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Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland

Grazing exclusion is an effective management practice to restore grassland ecosystem functioning. However, little is known about the role of soil microbial communities in regulating grassland ecosystem functioning during long-term ecosystem restorations. We evaluated the recovery of a degraded semia...

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Autores principales: Wang, Zhen, Li, Xiliang, Ji, Baoming, Struik, Paul C., Jin, Ke, Tang, Shiming
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8351616/
https://www.ncbi.nlm.nih.gov/pubmed/34381466
http://dx.doi.org/10.3389/fpls.2021.640789
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author Wang, Zhen
Li, Xiliang
Ji, Baoming
Struik, Paul C.
Jin, Ke
Tang, Shiming
author_facet Wang, Zhen
Li, Xiliang
Ji, Baoming
Struik, Paul C.
Jin, Ke
Tang, Shiming
author_sort Wang, Zhen
collection PubMed
description Grazing exclusion is an effective management practice to restore grassland ecosystem functioning. However, little is known about the role of soil microbial communities in regulating grassland ecosystem functioning during long-term ecosystem restorations. We evaluated the recovery of a degraded semiarid grassland ecosystem in northern China by investigating plant and soil characteristics and the role of soil microbial communities in ecosystem functioning after 22 years of grazing exclusion. Grazing exclusion significantly increased the alpha diversity and changed the community structure of bacteria, but did not significantly affect the alpha diversity or community structure of fungi. The higher abundance of copiotrophic Proteobacteria and Bacteroidetes with grazing exclusion was due to the higher carbon and nutrient concentrations in the soil, whereas the high abundance of Acidobacteria in overgrazed soils was likely an adaptation to the poor environmental conditions. Bacteria of the Sphingomonadaceae family were associated with C cycling under grazing exclusion. Bacteria of the Nitrospiraceae family, and especially of the Nitrospira genus, played an important role in changes to the N cycle under long-term exclusion of grazing. Quantitative PCR further revealed that grazing exclusion significantly increased the abundance of nitrogen fixing bacteria (nifH), ammonia oxidizers (AOA and AOB), and denitrifying bacteria (nirK and nosZ1). Denitrifying enzyme activity (DEA) was positively correlated with abundance of denitrifying bacteria. The increase in DEA under grazing exclusion suggests that the dependence of DEA on the availability of NO(3)(–) produced is due to the combined activity of ammonia oxidizers and denitrifiers. Our findings indicate that decades-long grazing exclusion can trigger changes in the soil bacterial diversity and composition, thus modulating the restoration of grassland ecosystem functions, carbon sequestration and soil fertility.
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spelling pubmed-83516162021-08-10 Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland Wang, Zhen Li, Xiliang Ji, Baoming Struik, Paul C. Jin, Ke Tang, Shiming Front Plant Sci Plant Science Grazing exclusion is an effective management practice to restore grassland ecosystem functioning. However, little is known about the role of soil microbial communities in regulating grassland ecosystem functioning during long-term ecosystem restorations. We evaluated the recovery of a degraded semiarid grassland ecosystem in northern China by investigating plant and soil characteristics and the role of soil microbial communities in ecosystem functioning after 22 years of grazing exclusion. Grazing exclusion significantly increased the alpha diversity and changed the community structure of bacteria, but did not significantly affect the alpha diversity or community structure of fungi. The higher abundance of copiotrophic Proteobacteria and Bacteroidetes with grazing exclusion was due to the higher carbon and nutrient concentrations in the soil, whereas the high abundance of Acidobacteria in overgrazed soils was likely an adaptation to the poor environmental conditions. Bacteria of the Sphingomonadaceae family were associated with C cycling under grazing exclusion. Bacteria of the Nitrospiraceae family, and especially of the Nitrospira genus, played an important role in changes to the N cycle under long-term exclusion of grazing. Quantitative PCR further revealed that grazing exclusion significantly increased the abundance of nitrogen fixing bacteria (nifH), ammonia oxidizers (AOA and AOB), and denitrifying bacteria (nirK and nosZ1). Denitrifying enzyme activity (DEA) was positively correlated with abundance of denitrifying bacteria. The increase in DEA under grazing exclusion suggests that the dependence of DEA on the availability of NO(3)(–) produced is due to the combined activity of ammonia oxidizers and denitrifiers. Our findings indicate that decades-long grazing exclusion can trigger changes in the soil bacterial diversity and composition, thus modulating the restoration of grassland ecosystem functions, carbon sequestration and soil fertility. Frontiers Media S.A. 2021-07-26 /pmc/articles/PMC8351616/ /pubmed/34381466 http://dx.doi.org/10.3389/fpls.2021.640789 Text en Copyright © 2021 Wang, Li, Ji, Struik, Jin and Tang. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Plant Science
Wang, Zhen
Li, Xiliang
Ji, Baoming
Struik, Paul C.
Jin, Ke
Tang, Shiming
Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland
title Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland
title_full Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland
title_fullStr Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland
title_full_unstemmed Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland
title_short Coupling Between the Responses of Plants, Soil, and Microorganisms Following Grazing Exclusion in an Overgrazed Grassland
title_sort coupling between the responses of plants, soil, and microorganisms following grazing exclusion in an overgrazed grassland
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8351616/
https://www.ncbi.nlm.nih.gov/pubmed/34381466
http://dx.doi.org/10.3389/fpls.2021.640789
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