Data from: Habitat corridors facilitate genetic resilience irrespective of species dispersal abilities or population sizes

Corridors are frequently proposed to connect patches of habitat that have become isolated due to human-mediated alterations to the landscape. While it is understood that corridors can facilitate dispersal between patches, it remains unknown whether corridors can mitigate the negative genetic effects for entire communities modified by habitat fragmentation. These negative genetic effects, which include reduced genetic diversity, limit the potential for populations to respond to selective agents such as disease epidemics and global climate change. We provide clear evidence from a forward-time, agent-based model (ABM) that corridors can facilitate genetic resilience in fragmented habitats across a broad range of species dispersal abilities and population sizes. Our results demonstrate that even modest increases in corridor width decreased the genetic differentiation between patches and increased the genetic diversity and effective population size within patches. Furthermore, we document a tradeoff between corridor quality and corridor design whereby populations connected by high quality habitat (i.e., low corridor mortality) are more resilient to sub-optimal corridor design (e.g. long and narrow corridors). The ABM also revealed that species interactions can play a greater role than corridor design in shaping the genetic responses of populations to corridors. These results demonstrate how corridors can provide long-term conservation benefits that extend beyond targeted taxa and scale up to entire communities irrespective of species dispersal abilities or population sizes.

廊道常被用于连接因人类活动改变景观而形成的孤立生境斑块。尽管学界已证实廊道可促进斑块间的个体扩散，但廊道能否缓解生境破碎化所影响的整个群落面临的负面遗传效应，目前仍无定论。这类负面遗传效应包括遗传多样性下降，会限制种群应对疾病流行、全球气候变化等选择压力的潜力。我们通过正向时间基于主体的模型（agent-based model, ABM）获得了明确证据：在涵盖多样物种扩散能力与种群规模的场景中，廊道能够提升破碎化生境中的遗传韧性。研究结果显示，即便廊道宽度小幅增加，也能降低斑块间的遗传分化，提升斑块内的遗传多样性与有效种群大小。此外，我们还发现廊道质量与廊道设计之间存在权衡关系：由高质量生境（即廊道内死亡率较低）连接的种群，对次优廊道设计（如狭长型廊道）的耐受能力更强。该ABM模型还揭示，相较于廊道设计，物种间相互作用对种群响应廊道的遗传特征塑造作用更为显著。上述研究结果表明，廊道能够带来长期的保护效益，其惠及范围不限于目标类群，且可推广至整个群落，不受物种扩散能力或种群规模的限制。