Abiotic contribution to total soil CO2 flux across a broad range of land-cover types in a desert region
Abiotic contribution to total soil CO2 flux across a broad range of land-cover types in a desert region
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沙漠地区多种土地覆盖类型的非生物对土壤总二氧化碳通量的贡献
DOI：
10.1007/s40333-016-0061-4
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发表时间：
2017-02
期刊：
影响因子：
--
通讯作者：
Li Yan
中科院分区：
文献类型：
--
作者：
Ma Jie;Liu Ran;Li Yan
土壤二氧化碳(CO2)通量是生态系统碳(C)收支的重要组成部分，由一系列生物和非生物过程共同决定。尽管有证据表明，非生物成分在土壤总二氧化碳通量中可能很重要，但它的相对重要性从未得到系统的评估。本研究通过对灭菌土壤和自然土壤CO2通量的对比测量，将新疆古尔班通古特沙漠不同土地覆盖类型(包括棉田、啤酒花地、盐生植物园、盐碱地、库边、天然盐碱地、沙丘丘顶和沙间低地)的CO2通量划分为生物通量(RBiotic)和非生物通量(Rabitic)。分析了兔类对RTotal的相对贡献，以及Rtalal、RBiotic和Rabiology的温度依赖性和主导因子。结果表明，在所有8个采样点中，兔类都对总贡献率有贡献，但贡献度和贡献率差异很大。其中，棉田和啤酒花田的兔类占总生物量的比例很低，而盐碱地和沙丘的兔类占总生物量的比例很高。在统计学上，随着RBiotic的降低，Rabiology与Rtalal的比率对数增加，这表明当RBiotic较低时，Rabiology对Rtalal的影响很大。这一模式证实，在大多数土壤中，土壤CO2通量以生物过程为主，但当生物过程较弱时，非生物过程也可能占主导地位。在每天的基础上，兔子不会导致二氧化碳的净增加或净损失，但它对瞬时二氧化碳通量的影响是显著的。在8个采样点中，总蒸散量的温度依赖性不同，并由CO2通量的主要过程(非生物或生物)决定。具体地说，RBiotic受土壤温度驱动，而Rabitic受土壤温度变化(ΔT)调节。也就是说，降温(ΔT<；0)导致负的兔化(即进入土壤的二氧化碳)，而升高温度(ΔT>；0)导致正的兔化(即从土壤释放二氧化碳)。如果不承认Rabiical，RBiotic在白天就会被高估，而在夜间就会被低估。虽然Rabiology可能不会改变土壤每日CO2交换的总和或净值，也可能不会直接构成碳汇，但它可以显著改变土壤CO2的瞬时表观通量，无论是在大小上还是在温度相关性上。因此，认识到土壤中广泛存在的总有机碳中的非生物成分，对于理解碳循环具有广泛的意义。
As an important component of ecosystem carbon (C) budgets, soil carbon dioxide (CO2) flux is determined by a combination of a series of biotic and abiotic processes. Although there is evidence showing that the abiotic component can be important in total soil CO2 flux (Rtotal), its relative importance has never been systematically assessed. In this study, after comparative measurements of CO2 fluxes on sterilized and natural soils, the Rtotal was partitioned into biotic flux (Rbiotic) and abiotic flux (Rabiotic) across a broad range of land-cover types (including eight sampling sites: cotton field, hops field, halophyte garden, alkaline land, reservoir edge, native saline desert, dune crest and interdune lowland) in Gurbantunggut Desert, Xinjiang, China. The relative contribution of Rabiotic to Rtotal, as well as the temperature dependency and predominant factors for Rtotal, Rbiotic and Rabiotic, were analyzed. Results showed that Rabiotic always contributed to Rtotal for all of the eight sampling sites, but the degree or magnitude of contribution varied greatly. Specifically, the ratio of Rabiotic to Rtotal was very low in cotton field and hops field and very high in alkaline land and dune crest. Statistically, the ratio of Rabiotic to Rtotal logarithmically increased with decreasing Rbiotic, suggesting that Rabiotic strongly affected Rtotal when Rbiotic was low. This pattern confirms that soil CO2 flux is predominated by biotic processes in most soils, but abiotic processes can also be dominant when biotic processes are weak. On a diurnal basis, Rabiotic cannot result in net gain or net loss of CO2, but its effect on transient CO2 flux was significant. Temperature dependency of Rtotal varied among the eight sampling sites and was determined by the predominant processes (abiotic or biotic) of CO2 flux. Specifically, Rbiotic was driven by soil temperature while Rabiotic was regulated by the change in soil temperature (ΔT). Namely, declining temperature (ΔT<0) resulted in negative Rabiotic (i.e., CO2 went into soil) while rising temperature (ΔT>0) resulted in positive Rabiotic (i.e., CO2 released from soil). Without recognition of Rabiotic, Rbiotic would be overestimated for the daytime and underestimated for the nighttime. Although Rabiotic may not change the sum or the net value of daily soil CO2 exchange and may not directly constitute a C sink, it can significantly alter the transient apparent soil CO2 flux, either in magnitude or in temperature dependency. Thus, recognizing the fact that abiotic component in Rtotal exists widely in soils has widespread consequences for the understanding of C cycling.
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影响因子：
9.4
作者：
Vargas, Rodrigo;Allen, Michael F.
通讯作者：
Allen, Michael F.
影响因子：
4
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
M. Roland;P. Serrano-Ortiz;A. Kowalski;Y. Goddéris;E. Sánchez‐Cañete;P. Ciais;F. Domingo;S. Cuezva;S. Sánchez-Moral;B. Longdoz;D. Yakir;R. Grieken;J. Schott;C. Cardell;I. Janssens
DOI：
10.3402/tellusb.v44i2.15428
发表时间：
1992-04
期刊：
Tellus B
影响因子：
--
作者：
J. Raich;W. Schlesinger
通讯作者：
J. Raich;W. Schlesinger
影响因子：
9.7
作者：
Elberling, B.;Gregorich, E. G.;Greenfield, L. G.
通讯作者：
Greenfield, L. G.