Invasion of Alternanthera philoxeroides in Heterogeneous Habitats: Implications for Its Ecological Control in Central China

Alternanthera philoxeroides (A. philoxeroides) is one of the worst invasive alien species in the world and poses serious threats to both ecological security and agricultural production in China. However, the effects of environmental factors on its growth across different habitat types remain insufficiently understood. To reveal the determining natural factors influencing the growth of A. philoxeroides, fieldwork, including 50 sample quadrats in six field sites, was conducted in the Yangtze River Basin of Hubei Province. In every quadrat, soil properties, soil moisture, pH, soil temperature, soil nutrients (N, P, and K), light intensity, plant cover, and aboveground plant fresh biomass were measured. Cluster analysis showed that A. philoxeroides habitats can be divided into five cluster groups: wetland, grassland, forest understory, farmland and aquatic communities. The results showed that both total community biomass and A. philoxeroides biomass were positively correlated with water content, whereas no significant relationships were found between biomass and soil nutrients, including N, P, and K. The biomass of A. philoxeroides was significantly higher in aquatic habitats, while no significant differences were observed among the other four terrestrial habitats. These findings suggest that hydrological management, together with early control in aquatic habitats, may be an effective strategy to limit the spread of A. philoxeroides.