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花棒(Hedysarum Scoparium)、踏郎(Hedysarum mongolicum)、紫穗槐(Amo-rpha fruticosa)三种灌木是榆林沙地固沙造林的常用树种。本文对三种固沙灌木的抗旱特征:包括蒸腾强度、体内水分状况、水势、自由水和束缚水等方面进行了试验和观测。试图从三种灌木的抗旱特征来探讨其林分演替规律的内在原因。一、试验区自然概况试验区位于榆林城西,毛乌素沙地南缘,海拔1100米左右,干燥度1.5,属于干草原气侯。试验区年平均气温7.9℃,绝对最高气温37.9℃,最低气温-27℃,无霜期150
Hedysarum Scoparium, Hedysarum mongolicum and Amo-rpha fruticosa were the common tree species for afforestation in the Yulin sandy land. In this paper, the drought-resistant characteristics of three kinds of sand-fixing shrubs were studied and tested, including the transpiration intensity, the water status in the body, the water potential, the free water and the irreducible water. Trying to explore the inherent causes of the succession rule of the stand from the drought resistance characteristics of the three shrubs. First, the natural conditions of the pilot area The experimental area is located in the west of Yulin City, the southern edge of the Mu Us sand, about 1100 meters above sea level, the dryness of 1.5, belongs to the steppe climate Hou. The annual average temperature of the experimental area 7.9 ℃, the absolute maximum temperature of 37.9 ℃, the lowest temperature of -27 ℃, frost-free period 150