摩天岭北坡东南部不同海拔梯度草本植物群落特征

The characteristics of herbaceous plant communities in the southeast of Motianling northern slope at different altitudes

海拔因子是影响植被生长的主导因子,对生态系统格局与过程有着深远的影响。本研究运用相关分析、逐步回归分析和Pearson相关系数检验对摩天岭北坡南段海拔600-1 500m草本植物多样性以及群落初级生产力进行分析。结果表明,1)物种多度与海拔梯度呈显著正相关关系(R2=0.278 4)(P<0.05),植物盖度与海拔梯度呈显著负相关关系(R2=0.43),草本层高度、密度与海拔梯度相关性不显著(P>0.05);2)植被地上生物量随海拔梯度的上升表现出先增后减的变化趋势,地下生物量随海拔变化差异较大,表现出先增后减再增的趋势;3)从功能群的角度分析,草本层植物功能群地上生物量和地下生物量随海拔梯度的变化趋势基本一致。摩天岭北坡东南部草本植物群落特征随海拔梯度变化显著,各功能群的地上、地下生物量差异显著。生物量与草本层植被盖度呈极显著正相关(P<0.01),生物量与植物高度和密度的相关性不显著,以及植物盖度、高度和密度之间相关程度不高。

Altitude is the dominant factor that influenced vegetation habitat differences which has a profound influence on ecosystem structure and process.The present study analyzed plants diversity and primary productivity of community in altitude of 600-1 500 mrange in the southern section of Motianling northern slope using the analysis of correlation,stepwise regression and the test of Pearson correlation coefficient.The results showed that the species abundance was significantly and positively correlated（R^2=0.278 4）with the altitude gradient（P〈0.05）,whereas plant coverage was significantly and negatively correlated（R^2=0.43）with the altitude gradient and there was weak correlation between altitude gradient and vegetation height and density（P〉0.05）.Furthermore,aboveground biomass firstly increased and then decreased with the increase of altitude,however,underground biomass changed more complicated which firstly increased,then decreased,and increased again with the increase of altitude.The variations of plant functional group of aboveground biomass and underground biomass were consistent with the variations of altitude gradient.All of the results showed that the characteristics of herbaceous communities had a significant change with attitude gradient in the southeast of Motianling northern slope.The difference of aboveground and underground biomass for each functional group was significant.There was highly significant positive correlation between biomass and the vegetation coverage of the herb layer（P〈0.01）,and no correlation between biomass and plant height and density;between plant coverage,height and density.