Universidade Estadual Paulista (UNESP), Instituto de Biociências, Departamento de Zoologia, Laboratório de Primatologia, Avenida 24A, 1515, 13506-900, CP199, Rio Claro, SP, Brazil.
Universidade Estadual Paulista (UNESP), Instituto de Biociências, Departamento de Ecologia, Laboratório de Biologia da Conservação, Avenida 24A, 1515, 13506-900, CP199, Rio Claro, SP, Brazil.
Sci Rep. 2017 Aug 9;7(1):7662. doi: 10.1038/s41598-017-08222-4.
The extinction of large frugivores has consequences for the recruitment of large-seeded plants with potential lasting effects on carbon storage in tropical rainforests. However, previous studies relating frugivore defaunation to changes in carbon storage ignore potential compensation by redundant frugivores and the effects of seed predators on plant recruitment. Based on empirical data of the recruitment success of a large-seeded hardwood tree species (Cryptocarya mandioccana, Lauraceae) across a defaunation gradient of seed dispersers and predators, we show that defaunation increases both seed dispersal limitation and seed predation. Depending on the level of seed predator loss, plant recruitment is reduced by 70.7-94.9% as a result of the loss of seed dispersers. The loss of large seed predators increases the net seed mortality by 7-30% due to the increased abundance of small granivorous rodents. The loss of large seed dispersers can be buffered by the compensatory effects of smaller frugivores in seed removal, but it is not sufficient to prevent a decrease in plant recruitment. We show that the conservation of both seed predators and dispersers is necessary for the recruitment of large-seeded plants. Since these plants contribute substantially to carbon stocks, defaunation can jeopardize the maintenance of tropical forest carbon storage.
大型食果动物的灭绝会对大种子植物的繁殖产生影响，从而对热带雨林的碳储存产生潜在的持久影响。然而，先前将食果动物减少与碳储存变化联系起来的研究忽略了冗余食果动物的潜在补偿作用以及种子捕食者对植物繁殖的影响。基于对一种大种子硬木树种（Cryptocarya mandioccana，樟科）在种子传播者和捕食者的除虫梯度上的繁殖成功率的经验数据，我们表明除虫会增加种子传播的限制和种子捕食。由于种子传播者的减少，植物的繁殖减少了 70.7-94.9%，这是由于种子捕食者的损失。大型种子捕食者的损失会因小型食谷啮齿动物数量的增加而导致净种子死亡率增加 7-30%。大型种子传播者的损失可以通过较小的食果动物在种子去除方面的补偿作用来缓冲，但不足以防止植物繁殖减少。我们表明，为了大种子植物的繁殖，必须同时保护种子捕食者和传播者。由于这些植物对碳储量有很大的贡献，除虫可能会危及热带森林碳储存的维持。
