PARENT SESSION
Oral Session # 68: Soil Ecology I: Communities, Respiration, and Nutrient Cycling.
Presiding: C Rumbaitis-del Rio
Thursday, August 7. 8:00 AM to 11:30 AM, SITCC Meeting Room 106.

NSF-IRCEB interannual climate variability and ecosystem processes in tallgrass praire: Soil respiration.

Verburg, Paul^*,1, Arnone, Jay¹, Schorran, David¹, ¹ Desert Research Institute, Reno, NV

ABSTRACT- Soil respiration represents one of the main C fluxes from terrestrial ecosystems to the atmosphere. Yet it is unclear how interannual climate variability will affect soil respiration and how long effects of an anomalously warm year on soil respiration will persist. In order to address this problem, we are measuring soil respiration in twelve intact tallgrass prairie monoliths (divided over four environmentally controlled growth chambers) using dynamic and static chambers. Measurements started in the spring of 2002 when temperatures in all growth chambers were similar. First results indicate that, despite variations in soil respiration rates between monoliths, average soil respiration rates were similar in each growth chamber. These results show that no pre-treatment differences existed between growth chambers despite variability in plant community structure. In addition, measurements of dynamic chambers agreed well with static chamber measurements. Soil respiration rates showed clear seasonal patterns and strong increases in soil respiration were observed after watering events. In February 2003, temperature in two growth chambers was increased by four degrees. Results of the first six months of this warming treatment on soil respiration will be discussed.

Key words: climate variability, soil respiration, tallgrass prairie