Crop pollination from native bees at risk from agricultural intensification
AUTOR(ES)
Kremen, Claire
FONTE
National Academy of Sciences
RESUMO
Ecosystem services are critical to human survival; in selected cases, maintaining these services provides a powerful argument for conserving biodiversity. Yet, the ecological and economic underpinnings of most services are poorly understood, impeding their conservation and management. For centuries, farmers have imported colonies of European honey bees (Apis mellifera) to fields and orchards for pollination services. These colonies are becoming increasingly scarce, however, because of diseases, pesticides, and other impacts. Native bee communities also provide pollination services, but the amount they provide and how this varies with land management practices are unknown. Here, we document the individual species and aggregate community contributions of native bees to crop pollination, on farms that varied both in their proximity to natural habitat and management type (organic versus conventional). On organic farms near natural habitat, we found that native bee communities could provide full pollination services even for a crop with heavy pollination requirements (e.g., watermelon, Citrullus lanatus), without the intervention of managed honey bees. All other farms, however, experienced greatly reduced diversity and abundance of native bees, resulting in insufficient pollination services from native bees alone. We found that diversity was essential for sustaining the service, because of year-to-year variation in community composition. Continued degradation of the agro-natural landscape will destroy this “free” service, but conservation and restoration of bee habitat are potentially viable economic alternatives for reducing dependence on managed honey bees.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=139226Documentos Relacionados
- Modelling pollination services across agricultural landscapes
- Agricultural intensification and the collapse of Europe's farmland bird populations.
- Induced intensification: Agricultural change in Bangladesh with implications for Malthus and Boserup
- Bees biodiversity, forage behavior and fruit production in gherkin crop (Cucumis anguria L.)
- Analysis of the agricultural productivity of the sugarcane crop in regions of new agricultural expansions of sugarcane