Data from: Expected spatial patterns of alien woody plants in South Africa's protected areas under current scenario of climate change

Although protected areas (PAs) are declared to provide sanctuaries for biodiversity, they are increasingly threatened by the synergistic effects of invasive alien species and climate change. Consequently, interventions are required to minimize the impacts of these threats on PAs' integrity. To inform these interventions in the South African context and under the current climate change scenario, we tested for geographic patterns of alien woody species distribution across the network of 1453 PAs using three alien invasion indices – alien species abundance, invaded area ratio and alien species richness. Our analysis shows that, under current climate change scenario, none of the PAs would be effective in shielding against alien plants and PAs that are geographically close tend to share similar invasion patterns. In addition, PAs that are hotspots of alien species are too geographically clustered but these findings are biome-dependent. Our outlier analysis reveals not only an island of disproportionately-rich PAs in alien species, but also identifies some alien-poor PAs. We suggest that PAs that are hotspots of alien species as well as outliers of disproportionately-rich PAs in alien species should be priority in monitoring and invasion control programmes in the face of climate change.

尽管保护区（Protected Areas，PAs）旨在为生物多样性提供庇护所，但它们正日益面临外来入侵物种与气候变化协同效应带来的威胁。因此，亟需采取干预措施以削弱此类威胁对保护区完整性的负面影响。为在当前气候变化情景下为南非境内的相关干预措施提供决策支撑，本研究针对该国1453个保护区组成的保护地网络，采用外来物种丰度、入侵面积占比、外来物种丰富度3项外来入侵评估指标，对外来木本物种的分布地理格局展开了分析。分析结果表明，在当前气候变化情景下，没有任何一座保护区能够有效抵御外来植物入侵；且地理位置邻近的保护区往往呈现相似的入侵格局。此外，外来物种热点保护区的地理分布呈现显著聚集特征，但该结论仅在特定生物群落中成立。本研究的异常值分析不仅识别出外来物种丰富度异常偏高的保护区孤岛，还发现了一批外来物种匮乏的保护区。基于上述研究结果，我们建议在气候变化背景下，应将外来物种热点保护区以及外来物种丰富度异常偏高的保护区孤岛，纳入入侵监测与防控工作的优先序列。