Abstract:

Tsuga dumosa forests were mainly distributed in the Hengduan Mountains and their extension areas in the southwestern region of China, including Xizang, Yunnan, and Sichuan. The current T. dumosa forests are mainly found in humid mountainous regions and mostly grow on mountain ridges, steep slopes, and along river banks. These forests experienced varying degrees of disturbances, both natural and anthropogenic. To reveal the spatial distribution, community composition and characteristics of T. dumosa forests, this study conducted systematic field investigation during the plant growing seasons in 2018 and 2021-2023. The investigation on T. dumosa forest communities across their entire distribution range in China, totaling 114 survey locations were selected and 178 sample plots were established. We recorded species composition, quantitative characteristics, habitat information, and other relevant details of the communities. The main results of the study were as follows: (1) In 178 sample plots of T. dumosa Forest Alliance (simply called T. dumosa forests), a total of 403 vascular plant species were recorded. (2) Tsuga dumosa forests were rich in community types. Through quantitative analytical methods, they have been classified into 11 Association Groups and 34 Associations. (3) The forests’ vertical stratification was obvious. In the arborous layer there were mainly T. domosa and species of Quercus, Abies, Lithocarpus, Picea, Acer and Rhododendron. (4) Tsuga dumosa’s regeneration was active. This study surely provides solid scientific data for a better understanding of the role of T. dumosa forests in the coniferous forest zone of China.

Key words: Tsuga dumosa forests, species composition, community characteristics, association group, association, southwestern China