Cros Emilie, Ng Elize Y X, Oh Rachel R Y, Tang Qian, Benedick Suzan, Edwards David P, Tomassi Suzanne, Irestedt Martin, Ericson Per G P, Rheindt Frank E
Department of Biological Sciences National University of Singapore Singapore Singapore.
Centre for Urban Greenery and Ecology National Parks Board Singapore Singapore.
Evol Appl. 2020 Mar 5;13(5):1026-1036. doi: 10.1111/eva.12918. eCollection 2020 May.
Habitat fragmentation is a major extinction driver. Despite dramatically increasing fragmentation across the globe, its specific impacts on population connectivity across species with differing life histories remain difficult to characterize, let alone quantify. Here, we investigate patterns of population connectivity in six songbird species from Singapore, a highly fragmented tropical rainforest island. Using massive panels of genome-wide single nucleotide polymorphisms across dozens of samples per species, we examined population genetic diversity, inbreeding, gene flow and connectivity among species along a spectrum of ecological specificities. We found a higher resilience to habitat fragmentation in edge-tolerant and forest-canopy species as compared to forest-dependent understorey insectivores. The latter exhibited levels of genetic diversity up to three times lower in Singapore than in populations from contiguous forest elsewhere. Using dense genomic and geographic sampling, we identified individual barriers such as reservoirs that effectively minimize gene flow in sensitive understorey birds, revealing that terrestrial forest species may exhibit levels of sensitivity to fragmentation far greater than previously expected. This study provides a blueprint for conservation genomics at small scales with a view to identifying preferred locations for habitat corridors, flagging candidate populations for restocking with translocated individuals and improving the design of future reserves.
栖息地破碎化是物种灭绝的主要驱动因素。尽管全球范围内的破碎化现象急剧增加，但其对具有不同生活史的物种的种群连通性的具体影响仍难以描述，更不用说量化了。在此，我们调查了来自新加坡（一个热带雨林岛屿，栖息地高度破碎）的六种鸣禽的种群连通性模式。我们利用每个物种数十个样本的全基因组单核苷酸多态性大规模数据集，研究了具有一系列生态特性的物种之间的种群遗传多样性、近亲繁殖、基因流动和连通性。我们发现，与依赖森林的林下食虫鸟类相比，边缘耐受物种和林冠层物种对栖息地破碎化具有更高的恢复力。后者在新加坡的遗传多样性水平比其他地方连续森林中的种群低三倍。通过密集的基因组和地理采样，我们确定了诸如水库等个体屏障，这些屏障有效地减少了敏感林下鸟类的基因流动，表明陆生森林物种对破碎化的敏感程度可能远高于先前的预期。本研究为小尺度保护基因组学提供了一个蓝图，旨在确定栖息地走廊的首选位置，标记用于重新引入个体的候选种群，并改进未来保护区的设计。
