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作者单位:Wei Wanga (1) (2) Kenji Ohse (2) Jianjun Liu (3) Wenhong Mo (2) Takehisa Oikawab (2)
1. School of Urban and Environmental Sciences, Northeast Normal University, Jilin, 130024, Changchun, People鈥檚 Republic of China 2. Institute of Biological Sciences, University of Tsukuba, Tsukuba, 305-8572, Ibaraki, Japan 3. Northwest Scientific University of Agriculture and Forestry, 712100, Yangling, People鈥檚 Republic of China
The spatial and temporal variations of soil respiration were studied from May 2004 to June 2005 in a C3/C4 mixed grassland of Japan. The linear regression relationship between soil respiration and root biomass was used to determine the contribution of root respiration to soil respiration. The highest soil respiration rate of 11-54 螠mol m-2 s-1 was found in August 2004 and the lowest soil respiration rate of 4.99 螠mol m-2 s-1 was found in April 2005. Within-site variation was smaller than seasonal change in soil respiration. Root biomass varied from 0.71 kg m-2 in August 2004 to 102 in May 2005. Within-site variation in root biomass was larger than seasonal variation. Root respiration rate was highest in August 2004 (5.7 螠mol m-2 s-1) and lowest in October 2004 (1.7 螠mol m-2 s-1). Microbial respiration rate was highest in August 2004 (5.8 螠mol m-2 s-1) and lowest in April 2005 (2.59 螠mol m-2 s-1). We estimated that the contribution of root respiration to soil respiration ranged from 31% in October to 51% in August of 2004, and from 45% to 49% from April to June 2005. Keywords C3/C4 mixed grassland microbial respiration root biomass root respiration soil respiration