Stevenson Pablo R, Link Andrés, González-Caro Sebastian, Torres-Jiménez María Fernanda
Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia.
Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia; Departamento de Ciencias Biológicas & Facultad de Administración, Universidad de Los Andes, Bogotá, Colombia.
PLoS One. 2015 Oct 22;10(10):e0140751. doi: 10.1371/journal.pone.0140751. eCollection 2015.
Frugivory is a widespread mutualistic interaction in which frugivores obtain nutritional resources while favoring plant recruitment through their seed dispersal services. Nonetheless, how these complex interactions are organized in diverse communities, such as tropical forests, is not fully understood. In this study we evaluated the existence of plant-frugivore sub-assemblages and their phylogenetic organization in an undisturbed western Amazonian forest in Colombia. We also explored for potential keystone plants, based on network analyses and an estimate of the amount of fruit going from plants to frugivores. We carried out diurnal observations on 73 canopy plant species during a period of two years. During focal tree sampling, we recorded frugivore identity, the duration of each individual visit, and feeding rates. We did not find support for the existence of sub assemblages, such as specialized vs. generalized dispersal systems. Visitation rates on the vast majority of canopy species were associated with the relative abundance of frugivores, in which ateline monkeys (i.e. Lagothrix and Ateles) played the most important roles. All fruiting plants were visited by a variety of frugivores and the phylogenetic assemblage was random in more than 67% of the cases. In cases of aggregation, the plant species were consumed by only primates or only birds, and filters were associated with fruit protection and likely chemical content. Plants suggested as keystone species based on the amount of pulp going from plants to frugivores differ from those suggested based on network approaches. Our results suggest that in tropical forests most tree-frugivore interactions are generalized, and abundance should be taken into account when assessing the most important plants for frugivores.
食果行为是一种广泛存在的互利共生关系,在这种关系中,食果动物获取营养资源,同时通过种子传播服务促进植物繁殖。然而,在诸如热带森林等多样的群落中,这些复杂的相互作用是如何组织起来的,我们还尚未完全了解。在本研究中,我们评估了哥伦比亚一片未受干扰的亚马逊西部森林中植物 - 食果动物亚组合的存在情况及其系统发育组织。我们还基于网络分析以及对从植物到食果动物的果实数量估计,探索了潜在的关键植物。在两年的时间里,我们对73种冠层植物物种进行了日间观察。在对目标树木采样期间,我们记录了食果动物的种类、每次单独访问的持续时间以及取食速率。我们没有找到支持亚组合存在的证据,比如专门的与一般化的传播系统。绝大多数冠层物种的访问率与食果动物的相对丰度相关,其中绒毛猴属(Lagothrix)和蛛猴属(Ateles)的蜘蛛猴发挥了最重要的作用。所有结果实的植物都被多种食果动物访问过,并且在超过67%的情况下,系统发育组合是随机的。在聚集的情况下,植物物种仅被灵长类动物或仅被鸟类食用,筛选与果实保护以及可能的化学含量有关。基于从植物到食果动物的果肉量被认为是关键物种的植物,与基于网络方法所认为的不同。我们的结果表明,在热带森林中,大多数树木 - 食果动物的相互作用是普遍存在的,并且在评估对食果动物最重要的植物时应考虑到丰度因素。