Wild bees and hoverflies per landscape type.
Abstract
Insects play an essential role in the pollination of many food crops and wild plants. It is not just honey bees, there is a wide spectrum of species of wild bees and hoverflies. Apart from the functional importance of pollinating insects, they form an important component of biodiversity in Dutch nature. There are, however, strong indications that both the numbers and the species diversity of pollinators have fallen sharply in recent decades. Through the National Bee Strategy, the Ministry of Agriculture, Nature and Food Quality (LNV) and more than fifty social partners work together with the main objective that by 2030, pollinators and pollination services will be sustainably preserved and promoted in our country. As a contribution to this, a "knowledge impulse for pollinators" has been created for the coming years, aimed at developing and disseminating knowledge, and raising awareness. The target group are actors who can contribute to the maintenance and promotion of populations of wild pollinators. Initiators of measures do not always have the required knowledge to complete the design and management of an area in such a way that it has optimum effect. This is also difficult in practice, because hundreds of species of wild bees and hoverflies occur in the Netherlands, each with their specific needs with regard to their habitat, and because different species occur or could occur in different types of landscape. Customization is therefore required. In order to design that customization efficiently, there is a need for an overview of different groups of pollinators with similar habitat requirements. The present report describes the first step in which cluster analysis was used to visualize the occurrence of bees and hoverflies in different landscape types. The basis for the analyses was formed by data files with inventory data from bees and hoverflies per kilometer-house, in combination with a GIS file with information about environmental factors. This has been used to identify clusters of kilometer cages (landscape types) with a similar spectrum of pollinator types. For each species, this matrix gives an overview of the landscape types in which the species mainly occurs, where many species can occur in several landscape types. The purpose of this information is to gain a quick insight into the relevant types of pollinators that (could) occur in a certain management region, to subsequently be able to take targeted measures that meet the requirements that these species place on their environment. The results thus also form the basis for the next phase in this module: specifying the ecological preconditions of pollinators with regard to food plates and the (micro) biotope for reproduction (also indicating which knowledge gaps still exist) and identifying effective measures. Different species groups will, after all, have different requirements and therefore require different measures.