Effects of environmental clines and herbivory for plant functional traits and response to climate change

University Of California-Irvine, Irvine CA

Investigators

Abstract

Over generations, wild species can adapt to their physical environment and evolve, for example, features that enable them to better survive drought. Species can also adapt in response to other species. For instance, being eaten by insects can select for the production of defensive chemicals in plants. This project will study how these two types of drivers of evolution, the physical and the biotic, can work in concert to direct evolution and to shape local adaptation within a species. Research will focus on how the availability of water and the presence of plant-eating insects have caused different populations of a widespread woody plant to evolve different abilities to withstand drought and damage. Results will improve basic scientific understanding of how multiple, natural forces can change organisms through evolution. The work will also advance practical understanding of how multiple aspects of global change, such as climate change and introduction of species into new habitats by humans, are likely to change the species with which people live. To help communicate this understanding to the public, the project will develop educational curricula for K-12 youth. Researchers will study the woody shrub Artemisia californica along 700 km (6o latitude) of the central and southern coast of California, a region in which precipitation variability is projected to increase. Genotypes from 20 source populations will be established in common gardens throughout the range of the species and subjected to ambient and reduced herbivory and to ambient and increased intra-annual variability in precipitation. The measurement of plant traits from these gardens will be complemented with measurements of herbivore tolerance, defense and resistance traits from a parallel field study. Population source sites will be characterized with respect to both the abiotic and biotic environment. By measuring patterns of natural selection on plant traits under current and manipulated environments, this study will document current patterns of local adaptation and forecast future evolutionary response to projected climate change.