Relative importance of flower visitors as effective pollinators along a disturbance gradient

• Applicant: Privatdozent Dr. Stefan Abrahamczyk
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 522385752

Research on pollination systems is generally based on the number of visits a pollinator makes to a plant, ignoring pollinator effectiveness that defines the quality of these visits. Uncovering the factors responsible for interspecific variation in pollinator effectiveness in ecologically distinct pollinator taxa is crucial for predicting their role in ecological and evolutionary processes. This knowledge is particularly relevant for human modified habitats which host an altered abundance and composition of pollinators. Impoverished pollinator assemblages in disturbed forests may result in the loss of pollination services, which negatively affects plant reproduction and can lead to the breakdown of mutualistic relationships. Our goal is to evaluate the relative contribution of distinct functional groups of flower visitors to plant reproductive success and identify the mechanisms behind pollination effectiveness along a disturbance gradient. Specifically, we will (1) analyze interaction patterns between plants and two functional pollinators groups (hummingbirds and bats) in forests with different levels of disturbance, (2) compare pollinator effectiveness of these two distantly related pollinator groups, (3) assess how ecological specialization of interacting species relate to plant reproduction, and (4) investigate the relationship between morphological traits of interacting partners and seed set. By addressing these aims, we will (i) gather a unique dataset on plant-pollinator interactions including diurnal and nocturnal flower visitors, thereby filling a persistent major gap in pollination studies which tend to focus on single pollinator groups; (ii) develop an experimental setting to quantify pollination effectiveness allowing for an estimate of the genuine role of pollinators in ecological communities; (iii) document the extent to which pollinator visits to plants depict interactions that contribute to plant reproductive success and thus, provide a more refined insight into network theory; (iv) evaluate the underlying mechanisms that may influence variation in pollination effectiveness for a better understanding of how ecological and trait-based processes shape mutualistic networks. The proposed research evaluating habitat disturbance effects on plant reproduction through shifts in pollination effectiveness will yield knowledge essential for determining how a loss of particular pollinator species or functional groups may affect reproductive success and consequently the structure and functioning of tropical ecosystems. Our research will be based on methods that have been tested in the field and known study sites, ensuring the quality of data and feasibility of the project. Furthermore, this proposal will benefit from recent studies on plant-pollinator interactions conducted in the project area and previous research collaboration between Costa Rican and German scientists.

• DFG Programme: Research Grants
• International Connection: Costa Rica
• Partner Organisation: Consejo Nacional de Rectores
• Cooperation Partner: Professorin Dr. Maria Alejandra Maglianesi Sandoz