National-scale mapping of potential floral resources for honeybees and native pollinators in New Zealand.

Floral resources are important food resources for pollinators. These resources are produced in different quantities depending on land cover and plant species composition, and the quantity of production varies seasonally. As such, land use change and management of natural resources can have substantial impacts on conservation through resource provision for pollinators, and also commercial enterprises through resources for honeybee hives which require adequate forage to be successful. In New Zealand, locations with vegetation that produce high-value honey also suffer from overcrowding of hives, as beekeepers compete for this valuable resource. At present, there is a lack of quantitative spatial data describing the production of these resources, especially over large spatial scales. Here, using maps of land cover and environment, and a large vegetation plot dataset, we show that the provision of floral resources for pollinators can be estimated spatially at national scales. These maps can be used to estimate the consequences of changing land cover, both historical and with future management actions, and to understand potential threats to floral resource provision. We find that the production of floral resources across New Zealand is highly seasonal, and overwhelmingly produced by indigenous land cover types, especially within public conservation land. Within forests, we show that floral production is dominated by a small number of plant families. Our results show the importance of native land cover for the provision of floral resources for commercial honeybee enterprises and also native pollinators. We anticipate our results will be a starting point to inform management decisions regarding the placement and stocking density of honeybee hives, and also the concession process for honeybee permits on public land. We also show how the restoration of woody ecosystems on cleared land can benefit the conservation of native pollinators by providing abundant and high-quality forage across all seasons.