半干旱区沙地芦苇对浅水位变化的生理生态响应

本文在半干旱区科尔沁沙地研究沙地芦苇生长发育对地下水位改变的响应。通过比较不同地下水位深度下沙地芦苇生态特征，结果表明：与对照相比，0-200cm的水位条件更利于沙地芦苇的生长。但是这种生长特点随着水位深度不同而有所差异。具体表现为40-120cm的水位条件下沙地芦苇的根冠比和垂直根长都随着水位深度的增加而逐渐增加，当地下水位大于120cm时根冠比的趋势则相反；根长密度值则表现出在0-120cm水位条件下的要大于120-200cm水位条件下的；而40cm的浅水位表现出了对沙地芦苇生长的抑制作用，即在这种水位条件下会抑制沙地芦苇的蒸腾光合作用、减小叶面积的增长，但是其最终的株高叶面积及生物量仍表现出优于对照的生长状况。

Eco-physiological response of Phragmites communis to water table changes in the Horqin Sand Land

This study examines growth responses of Phragmites communis to controlled changes in the water table in the semiarid areas of the Horqin Sand Land. Water table level treatments were a natural control which the water table is deeper than 200 centimeters, 40 centimeters, 80 centimeters, 120 centimeters and 180 centimeters below the soil surface. We found that the water table between 0-200 centimeter was more advantageous for Phragmites to grow than natural control. And also we found significantly different growing characteristics of Phragmites communis with the different water table depths.The root-shoot ratio and the vertical root length increased gradually as the water table decreased from 40-120 cm,whereas the root-shoot ratio increased below a water table of 120 cm. The root density of the Phragmites communis was higher at water tables of 0-120cm than at water tables of 120-200 cm. At shallow water tables above 40cm depth, although rates of transpiration and photosynthesis of Phragmites communis was inhibited, however plant height, leaf area and biomass of the Phragmites communis at shallow water was higher than that at natural control.