干旱条件下皇甫川流域4种灌木蒸腾特征比较研究

准格尔丘陵区位于鄂尔多斯高原的最西端,是黄河中游水土流失治理、生态环境建设的重点区域.2001年是该区域连续干旱的第3年,在植物生长旺季的8月中下旬,在自然条件下,对准格尔丘陵区主要人工种植灌木中间锦鸡儿、沙柳、羊柴和沙棘的蒸腾耗水特征应用LI-1600稳态气孔计进行野外测定.结果表明:沙棘的蒸腾速率无午休现象,在12:00～16:00时间段内都呈较高的蒸腾速率,其它3种植物的蒸腾速率日变化曲线则呈双峰型.以上4种植物日蒸腾速率从大到小的排列顺序为羊柴>沙棘>沙柳>中间锦鸡儿.在连续3年干旱和人为原因致使沙棘灌木林长势不好的情况下,沙棘单株叶片日蒸腾累计失水量为1169.57g.中间锦鸡儿、沙柳和羊柴的单株叶片日蒸腾累计失水量为分别为887.69g,3739.30g,1907.57g.该研究结果可为农牧交错带准格尔丘陵区水土保持、区域生态系统平衡需水分析以及生态系统恢复与重建提供基础数据.

A Study on Transpiration Characteristics of Main Shrubs Caragana intermedia,Salix psammophyla,Hedysarum mongolicum,Hippophae rhamnoides in Zhungeer Hill Region

The Zhungeer hill region is located in the west part of the Ordos Plateau,Inner Mongolia.It is a key region for soil erosion control and eco-environment reclaimation.The transpiration characteristics of main shrubs Caragana intermedia, Salix psammophyla,Hedysarum mongolicum, Hippophae rhamnoides ssp.sinensis in Zhungeer hill region,were measured under natural conditions by using a portable LI-1600 steady state porometer in the late August,2001.The results indicated that Hippophae rhamnoides ssp.sinensis had no noon expression with single-peak pattern.From (12:00) to 16:00,the transpiration rate all kept higher value.The diurnal changes of transpiration rates of other three shrubs were all double-peak curves.The order of diurnal transpiration rate of the four shrubs was Hedysarum mongolicum >Hippophae rhamnoides ssp. sinensis >Salix psammophyla > Caragana intermedia.Under the situation of continuous dry in recent three years, the diurnal water consumption of individual plant of Caragana intermedia, Salix psammophyla, Hedysarum mongolicum, Hippophae rhamnoides ssp. sinensis in mean size through transpiration was 887.69 g,3739.30 g,1907.57 g and 1169.57 g.The results provide the basic data for soil erosion control,ecosystem water balance, and ecosystem reclaimation in the farming-pastoral zone of northwest China.