晋西黄土区主要造林树种林地土壤水分生态条件分析

Analysis of Soil Water Content of Main Afforestation Species in Western Shanxi of Loess Plateau

黄土高原地区植被建设引起的土壤水分效应问题愈来受到关注,林地的水分生态条件分析成为构建结构稳定的森林植被的前提,以晋西黄土区主要造林树种刺槐、油松和侧柏的坡面林地为研究对象,通过林地土壤水分特征曲线测定及土壤水分动态变化监测,探讨其生长的水分生态条件,结果表明:本区人工林地的土壤持水力较高,土壤含水率随水势降低而递减的速度较慢;研究区主要造林树种中,刺槐及其混交林分的土壤水分利用范围最大,抗旱能力最强;无论丰水年或枯水年,坡面各林地土壤水分有效利用性大,土壤含水量在生长季都高于无效水临界值,林地土壤水分利用状况好,林分生长稳定。

Soil water content change causing by vegetation construction in Loess area was more and more attracting researchers＇ notice. Forest water condition analysis was the basis of construction of stable vegetation structure. This paper analyzed forest water condition of the main afforestation species in western Shanxi of Loess Plateau such as Pinus tabulaeformis, Robinia pseudoacacia and Platycladus orientalis, according to the soil water characteristic curves and soil water dynamic changes. Through comparing variety plants, the Robinia pseudoacacia and its mixed forest stand have the most preventing drought abilities. Whether in wet year or in dry year,soil water content of all testing forest stand were all higher than its unavailable soil water threshold value during growing season, and forest stand could grow stable and healthy.