title: [Temporal variation of soil respiration on sloping pasture of Heihe River basin and effects of temperature and soil moisture on it].
abstract: Employing LiCor 6400 gas exchange analyzer and soil respiration chamber attachment (LiCor Inc., Lincoln, NE, USA), this paper continuously measured the soil surface CO2 effluxes on the sloping pasture of Heihe River basin from early April to late October 2003 to investigate the soil CO2 efflux rate and its feedback to the changes of climate and land use. The results showed that from May to October, the diurnal variation of soil respiration was low at night, the lowest at 7:00, 6:30, 5:30, 6:00 and 7:00, raised rapidly at 7:00 - 8:30, and then descended at 16:00 - 18:30. The maximum soil CO2 efflux appeared at 15:00, 14:30, 14:30, 13:30, 14:00 and 15:00. The mean daily soil respiration rate was 0.31 - 6.98 micromol m(-2) s(-1), with the maximum in July and August, the second in May and September, and nearly consistent in April and October. Soil respiration rate had an exponential and power correlation with temperature and soil moisture, respectively.
authors.affiliation: Key laboratory of Forest Ecology and Environmnent, State Forestry Administration, Institute of Cold and Arid Regions Environmental and Engineering, Chinese Academy of Sciences, Lanzhou, China. changzq@lzb.ac.cn
authors.forename: Zongqiang
authors.initials: Z
authors.lastname: Chang
authors.forename: Zuomin
authors.initials: Z
authors.lastname: Shi
authors.forename: Qi
authors.initials: Q
authors.lastname: Feng
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Su
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis*; D017753:Ecosystem; D018517:Plant Roots / Q000502:physiology*; D018526:Plant Transpiration / Q000502:physiology*; D006109:Poaceae / Q000254:growth & development / Q000502:physiology*; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000032:analysis
chemical_list: D012987:Soil; D014867:Water; D002245:Carbon Dioxide