关键词: 冬麻豆群系, 地理分布, 植被分类, 群落结构, 物种组成

Abstract: Aims Salweenia wardii, a rare and endangered protected plant in China, is a extremely small population in the arid valleys of the Hengduan Mountainous. Ite habitat is fragile and severely fragmented, and systematic research on its community ecological adaptive mechanisms and conservation strategies remains lacking. Methods Based on literature and field sample surveys, we initially delineated the geographical distri-bution range of Salweenia wardii. Utilizing data from 18 survey plots collected between 2023 - 2024, we proposed a preliminary community classification scheme, accompanied by a detailed description of the community structure. Additionally, we also analyzed species composition in conjunction with data from 38 list quadrats obtained during the survey. Important findings The results showed that: (1) Salweenia wardii community was concentrated in Karuo District, Baju County, Luolong County and Chaya County of Chamdo City, and formed dominant communities in Karuo Town, Xiali Township, Qumba Township and Jiba Village, with distribution alti-tudes ranging from (3000) 3083 to 3657 (4400) m. (2) 74 vascular plants belonging to 28 families and 55 genera were recorded, mainly xerophytes in the families of Gramineae, Asteraceae, and Rosaceae. The life forms spectrum, dominated by deciduous shrubs and perennial herbs, along with the floristic charac-teristics featuring the coexistence of pan-tropical and north-temperate components, reflected their adaptive strategies to seasonal droughts and the evolutionary features of transitional zone in the Hengduan Mountains. (3) Based on variations in community structure and species composition, Salweenia wardii alliance could be classified into 6 association groups and 10 associations. (4) The population exhibited low natural regeneration capacity and relied on asexual reproduction for maintaice, necessitating urgent conservation measures. Our fingdings fill the gaps in the taxonomic study of Salweenia wardii and offers scientific basis and practical guidance for regiregional biodiversity conservation and ecosystems resto-ration.

Key words: Salweenia wardii alliance, geographical distribution, community classification, community structure, species composi-tion