宽阔水国家级自然保护区珙桐群落特征及演替趋势探析.doc

宽阔水国家级自然保护区珙桐群落特征及演替趋势探析 　　摘要 为了解贵州宽阔水自然保护区内国家I级重点保护植物珙桐的群落特征及演替趋势，采用径级划分，结合生活型谱及物种多样性系数，分析了珙桐的群落组成、群落结构及其更新特点，以揭示其群落演替趋势。结果表明：①珙桐群落样地中共记录维管植物20科22属24种，珙桐属群落优势树种；②群落垂直结构明显，乔木层和灌木层较发达，草本层不发达，群落以高位芽植物占优势（46.67%）；③整个群落的丰富度高达76种，Shannon-Wiener指数、Simpson指数、Pielon均匀度指数均表现出相同的趋势，为乔木层灌木层草本层；④研究地珙桐大部分呈成丛分布，单株分布极少；幼树幼苗均以萌生为主，老树与幼树的龄级相差较大，种群落处于衰老阶段。珙桐的天然更新能力变弱，加之受到灌木层优势种金佛山方竹的影响，以及随着种群的老龄化，更新层得不到发育，幼苗更新困难，其种群已处于危险状态，亟待保护 关键词 珙桐；生活型；物种多样性；更新；宽阔水国家级自然保护区 中图分类号 S792.99 文献标识码 A 文章编号 1007-5739（2016）22-0132-04 Abstract To understand the community characteristics and succession trend of the rare and endangered plant Davidia involucrata in Kuankuoshui National Nature Reserve，using the conventional methods of community investigation，combining with life form spectrum and species diversity coefficient，the paper revealed the succession population trends of Davidia involucrata，and then analyzed the community composition，community structure and its regeneration characteristics.The results showed that：①The population samples of Davidia involucrata had 20 families，22 genera and 24 species of vascular plants，Davidia involucrata was the community superiority species.②The community vertical structure was obvious，trees and shrub layers were more developed，but herb layer were less，and phanerophytes dominant in the community（46.67%）.③The richness of the whole community was as high as 76，the Shannon-Wiener index，Simpson index and Pielon index showed the same trend，tree layershrub layerherb layer.④In the research area，most of the Davidia involucrata were distributed in cluster，rare single bead distribution.The saplings and seedling were mainly to initiation，the old and the young were large different in age class and the population was also in the stage of aging.The ability of the natural regeneration of Davidia involucrata became weak，in addition to，influenced by the dominant species Chimonobambusa utilis in shrub layer，the layer of update couldn′t be developed and the seedling regeneration w