While biodiversity is well known as the diversity of different levels of organization in the living world (genetic diversity, species diversity, ecosystem diversity), it is also characterized by a wide range of interactions between living organisms. These close interactions make biodiversity the " living fabric of the planet ". Among these interactions, mutualisms between flowering plants and the animals that pollinate them play a central role in the functioning of terrestrial ecosystems. Indeed, flowering plants are at the base of most terrestrial food chains, including those of which humans are a part (agriculture) ; yet they depend mainly on pollinators for their reproduction.
In this lecture, I will describe how plant/pollinator interactions have evolved since they first appeared several hundred million years ago. This co-evolution has produced tremendous diversification, notably in flower shapes, colors and odors, as well as complex networks of plant/pollinator interactions, which have ensured their stability over time. I will also present the current state of plant/pollinator interactions. Both types of partner are suffering the consequences of human population growth and rising average living standards, which are associated with the destruction of natural habitats, pollution of remaining habitats, climate change and massive displacement of species on a global scale. These pressures are responsible for major changes in the composition of plant and pollinator communities, with possible consequences for their interactions. However, all these ongoing changes remain poorly understood, due to a lack of homogeneously collected data for plants, even more so for pollinators, and even more so for pollination interaction. I will show the potential of participatory sciences, partnerships between researchers and citizens around a common research project, to improve knowledge of biodiversity and its changes over time, particularly for plant/pollinator interactions. Finally, I'll look at how pollination works in agricultural areas, where many crops depend on pollinators for seed and fruit production. I will conclude with possible conservation options to preserve plant-pollinator interactions, both for themselves and for the services they provide to human societies.