云丘山植物群落主要优势种生态位研究

本文通过对山西省云丘山进行实地调查，用Hurlbert（HNB）指数和Levins（LNB）指数对该地区森林群落各层的优势种生态位宽度进行了测度，乔木层主要优势种白皮松和侧柏，灌木层主要优势种檀子栎和荆条，草本层主要优势种披针叶苔草和狗尾草的HNB和LNB分别是0．137、1．042、0．117、1．004，0．418、1．488和0．354、1．463，0．734、1．744、0．488、1．563；用Pianka公式对该地区优势种的生态位重叠状况进行研究，发现灌木层较乔木层种问竞争状况缓和、资源利用状况较好；分析了该地域各层优势种生态位宽度和生态位重叠的关系，探索了该地区森林群的优势种种间关联，阐明了该森林群落内的竞争机制，对揭示云丘山地区森林群落的演替有重要意义，也为该旅游景区的管理与优化提供一定的理论依据．

Niche of Dominant Population in Shanxi Yunqiu Mountain Ecological Location

The dominant species niche breadth of the communities are measured, using Levins index （LNB） and the Hurlbert index （HNB） by the field investigation in Shanxi Yunqiu Mountain. The main dominant species of arborous layer is Pinus bungeana and Platycladus orientalis, the main dominant species of shrub layer is Quercus baronii and Vitex negundo var. heterophylla, the main dominant species of hei＇baceous layer is Carex lanceolata and Setaria viridi.~, theil HNB and 1,NB are 0. 137,1. 042 and O. 117, 1. 004,0. 418,1. 488 and 0. 354,1. 463,0.734,1. 744 and 0. 488,1. 563. Using Pianka formulas niche overlap situation of the dom- inant species is studied in the region. The result shows that the shrub layer＇ s race condition is more ease, resource utilization situa- tion is better than that of arborous layer. We further analyzed the relationship of niche width and niche overlap for the dominant spe- cies among layers, explored the interspecific associaliou of the dominant species in the region, and clarified the competition mecha- nism in the forest communities. The study is very meaningful to reveal the succession of forest communities in Ynnqiu Mountain, and also provides a theoretical basis for the management and optimizing of nature reserves.