N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan Plateau
Alpine grasslands are sensitive to grazing and atmospheric nitrogen (N) deposition. Despite increases in N deposition, few field studies have assessed the effects of grazing in conjunction with increased N deposition on alpine grassland vegetation.In this two-year field study, we examined the effect...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-10-01
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| Series: | Ecological Indicators |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X2100563X |
| _version_ | 1819039477951102976 |
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| author | Hao Shen Shikui Dong Antonio DiTommaso Jiannan Xiao Yangliu Zhi |
| author_facet | Hao Shen Shikui Dong Antonio DiTommaso Jiannan Xiao Yangliu Zhi |
| author_sort | Hao Shen |
| collection | DOAJ |
| description | Alpine grasslands are sensitive to grazing and atmospheric nitrogen (N) deposition. Despite increases in N deposition, few field studies have assessed the effects of grazing in conjunction with increased N deposition on alpine grassland vegetation.In this two-year field study, we examined the effects of overgrazing and overgrazing plus N deposition on eco-physiological processes of alpine grassland plants at the functional group level. We found that both overgrazing and overgrazing plus N deposition altered species composition and the dominance of three plant functional groups (grasses, sedges, and forbs) in an alpine meadow and alpine steppe.In the overgrazing and overgrazing plus N deposition treatments, forbs dominated the plant community. Grass and sedge dominance decreased substantially, relative to a ungrazed treatment. The underlying eco-physiological processes that led to the forb-dominated plant community differed between the overgrazing and overgrazing plus N deposition treatments. Overgrazing plus N deposition increased forb dominance both directly by selective herbivory and indirectly by enhancing forb photosynthetic rates.Our results suggest that overgrazing concomitant with increases in N deposition will likely shift the plant community composition of alpine grasslands on the Qinghai-Tibetan Plateau from grass/sedge communities to forb-dominated communities in the future. |
| first_indexed | 2024-12-21T08:53:50Z |
| format | Article |
| id | doaj.art-ea6808f4e6ae4f3784598ce1c84da973 |
| institution | Directory Open Access Journal |
| issn | 1470-160X |
| language | English |
| last_indexed | 2024-12-21T08:53:50Z |
| publishDate | 2021-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ecological Indicators |
| spelling | doaj.art-ea6808f4e6ae4f3784598ce1c84da9732022-12-21T19:09:37ZengElsevierEcological Indicators1470-160X2021-10-01129107898N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan PlateauHao Shen0Shikui Dong1Antonio DiTommaso2Jiannan Xiao3Yangliu Zhi4College of Grassland Sciences, Beijing Forestry University, Beijing 100083, China; School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China; Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USACollege of Grassland Sciences, Beijing Forestry University, Beijing 100083, China; School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China; Department of Natural Resources, Cornell University, Ithaca, NY 14853, USA; Corresponding author at: College of Grassland Sciences, Beijing Forestry University, Beijing 100083, China. School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China.Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USASchool of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, ChinaSchool of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, ChinaAlpine grasslands are sensitive to grazing and atmospheric nitrogen (N) deposition. Despite increases in N deposition, few field studies have assessed the effects of grazing in conjunction with increased N deposition on alpine grassland vegetation.In this two-year field study, we examined the effects of overgrazing and overgrazing plus N deposition on eco-physiological processes of alpine grassland plants at the functional group level. We found that both overgrazing and overgrazing plus N deposition altered species composition and the dominance of three plant functional groups (grasses, sedges, and forbs) in an alpine meadow and alpine steppe.In the overgrazing and overgrazing plus N deposition treatments, forbs dominated the plant community. Grass and sedge dominance decreased substantially, relative to a ungrazed treatment. The underlying eco-physiological processes that led to the forb-dominated plant community differed between the overgrazing and overgrazing plus N deposition treatments. Overgrazing plus N deposition increased forb dominance both directly by selective herbivory and indirectly by enhancing forb photosynthetic rates.Our results suggest that overgrazing concomitant with increases in N deposition will likely shift the plant community composition of alpine grasslands on the Qinghai-Tibetan Plateau from grass/sedge communities to forb-dominated communities in the future.http://www.sciencedirect.com/science/article/pii/S1470160X2100563XN depositionOvergrazingPlant functional groupsPhotosynthesisRespiration |
| spellingShingle | Hao Shen Shikui Dong Antonio DiTommaso Jiannan Xiao Yangliu Zhi N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan Plateau Ecological Indicators N deposition Overgrazing Plant functional groups Photosynthesis Respiration |
| title | N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan Plateau |
| title_full | N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan Plateau |
| title_fullStr | N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan Plateau |
| title_full_unstemmed | N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan Plateau |
| title_short | N deposition may accelerate grassland degradation succession from grasses- and sedges-dominated into forbs-dominated in overgrazed alpine grassland systems on Qinghai-Tibetan Plateau |
| title_sort | n deposition may accelerate grassland degradation succession from grasses and sedges dominated into forbs dominated in overgrazed alpine grassland systems on qinghai tibetan plateau |
| topic | N deposition Overgrazing Plant functional groups Photosynthesis Respiration |
| url | http://www.sciencedirect.com/science/article/pii/S1470160X2100563X |
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