Characteristics and drivers of plant C, N, and P stoichiometry in Northern Tibetan Plateau grassland

Frontiers in Plant Science

Plant Science

Zhen Xing¹  Jiamin Zhao²  Wei Wang²  Xiangtao Wang³ 

[1] College of Resources and Environmental Sciences, Tibet Agriculture and Animal Husbandry University, Nyingchi, Tibet, China;College of Resources and Environmental Sciences, Tibet Agriculture and Animal Husbandry University, Nyingchi, Tibet, China;Key Laboratory of Forest Ecology in Tibet, Ministry of Education, Xizang Agriculture and Animal Husbandry College, Nyingchi, Tibet, China;Tibet Agricultural and Animal Husbandry University, College of Animal Science, Nyingchi, Tibet, China;

关键词: C;    N;    and P stoichiometry;    plant and soil;    grassland type;    influence factors;    North Tibetan Plateau;   

DOI  :  10.3389/fpls.2023.1092872

 received in 2022-11-08, accepted in 2023-03-14,  发布年份 2023

来源: Frontiers

【 摘 要 】

Understanding vegetation C, N, and P stoichiometry helps us not only to evaluate biogeochemical cycles and ecosystem functions but also to predict the potential impact of environmental change on ecosystem processes. The foliar C, N, and P stoichiometry in Northern Tibetan grasslands, especially the controlling factors, has been highlighted in recent years. In this study, we have collected 340 plant samples and 162 soil samples from 54 plots in three grassland types, with the purpose of evaluating the foliar C, N, and P stoichiometry and underlying control factors in three grassland types along a 1,500-km east-to-west transect in the Northern Tibetan Plateau. Our results indicated that the averaged foliar C, N, and P concentrations were 425.9 ± 15.8, 403.4 ± 22.2, and 420.7 ± 30.7 g kg−1; 21.7 ± 2.9, 19.0 ± 2.3, and 21.7 ± 5.2 g kg−1; and 1.71 ± 0.29, 1.19 ± 0.16, and 1.59 ± 0.6 g kg−1 in the alpine meadow (AM), alpine steppe (AS), and desert steppe (DS) ecosystems, respectively. The foliar C and N ratios were comparable, with values of 19.8 ± 2.8, 20.6 ± 1.9, and 19.9 ± 5.8 in the AM, AS, and DS ecosystems, respectively. Both the C/P and N/P ratios are the lowest in the AM ecosystem, with values of 252.2 ± 32.6 and 12.8 ± 1.3, respectively, whereas the highest values of 347.3 ± 57.0 and 16.2 ± 3.2 were obtained in the AS ecosystem. In contrast, the soil C, N, C/P, and N/P values decreased from the AM to DS ecosystem. Across the whole transects, leaf C, N, and P stoichiometry showed no obvious trend, but soil C and N concentrations showed an increasing trend, and soil P concentrations showed a decreasing trend with the increasing longitude. Based on the general linear model analysis, the vegetation type was the dominant factor controlling the leaf C, N, and P stoichiometry, accounting for 42.8% for leaf C, 45.1% for leaf N, 35.2% for leaf P, 52.9% for leaf C/N, 39.6% for leaf C/P, and 48.0% for leaf N/P; the soil nutrients and climate have relatively low importance. In conclusion, our results supported that vegetation type, rather than climatic variation and soil nutrients, are the major determinants of north Tibet grassland leaf stoichiometry.

【 授权许可】

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Copyright © 2023 Wang, Zhao, Xing and Wang