Invasion by exotic woody species is a major concern in grasslands worldwide. Woody invasions pose a particularly serious threat to forest–grassland mosaics globally, but the factors influencing the success of woody species in these systems, including the role of disturbances such as fire, are not well understood. In this study, we evaluated the role of fire in influencing mortality and regeneration success of three globally widespread woody invasives, Acacia mearnsii (black wattle), Cytisus scoparius (scotch broom) and Ulex europaeus (gorse) in the montane forest–grassland mosaics of the Nilgiri Biosphere Reserve in the Western Ghats biodiversity hotspot, India. Our results indicate that mortality and regeneration responses to fire are species-specific. Fire-induced adult mortality was highest in scotch broom and lowest in gorse, and high, but variable in wattle. Burning greatly increased the abundance of gorse and wattle seedlings, but only marginally increased scotch broom seedling abundance. Fire effects on invasive seedling densities were most pronounced at the edges of invasive patches. Overall, our results indicate that fires are likely to differentially affect invasion patterns of these three species, with fire potentially encouraging invasion by gorse and wattle and discouraging invasion by scotch broom.

外来木本物种的入侵是世界范围内草原上的主要关注点。木本植物入侵对全球的森林-草地马赛克构成了特别严重的威胁，但是影响木本植物在这些系统中成功的因素，包括诸如火等干扰的作用，尚未得到很好的了解。在这项研究中，我们评估影响死亡率和三个全球广泛的木本入侵物种再生成功，火的作用黑荆树（黑荆树），金雀儿（苏格兰扫帚）和荆豆（金雀鸟）位于印度西高止山脉生物多样性热点Nilgiri生物圈保护区的山地森林-草地马赛克中。我们的结果表明，死亡率和对火的再生响应是特定于物种的。火灾引起的成年人死亡率在苏格兰扫帚中最高，在金雀鸟中最低，虽然较高，但在篱笆中却有所不同。燃烧极大地增加了金雀花和荆树幼苗的丰度，但仅略微增加了苏格兰扫帚幼苗的丰度。火势对入侵苗木密度的影响在入侵斑块的边缘最为明显。总体而言，我们的结果表明，大火可能会不同地影响这三个物种的入侵方式，大火可能会鼓励金雀花和荆棘入侵，阻止苏格兰扫帚入侵。