Format: ORAL

Yasmine Antonini1, Montserrat Arista2, Fernanda Vieira Costa3, Alejandro Nez Cabajal4 and Juan Arroyo2

1- Departamento de Biodiversidade Evolução e Meio Ambiente, Universidade Federal de Ouro Preto, Ouro Preto - Brazil 2- Departamiento de Biologia Vegetal y Ecologia, Universidad Sevilla, Sevilla, Spain 3- Departamento de Ecologia, Universidade de Brasília, Brasília, DF, Brazil 4- Consejo Superior de Investigaciones Científicas (CSIC)- Estación Biológica de Doñana, Sevilla, Spain

Pollinator networks play a crucial role in maintaining biodiversity and ecosystem functioning, especially in mountainous regions. Across an elevation gradient and flowering seasons, several biotic and abiotic factors influence community assemblages of interacting species leading to a shift in species distribution, functioning, and ultimately topologies of species interaction networks. In this work, we analyzed the architecture of plant-pollinator networks by recording plant-insect interactions at 10 study sites between 1000 and 1800 m a.s.l., following the two major seasons (from spring to summer flowering seasons) in a Mediterranean mountainous region. Our research aimed to address the following questions: (1) The structure of networks is stable over time-space? (2) How does the topology of networks change over time? (3) Which environmental drivers shape network structure across time and space? We analyzed spatial (elevational) and temporal (weeks) network patterns using generalized linear models (GLMs) and quantified the influence of climate, richness of flowering plant species, and pollinator diversity on network structures using a multimodel inference framework. We recorded 3,343 interactions, 343 pollinators, and 44 plant species of which a majority involved interactions with bees and flies. We found that nestedness and robustness are constant both in space and time. However, we found that the specialization of plant-pollinator networks increased from spring to summer with the rise of the temperature. Further, network modularity decreases across seasons and plant-pollinator interactions were more specialized at higher elevations. We found that flower and pollinator species diversity and abundance, rather than direct effects of climate, better predict modularity and specialization networks. This study highlights changes in network architectures over time and space (elevation) supporting a potential sensitivity of plant-bee interactions to climate change and desertification, putting Mediterranean mountain biodiversity at risk.