Counting marmots…
Bottom-up effects of mutualism breakdown among subalpine legumes and N-fixing bacteria on the specialist solitary bee Osmia iridis Climate change affects species and their interactions, resulting in novel communities and modified ecosystem processes. Climatic change can disrupt interspecific interactions, including those between mutualists. Mutualistic interactions profoundly influence the structure and stability of ecological communities and can link species to a common fate. However, research on climate change-driven effects has largely focused on pairwise mutualisms, neglecting the higher-order interactions that can arise when species interact with multiple mutualists. In this project, I aim to explore the effects of climate change on tripartite interactions involving belowground mutualists (N-fixing bacteria), legume plants, and their specialist pollinators. Warming temperatures, advanced snowmelt, and drought are likely to cause a breakdown in the mutualism between N-fixing bacteria and legumes, leading to changes in the strength of the mutualism between plants and their pollinators. Climate-induced shifts in legume flowering phenology and decreases in legume floral functional trait quality caused by this breakdown are potentially increasing foraging time and energy demands for bees and altering their floral preferences. Such costs could translate to reduced fitness and novel selection pressures for both bees and flowering plants in the short-term.