Nitrogen pools and cycles in Tibetan Kobresia pastures depending on grazing

doi:10.1007/s00374-018-1280-y

	Nitrogen pools and cycles in Tibetan Kobresia pastures depending on grazing
	Sun, Yue 1; Schleuss, Per-Marten 2; Pausch, Johanna 3; Xu, Xingliang 4; Kuzyakov, Yakov 1,5,6
刊名	BIOLOGY AND FERTILITY OF SOILS
	2018-07-01
卷号	54 期号:5 页码:569-581
关键词	Kobresia pygmaea Gross mineralization Nitrogen uptake N-15 labeling Intensive grazing Grassland management
ISSN号	0178-2762
DOI	10.1007/s00374-018-1280-y
通讯作者	Xu, Xingliang(xuxingl@hotmail.com)
英文摘要	Kobresia grasslands on the Tibetan Plateau comprise the world's largest pastoral alpine ecosystem. Overgrazing-driven degradation strongly proceeded on this vulnerable grassland, but the mechanisms behind are still unclear. Plants must balance the costs of releasing C to soil against the benefits of accelerated microbial nutrient mineralization, which increases their availability for root uptake. To achieve the effect of grazing on this C-N exchange mechanism, a (NH4)-N-15 (+) field labeling experiment was implemented at grazed and ungrazed sites, with additional treatments of clipping and shading to reduce belowground C input by manipulating photosynthesis. Grazing reduced gross N mineralization rates by 18.7%, similar to shading and clipping. This indicates that shoot removal by grazing decreased belowground C input, thereby suppressing microbial N mining and overall soil N availability. Nevertheless, NH4 (+) uptake rate by plants at the grazed site was 1.4 times higher than at the ungrazed site, because plants increased N acquisition to meet the high N demands of shoot regrowth (compensatory growth: grazed > ungrazed). To enable efficient N uptake and regrowth, Kobresia plants have developed specific traits (i.e., efficient above-belowground interactions). These traits reflect important mechanisms of resilience and ecosystem stability under long-term moderate grazing in an N-limited environment. However, excessive (over)grazing might imbalance such C-N exchange and amplify plant N limitation, hampering productivity and pasture recovery over the long term. In this context, a reduction in grazing pressure provides a sustainable way to maintain soil fertility, C sequestration, efficient nutrient recycling, and overall ecosystem stability.
资助项目	National Key Research and Development Program of China[2016YFC0501802] ; National Natural Science Foundation of China[31470560] ; National Natural Science Foundation of China[41671253] ; German Research Council (DFG)[DFG KU 1184/14] ; China Scholarship Council (CSC)
WOS关键词	PLANT-SPECIES DIVERSITY ; BELOW-GROUND CARBON ; ALPINE MEADOW ; CLIMATE-CHANGE ; GRASSLAND ECOSYSTEMS ; INORGANIC NITROGEN ; MINERAL-NUTRITION ; ATMOSPHERIC CO2 ; N AVAILABILITY ; PLATEAU
WOS研究方向	Agriculture
语种	英语
出版者	SPRINGER
WOS记录号	WOS:000434829400002
资助机构	National Key Research and Development Program of China ; National Natural Science Foundation of China ; German Research Council (DFG) ; China Scholarship Council (CSC)
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/54708]
专题	中国科学院地理科学与资源研究所
通讯作者	Xu, Xingliang
作者单位	1.Univ Goettingen, Dept Agr Soil Sci, D-37077 Gottingen, Germany 2.Univ Bayreuth, Dept Soil Ecol, BayCEER, D-95447 Bayreuth, Germany 3.Univ Bayreuth, Dept Agroecol, BayCEER, D-95447 Bayreuth, Germany 4.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modelling, Beijing 100101, Peoples R China 5.Univ Gottingen, Dept Soil Sci Temperate Ecosyst, D-37077 Gottingen, Germany 6.Kazan Fed Univ, Inst Environm Sci, Kazan, Russia
推荐引用方式 GB/T 7714	Sun, Yue,Schleuss, Per-Marten,Pausch, Johanna,et al. Nitrogen pools and cycles in Tibetan Kobresia pastures depending on grazing[J]. BIOLOGY AND FERTILITY OF SOILS,2018,54(5):569-581.
APA	Sun, Yue,Schleuss, Per-Marten,Pausch, Johanna,Xu, Xingliang,&Kuzyakov, Yakov.(2018).Nitrogen pools and cycles in Tibetan Kobresia pastures depending on grazing.BIOLOGY AND FERTILITY OF SOILS,54(5),569-581.
MLA	Sun, Yue,et al."Nitrogen pools and cycles in Tibetan Kobresia pastures depending on grazing".BIOLOGY AND FERTILITY OF SOILS 54.5(2018):569-581.