Habitat fragmentation has a multitude of negative effects on biodiversity, including the facilitation of alien plant invasion. Of concern in South Africa is the spread of fleshy-fruited invasive plant species, which in many places are replacing indigenous vegetation in frequently disturbed and fragmented habitats. The availability of dispersers is among the most important factors for the successful invasion of fleshy fruited invasive plant species. Dispersers differ in their dispersal capacity, and the success of frugivore dispersed plants depends both on animal and plant traits. Here, we used the functional traits of fleshy-fruited invasive plants to test for specific associations with avian functional traits in Indian Ocean Coastal Belt Forests, KwaZulu-Natal Province, South Africa. We predicted that fleshy-fruited invasive plant species that were more likely to persist in disturbed Indian Ocean Coastal Belt Forests were small-seeded, open habitat species with longer fruiting period lengths. The use of multivariate analyses showed that avian seed dispersers and fleshy-fruited invasive plant species differed in the functional traits between species with each group (i.e. plants and avian dispersers) that were important for seed dispersal. For fleshy-fruited plants, morphological traits (seed size, fruit size) and phenological traits (fruiting period length) were more variable between the species. For avian species, the variation was in their morphology (body size, gape width, bill length), abundance and habitat specificity. As predicted, avian species that were potentially dispersing invasive plants were forest generalist and relatively abundant species persisting in the fragmented forest. Fleshy-fruited invasive plant species that were predicted to be effectively dispersed were small-seed, open habitat species with longer fruiting length including lantana (Lantana camara), white mulberry (Morus alba), Brazilian pepper (Schinus terebinthifolius) and bugweed (Solanum mauritianum). Overall, our study showed that easily measured traits were important for understanding forest invasion dynamics and give insights to management strategies that can be developed to minimise further infestations.

生境破碎化对生物多样性有很多负面影响，包括促进外来植物入侵。南非令人关注的是果肉入侵植物物种的传播，在许多地方，这些物种正在取代经常受干扰和零散的生境的本土植被。分散剂的可用性是成功入侵肉质果实入侵植物物种的最重要因素之一。分散剂的分散能力各不相同，而节食动物分散植物的成功取决于动物和植物的性状。在这里，我们使用果肉入侵植物的功能性状来测试与南非夸祖鲁-纳塔尔省印度洋沿海带森林中鸟类功能性状的特定关联。我们预测，在受干扰的印度洋沿海带森林中更可能持续存在的果肉入侵植物物种是小种子，开放生境物种，具有较长的结果期。多元分析的使用表明，鸟类种子分散剂和肉质入侵植物物种之间的功能性状各不相同，每组（即植物和鸟类分散剂）对于种子的传播很重要。对于果肉植物，形态性状（种子大小，果实大小）和物候性状（坐果期长度）在物种之间变化更大。对于鸟类而言，其形态（体长，裂口宽度，账单长度），丰度和生境特异性都存在差异。如预期的那样 可能扩散入侵植物的鸟类物种是森林通才，相对零散的物种仍在零散的森林中生存。预计能有效分散的肉质入侵植物是种子较长的小种子开放生境物种，包括马tana丹（马tana丹（Lantana camara），桑（桑属Morus），巴西胡椒（Schinus terebinthifolius）和杂草（Solanum mauritianum）。总体而言，我们的研究表明，易于测量的性状对于理解森林入侵动态非常重要，并为可以制定以最小化进一步侵扰的管理策略提供了见识。