白龙江干旱河谷不同坡向主要灌丛群落随海拔梯度变化的物种多样性研究

采用样方调查法，研究了白龙江干旱河谷不同坡向主要灌丛群落沿着海拔梯度的结构特征、物种多样性的变化规律，旨在了解白龙江干旱河谷不同海拔梯度植被特征和物种多样性变化，为白龙江干旱河谷区域不同海拔植被恢复提供理论依据。研究结果表明：（1）不同海拔梯度同一坡向物种数不同，同一海拔不同坡向物种数也不同，随着海拔的升高不同坡向物种数表现为先增加后减少的趋势，同一海拔梯度内不同坡向主要植被类型也不同。（2）主要灌木群落α多样性在不同坡向随着海拔梯度的升高，表现出先升高后减小的趋势。不同坡向草本群落α多样性随着海拔的升高，也表现出先升高后减小的趋势。对主要灌丛α多样性指数进行相关性分析得物种丰富度指数对物种多样性贡献率最大，表现为丰富度指数（D₁、D₂）> 生态优势度指数（SN）> 种间机遇指数（H）> 群落均匀度指数（R）。（3）不同坡向主要灌丛群落β多样性Whittaker指数沿着不同海拔梯度变化不大，最大值出现在海拔1250~1650m；Routledge和Codyβ多样性指数在海拔1450~1650m出现最大值，但是大体呈现出波形变化。草本β多样性随着海拔的升高变化较大，阳坡植物的β多样性指数在海拔1050~1250m达到最大，阴坡和半阴半阳坡在海拔区间1250~1450m达到最大，半阴半阳坡的β多样性指数均大于阳坡。白龙江干旱河谷不同坡向、不同海拔梯度物种α多样性和β多样性都不同，且不同坡向随着海拔梯度的变化物种α多样性和β多样性呈一定的相关性，说明海拔和坡向是影响生物多样性主要因子之一。

The Different Altitude Gradient Change Rules of the Main Shrub Community in Arid Valleys of the Bailongjiang River with Different Slope

The change rules of different slope on the structure characteristics and species diversity of the Main shrub community in arid valleys of the Bailongjiang River were studied with Quadrat survey method. Aim to understand the vegetation characteristic and Species diversity changes from different elevation gradient of arid valleys in bailongjiang river, It will provides the theory basis for vegetation restoration in this region.Results show that: (1)species are different in the same slope of different altitude gradient, as well as in the different slope of same altitude gradient. with the increase of altitude,the species of different slope show that increased after decreased first, The main vegetation types are also different in the same slope of different altitude gradient; (2)With the increase of altitude gradient, α-diversity of shrub community and α-diversity of herb community in different slope all showed that a trend from rise to decline . Correlation analysis was carried out on the α-diversity index, contribution rate of species diversity for the species diversity is the largest,it is showed that the richness index(D₁, D₂)> ecological dominance index(SN)> interspecific opportunity index(H)> evenness index of community(R); (3)With the change of altitude gradient, β-diversity Whittaker index of the main shrub community have less change in different slope, the maximum appeared at an altitude of 1 250-1 650 m,Routledge and Cody β-diversity index between an altitude of 1 450-1 650 m reache maximum, but generally presents the waveform changes. β-diversity of herb community have larger change, At an altitude of 1 050-1 250 m, β-diversity of herb community in the sunny slope reaches maximum. At an altitude of 1 250-1 450 m,β-diversity index of herb community in the semi-shady slope and semi-sunny slope reaches maximum, β-diversity index of herb community in the semi-shady slope and semi-sunny slope were higher than sunny slope. Species diversity α and diversity β are different that in Different slope directions and different altitudinal gradients in dry valleys of Bai Long River and different slope directions have a certain correlation with the change of altitudinal gradient, species diversity α and diversity β indicating that elevation and slope directions are one of the main factors affecting biodiversity.