Temperature sensitivity of soil organic carbon mineralization along an elevation gradient in the Wuyi Mountains, China

• Published in: PloS one Vol. 8; no. 1; p. e53914
• Main Authors: Wang, Guobing, Zhou, Yan, Xu, Xia, Ruan, Honghua, Wang, Jiashe
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.01.2013; Public Library of Science (PLoS)
• Subjects: Alpine environments; Altitude; Biochemistry; Biogeochemistry; Biology; Carbon; Carbon - chemistry; Carbon cycle; Chemistry; China; Climate change; Coniferous forests; Decomposition; Earth Sciences; Ecosystem biology; Ecosystems; Elevation; Environmental science; Forest soils; Forestry; Forests; Global warming; Intervals; Laboratories; Mineralization; Minerals - chemistry; Mountains; Organic carbon; Organic Chemicals - chemistry; Organic soils; Respiration; Sensitivity; Soil - chemistry; Soil carbon; Soil investigations; Soil moisture; Soil sciences; Soil surfaces; Soil temperature; Studies; Temperature; Temperature effects; Tropical forests
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0053914

Soil organic carbon (SOC) actively participates in the global carbon (C) cycle. Despite much research, however, our understanding of the temperature sensitivity of soil organic carbon (SOC) mineralization is still very limited. To investigate the responses of SOC mineralization to temperature, we sampled surface soils (0-10 cm) from evergreen broad-leaf forest (EBF), coniferous forest (CF), sub-alpine dwarf forest (SDF), and alpine meadow (AM) along an elevational gradient in the Wuyi Mountains, China. The soil samples were incubated at 5, 15, 25, and 35°C with constant soil moisture for 360 days. The temperature sensitivity of SOC mineralization (Q(10)) was calculated by comparing the time needed to mineralize the same amount of C at any two adjacent incubation temperatures. Results showed that the rates of SOC mineralization and the cumulative SOC mineralized during the entire incubation significantly increased with increasing incubation temperatures across the four sites. With the increasing extent of SOC being mineralized (increasing incubation time), the Q(10) values increased. Moreover, we found that both the elevational gradient and incubation temperature intervals significantly impacted Q(10) values. Q(10) values of the labile and recalcitrant organic C linearly increased with elevation. For the 5-15, 15-25, and 25-35°C intervals, surprisingly, the overall Q(10) values for the labile C did not decrease as the recalcitrant C did. Generally, our results suggest that subtropical forest soils may release more carbon than expected in a warmer climate.