宝天曼地区栓皮栎林恢复过程中高等植物物种多样性变化

对宝天曼地区不同恢复阶段栓皮栎林的高等植物物种多样性特征进行了初步分析。结果表明，各层物种丰富度和多样性指数在不同恢复阶段栓皮栎林表现出草本层＞灌木层＞乔木层的趋势。乔木层物种丰富度和多样性指数基本上随恢复时间的增加而增加；灌木层在未破坏的栓皮栎林内较低，而在其他恢复阶段的栓皮栎林内基本相同；草本层在恢复５年、１５年和２５年的栓皮栎林中较高，而在恢复４５年和未破坏的栓皮栎林内较低。乔木层物种均匀度指数在未破坏的栓皮栎林中较高，在恢复２５年的栓皮栎林中较低；灌木层在恢复４５年的栓皮栎林中较高，在恢复１５年的栓皮栎林较低；草本层在恢复５年的栓皮栎林中较高，在恢复１５年的栓皮栎林中较低。不同恢复阶段栓皮栎林各层次间的物种多样性差异大多不显著，只有乔木层和草本层及灌木层和草本层之间的物种丰富度指数有显著差异。不同恢复阶段栓皮栎林在乔木层物种多样性特征上的差异最大，在灌木层物种多样性特征上有一定差异，在草本层物种多样性特征上没有明显的差异。

CHANGES IN PLANT SPECIES DIVERSITY IN A RESTORATION SEQUENCE OF QUERCUS VARIABILIS FOREST STANDS IN BAO TIANMAN MOUNTAIN

Changes in plant species diversity in a restoration sequence of Quercus variabilis forest stands in Bao Tianman mountain were studied. The results show that species richness as and species diversity indexes of different layers in the forest stands are as follows:herb layer>shrub layer>tree layer. Tree species richness and species diversity index increased with the restoration time. Shrub species richness and diversity index were lower in original forest stand and higher in other forest stands. Herb species richness and species diversity index were higher in forest stands having 5 years, 15 years and 25 years of restoration and lower in forest stand having 45 years of restoration and in original forest stand. Tree species evenness index was higher in original forest stand and lower in forest stands having 25 years of restoration. Shrub species evenness index was higher in forest stand having 45 years of restoration and lower in forest stand having 15 years of restoration. Herb species evenness index was higher in forest stands having 5 years of restoration and lower in forest stand having 45 years of restoration. Most of differences between species diversity of tree layer, shrub layer and herb layer in the forest stands were not significant. Only differences between species richness of tree layer and herb layer and of shrub layer and herb layer were significant. Differences of tree species diversity between the forest stands were more significant, differences of shrub species diversity were significant, and differences of herb species diversity were not significant.