气候变化领域集成服务门户(CCPortal): C:N:P stoichiometry and nutrient limitation of stream biofilms impacted by grassland degradation on the Qinghai-Tibet Plateau

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DOI	10.1007/s10533-020-00685-4
	C:N:P stoichiometry and nutrient limitation of stream biofilms impacted by grassland degradation on the Qinghai-Tibet Plateau
	Ren Z.; Niu D.; Ma P.; Wang Y.; Wang Z.; Fu H.; Elser J.J.
发表日期	2020
ISSN	0168-2563
起始页码	31
结束页码	44
卷号	150 期号:1
英文摘要	Grassland degradation, a process of retrogressive succession, is an extensive global threat, especially on the Qinghai-Tibet Plateau. However, the influences of grassland degradation on carbon (C): nitrogen (N): phosphorus (P) ratios of streamwater and biofilms, as well as their implications for nutrient limitation, are not well studied. Assessing nutrient limitation and stoichiometry could facilitate understanding and mitigating the effects of nutrient input variations on stream ecosystems. Using a “space for time” substitution, contemporary grassland status quantified by landscape-level normalized difference vegetation index (NDVI) were used to study potential impacts of grassland degradation on nutrient cycling in streams feeding Qinghai Lake (China). C, N, and P concentrations and ratios of streamwater and benthic biofilms were assessed. The results showed that grassland degradation was associated with lower DOC, TN, DOC:TP, and TN:TP of streamwater, especially in September. DOC:TN:TP ratios of streamwater demonstrated relatively high variability with an average of 387:169:1 (molar). C, N, P biomass per unit area of stream biofilm also demonstrated considerable variability but their ratios were relatively constrained, with an average of 471:32:1. Moreover, biofilm C, N, and P concentrations and ratios were not closely associated with streamwater nutrients or grassland degradation. The complex chemical and biological composition of stream biofilms may make their stoichiometry difficult to interpret. However, the non-isometric relationships between biofilm C and P, as well as the large imbalance between C:N:P ratios of streamwater and biofilms, suggest that stream biofilms in this catchment are sensitive to P variation and potentially limited by DOC and P. By differentially impacting DOC and nutrient supplies, grassland degradation may alleviate P limitation but aggravate carbon limitation in stream biofilms. © 2020, Springer Nature Switzerland AG.
英文关键词	Dissolved organic matter; Grassland degradation; Nutrient limitation; Stoichiometry; Stream biofilms
语种	英语
scopus关键词	biofilm; catchment; concentration (composition); freshwater ecosystem; grassland; land degradation; NDVI; nutrient cycling; nutrient limitation; stoichiometry; streamwater; China; Qinghai; Qinghai Lake; Qinghai-Xizang Plateau
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/153116
作者单位	State Key Laboratory of Grassland Agro-Ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs; Engineering Research Center of Grassland Industry, Ministry of Education; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China; Flathead Lake Biological Station, University of Montana, Polson, MT 59860, United States; Division of Biological Sciences, University of Montana, Missoula, MT 59812, United States; Advanced Institute of Natural Sciences, Beijing Normal University At Zhuhai, Zhuhai, 519087, China
推荐引用方式 GB/T 7714	Ren Z.,Niu D.,Ma P.,et al. C:N:P stoichiometry and nutrient limitation of stream biofilms impacted by grassland degradation on the Qinghai-Tibet Plateau[J],2020,150(1).
APA	Ren Z..,Niu D..,Ma P..,Wang Y..,Wang Z..,...&Elser J.J..(2020).C:N:P stoichiometry and nutrient limitation of stream biofilms impacted by grassland degradation on the Qinghai-Tibet Plateau.Biogeochemistry,150(1).
MLA	Ren Z.,et al."C:N:P stoichiometry and nutrient limitation of stream biofilms impacted by grassland degradation on the Qinghai-Tibet Plateau".Biogeochemistry 150.1(2020).