[1]YAO Nan,ZHAO Ying,ZHANG Jianguo,et al.Soil Water and Heat Dynamics During Freezing and Thawing Period Under Three Grazing Densities in Grassland of Inner Mongolia[J].Research of Soil and Water Conservation,2017,24(05):132-138.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
24
Number of periods:
2017 05
Page number:
132-138
Column:
Public date:
2017-10-28
- Title:
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Soil Water and Heat Dynamics During Freezing and Thawing Period Under Three Grazing Densities in Grassland of Inner Mongolia
- Author(s):
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YAO Nan1, ZHAO Ying1,2, ZHANG Jianguo1, HE Hailong1, SI Bingcheng2,3, JIAO Rui1
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1. Collage of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China;
2. Department of Soil Science, University of Saskatchewan, Saskatoon, SK S7 N5 A8 Canada;
3. College of Water Resources and Architecture Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China
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- Keywords:
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Xilingol grassland; grazing intensities; soil freezing and thawing process; soil water and heat regime
- CLC:
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S152.7+5
- DOI:
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- Abstract:
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Inner Mongolia grassland is located at seasonally frozen ground. The soil freezing and thawing processes, associated with grazing intensity, have a significant impact on ecological and hydrological process in this region. However, the relevant research is limited. This paper is mainly focusing on soil water and heat regime during seasonal freezing and thawing period in Xilingol grassland under three typical grazing treatments, i. e., UG79 (ungrazed site since 1979), UG99 (ungrazed site since 1999), and HG (heavily grazed site since 1979), thereby clarifying how different extent of grazing affects rates and intensities of soil freezing and thawing, and snowmelting water infiltration. The results showed that snow thickness varied from different grazing treatments, and was the function of surface coverage such as litter. For instance, the snow thickness under HG site was far less than that in the other two ungrazed sites. Accordingly, the soil temperature fluctuated more strongly in HG. The area of unfrozen water content extended into 20—30 cm, 10—20 cm and 10—30 cm in HG, UG79 and UG99 site, respectively, due to the water migration caused by soil frozen. This trend was the strongest in UG99 characterizid by the zone of the largest root system which provides a better moisture condition to grass germination in the coming year. In other words, the soil moisture content after soil thawing is higher than before soil freezing due to the hydraulic lift of soil frozen. Consequently, among the three sites, the soil moisture content in UG99 site was the greatest, which reached to 0.19 m3/m3 after soil thawing. This result can provide the theoretical basis for reduction of grazing activity and reasonable grazing management in grassland of Inner Mongolia.