PARENT SESSION
Poster Session #65: Global Change.
Friday, August 9. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC

Effects on soil and plant nutrients under an extended growing season plus soil warming: A climate change scenario.

Ahlquist, Lorraine^*,1, Oberbauer, Steven¹, ¹ Florida International Univerisity, Miami, FL

ABSTRACT- General Circulation Models (GCMs) indicate that a doubling of the present-day concentrations of atmospheric CO₂ will result in an average annual global warming of 1.9-5.2 °C. Temperature increases are expected to be much larger towards the poles. One of the consequences of this warming is a probable increase in growing season length. These changes will strongly affect plants and soils, with large ecosystem consequences. In order to make predictions about future community structure at these northern latitudes, a predictive understanding of the responses of tundra plants and soils to global warming is required for these highly nutrient-limited ecosystems. In this study, we will examine the nutrient responses of plants and soils in response to experimentally extended growing season and soil warming in arctic Alaska. Our approaches will include litter decomposition bags, ion exchange membranes, plant tissue sampling, and soil solution sampling. We expect to see significant increases in soil nutrient availability under extended growing season and soil warming as a result of increased decomposition rates. Plant tissue nutrient concentrations and growth should increase under the extended season regimes. As a result, we expect large community changes as plants with greater uptake capacities take advantage of increased nutrient availability.

KEY WORDS: soil and nutrients, climate change, arctic Alaska