兰州南北两山侧柏人工林下草本层植物多样性

Herbaceous plant diversity of artificial understory of Platycladus orientalis in the North and South mountains of Lanzhou

【目的】探究兰州南北两山侧柏人工林下草本层植物的α多样性及其影响因子。【方法】以兰州南北两山侧柏人工同龄纯林为研究对象,采用样方法对林下草本层植物的α多样性进行研究。【结果】1)兰州南北两山侧柏人工林下草本层植物共有39种,其中在两山均出现的有13种,在南山区出现的有30种,在北山区出现的有22种;2)兰州南北两山侧柏人工林下草本层植物α多样性的主要影响因子是海拔、坡向及坡度,且物种多样性随海拔升高而降低,随坡向变化表现为阴坡>阳坡,物种均匀度随坡度增大而减小;3)兰州南北两山侧柏人工林下草本层群落整体呈正向演替,且南山区林下草本层群落的演替进程快于北山区。【结论】兰州南北两山侧柏林下草本层植物的α多样性较低,但发展趋势良好。

【Objective】In order to explore theαdiversity of herbaceous plants under artificial forests of Platycla⁃dus orientalis in the North and South Mountains of Lanzhou and its influencing factors.【Method】Taking the artifi⁃cial same age pure forest of Platycladus orientalis in the North and South Mountains of Lanzhou as the research ob⁃ject,the sample method was used to study the changes ofαDiversity of understory herbaceous plants.【Result】1)There were 39 species of herbaceous plants under Platycladus orientalis plantation in the North and South Mountains of Lanzhou,of which 13 species appeared in both mountains,30 species appeared in the South Mountain area and 22 species appeared in the North Mountain area.2)The main influencing factors ofɑdiversity in the herbaceous layer of Platycladus orientalis artificial forest in the North and South Mountains of Lanzhou were altitude,slope direction and slope.The species diversity decreased with the increase of altitude.As to the variation of species diversity with slope direction,it shows that the variation of shady slope was greater than that of sunny slope.And the species evenness de⁃creased with the increase of slope.3)The herbaceous layer community under Platycladus orientalis plantation in the North and South Mountains of Lanzhou showed positive succession as a whole,and the succession process of herba⁃ceous layer community under the forest in the South Mountain area was faster than that in the North Mountain area.【Conclusion】Theαdiversity of the understory herbaceous layer of Platycladus orientalis in the North and South Mountains of Lanzhou was low,but the development trend was good.