Response of Terrestrial Ecosystems along the Antarctic Peninsula to a Changing Climate

Arizona State University, Scottsdale AZ

Investigators

Abstract

The striking increases in air temperatures and ultraviolet-B radiation (UVB) documented along the west coast of the Antarctic Peninsula over the past 50 years represent a profound climatic change, arguably larger than experienced by any other region on earth over the last half century. Along with these well-documented changes, annual precipitation and the depth of winter snow pack also appear to be increasing along the Peninsula. These rapid changes in climate provide a unique opportunity to examine the effects of climate change on terrestrial ecosystems. Building on past work that focused on the impacts of warming and UVB on the performance of terrestrial vascular plants on the Peninsula, this project will examine how climate change alters nutrient (carbon and nitrogen) pools and cycling among plants, litter and soils in vascular-plant dominated communities, with the overall goal of predicting long-term effects on plant primary productivity. Two complementary approaches will be employed: experimental manipulation of the climate of plant communities and examining patterns in plant communities along environmental transects that represent long-term climatic gradients. In the first approach, shorter-term system responses to climate change will be examined by manipulating temperature, water availability, and UVB exposure of vascular-plant microcosms over three growing seasons. Scientists will assess how these manipulations influence plant growth and primary productivity, carbon dioxide fluxes, litter quality and decomposition, pools and turnover rates of C and N, and the structure of soil microbial and arthropod communities. These realistic environmental manipulations will allow for an accurate assessment of the effects of different future warming scenarios, as well as the effects of solar UVB. In the second approach, longer-term responses to warming will be evaluated by measuring pools of carbon and nitrogen in plants, litter and soils in plant communities along transects that represent gradients of long-term temperature regime. Analyzing the results from short-term warming manipulations in the context of patterns found along these gradients will make it possible to develop a conceptual model of warming impacts over longer time scales. The broader impacts of this project include: (1) Recruiting and training underrepresented, undergraduate students. (2) The dissemination of findings to the general public. (3) Contributing to society at large by improving our understanding of how climate change impacts plant productivity and ecosystem carbon storage. These impacts are societal concerns because they relate to crop production, as well as whether ecosystem responses to climate change will mitigate or promote continued buildups of greenhouse gases.