Abstract Detail

Ecology

Badillo, Berenice [1], Ochoa, Marissa E [2], Wright, Jessica W [3], Sork, Victoria [4].

Does foliar trichome abundance, morphology and plasticity vary with climate in a deciduous oak species?

As global climates warm dramatically, it is important to identify which traits affect a tree’s ability to respond to warmer climates and drought, an increasingly frequent occurrence in California’s Mediterranean climate. Foliar trichomes are one such trait because by increasing the thickness of the boundary layer that surrounds leaves, they can reduce excess transpiration. Utilizing an established common garden experiment at two U. S. D. A. Forest Service sites located in Chico and Placerville, California, we assessed whether valley oak (Quercus lobata) trees are genetically differentiated and/or phenotypically plastic with respect to foliar trichome morphology and abundance, and, if so, assess if these differences correlate with climate and geographic variables of the maternal site. We sampled fully developed leaves from 9-year-old trees representing 74 families across valley oak’s native range and dried them in coin envelopes before taking pictures of the abaxial side of the leaf at 1500x magnification. To estimate trichome abundance, pictures are divided into 4 quadrants by superimposing a grid in ImageJ and counting the number of hairs crossing the grid lines. Trichome morphologies were determined by counting the rays per trichome. Our findings indicate trichomes had a greater number of rays and trichome abundance in trees from coastal compared to inland seed sources. We also find that plasticity is associated with seed sources from warmer and more seasonal climates. Next steps will investigate the ecophysiological consequences for this morphological difference to see whether this trait is involved in oak response to rapid climate change. Such information will be needed to assess the value of including trichome characters in sourcing acorns for management of oak populations.

1 - University of California, Los Angeles, Ecology and Evolutionary Biology, 610 Charles E Young Dr S, Los Angeles, CA, 90095, USA
2 - University of California, Los Angeles, Department of Ecology and Evolutionary Biology, 612 Charles E. Young Drive South, 101 Hershey Hall, Box 957246, Los Angeles, CA, 90095, USA
3 - USDA Forest Service, Pacific Southwest Research Station, 1731 Research Park Dr., Davis, CA, 95618-6132, USA
4 - UCLA, ECOL & EVOL BIOL, Box 957239 , Los Angeles, CA, 90095, United States

Keywords:
valley oak
trichomes
Phenotypic plasticity
climate
common garden.

Presentation Type: Poster
Number: PEC033
Abstract ID:966
Candidate for Awards:None