渭北黄土高原主要造林树种根系分布特征的研究

采用土钻法研究了油松、刺槐、樟子松、华山松、侧柏和山杏６个树种的垂直根系分布特征。结果表明，立地条件对刺槐根系分布特征有明显的影响，林地土壤水分状况的差异是造成这种影响的关键所在；土壤种类、结构等对刺槐根系的分布特征也有很大影响；油松在幼年期（８年生）即可达到根系分布的最大深度，但根系密度却随着林龄的增大呈明显的增大趋势；不同树种在根系垂直分布特征方面存在着很大差异，其中刺槐根系分布最深。根据各树

Distribution patterns of root systems of main planting tree species in Weibei Loess Plateau

The vertical patterns of root systems of Pinus tabulaeformis,Robinia pseudoacacia,Platycladus orientalis,Pinus sylvestris var. mongolica,Pinus armandi,Prunus armeniacia var. ansu planted in the Weibei Loess Plateau were studied with soil auger.Site conditions had a significant effect on the vertical root distribution of R.pseudoacacia ,of which,soil moisture is the key factor.Soil species and soil structure also had great effect on the distribution. P.tabulaeformis had a maximum rooting depth at its young stage(8 years old),but the root density increased with age. There was a great difference in vertical root distribution among the tree species,of them, R.pseudoaccia rooted deepest,which negated the opinion that R.pseudoacacia is a shallow rooted tree species.According to the vertical root distribution of the tree species,the productivity of these species in the south facing site of yellow loess soil would be in order of R.pseudoacacia>Prunus armeniacia var. ansu > P.tabulaeformis>P.sylvestris var. mongolica>P.armandi>Platycladus orientalis .