鄂尔多斯地区两种典型沙质荒漠化阶段微气象特征的比较研究

COMPARISON OF MICRO-METEOROLOGICAL CHARACTERISTICS OF DIFFERENT STAGE IN DESERTIFICATION AREA ERDUOSI

本文旨在研究鄂尔多斯地区的两种典型的沙质荒漠化阶段的下垫面微气象特征 (净辐射、土壤水分、土壤温度、降水量、风速 )的变异性规律与沙质荒漠化之间的关系。两种典型沙质荒漠化阶段的群落类型分别为油蒿群落和牛心朴子群落。结果表明 ,由于沙质荒漠化不同阶段的下垫面的植被群落组成、结构和盖度的差异 ,引起净辐射、土壤含水量、近地层风速等产生较大差异。油蒿群落的太阳净辐射能明显比牛心朴子群落高 ;油蒿群落与牛心朴子群落的不同深度土壤水分差别很大 ,当降雨量在 4 5mm以下时 ,只能影响 0～ 4 0cm土深的土壤水分状况 ,而这一深度恰好是大部分植物根系分布的区域。油蒿群落比牛心朴子群落更有利于维持土壤温度的恒定。油蒿群落对近地面风速有明显的削减作用。

Since the micro_meteorological characteristics including net solar radiation, soil temperature, soil moisture, precipitation, and wind speed are response factors of desertification, so our study was focused on two communities of desertification stage: Artemisia ordosica and cynanchum komarocii. Net solar radiation, soil moisture and wind speed were changed remarkably in the two communities because of the community component, structure, and cover degree. Net radiation ( R n) of Artemisia ordosica community was higher than that of Cynanchum komarocii community and a difference of soil moisture was also in existence. The depth of soil moisture that can be affected by the rain depends on the depth of precipitation: When the monthly precipitation was lower than 45?mm, Only the upper 40?cm soil moisture runs up where there most of the root system was distributed. Artemisia ordosica community has more stable soil temperature than Cynanchum komarocii community as well as more efficiency in weakening wind speed.