气候变化领域集成服务门户(CCPortal): Variations in the nitrogen saturation threshold of soil respiration in grassland ecosystems

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DOI	10.1007/s10533-020-00661-y
	Variations in the nitrogen saturation threshold of soil respiration in grassland ecosystems
	Wang C.; Ren F.; Zhou X.; Ma W.; Liang C.; Wang J.; Cheng J.; Zhou H.; He J.-S.
发表日期	2020
ISSN	0168-2563
起始页码	311
结束页码	324
卷号	148 期号:3
英文摘要	Over the last century, anthropogenic activities have increased nitrogen (N) deposition considerably, which significantly affects ecosystem processes and has the potential to induce N saturation in the future. The continuous increase in N deposition may cause a non-linear response in soil respiration (Rs), an important component of carbon (C) cycling. However, little is known about N saturation threshold of soil respiration. In this study, we conducted coordinated experiments in four grassland types across northern China with four N addition levels to explore patterns in the Rs saturation threshold. Our results showed that an Rs saturation threshold generally exists in grassland ecosystems in response to N addition gradients. The N saturation threshold of Rs occurred at an average rate of 50 kg N ha−1 yr−1, but varied widely with grassland type; the N saturation threshold occurred at rates of 100, 50, 50, and 25 kg N ha−1 yr−1 in the alpine meadow, meadow steppe, typical steppe, and desert steppe, respectively. Autotrophic respiration (Ra) and heterotrophic respiration (Rh) responded to N addition gradients differently. Ra increased initially and became saturated at a rate of 50 kg N ha−1 yr−1 and declined thereafter. In contrast, Rh decreased monotonically after N addition. Structural equation models further confirmed that the effects of N addition gradients on Rs were primarily determined by the non-linear response of belowground biomass. Interestingly, the compiled global dataset showed that the N saturation threshold of Rs increased with precipitation and soil moisture. These findings indicate that the stimulating effect of N deposition on Rs and Ra might diminish with increasing N deposition in the future, especially in dry grassland ecosystems. © 2020, Springer Nature Switzerland AG.
英文关键词	Carbon cycling; Coordinated experiments; Nitrogen deposition; Precipitation; Threshold
语种	英语
scopus关键词	grassland; meadow; saturation; soil nitrogen; soil respiration; terrestrial ecosystem; threshold; China
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/153151
作者单位	Department of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871, China; Key Laboratory of Restoration Ecology for Cold Regions in Qinghai Province, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xinning Rd, Xining, 810008, China; Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Center for Global Change and Ecological Forecasting, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China; Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, China; State Key Laboratory of Grassland Agro-Ecosystems, and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, Gansu 730000, China
推荐引用方式 GB/T 7714	Wang C.,Ren F.,Zhou X.,et al. Variations in the nitrogen saturation threshold of soil respiration in grassland ecosystems[J],2020,148(3).
APA	Wang C..,Ren F..,Zhou X..,Ma W..,Liang C..,...&He J.-S..(2020).Variations in the nitrogen saturation threshold of soil respiration in grassland ecosystems.Biogeochemistry,148(3).
MLA	Wang C.,et al."Variations in the nitrogen saturation threshold of soil respiration in grassland ecosystems".Biogeochemistry 148.3(2020).