气候变化领域集成服务门户(CCPortal): Moisture and temperature effects on the radiocarbon signature of respired carbon dioxide to assess stability of soil carbon in the Tibetan Plateau

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DOI	10.5194/bg-21-1277-2024
	Moisture and temperature effects on the radiocarbon signature of respired carbon dioxide to assess stability of soil carbon in the Tibetan Plateau
	Tangarife-Escobar, Andres; Guggenberger, Georg; Feng, Xiaojuan; Dai, Guohua; Urbina-Malo, Carolina; Azizi-Rad, Mina; Sierra, Carlos A.
发表日期	2024
ISSN	1726-4170
EISSN	1726-4189
起始页码	21
结束页码	5
卷号	21 期号:5
英文摘要	Microbial release of CO 2 from soils to the atmosphere reflects how environmental conditions affect the stability of soil organic matter (SOM), especially in massive organic-rich ecosystems like the peatlands and grasslands of the Qinghai-Tibetan Plateau (QTP). Radiocarbon ( 14 C) is an important tracer of the global carbon cycle and can be used to understand SOM dynamics through the estimation of time lags between carbon fixation and respiration, often assessed with metrics such as age and transit time. In this study, we incubated peatland and grassland soils at four temperature (5, 10, 15 and 20 degrees C) and two water-filled pore space (WFPS) levels (60 % and 95 %) and measured the 14 C signature of bulk soil and heterotrophic respired CO 2 . We compared the relation between the Delta 14 C of the bulk soil and the Delta 14 CO 2 of respired carbon as a function of temperature and WFPS for the two soils. To better interpret our results, we used a mathematical model to analyse how the calculated number of pools, decomposition rates of carbon ( k ), transfer ( alpha ) and partitioning ( gamma ) coefficients affect the Delta 14 C bulk and Delta 14 CO 2 relation, with their respective mean age and mean transit time. From our incubations, we found that 14 C values in bulk and CO 2 from peatland were significantly more depleted (old) than from grassland soil. Our results showed that changes in temperature did not affect the Delta 14 C values of heterotrophic respired CO 2 in either soil. However, changes in WFPS had a small effect on the 14 CO 2 in grassland soils and a significant influence in peatland soils, where higher WFPS levels led to more depleted Delta 14 CO 2 . In our models, the correspondence between Delta 14 C, age and transit time highly depended on the internal dynamics of the soil ( k , alpha , gamma and number of pools) as well as on model structure. We observed large differences between slow and fast cycling systems, where low values of decomposition rates modified the Delta 14 C values in a non-linear pattern due to the incorporation of modern carbon ( 14 C bomb) in the soil. We concluded that the stability of carbon in the peatland and grassland soils of the QTP depends strongly on the direction of change in moisture and how it affects the rates of SOM decomposition, while temperature regulates the number of fluxes. Current land cover modification (desiccation) in Zoige peatlands and climate change occurring on the QTP might largely increase CO 2 fluxes along with the release of old carbon to the atmosphere potentially shifting carbon sinks into sources.
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Geology
WOS类目	Ecology ; Geosciences, Multidisciplinary
WOS记录号	WOS:001190664300001
来源期刊	BIOGEOSCIENCES
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/293869
作者单位	Max Planck Society; Leibniz University Hannover; Chinese Academy of Sciences; Institute of Botany, CAS; Swedish University of Agricultural Sciences
推荐引用方式 GB/T 7714	Tangarife-Escobar, Andres,Guggenberger, Georg,Feng, Xiaojuan,et al. Moisture and temperature effects on the radiocarbon signature of respired carbon dioxide to assess stability of soil carbon in the Tibetan Plateau[J],2024,21(5).
APA	Tangarife-Escobar, Andres.,Guggenberger, Georg.,Feng, Xiaojuan.,Dai, Guohua.,Urbina-Malo, Carolina.,...&Sierra, Carlos A..(2024).Moisture and temperature effects on the radiocarbon signature of respired carbon dioxide to assess stability of soil carbon in the Tibetan Plateau.BIOGEOSCIENCES,21(5).
MLA	Tangarife-Escobar, Andres,et al."Moisture and temperature effects on the radiocarbon signature of respired carbon dioxide to assess stability of soil carbon in the Tibetan Plateau".BIOGEOSCIENCES 21.5(2024).