Food Tank recently had the opportunity to ask The Xerces Society for Invertebrate Conservation some questions about their efforts to conserve pollinators. Scott Black, Executive Director of The Xerces Society, highlights what is threatening pollinators, why they are vital to ecology and agriculture, and what is being done to support farmers and encourage conservation.
FT: The Xerces Society, founded to preserve invertebrates, is currently engaged in Pollinator Conservation. Can you explain the risk to food production if pollinators continue to decline?
Pollinators are an essential link in earth's ecology. Nearly 85 percent of the world’s flowering plants depend upon pollinators to reproduce. This includes more than two-thirds of the world’s crop species. The fruits, seeds, and livestock feed produced by pollinators provides over 30 percent of the food that we consume—an estimated annual value of US$20 billion in the United States alone. The ecological service of pollination is being placed at risk by extensive and ongoing loss, alteration, and fragmentation of habitats, as well as pesticide use, which are all contributing to highly publicized pollinator declines.
The number of managed honey bee hives in the US has declined by 50 percent since 1950. The annual rate of loss of honey bee hives has now reached 30 percent. Bumble bees and other native pollinators are vital to crop pollination but may be faring even worse. For example, status reviews by the Xerces Society, in collaboration with bumble bee researchers across the continent, have established that at least one-third of native bumble bee species are at-risk. The threat to sustainable crop pollination is compounded by the fact that as these declines are occurring the demand for pollination is increasing; The area of cropland requiring bee pollination has doubled since 1960. We could experience significant pollination shortages unless we act to fix the problems.
FT: Bees are well-known pollinators and many are at-risk or in decline. What other pollinators are important for agriculture? Are any of these being used in concert with bees to pollinate farms?
Most people know that honey bees are important to agriculture but do not realize that they are not native to North America and need to be managed to supply pollination services. There are 4,000 species of bees in North America that pollinate both our wild plants and our crops. These native bees come in all shapes and sizes from tiny metallic green sweat bees to large black-and-yellow (or orange) bumble bees. Many other animals pollinate plants - including beetles, flies, butterflies, and moths - with some exceptions (flies pollinate chocolate). But most of these groups do not provide large-scale pollination of crop plants.
Native bees are vital to our agricultural production. An international team of scientists led by Lucas Garibaldi of Argentina’s Universidad Nacional de Río Negro undertook a study (published in the journal Science in 2013) that clearly showed native bees make a significant contribution to crop pollination across the globe. This study has prompted a renewed call to maintain and manage pollinator diversity for long-term agricultural production. The authors recommend that new practices for integrated management of both honey bees and wild insects are needed to enhance global yields of animal-pollinated crops and promote agricultural production. Some of these practices include the conservation or restoration of natural or semi-natural areas within croplands, the addition of diverse floral and nesting resources, and a more prudent use of insecticides that can kill pollinators.
FT: Pesticides threaten bee populations either by killing them directly or reducing the number of bees that can be reproduced. What else is threatening other pollinators?
While we now have to truck honey bees across the US for pollination, that was not always the case. Native bees and feral honey bees pollinated all of our crops until the mid-1900s when we started growing large monocultures (and took out the bee habitat) and started using broad spectrum insecticides. The driving forces behind the decline of native bees are likely habitat loss and alteration, pesticide use, the introduction of exotic bumble bee diseases, and perhaps climate change. Key threats include the conversion of grassland/prairie to cropland - millions of acres of habitat have been lost since 2008 - as well as the dramatic increase in use of systemic neonicotinoid insecticides on both croplands and urban landscapes over the last decade.
FT: What are some steps that farmers, from the corporate farmer to the backyard grower, can take to provide a hospitable habitat for pollinators? Do these steps change depending on the local landscape?
Agriculture, in particular, represents an enormous opportunity for the conservation of bees. Because farming is the single largest global land use, we must work with farmers to sustain biodiversity. Whether you are a small or large farmer you can conserve or restore natural or semi-natural areas within croplands, add diverse floral and nesting resources, and eliminate or use less (and more targeted) insecticides.
FT: The Xerces Society has a partnership with the United States Department of Agriculture’s (USDA) Natural Resource Conservation Service (NRCS). What are some of the tools available to farmers through this partnership?
Working with the NRCS, we have been able to present workshops and short courses to farmers and agricultural professionals in all 50 states, reaching 38,000 people over the last five years. This effort has led to the restoration of over 120,000 acres of pollinator habitat nationwide. We have trainings and tools that help farmers implement habitat projects and develop whole-farm conservation plans that include issues such as tillage, and offer IPM training, pesticide risk reduction training, and training on how to implement conservation biological control systems to lower insecticide use. We also help people understand how to use the US Farm Bill to help fund habitat work for pollinators through cost-share programs. The Xerces Society has developed a variety of print resources on all of these topics.