毛乌素沙地典型沙生灌木对土壤蒸发的影响

为了探求半干旱沙区植被恢复后沙生灌木对土壤蒸发的影响,本文利用微型蒸渗仪对盐池沙区的流动沙地、油蒿群落和沙柳群落的土壤蒸发进行了测定,并分析了2014年盐池降雨、风速、太阳辐射、相对湿度、空气温度、土壤机械组成分别与土壤蒸发的关系。结果表明:1) 植被恢复区油蒿群落和沙柳群落土壤蒸发总量比流动沙地分别高出27.91%和40.23%;2) 油蒿和沙柳样地黏粒含量比流动沙地分别高出220.59%和173.53%,油蒿样地和沙柳样地黏粒和粉粒的总含量比流动沙地分别高出63%和98%;3) 油蒿和沙柳样地土壤蒸发与风速、太阳辐射、温度等气象因子相关性不显著,流动沙地土壤蒸发与太阳辐射相关性显著。因此,在半干旱沙区植被恢复后,土壤蒸发有增大的趋势,这很可能与植被恢复后土壤中黏粒和粉粒含量的增加有关。 

Influence of typical sandy shrubs on soil evaporation in Mu Us Sandland,northwestern China

In order to study the influence of sandy shrubs on soil evaporation in dry land after restored vegetation, the soil evaporation of three site types of the mobile dunes, Artemisia ordosica community and Salix psammophila community was measured in Yanchi, Ningxia of northwestern China using micro-lysimeter. And we analyzed the effects of precipitation, wind, solar radiation, relative humidity, air temperature and soil particle size on the soil evaporation. The results were as follows:1) soil evaporation of A. ordosica community and S. psammophila community was about 27. 91% and 40. 23% higher than the mobile dunes, respectively. 2 ) For the contents of clay particles, A. ordosica community and S. psammophila community were about 220. 59% and 173. 53% higher than the mobile dunes, respectively. The contents of clay and silt particles of A. ordosica community and S. psammophila community were about 63% and 98% higher than the mobile dunes, respectively. 3) The soil evaporation of A. ordosica community and S. psammophila community was not correlated with wind speed, solar radiation, air temperature, and the soil evaporation of the mobile dunes was significantly correlated with solar radiation. Therefore, soil evaporation in dry land area has increasing tendency after restored vegetation. This is probably related to the increase of clay and silt particle content after vegetation restoration.