祁连山天涝池流域典型灌丛地上生物量沿海拔梯度变化规律的研究

摘要

This thesis focused on the alpine shrubs of Tianlaochi Watershed in Qilian Mountains.The relationship of the aboveground biomass of the alpine shrubs and its feasibly measured factors (plant height and canopy perimeter) were built based on field survey and experiments.The distribution rule of alpine shrubs biomass with the change of altitudinal gradient was studied.Results were as follows:in south facing slop,the average total aboveground biomass of shrub was 7375.8 kg · hm-2 ; in north facing slop,the average total aboveground biomass of shrub was 3055.6 kg · hm-2 ; as the altitude rising,the aboveground biomass of shrub on both south and north facing slope followed a unimodal curve,and the maximum and minimum biomass were 12101.6 kg · hm-2 and 2638.2 kg · hm-2 located at the altitude of 3200 m and 3500 m,respectively.In the four shrub types,the maximum aboveground biomass of Dasiphora fruticosa appeared at the altitude of 3150 m,Salix gilashanica at 3650 m,both Caragana jubata and Spiraea alpina at 3200 m.Comprehensive analysis indicates that aboveground biomass of shrubs in the Tianlaochi watershed follows a unimodal curve,which first increase then decrease at elevated altitude.%通过野外样地调查和试验,以祁连山寺大隆林区天涝池流域高山灌丛为研究对象,建立地上生物量与易测因子(冠幅周长和植株高度)之间的关系,对灌丛地上生物量随海拔梯度变化的分布规律进行研究.结果表明:阳坡和阴坡灌丛的平均总地上生物量分别为7375.8 kg·hm-2和3055.6 kg·hm-2；随着海拔高度升高,阳坡与阴坡灌丛地上生物量均呈单峰型曲线变化,其最大值分别分布在海拔3200m和3650m处,分别为12101.6 kg·hm-2和4084.8 kg·hm-2；在4种灌丛植物中,金露梅(Potentillafruticosa)和吉拉柳(Salix gilashanica)地上生物量最大值分别出现在海拔3150m和3650m,鬼箭锦鸡儿(Caragana jubata)和高山绣线菊(Spiraea alpina)最大值分布在海拔3200 m.综上可知,祁连山天涝池流域灌丛地上生物量随海拔升高呈先增加后减小的单峰型曲线变化.