Abundance and richness of pollinators in organic versus conventional apple orchards

摘要

One of the main factors that determines the yield of apple orchards is the pollination. Apple fruit growers use pollinating varieties to ensure it but few attention is paid on insect pollinators. The aims of the present work are to describe the community of insect pollinators in organic versus conventional apple orchards located in Catalonia (NE of Spain) and to assess their contribution to apple pollination. The trial was conducted in 2015 in 28 apple orchards. Half of this orchards were organic andthe rest were conventional. 17 orchards were placed in a landscape were more than the 65 % of the area was cultivated (province of Lleida), and the rest were located in a landscape were the cultivated area was about 30 % (province of Girona). In general, the richness of pollinators was very low since more than 90 % of flower visits were done by honey bee (Apis mellifera L). The flower visits by honey bees were significantly higher in the province of Girona compared to the province of Lleida. However, the highest abundance of honey bees in the orchards placed in the province of Girona did not significantly increase the fruit set. The type of management (organic vs. conventional) did not affect the community of pollinators and the fruit set of apple orchards. The results of this work highlights the importance of the landscape in the abundance of insect pollinators.