Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, Institute of Eco-Chongming, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China.
Ecology, Department of Biology, University of Konstanz, Konstanz, 78464, Germany.
Nat Commun. 2023 Oct 12;14(1):6244. doi: 10.1038/s41467-023-41607-w.
Darwin's naturalization conundrum describes two seemingly contradictory hypotheses regarding whether alien species closely or distantly related to native species should be more likely to naturalize in regional floras. Both expectations have accumulated empirical support, and whether such apparent inconsistency can be reconciled at the global scale is unclear. Here, using 219,520 native and 9,531 naturalized alien plant species across 487 globally distributed regions, we found a latitudinal gradient in Darwin's naturalization conundrum. Naturalized alien plant species are more closely related to native species at higher latitudes than they are at lower latitudes, indicating a greater influence of preadaptation in harsher climates. Human landscape modification resulted in even steeper latitudinal clines by selecting aliens distantly related to natives in warmer and drier regions. Our results demonstrate that joint consideration of climatic and anthropogenic conditions is critical to reconciling Darwin's naturalization conundrum.
达尔文归化难题描述了两个看似矛盾的假说，即与本地物种密切相关或疏远相关的外来物种在区域植物区系中应该更有可能归化。这两种预期都积累了经验支持，而这种明显的不一致是否可以在全球范围内得到调和尚不清楚。在这里，我们使用了 487 个全球分布的地区的 219,520 种本地和 9,531 种归化的外来植物物种，发现了达尔文归化难题的纬度梯度。在较高的纬度地区，归化的外来植物物种与本地物种的亲缘关系比在较低的纬度地区更为密切，这表明在更为恶劣的气候条件下，预先适应的影响更大。人类对景观的改造通过在温暖和干燥地区选择与本地物种疏远相关的外来物种，导致了更陡峭的纬度梯度。我们的研究结果表明，综合考虑气候和人为条件对于调和达尔文归化难题至关重要。
