Abstract Detail

Ecology

Oshiro, Juliet [1], Potts, Stephen [2], Fox, Laurel [3].

Trait-based phenological responses to climate of plant communities in coastal California.

Climate often cues plant phenology, but types of phenological responses differ between species. We address whether species with similar phenological responses to climate have a similar suite of traits. Our research is based on a historical dataset of flowering observations from the 1990s along with resurveys from 2011 through 2015 of 10 sites within Santa Cruz County, CA. Santa Cruz County is located within the coastal climate zone, and the study sites represent two habitat types: four inland sandhills sites, and three maritime and three inland grassland sites. Year round, once per month surveys recorded first and last flowering date, and duration of flowering of all species at each site. We hypothesize that phenological responses to climate represent two adaptive strategies: avoidance versus tolerance of the Mediterranean climate’s lengthening hot, dry summers. Therefore we analyzed traits that characterize drought tolerance, heat tolerance, and blooming season. We also considered ecological traits such as life-history, functional group and nativity to California. Finally, we included taxonomic family and superfamily, and relative abundance to control for phylogenetic and population size biases. We used a random forest analysis to determine which climate variables best predicted first flowering date, then used generalized additive models to determine how first flowering date responds to the six most important climate variables for groups of species with similar traits. In response to temperature we found advancement in winter/spring blooming annuals at grasslands; and delays in summer/fall blooming annuals at grasslands, and winter/spring blooming annuals at sandhills. Precipitation only affected non-native species and late blooming season annuals at sandhills. This approach allows us to predict species’ responses to climate based on their traits, and provides a mechanistic understanding of why species exhibit certain responses to climate change.

1 - University of California Santa Cruz, Ecology and Evolutionary Biology, 1156 High Street, Santa Cruz, Ca, 95064, USA
2 - Louisiana State University, Department of Biological Sciences, 103 Life Sciences Bldg, Baton Rouge, LA, 70803, USA
3 - University of California Santa Cruz, Ecology and Evolutionary Biology, 1156 High Street, Santa Cruz, Ca, 95064, United States

Keywords:
phenology
climate change
plant traits
coastal California
mediterranean climate.

Presentation Type: Oral Paper
Session: 14, Ecology Section: Plant Functional Traits and Responses
Location: 201/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 4:00 PM
Number: 14008
Abstract ID:545
Candidate for Awards:Ecological Section Best Graduate Student Paper