HR: 1340h
AN: B43A-0250    [Abstracts]
TI: Biotic and Abiotic drivers of soil respiration across a sagebrush fire chronosequence.
AU: * Bayless, M K
EM: meagankb@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000 E University Ave, Dept 3165, Laramie, WY 82070 United States
AU: Pendall, E
EM: pendall@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000 E University Ave, Dept 3165, Laramie, WY 82070 United States
AU: Ewers, B E
EM: beewers@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000 E University Ave, Dept 3165, Laramie, WY 82070 United States
AU: Naithani, K
EM: kn77@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000 E University Ave, Dept 3165, Laramie, WY 82070 United States
AB: Understanding responses of carbon pools and fluxes to disturbance in shrubland ecosystems is important because these systems represent a potentially dynamic but understudied component of the global carbon cycle. Our extensive study of ecosystem dynamics is currently being conducted at multiple scales across a fire chronosequence in south-central Wyoming, USA. Ecosystem succession following fire at our study area undergoes a predictable sequence of perennial grass regeneration followed by re-establishment of shrubs, primarily big sagebrush ( Artemesia tridentata). One of the major components of the larger study is soil carbon dynamics including soil respiration fluxes. Soil respiration measurements were obtained diurnally on both intact vegetative areas and for areas where all living vegetation was removed by cutting and herbicide. The measurements were obtained throughout the summer season on four ages of sagebrush ecosystem ranging in age from 2 years to 38 years old. We are investigating the influence of biotic and abiotic factors as drivers of soil respiration including ecosystem age, season, time of day, and pH. Preliminary results indicate that respiration rate changes with ecosystem age and is relative to vegetation structure. For each age, areas sampled where vegetation was removed had much less variability between observations than in areas where vegetation was left intact.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0490 Trace gases
SC: Biogeosciences [B]
MN: Fall Meeting 2005