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  • From: "Lawrence F. London, Jr." <lfl@intrex.net>
  • To: permaculture <permaculture@lists.ibiblio.org>
  • Subject: [permaculture] Our Forgotten Pollinators
  • Date: Sun, 08 Apr 2007 10:19:36 -0400

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*Our Forgotten Pollinators:
Protecting the Birds and Bees* 0
*By Mrill Ingram, Gary Nabhan and Stephen Buchmann. *

------------------------------------------------------------------------
*Source: Global Pesticide Campaigner
Volume 6, Number 4, December 1996
PANNA, San Francisco, CA *
* *
*A recent survey revealed that only a small percentage of the American
public understands the process of pollination or the diversity of
beneficial animals involved in pollinating plants.1 For most Americans,
pollen means allergies and bees mean stings. However, for one out of
every three bites you eat, you should thank a bee, butterfly, bat, bird
or other pollinator. *
*Pollination -- the transfer of pollen from one flower to another -- is
critical to fruit and seed production, and is often provided by insects
and other animals on the hunt for nectar, pollen or other floral
rewards. In fact, animals provide pollination services for over
three-quarters of the staple crop plants that feed human kind and for
90% of all flowering plants in the world. *
*According to the U.S. Department of Agriculture (USDA), we are facing
an "impending pollination crisis," in which both wild and managed
pollinators are disappearing at alarming rates owing to habitat loss,
pesticide poisoning, diseases and pests.2 For the first time ever, local
bee shortages in 1994 forced many California almond growers to import
the bulk of the honey bees they needed from other states to ensure that
their $800-million-a-year crop would be pollinated. Recent monitoring of
pumpkins in New York State determined that their blossoms were still
laden with pollen five hours after they opened in the morning, long
after they are typically stripped of all pollen by bees.3 *
*Food producers and consumers, scientists and educators, beekeepers and
wildlife enthusiasts who are concerned that a basic fact of life -- our
dependence on the functional relationships between plants and
pollinators -- is being ignored have joined together to form the
Forgotten Pollinators Campaign. The campaign seeks to heighten the
public's awareness of the importance of pollinators and to urge action
on the following points. Farms depend on pollinators *
*Insect pollination is a necessary step in the production of most fruits
and vegetables that we eat and in regeneration of many forage crops used
by livestock. Recent surveys document that more than 30 genera of
animals -- consisting of hundreds of species of floral visitors -- are
required to pollinate the 100 or so crops that feed the world.4 Only 15%
of these crops are serviced by domestic honey bees, while at least 80%
are pollinated by wild bees and other wildlife. *
*We must recognize that pollination is not a free service, and that
investment and stewardship are required to protect and sustain it.
Economic assessments of agricultural productivity should account for the
"cost" of sustaining wild and managed pollinator populations. U.S.
policymakers responsible for the recent cut in long-standing subsidies
to beekeepers for honey production have further jeopardized the
pollination services provided by honey bees, estimated to be 60 to 100
times more valuable than the market price of honey.5 Policy makers must
begin devising programs that reward farmers for implementing practices
to protect habitats of wild pollinators and provide incentives for those
who wish to manage a wider variety of pollinators to assist farmers and
orchard growers. A diversity of pollinators *
*Our recent analyses of global inventories of biodiversity indicate that
more than 100,000 different animal species -- and perhaps as many as
200,000 -- play roles in pollinating the 250,000 kinds of wild flowering
plants on this planet. In addition to countless bees (the world contains
an estimated 40,000 species of bees), wasps, moths, butterflies, flies,
beetles and other invertebrates, perhaps 1,500 species of vertebrates
such as birds and mammals serve as pollinators. Hummingbirds are the
best-known wildlife pollinators in the Americas, but perching birds,
flying foxes, fruit bats, possums, lemurs and even a gecko function as
effective pollinators elsewhere in the world. We must learn to
appreciate the benefits that a diversity of pollinators provides. *
*Honey bees in decline *
*The number of commercial U.S. bee colonies plummeted from 5.9 million
in the late 1940s to 4.3 million in 1985, and 2.7 million in 1995. The
loss of one quarter of all managed honey bee colonies since 1990 signals
one of the most severe declines U.S. agriculture has ever experienced in
such a short period. There are fewer bee hives in the U.S. today than at
any time in the last 50 years. *
*This demise has been brought on by the spread of diseases and parasitic
mites, invasion of Africanized honey bees, exposure to pesticides,
climatic fluctuations and elimination of government subsidies for
beekeepers.6 And an increasing number of places around the U.S. are
reporting pollinator scarcity.7 Studies of cucurbit pollination in
Arizona, Alabama and Maine revealed that honey bees are in fact
frequently absent from fields, and that bumblebees and ground nesting
squash bees are doing the majority of the pollination.8 In recent years,
some wildland habitats have lost 70% of their feral honey bees, which
make hives in rocky outcroppings and other cavities.9 *
*The arrival of Africanized bees in 99 U.S. counties since 1990 has
forced some beekeepers to abandon apiaries in highly populated areas for
fear of libel suits from neighbors. In addition, Africanized bees are
among the carriers of parasitic mites infect-ing thousands of U.S.
apiaries, killing off additional colonies.10 *
*To minimize further declines, honey bee colonies need better monitoring
and management. Yet, USDA is currently considering closing bee research
laboratories. Bee research must be strengthened and expanded to include
research on management of pollinators other than honey bees.
Increasingly, other pollinators will have to be deployed to take up the
slack created by the decline of honey-bee colonies. Orchard growers and
farmers need to ensure that neighboring wild habitats remain suitable
for wild pollinators if they are to secure pollination services for
their crops. *
*For such reasons, government agencies such as the USDA, SARH/Mexico and
Agriculture Canada should invest more resources in programs to manage a
diversity of pollinators, to stabilize remaining apiaries, and to reward
farmers for setting aside cropland and retaining hedgerows or windbreaks
where wild pollinators nest and forage. *
*Protection from toxins *
*Whether managed or wild, pollinators need protection from excessive
exposure to pesticides and other chemicals that can poison them or
impair their reproduction. These chemicals can also eliminate nectar
sources for pollinators, destroy larval host plants for moths and
butterflies, and deplete nesting materials for bees.11 *
*Few people realize that the U.S. now applies twice the amount of
pesticides it used when Rachel Carson published Silent Spring in 1962.12
In Canada during the mid-1970s, aerial spraying of coniferous forest
pests reduced native bee populations to the point that blueberry yields
fell below the norm for four years.13 *
*A large number of insecticides used in agriculture are toxic to
pollinating insects, but only honey bee colonies can be moved away from
fields prior to spraying. Even so, it has been estimated that 20% of all
losses of honey-bee colonies involve some degree of pesticide exposure.
According to a study on economic costs of pesticide use, honey bee
poisonings result in an annual loss of $13.3 million in the U.S.14 Wild
insect pollinators such as small solitary bees are even more vulnerable
than honey bees to organophosphate pesticides that have largely replaced
organochlorines like DDT. Field studies in the deserts of the U.S. have
found that pollinators remaining in small fragments of natural habitat
are particularly susceptible to insecticide spraying on adjacent
croplands.15 *
*Moreover, many crops that would benefit in quality and quantity from
more thorough pollination are not sufficiently pollinated because of
heavy pesticide applications. Cotton harvests, for example, could
increase by as much as 20% if the flowers were fully pollinated by bees,
and farm income could potentially increase by US$400 million per year.
However, using bees to enhance cotton has proven impossible on a large
scale where there has been continued intensive use of insecticides.16 *
*Pesticide applicators need training in monitoring pollinators as well
as pests. Pollination ecologists familiar with particular species can
work with pesticide applicators who know about timing and the drift
distances of chemicals under various weather conditions.17 When
pesticides are applied by aircraft, as much as 50% to 75% of the
chemicals sprayed can miss their target,18 leading to inadvertent
exposure of nontarget organisms such as pollinators. *
*Alternative agricultural techniques can provide non-toxic methods of
weed and insect control that incorporate use of habitat set-asides for
beneficial insect populations and require the use of fewer toxins.
Alternative strategies may help farmers reduce costs involved in crop
management, and at the same time allow them to market organic produce at
premium prices. *
*Both gardeners and farmers can rely on alternative non-toxic methods to
control pests and weeds. More widespread practice of such methods has
the potential to reduce wildlife exposure to insecticides, herbicides
and fungicides.19 Urban dwellers can also reduce the amounts of toxins
used around their homes, and by purchasing organic produce, they can
provide economic incentives for growers to switch to more pollinator-
friendly organic methods. *
*Habitat loss -- a major threat *
*Small isolated patches of wild habitat may look natural and healthy,
but they often lack essential pollinators and seed dispersers that
ensure regeneration of the biotic community.20 These animals typically
require more habitat area than that covered by populations of the rarest
plants. When large habitats are fragmented into small isolated patches,
it is not long before some of the animal residents decline in numbers to
the point that they no longer provide effective ecological services
beneficial to plants.21 Globally, over 100 species of birds and mammals
in sixty genera of vertebrate pollinators are already listed as
endangered, and untold numbers of invertebrates are at risk as well. *
*Because some wild pollinators need undisturbed habitat for nesting,
roosting and foraging, they are very susceptible to habitat degradation
and fragmentation. Some pollinators require plants that flower
sequentially, so that they have food sources throughout the season.
Elimination of these sources by herbicide spraying or clearing of native
vegetation can literally starve pollinators. In Costa Rica, wild bee
diversity in degraded forest land dropped from 70 to 37 species in just
14 years. Population declines have also been confirmed for butterflies,
moths, flying foxes and a host of other pollinators of food crops.22 *
*We must find ways to reward farmers for setting aside land to support
wild pollinators. Unplowed farmland set aside for several years can
produce vegetation that supports considerable insect diversity and
benefits nearby crops by providing pollinators and other beneficial
insects.23 Land use planners should work to create semi-natural buffers
around small wildlife reserves to connect protected areas with
undeveloped corridors and to designate pesticide-free zones within this
matrix. Greenbelts and habitat set-asides need not always consist of
pristine vegetation, but they must be large enough to provide safe
nesting sites and a range of floral resources. *
*Endangered pollinators -- endangered plants. *
*In the larger picture, native pollinators are as important for wild
plants as they are for crops. Yet the ultimate reproductive consequences
of pollinator scarcity on wild plants is not appreciated and remains
understudied.24 *
*In Iowa, where only 200 acres of unplowed "virgin" prairie remain
intact, prairie wildflowers now suffer low seed yields for lack of
adequate visitation rates by pollinators.25 Rare cacti in national parks
and adjacent to heavily sprayed cotton fields also suffer high levels of
floral abortion due to a paucity of moths.26 There are small nature
reserves nested within urban areas that contain rare plants, but their
flowers wither without producing fruit. In one small reserve within
urban Tokyo, for example, a primrose almost completely fails to set
seed, owing to local disappearance of its bumblebee pollinator.27 *
*The last remaining natural populations of a rare evening primrose live
in California's Antioch Dunes National Wildlife Refuge. Though the
primrose is protected, its hawkmoth pollinator has not reappeared after
years of pesticide spraying in nearby vineyards, and reproduction of the
plant has remained low.28 The primrose remains in jeopardy as it
produces few fruits and low percentages of viable seeds, while its weedy
neighbors produce many. This is just one of many examples where
pesticide use, decrease of nectar sources or larval host plants, and
other threats have triggered the decline of pollinators of endangered
plants. *
*Unfortunately, not even federally listed endangered plants are
regularly monitored for pollinator availability. A survey of federal
recovery plans for sixteen endangered plants growing near the U.
S./Mexico border revealed that the range of available pollinators had
been determined for only two of them, and threats to pollinators
themselves had not been taken into account at all. *
*Because of such "reciprocities," conservation policy and practice
should move toward sustaining or restoring ecological relationships,
rather than treating species as isolated organisms. "Critical habitat"
needs to be redefined to include needs of both rare plants and their
animal associates. When critical habitat has been designated for
endangered plants, it has almost always been done without determining
foraging and nesting areas required to ensure sufficient pollinators and
seed dispersers for long-term recovery of the plant in danger. To begin
to resolve some of these discrepancies, the Forgotten Pollinators
Campaign is currently working with entomologists and conservation
biologists to create pollinator monitoring protocols that can be used by
land managers around the country. Migratory pollinators require protection *
*Bats, hummingbirds, moths and butterflies are among the pollinators
that seasonally migrate long and short distances between mountain
ranges, regions and countries. Their migratory routes are often
well-defined "nectar corridors" where the sequence of flowering over a
season offers pollinators sufficient energy to sustain their journey.
Many of these nectar corridors are no longer fully intact, however; land
conversion has eliminated some floral resources over 20 to 60 mile
segments, in some cases longer than the distance energy-depleted
pollinators can fly in one day.29 *
*Scientists and policy makers need to collaborate across political
boundaries and regions to assess the continuity and health of migratory
corridors used by pollinators. Because some migrants travel 2,000 to
4,000 miles a year, habitat loss in one area of their range may limit
their populations overall. Certain migratory pollinator species
aggregate in large numbers in temporary roosts that are vulnerable to
human disturbance. Such roost sites should be protected throughout a
species' entire range since a refuge in just one portion will be
insufficient to support a viable population. International policy
agreements and environmental education efforts are needed to champion
migratory pollinators. *
*A threatened ecological service *
*Interactions between plants and their pollinators are essential to
healthy functioning of wild and agricultural communities. Habitat loss,
disease, and pesticides take their toll in different ways, but all
imperil these vital ecological relationships, many of which developed
through thousands of years of natural and cultural selection. *
*Three-quarters of the 100 or so crop species that feed the world depend
on animals as go-betweens to ensure that crops are pollinated. Crises
like those now faced by the honey-bee industry demonstrate that we lack
safety nets to protect agricultural yields. We can no longer justify
devoting all research and management dollars to a single or even a few
pollinators, but instead must support a diversification of the entire
pollination industry. *
*As a society, we need to recognize our debt to the "forgotten
pollinators." To successfully confront the impending pollinator crisis,
we must work together. Foresters, entomologists and conservationists
must devise workable plans for endangered plant species that include
pollinators. Farmers, orchard growers, and other land managers need to
consider pollinators as they make decisions about pesticides and land
use. Educators must emphasize the importance of pollinators in wild and
agricultural lands and the interconnectedness of life in general. *
*Urban dwellers can purchase organic produce, include nectar and host
plants for pollinators in their gardens, and rely on organic methods of
pest and weed control. Pollinator gardening provides hummingbirds,
butterflies and other wildlife with important sources of nectar as well
as increasing our awareness of the diversity of ecological relationships
in our own backyards. *
*In an era when human activities place increasing pressure on both
natural and rural landscapes, we cannot ignore the vital role of
pollination services and the frequently negative impacts that we are
having on plant/pollinator relationships *
* *
------------------------------------------------------------------------
* *
*Mrill Ingham has an M.S. in cultural geography and is coordinator of
the Forgotten Pollinators Campaign. Gary Paul Nabhan is an agricultural
ecologist and Director of Science at the Arizona-Sonora Desert Museum.
Stephen L. Buchmann is a research entomologist at the Carl Hayden Bee
Research Center in Tucson, Arizona. *
* *
*For more information, contact: The Forgotten Pollinators Campaign,
Arizona-Sonora Desert Museum, 2021 N. Kinney Road, Tucson, AZ 85743;
email Forgotten Pollinators <mailto:fpollen@azstarnet.com> *
*- Some pesticides highly toxic to bees
aldrin
bendiocarb
carbaryl
chlorpyrifos
diazinon
dichlorvos
dieldrin
dimethoate
endosulfan
EPN
fenitrothion
fenthion
heptachlor
malathion
methomyl
mevinphos
monocrotophos
parathion
pirimiphos-ethyl
phosmet
Sources: Basic Guide to Pesticides, Shirley Briggs, 1992.
Farm Chemicals Handbook, Meister Publishing Co., 1996. *
*References *
*1 National zoo 1994 *
*2 USDA-ARS, 1991, Pollination Workshop Proceedings, unpublished,
Denver, CO. *
*3 Watanabe, M.E., 1994, Pollination worries rise as honey bees decline,
Science 265:1170. *
*4 Prescott-Allen, R. and C. Prescott-Allen, 1990, How many crops feed
the world? *
*Conservation Biology 4(4): 365-374. Buchmann, S.L. and G.P. Nabhan,
1996, The Forgotten Pollinators, Island Press, Washington, D.C.. *
*5 McGregor, S.E. 1976, Insect Pollination of Cultivated Crop Plants,
USDA Agriculture Handbook 496, USDA, Washington, D.C. Southwick, E.E.,
and L. Southwick, Jr., 1992, Estimating the economic value of honey bees
(Hymenoptera Apidae) as agricultural pollinators in the United States,
Economic Entolmology 85(3):621-633. *
*6 USDA-ARS, 1991, Pollination Workshop Proceedings, unpublished,
Denver, Co. *
*7 Burd, M., 1994, Bateman's principle and plant reproduction: the role
of pollen limitation in fruit and seed set, Botanical Review 60:81-109.
Watanabe, M.E., 1994, Pollination worries rise as honey bees decline,
Science 265:1170. *
*8 The Forgotten Pollinators Campaign, October 1996. *
*9 Loper, G.M., 1995, A documented loss of feral bees due to mite
infestations in Southern Arizona, American Bee Journal, December: 823. *
*10 Hoff, F.L. and L.S. Willert, 1993, The U.S. Beekeeping Industry,
USDA, Washington, D.C. *
*11 Nabhan, G.P. and S.L. Buchmann, 1996 (in press), Pollination
services: biodiversity's direct link to world food stability, in G.
Daly, ed. Ecosystem Services, Island Press, Washington, D.C. *
*12 Carson, R., 1962, Silent Spring, Houghton-Mifflin, New York. Curtis,
J. and T. Profeta, 1993, After Silent Spring, Natural Resources Defense
Council, NY. *
*13 Kevan, P.G., 1975, Pollination and environmental conservation,
Environmental Conservation, 2(4): 293-298. *
*14 Pimentel, D., H. Acquay, M. Biltonen, P. Rice, M. Silva, J. Nelson,
V. Lipner, S. Giordano, A. Horowitz, and M. D'Arnore, 1992,
Environmental and economic costs of pesticide use, BioScience
42(10):750-760. *
*15 Suzan, H., G. P. Nabhan and D. T. Patten, 1994, Nurse plant and
floral biology of a rare night-blooming cereus, Peniocereus striatus
(Brandegee) Buxbaum, Conservation Biology, 8:461-470. *
*16 Pimentel, D., H. Acquay, M. BiltDnen, P. Rice, M. Silva, J. Nelson,
V. Lipner, S. Giordano, A. Horowitz, and M. D'Arnore, 1992,Environmental
and economic costs of pesticide use, BioScience 42(10):750-760. *
*17 Holmbert, M., 1993, Get the drift? Not! Successful Farming,
May/June, 39-40. *
*18 Pimentel, D., H. Acquay, M. BiltDnen, P. Rice, M. Silva, J. Nelson,
V. Lipner, S. Giordano, A. Horowitz, and M. D'Arnore, 1992,
Environmental and economic costs of pesticide use, BioScience
42(10):750-760. *
*19 Colborn, T., S. Dumanowski and J. P. Myers, 1996, Our Stolen Future.
Dutton, New York. *
*20 Hendrix, S. D., 1994, Effects of population size on fertilzation,
seed production, and seed predation in two prairie legumes, *
* North American Prairie Conference Proceedings 13: 115-119. Nabhan,
G. P. and S. L. Buchmann, 1996 (in press), Pollination services:
biodiversity's direct link to world food stability, in G. Daly, ed.,
Ecosystem Services, Island Press, Washington, D.C. *
*21 Hendrix, S.D., 1994, Effects of population size on fertilzation,
seed production, and seed predation in two prairie legumes, North
American Prairie Conference Proceedings 13: 115-119. *
*22 Buchmann, S.L. and G.P. Nabhan, 1996, The Forgotten Pollinators,
Island Press, Washington, D.C. *
*23 Corbet, S.A., 1995, Insects, plants and succession: advantages of
long-term set-aside, Agriculture Ecosystems & Environment 53:201-217. *
*24 Nabhan, G.P. and T. Fleming, 1993, The conservation of mutualisms,
Conservation Biology, 7(3): 457-459. *
*25 Hendrix, S.D., 1994, Effects of population size on fertilization,
seed production, and seed predation in two prairie legumes, North
American Prairie Conference Proceedings 13: 115-119. *
*26 Suzan, H., G.P. Nabhan and D.T. Patten, 1994, Nurse plant and floral
biology of a rare night-blooming cereus, Peniocereus striatus
(Brandegee) Buxbaum, Conservation Biology, 8:461-470. *
*27 Washitani, I., R. Osawa, H. Namai, and M. Niwa, 1994, Patterns of
female fertility in heterostylotis Primula seiboldii under severe
pollinator limitation, Journal of Ecology, 82:571-579. *
*28 Pavlik B.M., N. Ferguson, and M. Nelson, 1993, Assessing limitations
on growth of endangered plant populations, Biological Conservation, 65:
267-278. 29 Nabhan, G.P. and T. Fleming, 1993, The conservation of
mutualisms, Conservation Biology, 7(3): 457-459.*
* *





  • [permaculture] Our Forgotten Pollinators, Lawrence F. London, Jr., 04/08/2007

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