Root-induced changes in nutrient cycling in forests depend on exudation rates

	Root-induced changes in nutrient cycling in forests depend on exudation rates
	Yin, Huajun ; Wheeler, Emily ; Phillips, Richard P.
刊名	SOIL BIOLOGY & BIOCHEMISTRY
	2014
卷号	78 页码:213-221
关键词	Arbuscular mycorrhizal fungi Ectomycorrhizal fungi Plant-microbial feedbacks Priming effects Root exudation Rhizodeposition
通讯作者	Phillips, RP (reprint author), Indiana Univ, Dept Biol, 1001 E Third St, Bloomington, IN 47403 USA.
产权排序	1
合作状况	其它
英文摘要	(1) While it is well-known that trees release carbon (C) to soils as root exudates, the factors that control the magnitude and biogeochemical impacts of this flux are poorly understood. (2) We quantified root exudation and microbially-mediated nutrient fluxes in the rhizosphere for four similar to 80 year-old tree species in a deciduous hardwood forest, Indiana, USA. We hypothesized that trees that exuded the most carbon (C) would induce the strongest rhizosphere effects (i.e., the relative difference in nutrient fluxes between rhizosphere and bulk soil). Further, we hypothesized that tree species that associate with ectomycorrhizal (ECM) fungi would exude more C than tree species that associate with arbuscular mycorrhizal (AM) fungi, resulting in a greater enhancement of nutrient cycling in ECM rhizospheres. (3) Mass-specific exudation rates and rhizosphere effects on C, N and P cycling were nearly two-fold greater for the two ECM tree species compared to the two AM tree species (P < 0.05). Moreover, across all species, exudation rates were positively correlated with multiple indices of nutrient cycling and organic matter decomposition in the rhizosphere (P < 0.05). Annually, we estimate that root exudation represents 2.5% of NPP in this forest, and that the exudate-induced changes in microbial N cycling may contribute similar to 18% of total net N mineralization. (4) Collectively, our results indicate that the effects of roots on nutrient cycling are consequential, particularly in forests where the C cost of mining nutrients from decomposing soil organic matter may be greatest (e.g., ECM-dominated stands). Further, our results suggest that small C fluxes from exudation may have disproportionate impacts on ecosystem N cycling in nutrient-limited forests. (C) 2014 Elsevier Ltd. All rights reserved.
学科主题	Soil Science
收录类别	SCI
语种	英语
公开日期	2016-02-26
内容类型	期刊论文
源URL	[http://210.75.237.14/handle/351003/26496]
专题	成都生物研究所_生态研究
推荐引用方式 GB/T 7714	Yin, Huajun,Wheeler, Emily,Phillips, Richard P.. Root-induced changes in nutrient cycling in forests depend on exudation rates[J]. SOIL BIOLOGY & BIOCHEMISTRY,2014,78:213-221.
APA	Yin, Huajun,Wheeler, Emily,&Phillips, Richard P..(2014).Root-induced changes in nutrient cycling in forests depend on exudation rates.SOIL BIOLOGY & BIOCHEMISTRY,78,213-221.
MLA	Yin, Huajun,et al."Root-induced changes in nutrient cycling in forests depend on exudation rates".SOIL BIOLOGY & BIOCHEMISTRY 78(2014):213-221.