Assessment Of Agricultural Pollination Demand And Pollination Service Capacity Of Managed Honeybees In China And World

Human population is rising at an alarming rate,expected to grow above 9.7 billion people,requiring global agriculture at least to double its production to meet the increasing food and nutrients demand by 2050.Insect pollination makes a huge contribution to global agriculture and increases with agricultural dependence on pollinators.The increasing evidence shows a decline in wild insect pollinators worldwide,limiting crop pollination and production.Yet,it is unclear to what extent agriculture could be impacted by pollinator deficits –a case of Chinese agriculture.Also,as the most widely supplied pollinator,managed honeybee has increased in number globally with regional variations.The concern is whether these managed pollinators could sufficiently supply the agricultural pollination demand in the face of the decline of wild pollinators.Therefore,we applied a bioeconomic approach and pollinator supply-demand analyses to assess agricultural pollination demand and pollination service capacity of managed honeybee.To assess the extent Chinese agriculture could be impacted by pollinator deficits,data for 84 major crops in China between 1961 and 2018 were analyzed for the temporal trends in crop area and production,agricultural economic contribution of pollination,crop yield deficits,and honeybee pollination demand.Resultantly,agricultural dependence on insect pollinators has increased rapidly:both cultivated area and total production of pollinator-dependent crops increased faster than those of pollinator-independent crops during 1961-2018 in China.The total pollination service economic value represented 19.12% of the total production value of Chinese agriculture,approximately twice the 9.5% value estimated for global agriculture.Crops with higher pollinator dependence showed greater mean growth in cultivated areas than those with lower dependence,but lower mean crop production and yield growth.Crop yield growth was also more unstable with increasing pollinator dependence.The minimum demand for honeybee colonies was about three times the stocked number of honeybee colonies available in 2018.Furthermore,we found a decline in crop yield deficit with the increase in honeybee colony pollination service capacity.This indicates any future increases in the cultivated areas with pollinator-dependent crops will increase the need for more pollinators.To assess whether the managed pollinator honeybee could be able to supply optimum pollination service in agricultural systems worldwide,data for 49 honeybee-pollinated crops cultivated worldwide and stocked honeybee colonies were analysed for the pollination demand and pollination service capacity between 1989-2019 at levels of agriculturally important countries,regions and the world as a whole.Resultantly,demand for honeybee pollination increases rapidly,but the pollination service capacity of honeybee colonies decreases.Global demand for honeybee pollination raised about 2.3 times higher than the stocked number of honeybee colonies in 2019,growing annually at a rate of 1.78%,almost two times faster than 0.95% of honeybee colonies.On average,the pollination service capacity,growth rates of honeybee colony stock and pollination demand,and diversity of honeybee-pollinated crops varied significantly between regions.Additionally,the fluctuation of honeybee-pollination demand increased with increase in fluctuation of crop diversification.The oil crops,mostly moderate pollinator-dependents,accounted for over 70%of the global honeybee-pollination demand in 2019,whereas soybean and rapeseed together could utilize over 50% of the colonies demanded.This was the case in less diversified countries as few crops dominated the demand for honeybee pollination,such as agriculturally important countries in the Americas like Argentina,Brazil,and the USA,compared to more diversified countries such as China,India,and Japan in Asia.Collectively,our study shows the increase in agricultural dependence on pollinators,but there are far insufficient managed pollinators to supply the agricultural demand worldwide adequately.In conclusion,our study showed that agricultural dependence on insect pollinators has increased rapidly,but the pollination service capacity of managed honeybee colonies decreased globally.These results give emphasises on the importance of implementing pollinator-protecting measures,and integrated management of honeybees and wild pollinators assemblages for sustainable agriculture.Overall,our study contributes to the body of knowledge and can be helpful to stakeholders as an evidence-based tool used for prioritizing,designing,promoting,and implementing positive effective pollinator management strategies for attaining sustainable agriculture and global food and nutrients security.