Structure of Abies faxoniana subalpine coniferous forests in eastern Qing-Tibet plateau

Abstract

Subalpine coniferous forests are widely distributed in the east of the Qing-Tibet highland. They are attributed to the subalpine zone. Taking into consideration geobotanical descriptions of typical forests with Abies faxoniana predominant at the key site in the Miyaluo gorge in western Sichuan, the species composition, life forms, and biomorphological traits of leaves of plants belonging to this community are studied. It is shown that A. faxoniana forests are characterized by a high species diversity of plants belonging to various life forms. By the vertical structure, four layers may be discerned: tree layer, shrub layer, herb layer, and moss layer. The fir cenopopulation is characterized by a clear size and age polyvariation. The results indicate its stable existence and ability of self-support under the conditions investigated. These forests support a high biological diversity and a stable community structure, which have a great antierosional and water-protectional significance in supporting the water balance of the upper reaches of the Yangtze and Lantszhantsan rivers. All parts of these unique communities must be strictly protected.