不同放牧条件内蒙古草原土壤冻融期水热动态

发布时间：2018-01-22 01:17

  本文关键词： 锡林郭勒草原 放牧条件 冻融 水热状况　出处：《水土保持研究》2017年05期 　论文类型：期刊论文

【摘要】：内蒙古草原地处季节性冻土区,与放牧强度相关,土壤冻融过程对该地生态和水文过程有着显著影响,但相关研究相对欠缺。该文重点研究了内蒙古锡林郭勒草原3种放牧条件下UG79(1979年以来禁牧)、UG99(1999年以来禁牧)、HG(1979年以来持续放牧)季节性冻融期的土壤水热动态,以期准确理解放牧这一当地主要土地利用模式对土壤生态水文过程的影响。结果表明:与地上覆盖度相关,不同放牧条件下地表积雪厚度有明显差异,其中HG处理积雪厚度远小于其他处理,其土壤温度变化也最为剧烈。与不同处理土壤冻结速率相关,土壤冻结时HG,UG79和UG99的"聚墒区"分别为20—30cm,10—20cm和10—30cm,其中UG99"聚墒区"分布范围最广,且集中在牧草根系发达区域,对来年牧草生长提供了更好的水分条件。换言之,由于冻后聚墒效应,土壤消融期水分含量在土壤表层高于冻融前,其中UG99处理最大,达到了0.19m~3/m~3。该研究结果为内蒙古草原季节性冻土区控制放牧及合理的禁牧措施提供理论依据。
[Abstract]:The grassland of Inner Mongolia is located in the seasonal frozen soil area, which is related to the grazing intensity. The freezing and thawing process of the soil has a significant influence on the ecological and hydrological process. But the relative research is relatively lacking. This paper focuses on the study of UG79under three kinds of grazing conditions in Xilingol grassland of Inner Mongolia (forbidding grazing since 1979 and prohibiting grazing since 1999). Soil water and heat dynamics during seasonal freeze-thaw period of HG (continuous grazing since 1979). In order to understand the influence of grazing, the main land use model, on the soil eco-hydrological process, the results showed that there were significant differences in the thickness of snow cover under different grazing conditions. The thickness of snow in HG treatment was much smaller than that in other treatments, and the change of soil temperature was the most intense, which was related to the freezing rate of different treatments and HG during soil freezing. The "soil moisture accumulation area" of UG79 and UG99 were 20-30 cm ~ 10 ~ (-20) cm and 10 ~ (-30) cm, respectively, and the "soil moisture accumulation area" of UG99 was the most widely distributed. And concentrated in the developed area of forage roots, the forage growth in the next year to provide better water conditions. In other words, due to the effect of soil moisture accumulation after freezing, soil moisture content in the soil surface layer is higher than that before freezing and thawing. Among them, UG99 treatment was the largest, reaching 0.19 mg / m ~ (-3). The results provided a theoretical basis for grazing control and reasonable forbidding measures in the seasonal frozen soil region of Inner Mongolia steppe.
【作者单位】： 西北农林科技大学资源环境学院;Department
【基金】：国家自然科学基金项目(4137124,41371233,41501231)
【分类号】：S812.2
【正文快照】： 冻土是指温度低于0℃且含有冰的土壤[1],其对外界温度的变化十分敏感[2],伴随着温度变化土壤冻融交替现象频繁发生[3]。土壤冻融过程可以改变土壤的水力特性和微生物活性[4-8],影响地表、植被和大气之间的热量交换,甚至于区域气候特征。反之,气候变化也能引起土壤冻融过程的变，

本文编号：1453162