Plant-pollinator interactions: Diurnal and nocturnal pollinators

点击翻译按钮获取中文摘要

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.