Research on Community Diversity of Picea crassifolia Kom Forests in the North Slope of Qilian Mountain

摘要

On Basis of study on the species construction, flora, community structure, distribution pattern and dynamic of the Qilian Mountain (Northern Slope), comes out the following data. The community of Picea crassifolia Kom consists of 96 species of vascular plants of 25 families and 51 class, including 4 species of arbor, 29 species of bushes and 62 species of herbal plants. 31 classes, 59 species of mesotherm plants constitute the majority of the community, which indicates the links between species of the local community and those of the temperate zone. The dominant species are Picea crassifolia Kom, Dasiphora fruticosa Rydb, Dasiphora dahurica(Nertl) Kon.et Klob-Alis, Polygonum viviparum L, Carex Lanceolata Boott, Pedicularis muscicola Mcisn and so on. C diversity index fluctuates slightly within the altitude of 2470～2800 meters, which, however, tends to initially increase and subsequently decrease with the elevation of altitude. The vertical structure shifts notably with 4 major levels of arbors,bushes, herbal plants and musci. the richness indexes from high to low is the mixed forest of Picea crassifolia Kom ＞Pedicularis-Picea creassifdia mixed forest＞grass-Picea creassifdia mixed forest＞shurb-Picea creassifdia mixed forest＞moss-Picea creassifdia mixed forest; and Margalef index from high to low is the mixed forest of Picea crassifolia Kom＞Pedicularis-Picea creassifdia mixed forest＞grass-Picea creassifdia mixed forest＞shurb-Picea creassifdiamixed forest ＞moss-Picea creassifdia mixed forest. There are big differences among different types of mixed forests concerning vertical structure, species inter-relationship, spatial distribution pattern and community structure.