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The annual carbon dioxide cycle in a montane soil: Observations, modeling, and implications for weathering
Author(s) -
Solomon D. Kip,
Cerling Thure E.
Publication year - 1987
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr023i012p02257
Subject(s) - snowpack , snow , environmental science , carbon cycle , weathering , snowmelt , carbon dioxide , atmosphere (unit) , soil carbon , soil respiration , soil water , hydrology (agriculture) , atmospheric sciences , soil science , geology , ecosystem , chemistry , geomorphology , ecology , geography , geotechnical engineering , organic chemistry , meteorology , biology
Profiles of CO 2 concentrations in soil and snow, soil respiration, soil and snow temperatures, and shallow groundwater chemistry were monitored from March 1984 to July 1985 in a montane region near Brighton, Utah. Significant seasonal variations in the concentrations of CO 2 in soil and snow occurred, and two principal rise‐decline cycles were observed. During the first cycle the concentration of soil CO 2 at 35 cm rose from 4200 ppmv in July to a maximum of 12,400 ppmv in August and then declined to 4300 ppmv by October. This cycle is attributed to the changing production rate of soil CO 2 during the growing season. During the second cycle the concentration of CO 2 at 35 cm began to rise in November, reached a maximum of 7200 ppmv in early spring, and quickly declined to 3200 ppmv by late spring shortly after the snow cover had melted. This cycle is attributed to deterioration in the exchange of CO 2 between the soil and atmosphere due to a deep snowpack. A model based on Pick's second law of diffusion was developed to account for the temporal and spatial distribution of soil CO 2 . The model predicts that soil CO 2 at 35 cm is increased by as much as 15 times due to the deep snowpack. The elevated concentration of soil CO 2 , abundance of water, and above‐freezing soil temperatures imply that significant soil weathering occurs during the winter in montane regions.