15N enrichment as an integrator of the effects of C and N on microbial metabolism and ecosystem function
15N enrichment as an integrator of the effects of C and N on microbial metabolism and ecosystem function
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DOI：
10.1111/j.1461-0248.2008.01154.x
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发表时间：
2008-04-01
期刊：
影响因子：
8.8
通讯作者：
Hungate, Bruce A.
中科院分区：
文献类型：
--
作者：
Dijkstra, Paul;LaViolette, Corinne M.;Hungate, Bruce A.
有机碳和氮是土壤异养微生物所必需的，其生物有效性对生态系统碳氮循环有重要影响。我们在这里表明，自然N-15丰富的土壤微生物生物量的影响，碳和氮的可用性和生态系统的N处理。微生物N-15富集与土壤可溶性组分的C：N比呈负相关，与跨越半干旱、温带和热带气候、草原和森林以及超过400万年的生态系统发展的生态系统的净N矿化呈正相关。此外，在土壤培养过程中，微生物N-15富集的大幅增加对应于高的净N矿化率。这些结果支持了生物体的氮同位素组成是由氮同化与异化平衡决定的观点。因此，土壤微生物生物量的N-15富集综合了C和N有效性对微生物代谢和生态系统过程的影响。
Organic carbon (C) and nitrogen (N) are essential for heterotrophic soil microorganisms, and their bioavailability strongly influences ecosystem C and N cycling. We show here that the natural N-15 abundance of the soil microbial biomass is affected by both the availability of C and N and ecosystem N processing. Microbial N-15 enrichment correlated negatively with the C : N ratio of the soil soluble fraction and positively with net N mineralization for ecosystems spanning semiarid, temperate and tropical climates, grassland and forests, and over four million years of ecosystem development. In addition, during soil incubation, large increases in microbial N-15 enrichment corresponded to high net N mineralization rates. These results support the idea that the N isotope composition of an organism is determined by the balance between N assimilation and dissimilation. Thus N-15 enrichment of the soil microbial biomass integrates the effects of C and N avalbility on microbial metabolism and ecosystem process.