native California bumble bee foraging
on Eriophyllum staechadifolium
Many bee populations seem to be declining, threatening essential pollination services. There are many potential causes of bee declines and identifying which matter most for a given species or habitat is critical but challenging. One potentially powerful strategy uses statistical models that link bee abundances with environmental factors, such as floral resource availability or weather. Yet correlations between population trends and environmental variables alone do not confirm causation or mean the same patterns will apply in other times and places.