Collaborative Research: Landscape Genetic Connectivity of a Foundation Tree Species: Implications for Dependent Communities Facing Climate Change and Exotic Species Invasion

Desert Botanical Garden

Investigators

Abstract

An important topic of research today is how temperature affects the diversity of life on earth. At the same time as the climate is rapidly changing though, there is also rapid expansion of highly invasive, exotic species that additionally threaten biodiversity by displacing native species. The combined effects present an enormous challenge to land managers, as they may threaten established ecosystems and undermine the services they provide to humans. One way to meet this challenge is to study the effects on what are called foundation species. This study focuses on Fremont cottonwood, a foundation tree species that creates unique habitats along streams in the southwestern United States. These habitats support a high diversity of microbes, insects and animals, but are threatened by climate change along with a major invasive tree species, tamarisk, that displaces the native cottonwood and drastically alters the habitat and the beneficial ecosystem services it provides. The project uses genomic techniques, plus experiments that involve planting the same tree species in a range of areas, and computer modeling to determine gene flow among the cottonwoods along streams, to figure out how the cottonwood interacts with tamarisk, and to determine how tamarisk invasion changes all of the plants in these habitats and the services they provide. As environmental conditions change, foundation species must either adapt or go extinct. The loss of streamside habitats that are based on Fremont cottonwood is important because they are hotspots of biodiversity and provide services to local human populations in the region. This project may transform how we think of foundation species and how they respond to major disturbances, along with the other plants, animals and insects they harbor. This is useful for conservation planning. The project will provide lesson plans and teaching materials for elementary and high school teachers and opportunities for undergraduate and graduate students. It will also expand outreach to the public on how to approach the impacts of climate change and invasive species. The field experiments will be installed in collaboration with the Southwest Experimental Garden Array, which is focused on using genetics to address climate change impacts. The results will also be made available on a public outreach website.