中文摘要：

文章选择粤北英德九龙镇典型峰林平原为研究区,在不同地貌部位调查了生态环境的岩石裸露率和土壤厚度,以及植物物种、生物量、盖度等指标,运用物种α多样性指数和Jaccard相似性系数分析了植物多样性与相似性,结果表明：（1）不同地貌部位的岩石裸露率、土层厚度差异较大,峰壁岩石裸露率显著大于峰顶、坡麓和洼地,而洼地的土层厚度显著大于峰顶、峰壁和坡麓;（2）峰顶、峰壁、坡麓和峰间洼地的群丛依次为乔栯榕-竹叶椒＋檵木-纤毛鸭嘴草、乔栯榕-红背山麻杆＋檵木-五节芒、黄连木-灰白毛莓-纤毛鸭嘴草和长毛八角枫-藤金合欢＋粉单竹-纤毛鸭嘴草,优势种与层片结构有一定差异;（3）岩溶植物具有对环境的高度适应性,使不同地貌部位植被能够保持较高的覆盖度,但地势平缓、土层相对较厚的峰顶与峰间洼地的生物量要显著大于坡麓及峰壁;（4）岩石裸露率与土层厚度、土层厚度与生物量间都呈极显著的负相关关系;（5）峰顶与峰间洼地的物种数显著少于峰壁与坡麓,峰顶的Shannon-Wiener指数、Simpson指数和Pielou指数都显著低于其他部位,而峰壁的几项多样性指数均显著高于其他部位植被,岩溶环境地貌部位的多样性有助于提高生物多样性;（6）Jaccard相似性系数分析表明峰林空间异质性造成物种分布的差异,空间位置远近和地貌部位差异大小对物种分布影响至关重要。

英文摘要：

Aims to find out the relationship between vegetation community feature,species diversity and different landforms in karst peak forest.Two peak which are typical karst peak forest plain system in Jiulong town,Yingde City of northern Guangdong Province were selected as the research area.Plants variety,soil thickness,coverage of vegetation,biomass were investigated respectively by quadrat method at summit,cliff,slope foot,and peak forest depression in two peak.The biodiversity,such as Shannon-Wiener index,Simpson index and Pielou index were analyze with SPSS 10.0and compared with different landforms.The Jaccard correlation coefficient were adopted to discuss similarity among the different landforms.The results showed,（1）The coverage of rock and soil thickness are more different among the summit,cliff,slope foot,and peak forest depression,and the coverage of rock in cliff plots is bigger significantly than others plots,and the soil thickness in peak forest depression is bigger significantly than others plots;（2）The association of summit,cliff,slope foot,and peak forest depression is Ficus microcarpa-Zanthoxylum armatum＋Loropetalum chinese-Ischaemum indicum,Ficus microcarpa-Alchornea trewioides＋Loropetalum chinese-Miscanthus floridulus,Pistacia chinensis-Rubus tephrodes-Ischaemum indicum,Alangium kurzii-Acacia sinuata＋Lingnania chungii-Loropetalum chinese,dominant species and synusia structure are more different among the different landforms;（3）There are higher coverage of vegetation in karst peak forest due to adaptations of most plants for karst environment,but the standing biomass in summit and peak forest depression which have gently slopes and more thicker soil is bigger significantly than that of cliff and slope foot;（4）There are significantly negative correlation between coverage of rock and soil thickness,soil thickness and standing biomass;（5）The species in summit and peak forest depression are fewer significantly than that of cliff and slope foot.Shannon-Wiener index,Simpson index a