HR: 1340h
AN: B23A-0918    [Abstracts]
TI: Effects of aspect and elevation on carbon storage in the Dry Creek Experimental Watershed
AU: * Kunkel, M L
EM: melkunkel@mail.boisestate.edu
AF: Boise State University, Department of Geosciences Mailstop-1535 1910 University Drive, Boise, ID 83725-1535, United States
AU: Benner, S G
EM: sbenner@boisestate.edu
AF: Boise State University, Department of Geosciences Mailstop-1535 1910 University Drive, Boise, ID 83725-1535, United States
AU: Grigsby, M J
EM: michaelgrigsby@mail.boisestate.edu
AF: Boise State University, Department of Geosciences Mailstop-1535 1910 University Drive, Boise, ID 83725-1535, United States
AB: More understanding is needed of the role that semiarid lands play in the global storage of carbon and how changes of those lands will influence global warming. This study was conducted to identify the effect of aspect and elevation on total carbon and nitrogen storage in the Dry Creek Experimental Watershed. The 28-km2 watershed located is 16 km northeast of Boise, ID and ranges in elevation from 1000 to 2100m with an associated 37 cm to 100 cm precipitation gradient. The Samples were collected from mid slope sites throughout the watershed with data recorded for aspect, slope, elevation and vegetation at each of the 120 sampling points. Each site was sampled to a depth of 30 cm in 5 cm increments for 720 samples total. Soil analyses consisted of total carbon and nitrogen as well as clast-size distribution. Total carbon and nitrogen contents of the soil average 22 and 2.1 g kg-1, respectively, with ranges from 2.6 to 260 g kg-1 and 0.3 to 13 g kg-1. The ratio of nitrogen to carbon is inverse to accumulation with areas of high carbon accumulation exhibiting ratios as low as 1:22, while areas of low accumulation exhibiting ratios as high as 1:4. The lower and mid watershed locations (1000-1600m) show a strong influence of aspect on carbon and nitrogen accumulation with an average order of magnitude difference from southern to northern aspects. Elevation also influences carbon and nitrogen accumulation with lower sites of the same aspect showing 1/3 that of mid elevation sites. The upper watershed (1600-2000m) sites demonstrated similar results, but suggest a weaker link between carbon accumulation and aspect and elevation.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0486 Soils/pedology (1865)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting