Wildfire severity alters drivers of interaction beta-diversity in plant-bee networks

Spatial variation in species interactions (interaction β-diversity) and its ecological drivers are poorly understood, despite their relevance to community assembly, conservation, and ecosystem functioning. We investigated effects of wildfire severity on patterns and four proximate ecological drivers of interaction β-diversity in plant-bee communities across three localities in the Northern Rocky Mountains (Montana, USA). Wildfires decreased interaction β-diversity but increased interaction frequency (number of visits) and richness (number of links). After controlling for interaction frequency and richness, standardized effect sizes of interaction β-diversity were highest following mixed-severity wildfires, intermediate following high-severity wildfires, and lowest in unburned landscapes, suggesting that wildfire increases spatial aggregation of plant-bee interactions. Moreover, higher effect sizes in burned landscapes were largely determined by turnover in the species composition of bot...