共 59 条
Grazing-induced increases in soil moisture maintain higher productivity during droughts in alpine meadows on the Tibetan Plateau
被引:56
作者:
Zhang, Tao
[1
,3
]
Xu, Mingjie
[1
]
Zhang, Yangjian
[2
,3
,4
]
Zhao, Tianhong
[1
]
An, Tingting
[1
]
Li, Yingge
[1
]
Sun, Yi
[1
]
Chen, Ning
[2
,3
]
Zhao, Tingting
[1
]
Zhu, Juntao
[2
,3
]
Yu, Guirui
[2
]
机构:
[1] Shenyang Agr Univ, Coll Agron, Postdoctoral Res Stn Crop Sci, Shenyang 110866, Liaoning, Peoples R China
[2] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China
[3] Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
[4] Univ Chinese Acad Sci, Coll Resources & Environm, Beijing 100190, Peoples R China
基金:
中国国家自然科学基金;
国家重点研发计划;
中国博士后科学基金;
关键词:
Grazing;
Carbon fluxes;
Evapotranspiration;
Drought;
Alpine meadow;
GAP FILLING STRATEGIES;
ECOSYSTEM CO2 EXCHANGE;
WATER-VAPOR EXCHANGE;
INNER-MONGOLIA;
CLIMATE-CHANGE;
ABOVEGROUND BIOMASS;
SPECIES COMPOSITION;
CARBON-DIOXIDE;
EVAPOTRANSPIRATION;
GRASSLAND;
D O I:
10.1016/j.agrformet.2019.02.022
中图分类号:
S3 [农学(农艺学)];
学科分类号:
0901 ;
摘要:
Grazing is the primary land use practice in alpine ecosystems on the Tibetan Plateau. However, it remains unclear how grazing regulates levels of carbon and the water cycle in this ecosystem. A paired set of eddy covariance systems were set in adjacent fenced (FM) and grazed meadows (GM) to explore the grazing effects on alpine meadows. Aboveground biomass removed by grazing caused declines in grass transpiration (T), whereas the evaporation (E) was enhanced because of greater exposure to radiation, which in turn led to higher evapotranspiration (ET) in GM. However, the deep-layer soil moisture remained high because of the effects of mattic epipedon, which worked as a water-resistant layer. Therefore, the deep-layer soil moisture in GM was higher than that in FM because of decreased water consumption caused by the grazing-induced reduction in leaf area in GM. As a consequence, the deep-layer soil in GM could provide more water to help plants endure droughts. Additionally, grazing enhanced the sensitivity of productivity to soil moisture during the wet season in drought years, which could restore grassland productivity more quickly after droughts. Therefore, grazing could help this fragile ecosystem to withstand droughts to some extent and maintain higher productivity. This may provide us with an ecological approach for confronting global climate change.
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页码:249 / 256
页数:8
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