Abstract:

The paper aims to explore the composition and distribution characteristics of alien invasive plants under different habitat types, so as to provide scientific basis for the prevention and control of alien invasive plants in Anning City, Yunnan Province. Taking 12 land use types and 18 habitat types in Anning City as the research object, the field survey of alien invasive plants was conducted by comprehensive survey method and transect method from 2022 to 2025, and the composition and distribution characteristics of alien invasive plants in Anning City were studied combined with literature review. The survey results showed that there were 94 species of alien invasive plants in Anning City, belonging to 31 families and 70 genera, of which Compositae (22 species), Leguminosae (10 species) and Gramineae (8 species) were the dominant families, and the genus with the most species was Erigeron (4 species) and Amaranthus (4 species). The results of origin analysis showed that 65 alien invasive plants came from America, accounting for 56% of the total species. The analysis of introduction route showed that 65 species were introduced intentionally, accounting for 69.1%. The flora analysis showed that the families and genera of invasive plants in Anning City showed a strong worldwide and tropical distribution. From the perspective of invasion grade, the number of species in malignant invasive species (grade 1), serious invasive species (grade 2) and local invasive species (grade 3) were 16, 16 and 10 respectively. In terms of spatial distribution, Lianran Street (36 species) and Xianjie Street (36 species) had the largest number of invasive plants, followed by Taiping Xincheng Street (31 species). Among the 18 habitat types in Anning City, alien invasive plants were distributed, and the habitat type with the highest frequency was road/ traffic land, accounting for 16.39% of the total frequency. Villages and towns, vacant land/ wasteland, commercial/ office/ residential land, agricultural land, urban public green space and other five types of habitats were also more, accounting for more than 10% of the total frequency. The analysis showed that there were significant differences in the richness of alien invasive plants in the eight habitats (P<0.001), which was significantly higher in villages and towns than in other habitats, and the lowest in woodland. There were significant differences in the number and grade distribution of alien invasive plant species in each habitat. The number of species in villages and towns was the most (36 species), and the proportion of high hazard grade (1-2) was also high. The number of forest species was the least (13 species), and the proportion of each grade was the lowest. The proportion of road/traffic land, idle land/wasteland at grade 1-2 was more than 50%. Urban public green space, commercial/ office/ residential land were mainly of class 1-2. The invasion degree of agricultural land and water area land was lighter than that of other habitats. The results showed that the distribution of alien invasive plants in Anning City showed significant differences in different geographical regions and habitat types. These findings can provide data support for the development of scientific prevention and control strategies.

Key words: invasive alien plants, composition characteristics, distribution characteristics, habitat type, land use type, invasion level, flora, Anning City