title: Distinct temperature sensitivity of soil carbon decomposition in forest organic layer and mineral soil.
abstract: The roles of substrate availability and quality in determining temperature sensitivity (Q10) of soil carbon (C) decomposition are still unclear, which limits our ability to predict how soil C storage and cycling would respond to climate change. Here we determined Q10 in surface organic layer and subsurface mineral soil along an elevation gradient in a temperate forest ecosystem. Q10 was calculated by comparing the times required to respire a given amount of soil C at 15 and 25°C in a 350-day incubation. Results indicated that Q10 of the organic layer was 0.22-0.71 (absolute difference) higher than Q10 of the mineral soil. Q10 in both the organic layer (2.5-3.4) and the mineral soil (2.1-2.8) increased with decreasing substrate quality during the incubation. This enhancement of Q10 over incubation time in both layers suggested that Q10 of more labile C was lower than that of more recalcitrant C, consistent with the Arrhenius kinetics. No clear trend of Q10 was found along the elevation gradient. Because the soil organic C pool of the organic layer in temperate forests is large, its higher temperature sensitivity highlights its importance in C cycling under global warming.
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Xu
authors.affiliation: 1] State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.affiliation: 1] State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China.
authors.forename: Edith
authors.initials: E
authors.lastname: Bai
mesh_terms: D002244:Carbon / Q000737:chemistry*; D057231:Climate Change; D017753:Ecosystem; D065928:Forests; D057232:Global Warming; D008903:Minerals / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D013696:Temperature
chemical_list: D008903:Minerals; D012987:Soil; D002244:Carbon