Plant-pollinator interactions: Diurnal and nocturnal pollinators

在“物种相互作用网络重组”研究单元中，“植物-传粉者相互作用：日间和夜间传粉者”子项目侧重于植物与不同传粉者分类群之间的相互作用网络。在热带生态系统中，绝大多数开花植物依靠动物授粉。作为主要的花粉传递媒介，传粉者确保了98%的热带植物物种的种子生产。反过来，它们获得宝贵的资源，如花粉、花蜜或花油，这些对它们的健康至关重要。这些传粉媒介与嗜兽植物之间的共生关系导致了复杂的相互作用网络；这些网络的结构提供了对网络介导过程的稳定性的洞察，即植物授粉和传粉者的供应。反过来，网络结构和过程又受到群落组成变化及其分类和功能性状多样性的影响。群落组成和多样性往往在大规模干扰后发生严重改变，如集约化砍伐或森林砍伐，这可能通过破坏基本的潜在互惠相互作用而导致授粉稳定性下降。然而，令人惊讶的是，人们对热带植物-传粉者网络（以及由此产生的过程）的恢复力和恢复，或对恢复梯度上的结构变化知之甚少。我们的项目将通过探索沿着森林恢复梯度的植物-传粉者网络的恢复轨迹和动态来填补这一空白。它将重点研究两种昆虫模型组，即昼行性蜜蜂和夜行性飞蛾，并进一步包括蝙蝠和甲虫（通过研究单位内部的合作获得）。研究人员将对62个样地的花粉进行dna元条形码分析，这些样地采集的花粉来自林下和冠层，代表了从牧场到次生林到原生林的梯度。此外，我们将研究不同的传播、响应和相互作用性状（通常被认为对植物-传粉者相互作用很重要）在传粉者行会内部和行会之间的作用，以更好地了解潜在的性状规则。我们还将评估无刺蜂群和陷阱筑巢独居蜜蜂在适合度上的特定地点差异，以捕捉恢复对供给的影响。为了评估授粉的差异，我们将测量两种植物的果实恢复效应以及选定树种之间的花粉传递。

Within the research unit "Reassembly of species interaction networks", the subprojet " Plant-pollinator interactions: Diurnal and nocturnal pollinators " focuses on interaction networks between plants and different pollinator taxa. In tropical ecosystems, the vast majority of flowering plant species relies on animals for pollination. As major pollen transfer agents, pollinators ensure seed production of an estimated 98% of tropical plant species. In turn, they obtain valuable resources, such as pollen, nectar or floral oils, which are essential for their fitness. The mutualistic relationship between these pollinators and zoophilous plant species results in complex interaction networks; the structure of these networks provides insight into the stability of network mediated processes, i.e. pollination of plants and provisioning of pollinators. Networks structures and processes are in turn affected by variation in the composition of communities, as well as their taxonomic and functional trait diversity. Community composition and diversity are often severely altered following large-scale disturbance, such as intensive logging or deforestation, which results in decreased pollination stability, likely through disrupting essential underlying mutualistic interactions. Yet surprisingly little is known on the resilience and recovery of tropical plant-pollinator networks (and resulting processes) or on structural changes along recovery gradients.Our project will fill this gap by exploring recovery trajectories and dynamics of plant-pollinator networks along a forest recovery gradient. It will focus on two insect model groups, i.e. diurnal bees and nocturnal moths, and further includes bats and beetles (obtained through collaboration within the research unit). We will analyze pollen-based interaction networks using DNA-metabarcoding of pollen collected from bodies of individual specimens sampled in both the understory and canopy of 62 plots representing a gradient from pastures over secondary growth to primary forest. Moreover, we will investigate the role of different dispersal, response and interaction traits (generally considered important for plant-pollinator interactions) within and between pollinator guilds to better understand underlying trait-rules. We will also assess site-specific differences in fitness of stingless bee colonies and trap nesting solitary bees to capture effects of recovery on provisioning. To assess differences in pollination, we will measure recovery effects on fruit set of two phytometer plant species as well as in pollen transfer between selected tree species.