Reynoutria japonica is one of the most harmful invasive species in the world, dramatically reducing the diversity of resident vegetation. To mitigate the impact of R. japonica on ecosystems and properly manage affected areas, understanding the mechanisms behind this plant’s invasive success is imperative. This study aimed to comprehensively analyse plant communities invaded by R. japonica, taking into account species traits, habitat conditions and seasonal variability, and to determine the ecological profile of species that withstand the invader’s pressure. The study was performed in fallow and riparian areas in southern Poland. Pairs of adjacent plots were established at 25 sites with no obvious signs of recent human disturbance. One plot contained R. japonica, and the other contained only resident vegetation. For each plot, botanical data were collected and soil physicochemical properties were determined. Twelve sites were surveyed four times, in two springs and two summers, to capture seasonal variability. The presence of R. japonica was strongly associated with reduced resident plant species diversity and/or abundance. In addition to the ability to quickly grow and form a dense canopy that shades the ground, the success of the invader likely resulted from the production of large amounts of hard-to-decompose litter. The indirect impact of R. japonica by controlling the availability of nutrients in the soil might also play a role. A few species coexisted with R. japonica. They can be classified into three groups: (i) spring ephemerals – geophytic forbs with a mixed life history strategy, (ii) lianas with a competitive strategy and (iii) hemicryptophytic forbs with a competitive strategy. Species from the first two groups likely avoided competition for light by temporal or spatial niche separation (they grew earlier than or above the invasive plant), whereas the high competitive abilities of species from the third group likely enabled them to survive in R. japonica patches.

中文翻译：

---

功能性状预测驻地植物对波兰南部河岸和休耕社区 Reynoutria japonica 入侵的反应

Reynoutria japonica 是世界上最有害的入侵物种之一，极大地减少了居民植被的多样性。为了减轻 R. japonica 对生态系统的影响并妥善管理受影响的地区，了解这种植物入侵成功背后的机制势在必行。本研究旨在综合分析粳稻入侵的植物群落，考虑物种性状、栖息地条件和季节变化，并确定能够承受入侵者压力的物种的生态状况。该研究是在波兰南部的休耕和河岸地区进行的。在 25 个地点建立了成对的相邻地块，近期没有明显的人为干扰迹象。一个地块包含 R. japonica，而另一个地块仅包含常驻植被。对于每个地块，收集植物数据并确定土壤理化性质。在两个春季和两个夏季，对 12 个地点进行了四次调查，以捕捉季节性变化。R. japonica 的存在与减少的常驻植物物种多样性和/或丰度密切相关。除了能够快速生长并形成浓密的树冠遮蔽地面外，入侵者的成功很可能是由于产生了大量难以分解的垃圾。R. japonica 通过控制土壤中养分的有效性的间接影响也可能发挥作用。少数物种与 R. japonica 共存。它们可以分为三组：（i）春季短暂——具有混合生活史策略的地球植物，(ii) 具有竞争战略的藤本植物和 (iii) 具有竞争战略的半隐植物。前两组物种可能通过时间或空间生态位分离（它们比入侵植物早于或高于入侵植物生长）避免了对光的竞争，而第三组物种的高竞争能力可能使它们能够在 R. japonica 斑块中生存.