DISSERTATION RESEARCH: Climate change and biome range shifts at high elevations

University Of Washington, Seattle WA

Investigators

Abstract

Ecologists have long recognized that climate variables (such as temperature or snowfall) play a key role in determining the geographic ranges of species and types of communities. Thus, as our planet becomes warmer due to climate change, these ranges are expected to shift toward the poles and uphill. However, a complicating factor is that non-climatic variables (such as soil quality) also influence biological ranges and how rapidly organisms can respond to climate change. The goal of this research is to understand the importance of both climatic and non-climatic constraints on the future distribution of the highly diverse mountain meadow community at Mount Rainier National Park. Warming is predicted to result in an upward movement of these meadows, but two factors could constrain the rate at which this occurs. First, meadow plants may not be able to disperse seeds into newly suitable habitat at the rate it becomes available through warming ("dispersal limitation"). Second, seedlings may not be able to establish in the rocky and infertile soils present at higher elevations ("establishment limitation"). To develop a better understanding of how these meadows will respond to climate change the researchers will: 1) use climate data and statistical models to predict where meadows will occur in the future given climate change and assuming no non-climatic limitations; 2) quantify dispersal limitations by monitoring the distance that seeds are moved from parent plants; and 3) quantify establishment limitations by comparing plant performance in fertile versus infertile soils at Mount Rainier. Climate change will likely cause a reshuffling of species and communities around the world, transforming the ecosystems humans depend on. This study will improve our scientific understanding of how mountain meadows will respond to climate change, a critical step in preparing for and alleviating the negative effects of climate change. Because the researchers share results with Park managers at Mount Rainier, this research will directly inform local management decisions. Moreover, the researchers regularly communicate their results with K-12 students, undergraduates, and Park visitors.