辽东山地老秃顶子北坡植物物种多样性的垂直分布格局

基于野外样方调查数据,以物种丰富度、α多样性指数和β多样性指数为测度指标,分析了辽东丘陵地区相对高差为867 m的中山山地——老秃顶子北坡植物物种多样性沿海拔梯度的分布格局.结果表明：（1）老秃顶子北坡植物物种丰富度的垂直梯度变化规律比较复杂,但总体呈现出了在中海拔地段物种丰富度谷、峰值连续出现的分布格局; （2）老秃顶子北坡植物群落的Shannon-Wiener指数在海拔667-1 267 m森林群落分布段内,随着海拔的升高呈波浪状起伏,其值在1.37-2.07间变动; 在海拔1 267-1 347 m灌丛、草甸群落分布段内,随着海拔的升高呈大幅度增加态势,至海拔1 347 m处达最大值3.95.Si mpson指数在海拔667-1 267 m间,随着海拔的升高其值在0.98-0.99间起伏,没有明显变化; 在海拔1 267-1 347 m间,随着海拔的升高呈明显降低态势,至海拔1 347 m处达最小值0.85; （3）老秃顶子北坡植物群落的Jaccard指数的3个谷值分别反映了海拔767-867 m是落叶阔叶林向针阔混交林的过渡带,海拔1 067-1 167 m是暗针叶林向针阔混交林的过渡带,海拔1 317-1 347 m是灌丛群落向草甸群落的过渡带; 而Cody指数的2个峰值分别反映了海拔1 167-1 267 m是针阔混交林向落叶阔叶林的过渡带,海拔1 317-1 347 m是灌丛群落向草甸群落的过渡带.

Elevational patterns of plant species diversity on northern slope of Mt.Laotudingzi of Liaoning Eastern Mountains

Based on the data of open plots,the species richness,α diversity and β diversity as measure target,this paper analyzed the pattern of plant species diversity along altitudinal gradient on the northern slope of Mt.Laotudingzi,which was mid-size mountain and the relative height was 867 m in Liaoning Eastern Mountains.The results indicated that：（1）The pattern of plant species richness along elevational gradient was complicated.However,it represented that the valley and peak of species richness appeared continuously at the mid-altitudinal zone,namely the most lowest value of species richness appeared at 1 067 m in the dark coniferous forests which dominated by Abies nephrolepis and Picea jezoensis,and peaked at 1 167 m in the mixed coniferous and broad-leaved forests dominated by Betula costata and Abies nephrolepis,the value was 18 and 54.（2）The Shannon-Wiener showed wavy fluctuation with increasing elevation between 667 to 1 267 m in forests and its value was 1.37~2.07;It raised substantially along 1 267 to 1 347 m in shrubs and herbs,reaching maximum value 3.95 at 1 347 m on the northern slope of Mt.Laotudingzi.The Simpson index ranged from 0.98 to 0.99 along altitudinal gradient from 667 to 1 267 m,which means no obvious change;at 1 267~1 347 m,with increasing elevation the value was significantly reduced to 0.85 which was the minimum at 1 347 m.The pattern of α diversity along elevational gradient was more complex in tree layers,shrub and herb layers of the northern slope of Mt.Laotudingzi.（3）The three valleys of Jaccard index appearing at 767~867,1 067~1 167,and 1 317~1 347 m,correspond to transitional zones of the fallen broad-leaved forests to mixed coniferous and broad-leaved forests,dark coniferous forests to mixed coniferous and broad-leaved forests,shrubs to herbs,respectively.The Cody index peaked at 1 167~1 267 m which indicated the transitional of mixed coniferous and broad-leaved forests dominated by Betula costata to fallen broad-leaved forests dominated by Betula ermanii,and peaked