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The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau

The vegetation dynamic (e.g., community productivity) is an important index used to evaluate the ecosystem function of grassland ecosystem. However, the critical factors that affect vegetation biomass are disputed continuously, and most of the debates focus on mean annual precipitation (MAP) or temp...

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Autores principales: Liu, Biying, Sun, Jian, Liu, Miao, Zeng, Tao, Zhu, Juntao
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6638191/
https://www.ncbi.nlm.nih.gov/pubmed/31341736
http://dx.doi.org/10.7717/peerj.7272
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author Liu, Biying
Sun, Jian
Liu, Miao
Zeng, Tao
Zhu, Juntao
author_facet Liu, Biying
Sun, Jian
Liu, Miao
Zeng, Tao
Zhu, Juntao
author_sort Liu, Biying
collection PubMed
description The vegetation dynamic (e.g., community productivity) is an important index used to evaluate the ecosystem function of grassland ecosystem. However, the critical factors that affect vegetation biomass are disputed continuously, and most of the debates focus on mean annual precipitation (MAP) or temperature (MAT). This article integrated these two factors, used the aridity index (AI) to describe the dynamics of MAP and MAT, and tested the hypothesis that vegetation traits are influenced primarily by the AI. We sampled 275 plots at 55 sites (five plots at each site, including alpine steppe and meadow) across an alpine grassland of the northern Tibet Plateau, used correlation analysis and redundancy analysis (RDA) to explore which key factors determine the biomass dynamic, and explained the mechanism by which they affect the vegetation biomass in different vegetation types via structural equation modelling (SEM). The results supported our hypothesis, in all of the environmental factors collected, the AI made the greatest contribution to biomass variations in RDA , and the correlation between the AI and biomass was the largest (R = 0.85, p < 0.05). The final SEM also validated our hypothesis that the AI explained 79.3% and 84.4% of the biomass variations in the alpine steppe and the meadow, respectively. Furthermore, we found that the soils with higher carbon to nitrogen ratio and soil total nitrogen had larger biomass, whereas soil organic carbon had a negative effect on biomass in alpine steppe; however, opposite effects of soil factors on biomass were observed in an alpine meadow. The findings demonstrated that the AI was the most critical factor affecting biomass in the alpine grasslands, and different reaction mechanisms of biomass response to the AI existed in the alpine steppe and alpine meadow.
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spelling pubmed-66381912019-07-24 The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau Liu, Biying Sun, Jian Liu, Miao Zeng, Tao Zhu, Juntao PeerJ Biogeography The vegetation dynamic (e.g., community productivity) is an important index used to evaluate the ecosystem function of grassland ecosystem. However, the critical factors that affect vegetation biomass are disputed continuously, and most of the debates focus on mean annual precipitation (MAP) or temperature (MAT). This article integrated these two factors, used the aridity index (AI) to describe the dynamics of MAP and MAT, and tested the hypothesis that vegetation traits are influenced primarily by the AI. We sampled 275 plots at 55 sites (five plots at each site, including alpine steppe and meadow) across an alpine grassland of the northern Tibet Plateau, used correlation analysis and redundancy analysis (RDA) to explore which key factors determine the biomass dynamic, and explained the mechanism by which they affect the vegetation biomass in different vegetation types via structural equation modelling (SEM). The results supported our hypothesis, in all of the environmental factors collected, the AI made the greatest contribution to biomass variations in RDA , and the correlation between the AI and biomass was the largest (R = 0.85, p < 0.05). The final SEM also validated our hypothesis that the AI explained 79.3% and 84.4% of the biomass variations in the alpine steppe and the meadow, respectively. Furthermore, we found that the soils with higher carbon to nitrogen ratio and soil total nitrogen had larger biomass, whereas soil organic carbon had a negative effect on biomass in alpine steppe; however, opposite effects of soil factors on biomass were observed in an alpine meadow. The findings demonstrated that the AI was the most critical factor affecting biomass in the alpine grasslands, and different reaction mechanisms of biomass response to the AI existed in the alpine steppe and alpine meadow. PeerJ Inc. 2019-07-15 /pmc/articles/PMC6638191/ /pubmed/31341736 http://dx.doi.org/10.7717/peerj.7272 Text en ©2019 Liu et al. http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Biogeography
Liu, Biying
Sun, Jian
Liu, Miao
Zeng, Tao
Zhu, Juntao
The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau
title The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau
title_full The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau
title_fullStr The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau
title_full_unstemmed The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau
title_short The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau
title_sort aridity index governs the variation of vegetation characteristics in alpine grassland, northern tibet plateau
topic Biogeography
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6638191/
https://www.ncbi.nlm.nih.gov/pubmed/31341736
http://dx.doi.org/10.7717/peerj.7272
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