气候变化领域集成服务门户(CCPortal): Sensitivity of soil organic matter to climate and fire in a desert grassland

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DOI	10.1007/s10533-020-00713-3
	Sensitivity of soil organic matter to climate and fire in a desert grassland
	Hou E.; Rudgers J.A.; Collins S.L.; Litvak M.E.; White C.S.; Moore D.I.; Luo Y.
发表日期	2020
ISSN	0168-2563
英文摘要	Drylands contain a third of the organic carbon stored in global soils; however, the long-term dynamics of soil organic carbon in drylands remain poorly understood relative to dynamics of the vegetation carbon pool. We examined long-term patterns in soil organic matter (SOM) against both climate and prescribed fire in a Chihuahuan Desert grassland in central New Mexico, USA. SOM concentration was estimated by loss-on-ignition from soils at 0–20 cm depth each spring and fall for 25 years (1989–2014) in unburned desert grassland and from 2003 to 2014 following a prescribed fire. SOM concentration did not have a long-term trend but fluctuated seasonally at both burned and unburned sites, ranging from a minimum of 0.9% to a maximum of 3.3%. SOM concentration declined nonlinearly in wet seasons and peaked in dry seasons. These long-term results contrast not only with the positive relationships between aboveground net primary production and precipitation for this region, but also with previous reports that wetter sites have more SOM across drylands globally, suggesting that space is not a good substitute for time in predicting dryland SOM dynamics. We suggest that declines in SOM in wet periods are caused by increased soil respiration, runoff, leaching, and/or soil erosion. In addition to tracking natural variability in climate, SOM concentration also decreased 14% following prescribed fire, a response that magnified over time and has persisted for nearly a decade due to the slow recovery of primary production. Our results document the surprisingly dynamic nature of soil organic matter and its high sensitivity to climate and fire in a dry grassland ecosystem characteristic of the southwestern USA. © 2020, Springer Nature Switzerland AG.
英文关键词	Climate sensitivity function; Climate variability; Desert grassland; Soil organic matter; Standardized Precipitation Evapotranspiration Index
语种	英语
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153167
作者单位	Department of Biological Sciences, Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, United States; Department of Biology, MSC03-2020, University of New Mexico, Albuquerque, NM, United States
推荐引用方式 GB/T 7714	Hou E.,Rudgers J.A.,Collins S.L.,et al. Sensitivity of soil organic matter to climate and fire in a desert grassland[J],2020.
APA	Hou E..,Rudgers J.A..,Collins S.L..,Litvak M.E..,White C.S..,...&Luo Y..(2020).Sensitivity of soil organic matter to climate and fire in a desert grassland.Biogeochemistry.
MLA	Hou E.,et al."Sensitivity of soil organic matter to climate and fire in a desert grassland".Biogeochemistry (2020).