High-density native-range species affects the invasive plant Chromolaena odorata more strongly than species from its invasive range

Invasive plant species often form dense mono-dominant stands in areas they have invaded, while having only sparse distribution in their native ranges, and the reasons behind this phenomenon are a key point of research in invasive species biology. Differences in species composition between native and invasive ranges may contribute to the difference in distribution status. In this study, we found that the high-density condition had a more negative effect on C. odorata than the low-density condition when co-grown with neighbor plants from its native range in Mexico, while this pattern was not in evidence when it was grown with neighbors from its invasive range in China. Different competitive ability and coevolutionary history with C. odorata between native-range neighbors and invasive-range neighbors may lead to the inconsistent patterns.外来入侵植物通常在入侵区域形成高密度单优种群落，而在原生分布区仅呈稀疏分布，该现象背后的成因是入侵生物学领域的核心研究议题之一。原生分布区与入侵分布区的物种组成差异，可能是导致二者分布格局差异的重要因素。本研究发现，当与原生分布区（墨西哥）的伴生植物共培养时，高密度条件对C. odorata的抑制作用强于低密度条件；而当与入侵分布区（中国）的伴生植物共培养时，并未观察到该规律。原生分布区伴生植物与入侵分布区伴生植物对C. odorata的竞争能力及二者与C. odorata的协同进化历史均存在差异，这可能是导致上述实验结果不一致的原因。