DOI: 10.1111/gcb.13491
论文题名: Sensitivity of soil carbon fractions and their specific stabilization mechanisms to extreme soil warming in a subarctic grassland
作者: Poeplau C. ; Kätterer T. ; Leblans N.I.W. ; Sigurdsson B.D.
刊名: Global Change Biology
出版年: 2017
卷: 23, 期: 3 起始页码: 1316
结束页码: 1327
语种: 英语
英文关键词: global change
; soil carbon fractionation
; soil organic matter
; soil warming
; temperature manipulation
; temperature sensitivity
; trophic fractionation
; δ13C
英文摘要: Terrestrial carbon cycle feedbacks to global warming are major uncertainties in climate models. For in-depth understanding of changes in soil organic carbon (SOC) after soil warming, long-term responses of SOC stabilization mechanisms such as aggregation, organo-mineral interactions and chemical recalcitrance need to be addressed. This study investigated the effect of 6 years of geothermal soil warming on different SOC fractions in an unmanaged grassland in Iceland. Along an extreme warming gradient of +0 to ~+40 °C, we isolated five fractions of SOC that varied conceptually in turnover rate from active to passive in the following order: particulate organic matter (POM), dissolved organic carbon (DOC), SOC in sand and stable aggregates (SA), SOC in silt and clay (SC-rSOC) and resistant SOC (rSOC). Soil warming of 0.6 °C increased bulk SOC by 22 ± 43% (0–10 cm soil layer) and 27 ± 54% (20–30 cm), while further warming led to exponential SOC depletion of up to 79 ± 14% (0–10 cm) and 74 ± 8% (20–30) in the most warmed plots (~+40 °C). Only the SA fraction was more sensitive than the bulk soil, with 93 ± 6% (0–10 cm) and 86 ± 13% (20–30 cm) SOC losses and the highest relative enrichment in 13C as an indicator for the degree of decomposition (+1.6 ± 1.5‰ in 0–10 cm and +1.3 ± 0.8‰ in 20–30 cm). The SA fraction mass also declined along the warming gradient, while the SC fraction mass increased. This was explained by deactivation of aggregate-binding mechanisms. There was no difference between the responses of SC-rSOC (slow-cycling) and rSOC (passive) to warming, and 13C enrichment in rSOC was equal to that in bulk soil. We concluded that the sensitivity of SOC to warming was not a function of age or chemical recalcitrance, but triggered by changes in biophysical stabilization mechanisms, such as aggregation. © 2016 John Wiley & Sons Ltd 资助项目: Poeplau, C.
; Thuenen Institute of Climate-Smart Agriculture, Bundesallee 50, Germany
; 电子邮件: Christopher.poeplau@thuenen.de
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61027
Appears in Collections: 影响、适应和脆弱性
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作者单位: Thuenen Institute of Climate-Smart Agriculture, Bundesallee 50, Braunschweig, Germany; Department of Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden; Department of Biology, University of Antwerp, Wilrijk, Belgium; Agricultural University of Iceland, Hvanneyri, Borgarnes, Iceland
Recommended Citation:
Poeplau C.,Kätterer T.,Leblans N.I.W.,et al. Sensitivity of soil carbon fractions and their specific stabilization mechanisms to extreme soil warming in a subarctic grassland[J]. Global Change Biology,2017-01-01,23(3)