气候变化领域集成服务门户(CCPortal): Roots regulate microbial N processes to achieve an efficient NH4+ supply in the rhizosphere of alpine coniferous forests

CCPortal

DOI	10.1007/s10533-021-00811-w
	Roots regulate microbial N processes to achieve an efficient NH4+ supply in the rhizosphere of alpine coniferous forests
	Zhu X.; Liu D.; Yin H.
发表日期	2021
ISSN	1682563
英文摘要	Despite multiple pieces of evidence that root-derived carbon (C) can profoundly regulate mineral nitrogen (N) cycling, it is still not elucidated whether tree roots differentially modulate the production and retention of ammonium (NH4+) versus nitrate (NO3−) through the rhizosphere effect (RE). Using the 15N isotope labeling technique, we investigated how plant roots regulated the production and retention of NH4+ and NO3− via rhizosphere processes and thus affected soil N availability in two alpine coniferous forests. Meanwhile, the activities of enzymes associated with N cycling and soil physicochemical properties in the rhizosphere and bulk soils were measured to explore the underlying mechanism. The results showed that roots induced positive REs of gross mineralization, microbial NH4+ immobilization, and dissimilatory nitrate reduction to ammonium (DNRA) to improve rhizosphere NH4+ availability. These positive REs can be attributed to higher microbial biomass C and N contents and higher activities of N cycling-associated enzymes that are fueled by root-derived C inputs. In contrast, the REs on NO3− production were negative, which could be due to a higher soil C:N ratio and greater microbial NH4+ immobilization in the rhizosphere soil than those in the bulk soil, thus leading to relatively low NO3− availability in the rhizosphere. Collectively, our results provide field-based empirical evidence that plant roots can stimulate NH4+ production and immobilization, whereas they can limit NO3− production to achieve a high rhizosphere NH4+ supply in alpine coniferous forests. These findings provide comprehensive insights into how plants sustain nutrient supply and growth via mediating soil microbial N processes in the rhizosphere. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
英文关键词	Alpine forests; Mineral N production and retention; Nutrient availability; Rhizosphere effect
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/184641
作者单位	Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
推荐引用方式 GB/T 7714	Zhu X.,Liu D.,Yin H.. Roots regulate microbial N processes to achieve an efficient NH4+ supply in the rhizosphere of alpine coniferous forests[J],2021.
APA	Zhu X.,Liu D.,&Yin H..(2021).Roots regulate microbial N processes to achieve an efficient NH4+ supply in the rhizosphere of alpine coniferous forests.Biogeochemistry.
MLA	Zhu X.,et al."Roots regulate microbial N processes to achieve an efficient NH4+ supply in the rhizosphere of alpine coniferous forests".Biogeochemistry (2021).