Tropical ecosystems adapted to high water availability may be highly impacted by climatic changes that increase soil and atmospheric moisture deficits. Many tropical regions are experiencing significant changes in climatic conditions, which may induce strong shifts in taxonomic, functional and phylogenetic diversity of forest communities. However, it remains unclear if and to what extent tropical forests are shifting in these facets of diversity along climatic gradients in response to climate change. Here, we show that changes in climate affected all three facets of diversity in West Africa in recent decades. Taxonomic and functional diversity increased in wetter forests but tended to decrease in forests with drier climate. Phylogenetic diversity showed a large decrease along a wet-dry climatic gradient. Notably, we find that all three facets of diversity tended to be higher in wetter forests. Drier forests showed functional, taxonomic and phylogenetic homogenization. Understanding how different facets of diversity respond to a changing environment across climatic gradients is essential for effective long-term conservation of tropical forest ecosystems.

适应气候变化的热带生态系统可能会受到严重影响，因为气候变化会增加土壤和大气中的水分亏缺。许多热带地区的气候条件正在发生重大变化，这可能导致森林群落的分类，功能和系统发育多样性发生强烈变化。但是，目前尚不清楚热带森林是否应在这些多样性方面以及在何种程度上沿着气候梯度在响应气候变化的情况下转移。在这里，我们表明气候变化影响了近几十年来西非多样性的所有三个方面。在较湿的森林中，分类学和功能多样性增加，但在气候较干燥的森林中，分类学和功能多样性趋于减少。系统发育多样性显示沿干湿气候梯度有很大的减少。值得注意的是 我们发现，在潮湿的森林中，多样性的三个方面都趋于更高。较干燥的森林表现出功能性，分类学和系统发育均质性。了解有效的长期保护热带森林生态系统至关重要的是，了解多样性的不同方面如何应对整个气候梯度变化的环境。