干旱区生态环境知识资源中心(Arid): Soil CO2 influx in drylands: A conceptual framework and empirical examination

Arid

DOI	10.1016/j.soilbio.2021.108209
	Soil CO2 influx in drylands: A conceptual framework and empirical examination
	Sagi, Nevo; Zaguri, Moshe; Hawlena, Dror
通讯作者	Sagi, N (corresponding author), Hebrew Univ Jerusalem, Alexander Silberman Inst Life Sci, Dept Ecol Evolut & Behav, Risk Management Ecol Lab, Jerusalem, Israel.
来源期刊	SOIL BIOLOGY & BIOCHEMISTRY
ISSN	0038-0717
EISSN	1879-3428
出版年	2021
卷号	156
英文摘要	Soil CO2 flux is dominated in most ecosystems by respiration of soil organisms and roots, and is therefore expected to be positive (i.e., efflux) during dark hours. Growing evidence from various ecosystems contradicts this expectation, showing nocturnal soil CO2 influx. Little is known about this puzzling phenomenon and the underlying mechanisms governing it. We attempted to bridge this knowledge gap by proposing the dryland carbon influx (DCI) framework. Based on Henry's law, decreases in soil temperature stimulate CO2 dissolution in soil solutions, creating a CO2 concentration gradient between soil air and the atmosphere. This may lead to CO2 diffusion from the atmosphere into the soil. This influx is expected to be stronger at lower temperatures, high soil to atmosphere temperature gradients, and in CaCO3 rich alkaline soils that characterize drylands. The soil abiotic influx is expected to govern the overall CO2 flux when dry conditions and low soil organic matter limit organismal respiration. We examined the underlying conditions predicted by the DCI framework using a literature review and soil CO2 flux measurements from the Negev Desert. We found 24 studies that reported dark soil CO2 influx, almost exclusively from drylands. CO2 influx was recorded mainly in alkaline soils, was positively correlated with pH levels, and was associated predominantly with low soil temperature, decreasing soil temperature or a positive soil to air thermal gradient. CO2 influx was found not only in dry soils but also in poor organic content wet soils. In the Negev Desert, CO2 influx occurred only when (a) soil temperature was higher than air temperature and was decreasing, and (b) soil moisture was 7.76% or lower. Only above this threshold, a positive association between CO2 efflux and microbial biomass was found. Our results largely support the DCI framework, suggesting that soil CO2 influx is prevalent across drylands worldwide, facilitated by the edaphic and climatic conditions that induce abiotic CO2 exchange and restrain biotic respiration. Considering the abiotic contribution to soil CO2 flux, and determining the conditions that regulate it may substantially improve our carbon budget calculations, and estimations of soil biotic respiration.
英文关键词	Abiotic soil CO2 flux Arid Carbon uptake Carbonates Deserts Soil respiration Soil CO2 influx
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000640189100031
WOS关键词	LAND-COVER TYPES ; MICROBIAL COMMUNITIES ; GURBANTUNGGUT DESERT ; ALKALINE SOILS ; RESPIRATION ; FLUX ; CARBON ; EXCHANGE ; IMPACT ; ECOSYSTEMS
WOS类目	Soil Science
WOS研究方向	Agriculture
来源机构	Hebrew University of Jerusalem
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/351779
作者单位	[Sagi, Nevo; Zaguri, Moshe; Hawlena, Dror] Hebrew Univ Jerusalem, Alexander Silberman Inst Life Sci, Dept Ecol Evolut & Behav, Risk Management Ecol Lab, Jerusalem, Israel
推荐引用方式 GB/T 7714	Sagi, Nevo,Zaguri, Moshe,Hawlena, Dror. Soil CO2 influx in drylands: A conceptual framework and empirical examination[J]. Hebrew University of Jerusalem,2021,156.
APA	Sagi, Nevo,Zaguri, Moshe,&Hawlena, Dror.(2021).Soil CO2 influx in drylands: A conceptual framework and empirical examination.SOIL BIOLOGY & BIOCHEMISTRY,156.
MLA	Sagi, Nevo,et al."Soil CO2 influx in drylands: A conceptual framework and empirical examination".SOIL BIOLOGY & BIOCHEMISTRY 156(2021).