Fire is associated with positive shifts in bumble bee (Bombus vosnesenskii) body size and bee abundance in the Southern Sierra Nevada Mountains

Climate change is increasing the frequency and severity of wildfires
worldwide. Although wildfires are typically viewed as destructive,
emerging research suggests they may have benefits for some species,
including some pollinators. One reason for this is that wildfires can
increase floral resource availability in the years immediately following
the burn, potentially creating more favorable conditions for pollinator
foraging and reproduction. In this study, we focused on how the 2021 KNP
Complex Fire impacted the bumble bee Bombus vosnesenskii in the Southern
Sierra Mountains, where the effects of fire on this pollinator species
have not been previously explored. Consistent with bumble bee studies in
other areas, we found an increase in the size of B. vosnesenskii workers
in recently burned areas. This effect was detectable despite a limited
number of sampling events and locations in our study, and irrespective of
the habitat type (meadow versus forest) in which sampling occurred. We
failed to detect increased floral resource availability (abundance or
diversity) in burned areas but did observe unique floral communities in
burned areas. Our findings contribute to our growing understanding of
fire’s impact on pollinators and support the broad idea that fire might
have benefits for some organisms.