Abstract:

Aims Helianthemum songaricum is an ancient Mediterranean remnant plant species endemic to central Asia, and it is a dominant species of a unique desert community in west Erdos, Nei Mongol, China. We studied the distributions, classification and characteristics of the H. songaricum communities.
Methods We collected species composition for 18 plots from literatures and field investigation during the growing seasons of 2016 and 2017. We then applied TWINSPAN to classify community types.
Important findings (1) The H. songaricum communities were primarily distributed in the north and south of the Arbas Mountains and Qianli Ravine in west Erdos, with some in the southern and northern Helan Mountain. (2) In total, 58 seed plant species belonging to 39 genera from 17 families were recorded, including 18 shrub and subshrub, 27 perennial and 13 annual herbaceous species. Super-xerophytes and xerophytes were the two major ecological types, accounting for 26% and 50%, respectively. The Central Asia-Eastern Asia was the major floristic elements, followed by the Palaeo-Mediterranean and the Gobi elements. (3) Based on the life forms and species composition, the H. songaricum communities was divided into three major association groups, i.e., H. songaricum-herbs desert group, H. songaricum-shrubs-herbs desert group and H. songaricum-subshrub desert group, which were further divided into 10 associations.

Key words: Helianthemum songaricum, desert, community characteristic, life form, community classification