One of the co-authors of the study, Stephen Wratten of Lincoln University’s Bio-Protection Research Centre, said that it was no secret that a global decline in the populations of insect pollinators poses a major threat to food and nutritional security.
In New Zealand, where most wild bees have been lost to varroa mite and cultivated bees are becoming resistant to varroa pesticides, bee colonies are in terminal decline, while functioning beehives are becoming increasingly expensive for farmers to rent.
“We know the decline in bee populations is going to have a major impact on our economy, but we wanted to measure the impact,” said Prof. Wratten.
Previous methods of estimating the economic value of pollination have focused on desktop calculations of the value of crops and the dependency of those crops on pollinators. Prof. Wratten says the experimental manipulation of pollination rates is a more direct estimation of the economic value of pollination, or ecosystem services (ES).
The research team conducted a study in commercial fields producing pak choi for seed production. Some of the plants were covered with thin white mesh bags for varying time periods, preventing honeybees and fly species, which are key pollinators for the crop, from accessing the plants.
After changes in seed yield, seeds per pod and proportion of unfertilised pods as a result of changing pollination rates were identified, they then extrapolated the economic impact of varying pollination rates to the main 18 pollination-dependent crops in New Zealand.
The economic impacts of loss of pollinators include higher prices for consumers as crop yields are reduced and food production costs increase, he said.
“It’s critical to understand marginal changes in ES and their economic consequences in order to identify appropriate policy responses and avert further losses.
“Modifying existing agricultural systems to enhance ES requires a range of mechanisms, such as payments for it. Current policies at a national and global level continue to largely ignore the value of ES contributions such as biological control and pollination.”
Prof, Wratten says that farmers worldwide need help to put appropriate diversity back into their lands.
“There is a lot of scientific knowledge accumulating but this has to be turned into ‘recipes’ for end users like farmers to understand and implement. The big challenge is to have a recipe that works. Give farmers the right seeds to plant. Make sure the bees get what they need. It’s not about planting pretty flowers. It’s the science that counts.”
He believes that the best way to deliver this is through what he calls “farmer teachers”—farmers who understand and use the recipe, who will get out into the paddock and be heard by other farmers.