晋西刺槐和油松人工林的耗水量特征

以山西省方山县和吉县的刺槐和油松人工林为研究对象,根据调查样地、解析木和气象资料,估算了其耗水量。结果表明:(1)人工林耗水量随林龄增加而增大,达一定林龄后将超过降水量。这个林龄对于位于阳坡的方山县刺槐林为15年;位于半阳坡的吉县刺槐林和油松林分别为5年和23年。(2)在现降水条件下,人工林耗水量达不到需水量,存在着水分不足的胁迫。研究区生长季各月份按耗水量从高至低的排序为:7月,6月,8月,5月,9月,10月,现降水条件限制了人工林需水量及其在生长季内的合理分配。因此,有必要根据现降水条件结合经营目标调控不同生长阶段的林分密度。

Water Consumption Characteristics of Black Locust and Pitch Pine Plantation in Western Shanxi

This research analyzed the data of forest stand, sample trees and meteorological condition for plantation of Robinia pseudoacacia and Pinus tabulaeformis in Fangshan County and Ji County of Shanxi Province, to investigate the water-consumption. The results showed: (1) The water-consuming quantity of plantation increases with increasing forest age. The water-consumption will exceed the precipitation when the stand reaches a certain age. It is 15 years for the plantation of sunny slope Robinia pseudoacacia in Fangshan County; 5 years for the half-sunny slope Robinia pseudoacacia plantation and 23 years for the plantation of half-sunny slope Pinus tabulaeformis in Ji County. (2) Under the current precipitation condition, the water-consumption can't reach its required level, there is insufficient water stress. The order of water-consumption quantity in growing season from high to low is Jul, Jun, Aug, May, Sep and Oct. The precipitation condition limits the plantation's demand on water and its rational distribution during growing season. Therefore, it is necessary to control or regulate the stand density in different growth stages with a consideration of the management objectives and the precipitation input.