Response of soil respiration to grazing in an alpine meadow at three elevations in tibet.
Alpine meadows are one major type of pastureland on the Tibetan Plateau. However, few studies have evaluated the response of soil respiration (R(s)) to grazing along an elevation gradient in an alpine meadow on the Tibetan Plateau. Here three fenced enclosures were established in an alpine meadow at three elevations (i.e., 4313 m, 4513 m, and 4693 m) in July 2008. We measured R s inside and outside the three fenced enclosures in July-September, 2010-2011. Topsoil (0-20 cm) samples were gathered in July, August, and September, 2011. There were no significant differences for R s , dissolved organic C (DOC), and belowground root biomass (BGB) between the grazed and ungrazed soils. Soil respiration was positively correlated with soil organic C (SOC), microbial biomass (MBC), DOC, and BGB. In addition, both R s and BGB increased with total N(TN), the ratio of SOC to TN, ammonium NH₄ ⁺-H₄⁺-N), and the ratio of NH₄⁺-N to nitrate N. Our findings suggested that the negligible response of R s to grazing could be directly attributed to that of respiration substrate and that soil N may indirectly affect R(s) by its effect on BGB.
Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Key Laboratory of Ecosystem Network Observation and Modeling, Lhasa Plateau Ecosystem Research Station, Beijing 100101, China.
Gang
G
Fu
Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Key Laboratory of Ecosystem Network Observation and Modeling, Lhasa Plateau Ecosystem Research Station, Beijing 100101, China.
Xianzhou
X
Zhang
Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Key Laboratory of Ecosystem Network Observation and Modeling, Lhasa Plateau Ecosystem Research Station, Beijing 100101, China.
Chengqun
C
Yu
Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Key Laboratory of Ecosystem Network Observation and Modeling, Lhasa Plateau Ecosystem Research Station, Beijing 100101, China.
Peili
P
Shi
Department of Microbiology and Plant Botany, Center for Spatial Analysis, University of Oklahoma, Norman, OK 73019, USA.
Yuting
Y
Zhou
Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Key Laboratory of Ecosystem Network Observation and Modeling, Lhasa Plateau Ecosystem Research Station, Beijing 100101, China ; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Yunlong
Y
Li
Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Key Laboratory of Ecosystem Network Observation and Modeling, Lhasa Plateau Ecosystem Research Station, Beijing 100101, China ; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Pengwan
P
Yang
Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Key Laboratory of Ecosystem Network Observation and Modeling, Lhasa Plateau Ecosystem Research Station, Beijing 100101, China.
Zhenxi
Z
Shen
D017753:Ecosystem; D012987:Soil / Q000737:chemistry*; D018609:Tibet
D012987:Soil