Abstract Detail

Ecology

Ryan, Elizabeth [1], Cleland, Elsa [2].

Clinal variation in phenological traits influences drought response of California poppy across its native range.

Species distribution models are often used to predict spatial variation in species persistence in the face of climate change, but these models neglect key factors such as local biotic interactions and genetic variation among populations that could influence population persistence. In the western U.S. increasingly severe droughts are a predicted component of climate change. We investigated clinal variation in phenological traits sensitive to drought, fitness and plastic responses to drought for 16 populations of Eschscholzia californica (California poppy) distributed across a clinal gradient in California characterized by fivefold variation in annual precipitation. Plants were grown in treatments approximating the precipitation regimes of the wettest and driest sites, and in the presence and absence of home soil. Phenological plant traits (i.e. emergence timing, flowering timing, growing season length) and fitness (i.e. biomass and seed production) both exhibited clinal variation. Southern, arid, populations emerged later, flowered earlier, had shorter growing seasons, and had higher fitness than northern, humid, populations. Our phenological traits of interest, as well as plasticity in two of these traits, emergence timing and growing season length, were correlated with fitness. The drought treatment decreased growing season length more for plants from humid populations than arid populations, while the ample water treatment increased biomass more for plants from arid populations than humid populations. Thus, arid populations that tolerate conditions north of current distributions are particularly promising candidates for assisted migration to northern sites, and could improve the chances of persistence in the face of drought. However, local biotic interactions could be lost when populations move across space: individuals grown in their home soil emerged earlier and produced more biomass than when grown in away soil, regardless of population source. Current predictive modelling approaches may be insufficient for species exhibiting strong clinal variation, beneficial local biotic interactions, and high population-level variation in plasticity.

1 - University of California San Diego, Biological Sciences, EBE, 740 Sapphire Street, APT 11, San Diego, CA, 92109, United States
2 - University Of California, San Diego, 9500 Gilman Dr. #0116, La Jolla, CA, 92093, United States

Keywords:
Plasticity
drought
intraspecific trait variation
clinal variation
phenology
Soil.

Presentation Type: Oral Paper
Session: ECO4, Ecology 4: Plant, Population, Community and Ecosystem Response to Environmental Stressors and Change PLUS Plant Biology (Aeroallergens and Phytochemical Differences)
Location: San Luis 1/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 9:00 AM
Number: ECO4005
Abstract ID:419
Candidate for Awards:None