Early genetic consequences of defaunation in a large-seeded vertebrate-dispersed palm (Syagrus romanzoffiana)

Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, defaunation may disrupt plant-disperser mutualisms, thus reducing levels of seed-mediated gene flow and genetic variation in animal-dispersed plants. This may ultimately limit their adaptive potential and ability to cope with environmental change. Tropical forest remnants are typically deprived of medium to large vertebrates upon which many large-seeded plants rely for accomplishing effective seed dispersal. Our main goal was to examine the potential early genetic consequences of the loss of large vertebrates for large-seeded vertebrate-dispersed plants. We compared the genetic variation in early-stage individuals of the large-seeded palm Syagrus romanzoffiana between continuous protected forest and nearby partially defaunated fragments in the Atlantic Forest of South America. Using nine microsatellites, we found lower allelic richness and stronger fine-scale spatial genetic structure in the ...

植物种群正遭受人为生境干扰的严重威胁。尤为关键的是，动物区系丧失（defaunation）可能破坏植物与传播者之间的互利共生关系，进而降低动物传播植物的种子介导的基因流（seed-mediated gene flow）水平与遗传变异程度。这最终会限制其适应潜力以及应对环境变化的能力。热带森林残片断（tropical forest remnants）通常丧失了众多大种子植物实现有效种子传播所依赖的中大型脊椎动物类群。本研究的核心目标为探究大型脊椎动物丧失对脊椎动物传播型大种子植物可能产生的早期遗传效应。我们以南美洲大西洋森林（Atlantic Forest）中的连续保护林与邻近局部动物区系丧失的片断化林块为研究对象，对比了大种子棕榈植物*Syagrus romanzoffiana*早期个体的遗传变异情况。借助9个微卫星标记（microsatellites）开展分析后，我们发现更低的等位基因丰富度（allelic richness）以及更强的精细空间遗传结构（fine-scale spatial genetic structure）出现在……