Frugivore loss limits recruitment of large-seeded trees
Frugivore loss limits recruitment of large-seeded trees
复制标题
食果动物的损失限制了大种子树木的补充
DOI：
10.1098/rspb.2011.0185
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
D. Kelly
中科院分区：
文献类型：
--
作者：
D. Wotton;D. Kelly
尽管全球食果性动物数量的减少可能会扰乱种子传播互惠作用，并抑制植物的招募，但量化植物再生的可能减少一直是困难的，也很少尝试。我们使用操纵性析因实验来量化两个大种子新西兰树种的招募对扩散的依赖(即果肉去除和种子离开亲本区域)。完全扩散失败将导致2年生苗阶段的招募减少66%至81%，与引入的哺乳动物种子和苗木捕食者的协同作用使减少至92%至94%。扩散失败通过影响种子捕食、萌发和(特别是)幼苗存活来减少更新，包括依赖距离和密度的(Janzen-Connell)效应。这两个物种的传播目前在很大程度上依赖于单一的食果动物，今天许多水果仍然没有被吃掉。目前的果食动物损失水平以及哺乳动物种子和苗木捕食者导致两年后苗木减少57%至84%。我们的研究证明了种子传播对当地植物种群持续存在的重要性，并证实了对果食性下降对群落影响的担忧。
Although global declines in frugivores may disrupt seed dispersal mutualisms and inhibit plant recruitment, quantifying the likely reduction in plant regeneration has been difficult and rarely attempted. We use a manipulative factorial experiment to quantify dependence of recruitment on dispersal (i.e. fruit pulp removal and movement of seed away from parental area) in two large-seeded New Zealand tree species. Complete dispersal failure would cause a 66 to 81 per cent reduction in recruitment to the 2-year-old seedling stage, and synergistic interactions with introduced mammalian seed and seedling predators increase the reduction to 92 to 94 per cent. Dispersal failure reduced regeneration through effects on seed predation, germination and (especially) seedling survival, including distance- and density-dependent (Janzen–Connell) effects. Dispersal of both species is currently largely dependent on a single frugivore, and many fruits today remain uneaten. Present-day levels of frugivore loss and mammal seed and seedling predators result in 57 to 84 per cent fewer seedlings after 2 years. Our study demonstrates the importance of seed dispersal for local plant population persistence, and validates concerns about the community consequences of frugivore declines.