Labile, recalcitrant, and microbial carbon and nitrogen pools of a tallgrass prairie soil in the US Great Plains subjected to experimental warming and clipping
Labile, recalcitrant, and microbial carbon and nitrogen pools of a tallgrass prairie soil in the US Great Plains subjected to experimental warming and clipping
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DOI：
10.1016/j.soilbio.2008.10.003
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发表时间：
2009-01-01
影响因子：
9.7
通讯作者：
Luo, Yiqi
中科院分区：
文献类型：
--
作者：
Belay-Tedla, Asfaw;Zhou, Xuhui;Luo, Yiqi
碳（C）和氮（N）通量在很大程度上受陆地土壤中这些元素的小但高度生物反应性的不稳定库控制，而长期C和N储存则由长寿命的柠檬酸盐组分决定。这些库的大小变化和重新分配，以应对全球变暖可能会大大影响长期的陆地碳和氮储存。然而，这种变化并没有在野外变暖实验中得到仔细研究。本研究采用硫酸水解，以量化的变化不稳定和arbitcitrant C和N组分的土壤中的tallgrass草原生态系统，已持续升温或没有修剪约2.5年。变暖显著增加了不稳定的C和N组分在未修剪的地块，导致373毫克C kg（-1）干土和15毫克N kg-1干土的增量，在此期间，而修剪显着降低这些浓度在温暖的地块。变暖也显着增加土壤微生物生物量C和N在未修剪的地块，并增加土壤微生物/不稳定的C和N的比例，表明微生物的C-和N-利用效率的增加。顽拗性和总C和N含量没有显着变暖的影响。对于所有测量池，只有不稳定和微生物生物量C组分表现出显着的变暖和修剪之间的相互作用，表明依赖于修剪的变暖效应。我们的研究结果表明，增加土壤不稳定和微生物的C和N组分可能间接导致变暖增加植物生物量输入，这可能是大于变暖增强分解不稳定的有机化合物。出版社：Elsevier Ltd
Carbon (C) and nitrogen (N) fluxes are largely controlled by the small but highly bio-reactive, labile pools of these elements in terrestrial soils, while long-term C and N storage is determined by the long-lived recalcitrant fractions. Changes in the size of these pools and redistribution among them in response to global warming may considerably affect the long-term terrestrial C and N storage. However, such changes have not been carefully examined in field warming experiments. This study used sulfuric acid hydrolysis to quantify changes in labile and recalcitrant C and N fractions of soil in a tallgrass prairie ecosystem that had been continuously warmed with or without clipping for about 2.5 years. Warming significantly increased labile C and N fractions in the unclipped plots, resulting in increments of 373 mg C kg(-1) dry soil and 15 mg N kg-1 dry soil, over this period whilst clipping significantly decreased such concentrations in the warmed plots. Warming also significantly increased soil microbial biomass C and N in the unclipped plots, and increased ratios of soil microbial/labile C and N, indicating an increase in microbial C- and N-use efficiency. Recalcitrant and total C and N contents were not significantly affected by warming. For all measured pools, only labile and microbial biomass C fractions showed significant interactions between warming and clipping, indicating the dependence of the warming effects on clipping. Our results suggest that increased soil labile and microbial C and N fractions likely resulted indirectly from warming increases in plant biomass input, which may be larger than warming-enhanced decomposition of labile organic compounds. Published by Elsevier Ltd.