title: Effects of Soil Temperature and Moisture on Soil Respiration on the Tibetan Plateau.
abstract: Understanding of effects of soil temperature and soil moisture on soil respiration (Rs) under future warming is critical to reduce uncertainty in predictions of feedbacks to atmospheric CO2 concentrations from grassland soil carbon. Intact cores with roots taken from a full factorial, 5-year alpine meadow warming and grazing experiment in the field were incubated at three different temperatures (i.e. 5, 15 and 25°C) with two soil moistures (i.e. 30 and 60% water holding capacity (WHC)) in our study. Another experiment of glucose-induced respiration (GIR) with 4 h of incubation was conducted to determine substrate limitation. Our results showed that high temperature increased Rs and low soil moisture limited the response of Rs to temperature only at high incubation temperature (i.e. 25°C). Temperature sensitivity (Q10) did not significantly decrease over the incubation period, suggesting that substrate depletion did not limit Rs. Meanwhile, the carbon availability index (CAI) was higher at 5°C compared with 15 and 25°C incubation, but GIR increased with increasing temperature. Therefore, our findings suggest that warming-induced decrease in Rs in the field over time may result from a decrease in soil moisture rather than from soil substrate depletion, because warming increased root biomass in the alpine meadow.
authors: College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China.
authors: Xiaoying
authors: X
authors: Bao
authors: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.
authors: Xiaoxue
authors: X
authors: Zhu
authors: Institute of Soil and Water Conservation, Northwest A&F University, 26 Xinong Rd., 712100 Yangling, China.
authors: Xiaofeng
authors: X
authors: Chang
authors: Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.|CAS Center for Excellence of Tibetan Plateau Earth Science, Chinese Academy of Sciences, Beijing 100101, China.
authors: Shiping
authors: S
authors: Wang
authors: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.
authors: Burenbayin
authors: B
authors: Xu
authors: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.
authors: Caiyun
authors: C
authors: Luo
authors: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.
authors: Zhenhua
authors: Z
authors: Zhang
authors: Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.|College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China.
authors: Qi
authors: Q
authors: Wang
authors: College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China.
authors: Yichao
authors: Y
authors: Rui
authors: College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China.
authors: Xiaoying
authors: X
authors: Cui
mesh_terms: D000704:Analysis of Variance; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D018533:Biomass; D002244:Carbon / Q000032:analysis; D019069:Cell Respiration / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D006813:Humidity; D009584:Nitrogen / Q000032:analysis; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D012987:Soil; D013696:Temperature; D018609:Tibet; D013997:Time Factors
chemical_list: D012987:Soil; D002244:Carbon; D005947:Glucose; D009584:Nitrogen