准格尔丘陵区植物群落、人工草地和灌木林地水分生态特征比较

Comparison on Water Ecology of Plant Community,Artificial Grassland and Shrub Forest Land in Zhungeer Hilly Region

准格尔丘陵区位于鄂尔多斯高原最西端 ,是黄河中游水土流失治理、生态环境建设的重点区域。2 0 0 1年 8月中下旬 ,在自然条件下 ,对准格尔丘陵区主要天然优势植物群落百里香群落、沙打旺人工草地和沙棘灌木林的蒸腾耗水特征应用 L I- 1 6 0 0稳态气孔计同时进行野外测定。结果表明 :百里香和沙棘的蒸腾速率都无午休现象 ,百里香蒸腾速率峰值出现在下午 1 6 :0 0 ;沙棘在 1 2 :0 0～ 1 6 :0 0时间段内都呈较高的蒸腾速率 ,两者都为单峰型。达乌里胡枝子、糙隐子草和沙打旺的蒸腾速率日变化曲线则呈不明显的双峰型。以上 5种植物日蒸腾速率平均值从大到小的排列顺序为百里香 >达乌里胡枝子 >沙棘 >糙隐子草 >沙打旺。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 ,单位面积 (1 m× 1 m )沙打旺人工草地日蒸腾累计失水量最大 ,为 75 70 .5 g,百里香群落居中 ,为 2 0 71 .4 g,沙棘灌木林最小 ,为 1 1 6 9.

The Zhungeer hilly 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 restoration in the middle reach of Yellow River. On 20 August 2001, the transpiration characteristics of Thymus serpyllum community, Astragalia adsurgens cv. artificial grassland and Hippophae rhamnoides shrubs forest land were measured under natural conditions by using a portable LI 600 stable stomatal. The results indicated that transpiration rate of Thymus serpyllum and Hippophae rhamnoides had no noon expression, was single peak pattern. For Thymus serpyllum, the highest value appeared in 16:00, for Hippophae rhamnoides, from 12:100~16:00, the rate was all higher. However, transpiration rate of Lespedeza davurica, Cleistogenes squarrosa and Astragalia adsurgens cv. were bimodal pattern. The order of mean of transpiration rate in one day is Thymus serpyllum>Lespedeza davurica>Hippophae rhamnoides>Cleistogenes squarrosa>Astragalia adsurgens cv.. In condition, weather was dry for continuous three years, and some other reasons, water consumption by transpiration of Astragalia adsurgens cv. artificial grassland was biggest, was 7 570.5 g/m 2,Thymus serpyllum community was middle,is 2 071.4 g/m 2, Hippophae rhamnoides shrub forest land was smallest, was 1 169.8 g/m 2.