title: Changes in Temperature Sensitivity and Activation Energy of Soil Organic Matter Decomposition in Different Qinghai-Tibet Plateau Grasslands.
abstract: Qinghai-Tibet Plateau grasslands are unique geographical regions and store substantial soil organic matter (SOM) in the soil surface, which make them very sensitive to global climate change. Here, we focused on three main grassland types (alpine meadow, steppe, and desert) and conducted a soil incubation experiment at five different temperatures (5, 10, 15, 20, and 25°C) to investigate SOM decomposition rates (R), temperature sensitivity (Q10), and activation energy (Ea). The results showed that grassland type and incubation temperature had significant impact on R (P < 0.001), and the values of R were exponential correlated with incubation temperature in three alpine grasslands. At the same temperature, R was in the following order: alpine meadow > alpinesteppe > alpine desert. The Q10 values differed significantly among different grasslands, and the overall trends were as follows: alpine meadow (1.56 ± 0.09) < alpine steppe (1.88 ± 0.23) < alpine desert (2.39 ± 0.32). Moreover, the Ea values differed significantly across different grassland types (P < 0.001) and increased with increasing incubation time. The exponential negative correlations between Ea and R at 20°C across all grassland types (all Ps < 0.001) indicated that the substrate-quality temperature hypothesis is applicable to the alpine grasslands. Our findings provide new insights for understanding the responses of SOM decomposition and storage to warming scenarios in this Plateau.
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; Institute of Grassland Science, Northeast Normal University, Changchun, 130024, China; Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun, 130024, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Nianpeng
authors.initials: N
authors.lastname: He
authors.affiliation: Agricultural and Animal Husbandry College of Tibet University, Linzhi, 860000, China.
authors.forename: Xuehong
authors.initials: X
authors.lastname: Wei
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zuo
mesh_terms: D002980:Climate; D057231:Climate Change; D004784:Environmental Monitoring; D065948:Grassland; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D006109:Poaceae; D012987:Soil / Q000737:chemistry*; D013816:Thermodynamics; D018609:Tibet
chemical_list: D012987:Soil