The growing invasion of ecosystems by invasive alien plants (IAPs) has substantially affected biodiversity worldwide, compromising provision of ecosystem services. In this study, we present evidence of the impacts of an IAP, Robinia pseudoacacia L., on native plant diversity in montane rangelands of South Africa and its threats to grazing, an ecosystem service. We assessed stand characteristics, understory vegetation composition and rangeland condition similarities in invaded and uninvaded sites. We observed a shift in grass communities after invasion by R. pseudoacacia as invaded communities differed by 96% from uninvaded rangeland. Invaded habitat was dominated by nitrophilous, shade-tolerant alien ruderals that follow the primitive C₃ carbon fixation pathway. Nitrogen fixation and light-demanding properties of R. pseudoacacia are likely to be the main factors driving these changes. As a result, range condition was significantly lower in invaded habitats with smaller and dense trees (180 ± 24.3) (mean ± standard error) when compared with adjacent uninvaded habitat (401 ± 24.3). These preliminary findings support an urgent need for sustainable control of R. pseudoacacia as an effective approach to stop further reduction in grazing capacity and losses in livestock production.

外来入侵植物（IAPs）对生态系统的入侵日益严重，严重影响了世界范围内的生物多样性，损害了生态系统服务的提供。在这项研究中，我们提出了IAP刺槐（Robinia pseudoacacia L）的影响的证据。，关于南非山地牧场的本土植物多样性及其对放牧的威胁，这是一种生态系统服务。我们评估了入侵和未入侵地点的林分特征，林下植被组成和牧场条件的相似性。我们观察到在草地群落的转变入侵后刺槐作为入侵社区免受未侵入草场不同了96％。入侵的栖息地主要是遵循原始C ₃的耐氮，耐荫的外来生物碳固定途径。伪金合欢菌的固氮和对光的需求可能是驱动这些变化的主要因素。结果，与相邻的未入侵生境相比（401±24.3），树木较小且茂密的入侵生境的射程条件明显较低（180±24.3）（平均值±标准误差）。这些初步发现支持迫切需要对伪阿拉伯树的可持续控制，以此作为停止进一步减少放牧能力和牲畜生产损失的有效方法。