Landscape Heterogeneity Drive Plant Assemblage Dynamics and Invasibility of Semi‐Natural Grasslands Under the Long‐Term Invasion of <em>Ageratina adenophora</em>

Grasslands degradation, a critical ecological problem worldwide, threatening ecosystem integrity and functional service. Although previous studies have documented the drivers regarding climate change, overgrazing and anthropogenic perturbation, research concerning invasive alien plant impact on grassland ecosystem remains insufficient. The present study, integrating of pairwise field investigation -Ageratina adenophora invasion and non-invasion plots across heterogeneous grassland types (tropical grasslands, TG; tropical shrub-grasslands, TS; warm-temperate grasslands, WG; and warm-temperate shrub-grasslands, WS) and A. adenophora-indigenous plants phytotoxicity bioassay, aims to assess the invasibility and resilience of heterogeneous grassland landscape to A. adenophora invasion. The field investigation demonstrated the greater vulnerability of TG and TS to A. adenophora invasion, whereas WG and WS possessing higher resilience. In addition, regression analysis revealed significant reductions of Shannon-Wiener index and Pielou index as the A. adenophora important value reach the threshold 0.36. Bioassay showed that A. adenophora aqueous extracts inhibit seeds germination and seedlings growth of recipient plants, with Saccharum arundinaceum exhibiting the highest tolerance to A. adenophora stress. In summary, our finding not only highlights the flora communities dynamics and invasibility of diverse grasslands driven by A. adenophora invasion in the subtropic regions but also verifies S. arundinaceum potential for A. adenophora replacement management.