Understanding the impact of climate change on honey bees' distribution in Pakistan: A predictive approach using historical data

Abstract

This study investigated the potential future distribution of three honey bee species, viz., Apis florea, Apis cerana, and Apis dorsata in Pakistan. The data was collected based on sighting records through field surveys, literature review, and from the Global Biodiversity Information Facility (GBIF). Maxent software was used to incorporate GPS coordinates and bioclimatic data to predict the future distribution of the honey bee species in Pakistan.  A model habitat suitability based on 19 different bioclimatic variables from WorldClim was used to compare current and projected (2050) climatic scenarios. The results indicated a general warming trend for all three species with expected average annual increases in temperature and precipitation. Apis florea is scheduled to face a 2.5°C rise in the annual mean temperature, while Apis cerana and Apis dorsata will face increases of 2.4°C and 2.3°C, respectively. An increase in precipitation ranging from 50 to 60 mm annually is expected. This expected increase in temperature and precipitation could enhance foraging behaviour during a few months of the year, and the heat stress in warmer months poses a significant challenge to the survival of the honey bee species. Moreover, variations in seasonal patterns, including mild winter and increased humidity, could disrupt honey bees' activity, the colony dynamics, and plants' physiology. These factors require making resilient habitats for honey bees, and this can be done by planting resilient plants and maintaining habitats that provide suitable shelter from extreme heat. It is recommended that species distribution models should also consider other variables, including land use changes, pesticide use, and disease prevalence, to provide a more comprehensive understanding of how honey bee species may respond to climate change in the future.