Impacts of changes in vegetation cover on soil water heat coupling in an alpine meadow of the Qinghai-Tibet Plateau, China
文献类型：期刊论文
| 作者 | Genxu, W.1,2; Hongchang, H.2; Guangsheng, L.2; Na, L.1 |
| 刊名 | HYDROLOGY AND EARTH SYSTEM SCIENCES
 |
| 出版日期 | 2009 |
| 卷号 | 13期号:3页码:327-341 |
| ISSN号 | 1027-5606 |
| 合作状况 | 国内 |
| 英文摘要 | Alpine meadow is one of the most widespread grassland types in the permafrost regions of the Qinghai-Tibet Plateau, and the transmission of coupled soil water heat is one of the most crucial processes influencing cyclic variations in the hydrology of frozen soil regions, especially under different vegetation covers. The present study assesses the impact of changes in vegetation cover on the coupling of soil water and heat in a permafrost region. Soil moisture (theta(nu)), soil temperature (T(s)), soil heat content, and differences in theta(nu)-Ts coupling were monitored on a seasonal and daily basis under three different vegetation covers (30, 65, and 93%) on both thawed and frozen soils. Regression analysis of theta(nu) vs. T(s) plots under different levels of vegetation cover indicates that soil freeze-thaw processes were significantly affected by the changes in vegetation cover. The decrease in vegetation cover of an alpine meadow reduced the difference between air temperature and ground temperature (Delta T(a-s)), and it also resulted in a decrease in T(s) at which soil froze, and an increase in the temperature at which it thawed. This was reflected in a greater response of soil temperature to changes in air temperature (Ta). For Delta T(a-s) outside the range of -0.1 to 1.0 degrees C, root zone soil-water temperatures showed a significant increase with increasing Delta T(a-s); however, the magnitude of this relationship was dampened with increasing vegetation cover. At the time of maximum water content in the thawing season, the soil temperature decreased with increasing vegetation. Changes in vegetation cover also led to variations in theta(nu)-T(s) coupling. With the increase in vegetation cover, the surface heat flux decreased. Soil heat storage at 20 cm in depth increased with increasing vegetation cover, and the heat flux that was downwardly transmitted de-creased. The soil property varied greatly under different vegetation covers, causing the variation of heat conductivity and water-heat hold capacity in topsoil layer in different vegetation cover. The variation of heat budget and transmitting in soil is the main factor that causes changes in soil thawing and freezing processes, and theta(nu)-T(s) coupling relationship under different vegetation fractions. In addition to providing insulation against soil warming, vegetation in alpine meadows within the permafrost region also would slow down the response of permafrost to climatic warming via the greater water-holding capacity of its root zone. Such vegetation may therefore play an important role in conserving water in alpine meadows and maintaining the stability of engineering works constructed within frozen soil of the Qinghai-Tibet Plateau. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Geosciences, Multidisciplinary ; Water Resources |
| 研究领域[WOS] | Geology ; Water Resources |
| 关键词[WOS] | BOREAL PEATLAND ; ENERGY-EXCHANGE ; PERMAFROST ; CLIMATE ; ATMOSPHERE ; ECOSYSTEM ; ALASKA ; FLUX |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000264741100005 |
| 公开日期 | 2010-09-16 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/1984]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） |
| 作者单位 | 1.Chinese Acad Sci, Inst Mt Hazards & Environm, Chengdu 610041, Peoples R China 2.Lanzhou Univ, Coll Resources & Environm, Lanzhou 730000, Peoples R China |
| 推荐引用方式 GB/T 7714 | Genxu, W.,Hongchang, H.,Guangsheng, L.,et al. Impacts of changes in vegetation cover on soil water heat coupling in an alpine meadow of the Qinghai-Tibet Plateau, China[J]. HYDROLOGY AND EARTH SYSTEM SCIENCES,2009,13(3):327-341. |
| APA | Genxu, W.,Hongchang, H.,Guangsheng, L.,&Na, L..(2009).Impacts of changes in vegetation cover on soil water heat coupling in an alpine meadow of the Qinghai-Tibet Plateau, China.HYDROLOGY AND EARTH SYSTEM SCIENCES,13(3),327-341. |
| MLA | Genxu, W.,et al."Impacts of changes in vegetation cover on soil water heat coupling in an alpine meadow of the Qinghai-Tibet Plateau, China".HYDROLOGY AND EARTH SYSTEM SCIENCES 13.3(2009):327-341. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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