Functional importance of avian seed dispersers changes in response to human-induced forest edges in tropical seed-dispersal networks
Functional importance of avian seed dispersers changes in response to human-induced forest edges in tropical seed-dispersal networks
复制标题
DOI：
10.1007/s00442-014-3056-x
复制
发表时间：
2014-09
期刊：
影响因子：
2.7
通讯作者：
Francisco Saavedra;I. Hensen;S. Beck;K. Böhning‐Gaese;Denis Lippok;T. Töpfer;M. Schleuning
中科院分区：
文献类型：
--
作者：
Francisco Saavedra;I. Hensen;S. Beck;K. Böhning‐Gaese;Denis Lippok;T. Töpfer;M. Schleuning
虽然种子传播网络越来越多地用于推断生态系统的功能，很少有研究调查这些网络的属性和动物种子传播的生态系统功能之间的联系。我们调查了食果动物群落和种子传播的变化与生境干扰和测试之间的关系是否形态特征和种子传播者的功能角色的变化，在人为引起的森林边缘。我们记录了玻利维亚安第斯山脉热带山地森林中肉质果类植物和食果鸟类之间的相互作用频率，并记录了与种子传播有效性的定量（种子去除率）和定性（种子沉积模式）成分相关的功能性鸟类特征（体重、张口宽度和翅尖长度）。我们发现食果鸟类的丰度和丰富度在森林边缘较高。更多的果实被移除，分散的种子在边缘比在内部更少聚集。此外，功能和相互作用的多样性较高的边缘比在内部，但功能和相互作用的均匀度没有差异。在林内，鸟种间的相互作用强度随鸟体质量、张口宽度和翅尖长度的增加而增加，但与林缘鸟类形态无关。我们的研究表明，增加功能和相互作用的多样性和均匀分布的相互作用强度在鸟类形态导致种子传播的数量和暂定提高质量。这也表明，物种特征对生态系统功能的影响可以沿着小尺度梯度的人类干扰。
Although seed-dispersal networks are increasingly used to infer the functioning of ecosystems, few studies have investigated the link between the properties of these networks and the ecosystem function of seed dispersal by animals. We investigate how frugivore communities and seed dispersal change with habitat disturbance and test whether relationships between morphological traits and functional roles of seed dispersers change in response to human-induced forest edges. We recorded interaction frequencies between fleshy fruited plants and frugivorous bird species in tropical montane forests in the Bolivian Andes and recorded functional bird traits (body mass, gape width and wing tip length) associated with quantitative (seed-removal rate) and qualitative (seed-deposition pattern) components of seed-dispersal effectiveness. We found that the abundance and richness of frugivorous birds were higher at forest edges. More fruits were removed and dispersed seeds were less clustered at edges than in the interior. Additionally, functional and interaction diversity were higher at edges than in the interior, but functional and interaction evenness did not differ. Interaction strength of bird species increased with body mass, gape width and wing tip length in the forest interior, but was not related to bird morphologies at forest edges. Our study suggests that increases in functional and interaction diversity and an even distribution of interaction strength across bird morphologies lead to enhanced quantity and tentatively enhanced quality of seed dispersal. It also suggests that the effects of species traits on ecosystem functions can vary along small-scale gradients of human disturbance.