Diversity and Conservation of Mesoamerican Bees: Relative Effects of Three Major Threats Within the Potential Distribution of Bee Species

Bees have gained attention in recent years due to their importance as pollinators of crops and wild plants, as well as their global decline. Different causes for the decline in bee populations have been studied separately; however, the interactions among these causes are not well understood. We used a method that jointly analyzes the three principal threats affecting the distribution of bees in Mesoamerica, namely climate change, deforestation, and anthropogenic disturbance, the latter being a proxy of the exposure to pesticides and habitat loss. We analyzed records for 30 bee species across Mesoamerica, divided into three biological groups: stingless bees, bumblebees, and solitary bees. Furthermore, we used available climate and land-use data with a 5-km resolution to calculate current and future potential distributions given climate change, and within projected distributions, deforestation, and anthropogenic disturbance. The distribution of most bee species (73%) is expected to be affected by the threats included in the study. Of all species, 10% are likely to be affected by these threats to a moderate degree or not at all. By 2050, 84%, and 16% of species are expected to decrease and increase their range given climate change scenarios, respectively. Based on our results, we were able to weigh the relative impact of different threats on species distributions, and therefore inform conservation actions. Finally, we discuss the potential uses of this analysis, as well as caveats when scaling our results. We also address the implications of the intensity of the threats facing each biological group and provide suggestions for bee conservation in the Mesoamerican biodiversity hotspot region.