Abstract: Potaninia mongolica, a nationally protected plant species of Class II in China, is a Tertiary relict whose communities form a distinctive desert landscape on the eastern margin of the Afro-Asian desert region. Based on field survey data collected from September 1998 to August 2024, supplemented by relevant literature, this study investigated the geographical distribution, community characteristics, and community classification of Potaninia mongolica desert communities. Survey sites were located in Etoke Banner and Hangjin Banner of Ordos City, Alxa Left Banner and Alxa Right Banner of Alxa League, Urad Rear Banner and Urad Middle Banner of Bayannur City in Nei Mongol Autonomous Region, as well as Minqin County of Wuwei City and Linze County of Zhangye City in Gansu Province, China, and South Gobi Province and East Gobi Province of Mongolia. A total of 83 community investigation plots were established, including 67 quadrats and 16 registration plots (field-recorded coordinates of Potaninia mongolica distribution without quadrats). In the quadrat, one to three shrub quadrats (10 m × 10 m, with some early quadrats slightly smaller) were randomly placed within Potaninia mongolica communities, and each was divided into four sub-quadrats (5 m × 5 m). If herbaceous plants were present, herbaceous quadrats (1 m × 1 m) were established within the sub-quadrats. For each species in the shrub and semi-shrub layers, species name, height, and crown diameter were recorded. For the herbaceous layer, species name, height, clump diameter, and individual count were documented. The registration plots recorded basic information such as species composition, dominant species, and community types. The results showed that: (1) Potaninia mongolica communities were mainly distributed in the eastern part of the Mongolian Plateau desert region. (2) The field investigation was recorded 42 species of seed plants belonging to 30 genera and 10 families, including 1 tree species, 15 shrub species, 15 semi-shrub species, 8 perennial herbaceous species and 3 annual herbaceous species. In terms of water ecological types, there were 21 strongly xerophytic species and 19 xerophytic species. (3) Based on dominant species and community structure, Potaninia mongolica desert communities can be classified into four association group: Potaninia mongolica temperate shrub desert group, Potaninia mongolica-bunchgrass desert group, Potaninia mongolica-temperate semi-shrub desert group, and Potaninia mongolica-temperate shrub desert group, which can be further subdivided into 25 associations. (4) Potaninia mongolica communities occur in arid, cold desert climate zones characterized by very low precipitation. This dataset is comprehensive and of high scientific value, providing critical evidence for understanding the geographical distribution, species composition, and structural features of Potaninia mongolica communities. It offers essential baseline data for further research on the basic characteristics of these communities and supports the compilation of the desert volume of Vegetation of China.

Key words: Potaninia mongolica desert, community characteristics, geographical distribution, community classification