关岭县石漠化地区立地因子对白刺花群落特征的影响

Influence of Topographic Factors on the Community Characteristics of Sophora davidii in Rocky Desertification Area of Guanling County

为探究贵州省关岭县石漠化地区白刺花群落组成及多样性特征与地形因子的关系,采用典型样地法进行群落植被调查,基于岩石裸露程度、海拔、坡向、坡度等地形因子对所调查的白刺花群落进行分组,分别统计、分析其生物量、物种多样性(物种丰富度D、Margalef丰富度指数R、Shannon-Wiener多样性指数H、Pielou均匀度指数J和Simpson优势度指数C)在不同地形因子间的差异。结果显示:(1)地形因子对白刺花群落生物量的影响显著,强度石漠化立地上的白刺花群落其生物量显著低于其他岩石裸露程度的群落,中海拔、缓坡及阳坡的白刺花群落生物量显著高于其他海拔、坡度及坡向的群落。(2)地形因子中,仅有海拔对白刺花群落物种丰富度、灌木多样性指数的影响显著,低海拔白刺花群落的物种丰富度显著低于中海拔和高海拔;高海拔群落的灌木多样性指数(Shannon)和优势度指数(Simpson)显著高于其他海拔的群落。(3)岩石裸露程度、海拔及坡向均对白刺花群落的草本多样性有影响,中度石漠化的草本均匀度指数(Pielou)显著低于其他岩石裸露程度的,低海拔和半阴坡的草本多样性程度整体高于其他地形因子。可得结论,地形因子对白刺花生物量的影响比对物种多样性的影响更为明显,通过地形因子对白刺花群落特征的影响可为白刺花群落的保护及石漠化土地的恢复提供理论基础。

The main purpose of this study was to explore the community composition and diversity characteristics of the Sophora davidii in rocky desertification area of Guanling County,Guizhou Province,as well as to provide the theoretical basis of the S.davidii community protection and desertification restoration.We investigate the above-ground biomass and biodiversity(species richness,Margalef index,Shannon-Wiener index,Pielou index and Simpson index)of S.davidii community at different topography which is the most visualized factor,such as rock exposure,elevation,slope aspect and slope degree.The result show that:1)The topographic factors effect on the above-ground biomass of S.davidii community is significant,the above-ground biomass of community on the intensity rocky desertification is significant lower than that on the other degree of rock exposure.Meanwhile,the above-ground biomass of community on middle elevation,slight slope gradient and sunny slope are significantly higher than that on the other levels of elevation,slope gradient and slope aspect.2)The topographic factors effect on species richness are not significant except for elevation,the species richness on the low elevation is significantly lower than that on the middle and high elevation.3)The topographic factors’effect on shrub community diversity index is not significant except for elevation,and the shannon-winner index and simpson index on the high elevation is significantly higher than that on the middle and low elevation.4)The effect of rock exposure,elevation and slope aspect on grass community diversity are significant,the Pielou index on moderate rocky desertification is significantly lower than that on the other rock exposure levels,while grass community diversity on the low elevation and shady slope is overall significantly higher than that on other elevation and slope aspect levels.This study indicates that the influence of topographic factor on the community biomass is significant than that on the biodiversity index.By investigating the influence of topographic factors on S.davidii community characteristics,relevant suggestions for the protection and restoration of the initial stage of rocky desertification could be made.