A través de ENSSER, European Network of Scientists for Social and Environmental Responsibility (http://www.ensser.org/) y de Ecoflor (webecoflor.webs.uvigo.es/), me llega la noticia de que la Plataforma Intergubernamental sobre Biodiversidad y Servicios Ecosistémicos, y en particular su coordinador del grupo de Evaluación de la Polinización, Hien Ngo, han dado a conocer un resumen dirigido a gestores y políticos en relación con la evaluación temática sobre polinizadores, polinización y producción alimentaria.
Brevemente, se trata de evaluar el papel de la polinización animal como un servicio ambiental de regulación ecosistémica que sustenta la producción de alimentos, interpretando éste como una oferta del mundo natural hacia los humanos que permite una buena calidad de vida. Para ello, se centra la atención en el papel de los polinizadores nativos y no nativos (gestionados por los humanos), en el estado y las tendencias de las poblaciones de polinizadores, en las redes de la polinización plantas y polinizadores, en los impactos sobre el bienestar humano, en la producción de alimentos en respuesta a los descensos de las tasas de polinización y en los déficits y la eficacia de las respuestas.
Las líneas maestras de dicho documento son (tal cual están reflejadas en el documento, http://www.ipbes.net/sites/default/files/downloads/SPM_Pollinators_unedited%20advance.pdf):
Values of pollinators and pollination
- Animal pollination plays a vital role as a regulating ecosystem service in nature.
- More than three quarters of the leading types of global food crops rely to some extent on animal pollination for yield and/or quality.
- Given that pollinator-dependent crops rely on animal pollination to varying degrees, it is estimated that 5–8 per cent of current global crop production is directly attributed to animal pollination with an annual market value of $235 billion–$577 billion (in 2015, United States dollars1) worldwide.
- The importance of animal pollination varies substantially among crops, and therefore among regional crop economies.
- Pollinator-dependent food products are important contributors to healthy human diets and nutrition.
- The vast majority of pollinator species are wild, including more than 20,000 species of bees, and some species of flies, butterflies, moths, wasps, beetles, thrips, birds and bats and other vertebrates. A few species of bees are widely managed, including the western honey bee (Apis mellifera), the eastern honey bee (Apis cerana), some bumble bees, some stingless bees, and a few solitary bees.
- Both wild and managed pollinators have a globally significant role in crop pollination, although their relative contributions differ according to crop and location. Crop yield and/or quality depends on both the abundance and diversity of pollinators.
- Pollinators are a source of multiple benefits to people, beyond food provisioning, contributing directly to medicines, biofuels (e.g. canola3, palm oil), fibres (e.g, cotton, linen), construction materials (timbers), musical instruments, arts and crafts, recreational activities and as sources of inspiration for art, music, literature, religion, traditions, technology and education.
- A good quality of life for many people relies on ongoing roles of pollinators in globally significant heritage; as symbols of identity; as aesthetically significant landscapes and animals; in social relations; for education and recreation; and governance interactions.
Status and trends in pollinators and pollination
- Wild pollinators have declined in occurrence and diversity (and abundance for certain species) at local and regional scales, in North West Europe and North America.
- The number of managed western honey bee hives has increased globally over the last five decades, even though declines have been recorded in some European countries and North America over the same period.
- The International Union for Conservation of Nature (IUCN) Red List assessments indicate that 16.5 per cent of vertebrate pollinators are threatened with global extinction (increasing to 30 per cent for island species). There are no global Red List assessments specifically for insect pollinators. However, regional and national assessments indicate high levels of threat for some bees and butterflies.
- The volume of production of pollinator-dependent crops has increased by 300 per cent over the last five decades making livelihoods increasingly dependent on the provision of pollination. However, overall these crops have experienced lower growth and lower stability of yield than pollinator-independent crops. Drivers of change, risks and opportunities, and policy and management options.
- The abundance, diversity and health of pollinators and the provision of pollination are threatened by direct drivers which generate risks to societies and ecosystems.
- Strategic responses to the risks and opportunities associated with pollinators and pollination range in ambition and timescale, from immediate, relatively straightforward responses that reduce or avoid risks, to larger scale and longer-term responses that aim to transform agriculture, or society’s relationship with nature.
- A number of features of current intensive agricultural practices threaten pollinators and pollination. Moving towards more sustainable agriculture and reversing the simplification of agricultural landscapes offer key strategic responses to risks associated with pollinator decline.
- Practices based on indigenous and local knowledge, in supporting an abundance and diversity of pollinators can, in co-production with science, be a source of solutions to current challenges.
- The risk to pollinators from pesticides is through a combination of the toxicity and the level of exposure, which varies geographically with compounds used, and the scale of land management and habitat in the landscape. Pesticides, particularly insecticides, have been demonstrated to have a broad range of lethal and sublethal effects on pollinators in controlled experimental conditions.
- Exposure of pollinators to pesticides can be decreased by reducing the use of pesticides seeking alternative forms of pest control, and adopting a range of specific application practices, including technologies to reduce pesticide drift. Actions to reduce pesticide use include promoting Integrated Pest Management supported by educating farmers, organic farming and policies to reduce overall use.
- Most agricultural genetically modified organisms (GMOs) carry traits for herbicide tolerance (HT) or insect resistance (IR).
- Bees suffer from a broad range of parasites, including Varroa mites in western and eastern honey bees. Emerging and re-emerging diseases are a significant threat to the health of honey bees, bumble bees and solitary bees especially when managed commercially.
- The ranges, abundances, and seasonal activities of some wild pollinator species (e.g., bumble bees and butterflies) have changed in response to observed climate change over recent decades.
- Many actions to support wild and managed pollinators and pollination could be implemented more effectively with improved governance.