INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Stability of pollination services in agricultural landscapes
Autor/es:
GARIBALDI, L. A.
Lugar:
Fukuoka
Reunión:
Simposio; JSPS International Symposium on Pollinator Conservation: Conservation and Sustainable Use of Pollinators: towards Global Assessments; 2012
Resumen:
Growth of the human population imposes major challenges for sustainability by meeting increasing global demand for agricultural products, while maintaining multiple ecosystem services and biodiversity. The stability (inverse of variability) of ecosystem functions is an important component of sustainability; however, the consequences of variation in ecosystem services for both average agricultural output and its stability have received little attention. This dissertation will explore, firstly, a general graphical model based on Jensen’s inequality, of yield–resource relations and consider implications for land conversion. For the case of animal pollination as a resource influencing crop yield, this model predicts that incomplete and variable pollen delivery reduces yield mean and stability more for crops with greater dependence on pollinators. Data collected by the Food and Agriculture Organization of the United Nations during 1961–2008 support these predictions. Indeed, lower yield growth was compensated by increased land cultivation to enhance production of pollinator-dependent crops, but at the risk of further eroding ecosystem services because of the reduction of natural areas. Therefore, this dissertation will explore, secondly, whether isolation from florally diverse natural and semi-natural areas reduces the spatial and temporal stability of flower-visitor richness and pollination services in crop fields. Data from 29 studies with contrasting biomes, crop species and pollinator communities showed that stability of flower-visitor richness, visitation rate (all insects except honey bees) and fruit set all decreased with distance from natural areas. In contrast, honey bee visitation did not change with isolation and represented >25% of crop visits in 21 studies. Therefore, wild pollinators are relevant for crop productivity and stability even when honey bees are abundant. Results show that pollen limitation hinders yield growth of pollinator-dependent crops, decreasing temporal stability of global agricultural production, while promoting compensatory land conversion to agriculture. Policies to preserve and restore natural areas in agricultural landscapes should enhance levels and reliability of pollination services.