沙障对流沙地植被和土壤养分的影响

机械沙障是风沙防治的重要工程措施。以设置在腾格里沙漠东南缘的沙坡头和吊坡梁不同年份的高密度聚乙烯(HDPE)沙障和麦草沙障为研究对象,分析沙障对植被生长和土壤养分的影响。结果表明:2012年和2010年布设的HDPE沙障中植被的物种数大于同期草方格沙障中的物种数;两种沙障内植被的物种多样性指数较低,且随沙障布设时间增加而增高,同期布设的HDPE沙障比草方格沙障的多样性指数高。沙障使土壤pH值总体呈降低的趋势,草方格沙障内的土壤pH值低于HDPE沙障内的土壤pH值;沙障内表层土壤(0~5 cm)的全氮、有机碳、速效钾、速效磷含量高于裸沙表层,呈增加的趋势,两种沙障间的表层土壤养分含量差异不显著。

Effects of Sand Barriers on Vegetation and Soil Nutrient in Sand Dunes

Mechanical sand barrier is one of the important engineering measures for blown sand control. Effects of HDPE sand barrier and Straw sand barrier, set in different years in Shapotou and Diaopoliang located on the southeast edge of Tengger Desert, on vegetation growth and soil nutrients were measured.The results indicated that the index of species diversity of vegetation in the two barriers was lower and increased with the increase of sand barrier disposition time. The HDPE sand barrier had a higher diversity index than the grass grid barrier;the number of species in the HDPE sand barrier deployed in 2012 and 2010 was bigger than the that in the grass barrier.The two kinds of sand barrier settings made the pH value of soil decrease generally, the pH value of grass grid barrier was lower than that of HDPE sand barrier.The contents of total nitrogen, organic carbon, available potassium and available phosphorus in soils of sand barrier (0-5 cm) increased, and within 0-40 cm, the nutrient content of surface soil was higher than other soil layers, but there was no significant difference in the nutrient contents of topsoil between the two sand barriers.