into the pools. Further, we found that the ratio of total native cover to total exotic cover decreased around the pool edges. These findings indicate that the native communities in our study’s restored vernal pools are not resistant to exotic invasion. One way that restoration projects may increase a vernal pool’s resistance to invasion is by employing an array of invasive species management techniques in addition to short-term weeding, such as bolstering the native seed bank and sourcing seed from competitive native ecotypes.

1 - University of California, Santa Barbara, Ecology, Evolution, & Marine Biology, 6540 El Colegio Road, Apartment #4202, Santa Barbara, CA, 93106, USA
2 - University of California, Santa Barbara, Ecology, Evolution, & Marine Biology, Santa Barbara, CA, 93106, USA

Keywords:
vernal pool
conservation and restoration
Invase plant species
California.

Presentation Type: Poster
Session: P, Ecology Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PEC004
Abstract ID:186
Candidate for Awards:None