Distribution Law and Population Characteristics of Abies faxoniana Forest in Wolong Natural Reserve,Sichuan Province

In wolong nature reserve, Abies faxoniana forests are mainly distributed in moist shade slope or half-shade slope of the mountains with an elevation from 2 700 m to 3 800 m. Abies faxoniana forest could develop a variety of community types, such as Abies faxoniana-Fargesia nitida forest, Abies faxoniana-Yushania brevipaniculata forest, Abies faxoniana-Bashania fangiana forest,Abies faxoniana-Rhododendron faberi sp. prattii forest, Abies faxoniana-Rhododendron kyawii forest and Abies faxoniana-Rhododendron watsonii forest. The height of Abies faxoniana trees decreased with the increasing of the altitude in the same diameter class. The age structures of population of Abies faxoniana were growing types in areas with the elevations of 2 700 m, 2 900 m, 3 100 m and 3 300 m, and a stable type in the area with an elevation of 3 600 m. There were intense interspecific competitions at shrub level. The main competitor of Abies faxoniana population was Fargesia nitida in areas with the elevation from 2 700 m to 3 200 m, and Rhododendron faberi sp. prattii and Rhododendron watsonii in areas with the elevation from 2 700 m to 3 200 m. They all had influence on reproduction and regeneration of Abies faxoniana population. Abies faxoniana population often suffered diseases, insect pests, mammal damage, wind damage and snow disaster, thus resulting in an adverse effect on growth, development and number of Abies faxoniana population.