Pollinator conservation for crop production

CHACOFF, NATACHA P.

Buenos Aires

Congreso; Apimondia; 2011

Flower-visiting animals, especially insects, provide pollination services in the form of delivery of sufficient pollen, in terms of both quantity and quality, for ovule fertilization to nearly 70% of the crops worldwide. Apis mellifera, the most important pollinator for the vast majority of crops is not the most efficient pollinator for many of them. For instance, stingless bees pollinate mango and macadamia, carpenter bees are the most efficient pollinator of the passion fruit, bumblebees pollinate effectively tomatoes and leaf cutter bees are efficient pollinators of many annual crops. Biodiversity loss and particularly the claimed decline of Apis mellifera have raised the attention on crop pollination for the provision of sufficient food, leading the focus on natural and semi-natural areas for the provision of pollinators. Natural or semi-natural areas within agricultural landscapes often provide habitat for wild pollinator species, from which they forage on flowering crop and weed plants in arable fields. Although flowering crops themselves often provide important resources for many pollinator species, the short duration of floral availability, low diversity of floral and nesting resources, and pesticide application and tillage often compromise the capacity for these cropped areas, on their own, to support diverse and abundant pollinator communities. Recent studies showed that mean levels of flower-visitor richness, visitation rate, fruit production and temporal and spatial stability in croplands decline with distance from natural areas. Predictive models of pollination services across landscapes are now being developed. These models include pollinators flight distances, nesting requirements and flower abundance across a landscape as their principal inputs. So far, these models are capturing , on average, only about 20% of the variation in observed pollinator abundance. It is proposed that better estimations of fight distances and characterization of nesting sites are needed to improve their fit. However the knowledge we have to date, depicts a picture where abundant and diverse communities of pollinators ensuring high-quality and stable pollination services are only possible in agricultural mosaics, which include remnants of natural and semi-natural habitats.