Microbial nitrogen limitation increases decomposition
Microbial nitrogen limitation increases decomposition
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DOI：
10.1890/06-1847.1
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发表时间：
2007-08-01
期刊：
影响因子：
4.8
通讯作者：
Fierer, Noah
中科院分区：
文献类型：
--
作者：
Craine, Joseph M.;Morrow, Carl;Fierer, Noah
随着全球对生态系统的人为养分输入不断增加，关于养分在有机物分解中的作用存在着长期存在的基本问题。我们测试了外源氮和磷输入对各种凋落物和土壤类型凋落物分解的影响。在一个实验中，比较了单独添加到单一土壤中的各种植物的C矿化，而在第二个实验中，比较了来自单一基质的C矿化在50个土壤中的情况。与基本的化学计量分解理论相反，低氮有效性可以增加凋落物的分解，因为微生物利用不稳定的底物从顽固的有机物中获取氮。这种“微生物氮开采”一直受到高土壤氮供应或底物氮浓度的抑制。没有证据表明施磷肥增加了短期和长期矿化。这些结果表明，为了预测生态系统碳储量对人为养分有效性变化的响应，需要对基本化学计量分解理论进行修正，并相应地重构生态系统模型。
With anthropogenic nutrient inputs to ecosystems increasing globally, there are long-standing, fundamental questions about the role of nutrients in the decomposition of organic matter. We tested the effects of exogenous nitrogen and phosphorus inputs on litter decomposition across a broad suite of litter and soil types. In one experiment, C mineralization was compared across a wide array of plants individually added to a single soil, while in the second, C mineralization from a single substrate was compared across 50 soils. Counter to basic stoichiometric decomposition theory, low N availability can increase litter decomposition as microbes use labile substrates to acquire N from recalcitrant organic matter. This "microbial nitrogen mining" is consistently suppressed by high soil N supply or substrate N concentrations. There is no evidence for phosphorus mining as P fertilization increases short- and long-term mineralization. These results suggest that basic stoichiometric decomposition theory needs to be revised and ecosystem models restructured accordingly in order to predict ecosystem carbon storage responses to anthropogenic changes in nutrient availability.