In recent decades, the Protected Areas of Rome have seen an increase in average temperatures (1.7-2.0°C), well above the global increase of 1.5°C, accompanied by prolonged droughts and more frequent heat waves. These climate changes affect the distribution of pollinators, causing habitat loss and the local disappearance of species. Being ectothermic, these organisms are a direct example of how variations in temperature and precipitation can aggravate stress and mortality. The plants on which they depend are also affected, risking changing phenological cycles or disappearing, causing temporal misalignments that reduce the availability of food resources.
Climatologists develop future climate “scenarios” based on the mitigation strategies adopted, ranging from a complete transition to renewable energy to a continued use of fossil fuels. Species “distribution models” can be used to analyse the effects on biodiversity, illustrating how their distributions could change based on climate scenarios and environmental conditions.
A worrying picture emerges from the results of distribution models applied to pollinators in the Protected Areas of Rome. The climate suitability maps, both in the optimistic and pessimistic scenarios, highlight a general decline in pollinator richness, with a more marked reduction in the second scenario. Only small areas show stability or an increase in the number of pollinators, while large areas show a loss of these species. This picture suggests that, although emission mitigation techniques can reduce the negative effects on pollinators, they may not be sufficient to ensure their conservation. Therefore, field interventions, such as those implemented by the BeeAdapt project, are essential, such as the implementation of sustainable agricultural practices and the increase of host plants.
Text edited by: Dino Biancolini and Marina Baldi, CNR – Institute for BioEconomy
Sources:
Guisan, A., W. Thuiller, and N. E. Zimmermann. 2017. Habitat Suitability and Distribution Models: With Applications in R. Page Habitat Suitability and Distribution Models. Cambridge University Press, Cambridge.
Fick, S. E., and R. J. Hijmans. 2017. WorldClim 2: new 1-km spatial resolution climate surfaces for global land areas. International Journal of Climatology 37:4302–4315.
Vasiliev, D., and S. Greenwood. 2021. The role of climate change in pollinator decline across the Northern Hemisphere is underestimated. Science of The Total Environment 775:145788.
GBIF.org. 2023a. Apoidea. Global Biodiversity Information Facility. https://www.gbif.org/occurrence/download/0060344-231002084531237.
GBIF.org. 2023b. Lepidoptera. Global Biodiversity Information Facility. https://www.gbif.org/occurrence/download/0060342-231002084531237.
