Dung decomposition and secondary seed dispersal by dung beetles

在“物种相互作用网络的重组”研究单位内，“粪便分解和蜣螂的二次种子传播”分项目侧重于植物种子、哺乳动物和蜣螂之间的三重营养网络。将在沿着森林恢复时序的所有样地监测粪甲虫，并分析甲虫肠道内容物中所含的哺乳动物DNA，以构建哺乳动物-甲虫营养网络。物种特有的粪便性状，如挥发物和营养物质的特点和相关的甲虫的偏好之间的哺乳动物物种使用陷阱与合成化合物。此外，我们还将比较甲虫物种在广泛的甲虫饮食（粪便，腐肉，腐烂的水果和千足虫）和他们的时间活动模式在白天和晚上的分布。粪埋率和二次种子传播的实验将有助于量化甲虫对种子传播内核的贡献和它们对扰动的反应。种子的命运预计会有所不同，这取决于种子的大小和其他性状与蜣螂的特点。甲虫、粪便和种子的功能性状将与森林恢复中的三营养网络结构及其动态有关。

Within the research unit "Reassembly of species interaction networks", the subprojet "Dung decomposition and secondary seed dispersal by dung beetles" focuses on tritrophic networks between plant seeds, mammals and dung beetles. Dung beetles will be monitored in all plots along the forest recovery chronosequence, and the mammalian DNA contained in the beetles' gut contents will be analysed to construct trophic mammal - beetle networks. Species-specific dung traits such as volatiles and nutrients will be characterized and related to the beetles' preferences among mammal species using traps with synthetic compounds. We will additionally compare the distribution of beetle species across a broad spectrum of beetle diets (dung, carrion, rotten fruit and millipedes) and their temporal activity pattern during day and night. An experiment on dung burial rate and secondary seed dispersal will help to quantify the beetles' contribution to seed dispersal kernels and their responses to perturbation. The fate of seeds is expected to differ depending on seed size and other traits in relation to dung beetle characteristics. Functional traits of beetles, dung and seeds will be related to the structure of tritrophic networks and their dynamics in recovering forests.