Aim: Bees play an important role in natural ecosystems and the world’s food supply. In the past decades, bee abundance and diversity have declined globally. This has resulted in decreased pollination services for natural ecosystems and the agricultural sector at the field scale. One of the causes of the decline in bee abundance and diversity is the use of pesticides. Linking pesticide use, land use and bee presence could provide crucial insights into areas and pesticides that pose a significant threat to the abundance and diversity of bees. Obtaining actual figures of farmer pesticide use is rarely possible. Therefore, we designed a method to study the effects of potential pesticide use on the survival and distribution of honey- and bumblebees.
Location: The Netherlands.
Methods: A pesticide risk model was implemented incorporating a hazard quotient as the risk assessment. The number of allowed pesticide active ingredients per crop that could pose a risk to honeybees and bumblebees were linked to the Dutch crop parcel locations for 2015 and 2016. The potential pesticide risk maps were analyzed using honeybee colony survival and bumblebee presence data.
Results: Non-significant negative effects of potential pesticide risk on honeybee colony survival and bumblebee presence were found. A significant negative effect of greenhouses was identified for both honeybees and bumblebees. The most important factors in the models predicting honeybee colony survival and bumblebee presence were urban land areas and natural grasslands respectively, both showing a positive effect.
Main conclusions: Here, the first attempt to estimate and map pesticide risk to bees in the Netherlands in a country-wide manner is presented. The results could provide crucial high-resolution insights for bee conservation action and facilitate the increase of pollination services in natural ecosystems and the agricultural sector on a local and country-wide scale
