EvaluaTing the functional role of the hummingbiRd hAwkmoth, Macroglossum stellatarum aloNg itS mIgratory paThway: implications for ecosystem functioning (TRANSIT)
Predicting how species, communities and ecosystems will respond to global environmental change remains a key scientific challenge. Much progress has been done in understanding how species interact and assemble into complex networks. However, the dynamic nature of these species assemblages and the role of biodiversity in shaping them remain poorly understood. To fill these gaps, we will survey plant-pollinator interactions along the migratory pathway of the hummingbird hawkmoth, Macroglossum stellatarum, which coincides with a pollinator diversity gradient, to address three main questions: 1. How does pollinator species diversity within the community and the migratory behaviour of a species affect its functional role? We will evaluate how M. stellatarum ́s functional role changes throughout its migratory pathway: from Spain where migratory and resident populations co-exist, to Switzerland where all individuals annually migrate in late May, and the consequences this has for plant reproductive success. 2. How does pollinator functional diversity affect ecosystem function? We will focus on the relationship between community dynamics and the spatial network of pollination events generated by different pollinator species, including M. stellatarum along its migratory pathway, and test the effects for population persistence and potential longer-term evolutionary responses. 3. How will climate change affect M. stellatarum ́s migratory behaviour and what will the consequences be for ecosystem functioning? We will evaluate how climate change might affect the migratory behaviour of M. stellatarum, and the consequences this might have for other pollinator species it co-exists with. We will develop models based on the knowledge generated in previous objectives to predict how communities will re-assemble and use them together with process-based models to forecast effects on ecosystem function. By connecting empirical data with complex theoretical models, TRANSIT will represent a fundamental step to improve our ability to predict the outcome of ecosystem disturbances and their impact on community structure and function, while focusing on multiple levels of biodiversity: from species, interactions and communities to functions.