title: Accelerated soil carbon turnover under tree plantations limits soil carbon storage.
abstract: The replacement of native forests by tree plantations is increasingly common globally, especially in tropical and subtropical areas. Improving our understanding of the long-term effects of this replacement on soil organic carbon (SOC) remains paramount for effectively managing ecosystems to mitigate anthropogenic carbon emissions. Meta-analyses imply that native forest replacement usually reduces SOC stocks and may switch the forest from a net sink to a net source of atmospheric carbon. Using a long-term chronosequence during which areas of subtropical native forest were replaced by Chinese fir, we show by direct measurement that plantations have significantly accelerated SOC turnover compared with native forest, an effect that has persisted for almost a century. The immediate stimulation of SOC decomposition was caused by warmer soil before the closure of the plantation's canopy. Long-term reductions in SOC mean residence times were coupled to litter inputs. Faster SOC decomposition was associated with lower soil microbial carbon use efficiency, which was due to smaller litter inputs and reduced nutrient availabilities. Our results indicate a previously unelucidated control on long-term SOC dynamics in native forests and demonstrate a potential constraint on climate mitigation when such forests are replaced by plantations.
authors.affiliation: Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Guangshui
authors.initials: G
authors.lastname: Chen
authors.affiliation: Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Xie
authors.affiliation: Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Jianfen
authors.initials: J
authors.lastname: Guo
authors.affiliation: Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Ren
authors.initials: R
authors.lastname: Gao
authors.affiliation: Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Institute of Biological &Environmental Sciences, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK.
authors.forename: David
authors.initials: D
authors.lastname: Robinson
mesh_terms: D018533:Biomass; D002244:Carbon / Q000737:chemistry*; D057486:Carbon Cycle; D017753:Ecosystem; D004777:Environment; D065928:Forests; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D013696:Temperature; D014197:Trees
chemical_list: D012987:Soil; D002244:Carbon