风和风沙流对不同固沙植物生理状况的影响

EFFECTS OF WIND AND WIND SAND CURRENT ON THE PHYSIOLOGICAL STATUS OF DIFFERENT SAND FIXING PLANTS 

在野外风洞条件下，对风和风沙流影响固沙植物的生理状况进行了研究。结果表明：风和风沙流对不同植物的影响不同，风对结皮和苔藓的影响在于吹蚀和干燥，对草本和灌木的影响主要是：１．通过迫使气孔关闭、降低叶温和胞间ＣＯ２浓度来抑制光合作用；２．加强蒸腾作用，减小水分利用率；３．降低叶片水势和土壤含水量，从而加强干燥作用。而风沙流对结皮和苔藓的影响主要在于剥蚀和堆积，对草本和灌木的影响主要是机械损伤作用，对光合和水分利用的影响将更加剧烈。不同类型植物对两种胁迫的适应程度不同。

In the field wind tunnel, the physiological status—gas exchange characteristics and water relationship of three kinds of sand fixing plants (including crust and bryophyte)—were studied under wind blowing and wind sand current condition, respectively. The effects of wind and wind sand current were different. Wind caused erosion and desiccation of crust and bryophyte.The effects of wind on grass and shrub included:inhibited photosynthesis by expanded stomata; decreased leaf temperature and intercellular CO 2 concentrations;enhanced transpiration and decreased water use efficiency;aggravated desiccation by lowered leaf water potential and water capacity of soil. But the effects of wind sand current on crust and bryophyte were denudation and cumulation, on grass and shrub were mainly mechanical injury and more did on photosynthesis and water usage. The result that different plants responsed differently in adaptation to wind and wind sand current stress may provide scientific basis for selecting sand fixing plants.