晋西黄土区坡面林地土壤持水性能研究

Study on the Water-conserving Capabilities of Soils under the Sloped Woodlands in the Loess Area in West Shanxi Province

运用先进的测定方法对不同林分的土壤持水性能进行研究,通过对土壤水分特征曲线的拟合,掌握不同林分土壤比水容量,并对不同林地的土壤水分进行分类,计算出不同林地土壤水分有效性的临界点,从而求出不同林地的有效水范围。在研究区内主要造林树种比较中,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。

The Loess Plateau is one of the regions with the most serious soil erosion and the most vulnerable e cological environment in the world. The multi-year practice has proved that the project of withdrawing from farming to afforesting and grass planting is an effective measure for regenerating vegetation and improving ecological environment. In this paper, the experimental field of Beijing Forestry University in Jixian County, west Shanxi Province, is taken as the study area to study the water-conserving capabilities of soils under the different standing forests in the loess area. In the study area it belongs to the warm-temperate climate, the annual temperature and precipitation are 10℃and 575. 9 mm respectively, and the frost-free period is about 170 days. The afforested forests are mainly composed of Robinia pseudoacacia and Pinus tabulaeformis, and most forests are pure or accompanied by Populus davidiana . The curves of soil moisture contents are regressed, the moisture contents in soils under the different standing forests are classified, and the critical effectivities of the moisture contents in soils under the different standing forests are calculated so as to derive the effective moisture contents in soils under the different forests. The comparison between the tree species reveals that the forests of Robinia pseudoacacia and its mixed forests have the highest range of soil moisture utilization and the strongest drought-resistant capability.