[permaculture] Status of Pollinators in North America
Lawrence F. London, Jr.
lflj at intrex.net
Wed Dec 19 17:28:59 EST 2007
Nature 450, 1162-1163 (20 December 2007) | doi:10.1038/4501162b;
Published online 19 December 2007
Fruits of their labour
Susan J. Mazer1
BOOK REVIEWED-Status of Pollinators in North America
by The Committee on the Status of Pollinators in North America, National Research Council of the National Academies
The National Academies Press: 2007. 307 pp. $56
Forests, prairies, meadows, seashores and wetlands all depend on a diverse and healthy community of pollinators. Wild
pollinator populations living in intact and healthy forests, woodlands and fields contribute to the success of a variety
of crops — including coffee, watermelons, cucumbers and sunflowers.
It is therefore troubling to hear that pollinator populations are declining or at risk of extinction, the sobering
subject of the Status of Pollinators in North America. This is a report by a US National Research Council committee,
created in 2005 to assess the reality and causes of pollinator declines in agricultural and natural systems, and to
offer recommendations to ensure the long-term stability of pollination services.
The committee synthesized the results of some 1,200 research articles and reports, focusing on empirical studies of
pollinators and their effects on wild and domesticated plant species. No pollinator escapes: changes in population size
and distribution of pollinating ants, bees, wasps, beetles, flies, butterflies, moths, birds and bats are all summarized.
Unhappy honeybee: efforts are afoot to restore plummeting pollinator populations.
The committee casts an even wider net by enlisting the expertise of applied researchers, honeybee specialists,
non-governmental organizations, managers of pollinator databases and industry consultants, who all participated in a
symposium at the National Academies in 2005.
A few basic facts highlight the value of domesticated and wild pollinators, and the risks that they face. Honeybees
(Apis mellifera), the most widely managed, carefully monitored, and commercially distributed pollinator, are used for
the fruit and seed production of more than 100 crops (all non-cereals) in the United States. Estimates of their economic
value in the United States range from $150 million (at present, the total annual cost of bee-colony rental) to almost
$19 billion (the estimated value that farmers would pay if pollinators weren't freely available in nature).
For some crops, honeybees are ineffective pollinators compared with native bees or managed wasps. Some of these
alternative pollinators are managed, at a much smaller scale, which itself is risky because rare events — such as
disease or environmental change — are more likely to wipe out small populations than large ones. Other domesticated
plant species rely exclusively on native bats or birds, whose fate is linked to habitat destruction.
Changes in abundance have been monitored for only a small fraction of the species known to be effective pollinators;
there is a growing list of factors implicated in population declines. In the United States, honeybee colonies have more
than halved since 1947 (from 5.5 million to 2.4 million). Parasitic mites and pathogens, insecticides used to control
crop pests and displacement by Africanized honeybees, are all to blame and may also affect managed populations of
non-Apis pollinators. Toxic effects of secondary compounds produced by genetically engineered plants are suspected.
Habitat modification is probably still the prime culprit in the decline or endangered status of several species of wild
A sustained pollinator decline in North America, for example, would mean lower yields from crops that depend on animals
for pollination, and so prices would increase; or there would be less variety available as farmers switch from growing
insect-pollinated crops to the restricted range of self-fertilizing ones that give reliable fruit or grain production.
Farmers have known for centuries what the public and legislators may be accepting just in time: a field of crops without
pollinators is a harbinger of a greater calamity. Status of Pollinators offers a host of straightforward and
complementary recommendations to help prevent crop failures and the collapse of native plant communities. There isn't a
silver bullet to zap the problem: simultaneous application of a variety of solutions will be necessary to sustain a
healthy and diverse community of pollinators nationwide.
For example, we need more research entomologists, plant-population biologists, geneticists, agricultural ecologists and
systematists. To identify regions vulnerable to pollination failure, we should run international pollinator-monitoring
programmes. For long-term pollinator security, Mexico, Canada and the United States should pursue collaborative breeding
programmes to identify and manage pollinators other than Apis. Land-use practices friendly to pollinators should be
adopted by industrial, public and residential landowners. Educational institutions should promote awareness of the
intimate connection between plants, their pollinators, our diets and our economy. In the United States, only a
continent-wide commitment to the protection of pollinators will allow future generations to enjoy the fruits of their
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