by Howard Youth
Many city dwellers’ only familiarity with farmland is whizzing past crop rows, orchards, or pastures during weekend escapes from the city. Yet outside of our cities and throughout developing nations, farming is the most common livelihood. Regardless of whether farming occupies little or much of our time, no one can deny that the various fields within this industry sustain us. But how often do we think of how agricultural lands sustain wildlife?
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| Green iguanas (Iguana iguana) like this one inhabit an abandoned coffee farm in Trinidad. (Jessie Cohen/NZP) |
Agricultural landscapes predominate in many countries. For example, crops and grazing lands cover half of the United States’ land surface and about half of Europe’s. (About 75 percent of the United Kingdom is dedicated to agriculture.) In contrast, eight to ten percent of the Earth’s land falls under some sort of habitat protection—parks, reserves, refuges, and the like—and these areas are widely scattered and greatly affected by what goes on with the land that surrounds them. With so much of the Earth’s land tied up in agriculture and likely to stay that way, it’s worth a look at how growing our food can benefit wildlife. Many farmers are conservationists in at least some ways. It comes with the territory. For instance, since the Dust Bowl days of the 1930s, U.S. farmers and farm agencies have been preoccupied with conserving soil in marginal areas. As they toil away on their acreage, farmers worldwide come to know the local flora and fauna with which they share their land. Today, conservationists and farmers—including individuals who are both—are investigating new ways to make their real estate more productive for wildlife, as well as for their crops.
In recent years, huge corporate-owned farms have swept up small, individually owned farms in many regions, a trend that affects not only farmers but also wildlife. In 1999, Peter Rosset, executive director of the nongovernmental organization Food First, wrote that “though small farmers have been driven out of rural areas across the world in their millions over the last five decades, they still persist. In many areas, such as the U.S., they continue to be numerically dominant. In the ‘Third World,’ they are central to the production of staple foods.” In the United States, 60 percent of all farms are smaller than 180 acres.
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| Poor soil conservation, drought, and dust storms devastated Great Plains farms in The Dust Bowl days of the 1930s. (USDA NRCS) |
Bigger is not necessarily better—not just in terms of farms’ environmental benefits but also their overall productivity. “Productivity has been so much geared, in our lifetime, to yield of a single crop,” says Robert Rice, policy research scientist at the Smithsonian Migratory Bird Center (SMBC). “But when you start looking at farms and step back from yield, small- to medium-sized farms’ total productivity—everything that comes out of a farm—is much higher per unit area.” This includes manure, plants grown along field edges, and other products. Small-farm practices often include closely tied crop mixtures, more efficient use of irrigation, less reliance upon large machinery, and use of manure and compost, rather than chemical fertilizers. A patchwork of small farms, interspersed with wilder plots, also produces better wildlife habitat than the relatively sterile environment created by huge fields of just one crop. “On small farms,” says Rice, “wildlife is another added value.”
To find evidence of small farmers’ green handiwork, look no further than your enlivening cup of morning coffee—that is, depending upon the brand you choose. Shadegrown coffee is grown the traditional way, beneath a tropical forest canopy that also shelters resident and migratory birds and other wildlife, and is often combined with other small cultivations, such as fruit trees.
“Hummingbird diversity is always very high on these properties,” says Russell Greenberg, SMBC’s director. “We’ve had as many as 13 species over the course of a year on rustic shade-grown sites in Chiapas, Mexico.” Greenberg and his colleagues tallied 180 bird species occupying various parts of shade-coffee plantations , including many warblers, flycatchers, orioles, and other Neotropical migrants that pass through or winter there, but breed and nest in the United States and Canada. Bat diversity was also high, and depending upon the amount of adjacent wild habitat remaining, shade-coffee plantations may also be home to small cats, such as margay (Leopardus wiedii), and primates, including mantled howler monkeys (Alouatta palliata) in Nicaragua and marmosets in Peru. In Peru, a more biologically diverse country than Mexico, Greenberg and his colleagues found 260 bird species, including seven woodcreeper species at one plantation.
Shade-grown coffee requires far fewer chemical inputs than coffee grown on “modern” sun-coffee farms, where pesticides and fertilizers are heavily used. Beginning in the 1970s, sun-coffee farms sprang up in efforts to boost coffee production. Some large coffee-shop chains now sell shade-grown coffees, but the largest brand-name companies have yet to dabble in more environment- and bird-friendly coffees. “Right now, the whole shade crop goes for specialty coffee,” says Rice. “It has to prove itself in the marketplace before the big guys will get involved.” Meanwhile, over the past four to five years, the coffee market has crashed, as worldwide coffee supply has boomed and coffee prices have plummeted. Many small coffee producers are abandoning their operations for other endeavors. In some areas, shade-grown coffee may help producers hang on. “Even in the best years, shade systems don’t compete in terms of yields with open-to-the-sun properties, but when prices fall short, they can still maintain production at pretty much the same effort because many of them don’t use all the costly inputs,” says SMBC’s Rice.
The coffee crisis is causing many coffee operations to grind to a halt. “An abandoned coffee farm quickly reverts to second-growth forest,” says Rice, “and becomes wild and woolly pretty soon. From a social and economic perspective, though, it’s devastating.” However, such properties could generate revenue as ecotourist venues, as does the Asa Wright Nature Center on the Caribbean island of Trinidad. Once a coffee, cacao, and citrus plantation, the property has reverted to the wild. Mature coffee trees mingle with tree ferns, cecropia trees, and other returning native vegetation, which provides habitat for toucans, ornate hawk-eagles, green iguanas, large rodents called agoutis, and electric-blue morpho butterflies. The colorful creatures in turn attract thousands of domestic and international tourists each year. But not many properties face such bright prospects, and Rice adds that abandoned coffee farms, instead of re-growing as forest, may be converted to other less wildlife-friendly operations, perhaps being clear-cut for timber and turned into cattle farms.
Cacao, the plant that produces the famed pods from which cocoa is made, is another crop often planted under a forest canopy on small farms. Plagued by disease and falling prices, though, cacao is on the decline in many areas. Ivory Coast and Brazil are among the big producers.
In addition, other agricultural practices in different parts of the world support varied wildlife—cultivations of cork oak, various fruits, and other crops—although they do not fully substitute for natural forests. Farm operations that minimize the use of harmful pesticides, such as organic farms, provide more diverse food sources and safer habitats for wildlife. In Ontario, scientists also found greater bird-species richness and abundance on organic properties. In the UK, declining skylarks have been found at higher densities on organic fields than on those sprayed with pesticides. The UK’s organic fields also held a far greater diversity of wild plants, butterflies, and spiders. Organic farms, however, only constitute about three percent of British farmland. In the U.S., certified organic agricultural land increased by 74 percent between 1997 and 2001, but still represents a mere 0.3 percent of all agricultural land.
Splendor in the Grasses
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| Native grasses provide Yellow-rumped warblers (Dendroica coronata) and other migratory birds with food and nesting sites. (Dennis Larson/USDA NRCS) |
Spaniards introduced cattle and horses to the New World during colonial times. One of the first regions where livestock began to roam was around Veracruz, Mexico, east of what is now the sprawling metropolis of Mexico City and west of the Yucatan Peninsula. While domesticated cows and horses were new animals for the region, they were not the first large grazing animals to have lived there.
“About 10,000 years ago, Central America [and parts of Mexico] looked more like Africa than you might imagine,” says SMBC’s Greenberg. The native acacia, Acacia pennatula, was dispersed by large, now-extinct ungulates that ate their seedpods and spread the seeds via their manure. Today, cows and horses do the same, and people living in this dry region collect the pods for cattle feed and cut some of the trees for firewood. Greenberg and his colleagues have been studying this long-term land use and are finding that acacia-studded pastures in Mexico and Central America provide important wildlife habitat. Greenberg says that the native acacias flourish like mesquite species (Prosopis sp.) do in the southwestern United States and Mexico. “As long as there’s an acacia and a cow, acacia will spread and take over pasture. This is how it works in Africa with various large ungulates, except that fire plays a limiting role there,” he says. In Central America, people limit acacia growth by cutting.
The result is a varied landscape that attracts many birds, particularly Neotropical migrants. “We found that there are more migrants in southern Mexico in these acacias than in other habitats we surveyed,” including lowland and mid-elevation forests, pine-oak woods, and other agricultural areas.
Elsewhere, controlled grazing is compatible with wildlife conservation efforts, especially if a little care is taken regarding the choice of forage grasses. In temperate pastures in the United States and Canada, native, warm-season grasses such as switchgrass (Panicum virgatum) and big bluestem (Andropogon gerardii) provide food, cover, and nesting sites for many declining grassland bird species and small mammals. These grasses are at their best for grazing and harvesting in warm months. Before then, they provide important nesting and feeding cover for wildlife. According to William M. Giuliano, a biologist at Fordham University’s Louis Calder Center–Biological Field Station, these grasses can be a hard sell to farmers who are skeptical of conservationists who push the grasses. “However, seeing is believing,” he says. “Although establishment costs are higher than for other grasses, it’s a worthwhile long-term investment because once established, these fields will never need to be seeded, limed, or fertilized again. And the soil will continue to improve on these sites naturally.”
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| Buffer areas planted in native grasses provide critical habitat for declining bird species. (Dennis Larson/USDA NRCS) |
Farmers planting warm-season grasses need to be patient, but for both farmers and wildlife, it is worth the effort, according to Giuliano. He and his colleague Sudie E. Daves of California University of Pennsylvania studied warm-season versus cold-season grasses on private Pennsylvanian farms. Their results, published in the journal Biological Conservation in 2002, included the revelation that bird species’ abundance and richness were 1.6 times greater in warm-season grass fields than in cool-season grass fields. Birds in warmseason grass fields also had greater nesting success. “From a wildlife perspective, the stuff is great food and cover—even what’s left after harvest—but it shouldn’t be harvested until after the first of July to avoid harming nesting wildlife,” says Giuliano. “But even with this late harvest, farmers realize increased forage production over other grasses.” Warm-season grasses also provide cover for migrating and wintering birds.
Incentives for Conservation
From 2002 to 2007, 39.2 million U.S. acres will be enrolled
in the U.S. Department of Agriculture’s (USDA’s)
Conservation Reserve Program (CRP), which compensates
farmers for setting aside land for conservation purposes.
Hundreds of thousands of farmers enroll land for ten
to 15 years, taking acreage out of production, planting
grasses and trees, restoring wetlands, or grazing or
harvesting hay in a way that is compatible with wildlife
conservation, erosion control, and the protection of
water resources.
One environmental concern regarding this program has been the use of exotic grasses: While many farmers plant their CRP acreage in native grasses, others choose to plant highly invasive and exotic crested wheatgrass. However, the USDA recently revised its CRP Environmental Benefits Index (EBI), which rates properties and provides a disincentive for farmers to use crested wheatgrass on large areas of land. While not illegal, crested wheatgrass, if present in large stands, will not win a farmer a high EBI score. A lower score brings less compensation per acre.
Overall, since its inception in 1985, the CRP helped many declining grassland birds regain ground, including sharp-tailed grouse (Tympanuchus phasianellus), dickcissels (Spiza americana), and Henslow’s sparrows (Ammodramus henslowii). The CRP now includes activities that encourage farmers to plant buffer strips of vegetation that reduce erosion and runoff while attracting wildlife, replant acreage in trees or native grasses, and restore wetlands, especially along waterways.
Across the Atlantic, some British farmers—inspired in part by conservation-oriented subsidies that began in the 1990s—started preserving hedgerows and wet meadows, and not planting crops that need harvesting at peak nesting season for field birds. Also, under the United Kingdom’s Agriculture Act of 1986, the government began paying farmers to maintain or enhance their lands’ biological diversity and historic value within more than 40 Environmentally Sensitive Areas (ESAs). More than 6.1 million acres now fall under the ESA program, an area almost three times as large as Yellowstone National Park. In addition, critically important wildlife habitats are set aside as Sites of Special Scientific Interest (SSSI) under the Wildlife and Countryside Act of 1981. Many of these are at least partly surrounded by farmland. How these farms are managed will have a great effect on how well the SSSIs can provide for wildlife.
Agricultural programs and policies guide farmers on which crops and how much to produce and sometimes—as mentioned above—also nudge them to manage their lands for the benefit of soil, water, and wildlife. But these aims often prove difficult to balance. For example, U.S. farmers enrolled in the CRP can also qualify for price supports that encourage them to plow up previously unplanted acreage, an activity environmentalists call sodbusting. Also, for decades the European Union’s (EU’s) Common Agricultural Policy (CAP) has fueled agricultural intensification that has helped dramatically change the UK’s and other European nations’ countryside to the detriment of small farmers and wildlife alike. There have been no EU-wide environmental standards with which farmers must comply; to receive public support funds, they just need to produce. This has come at the cost of habitat loss, erosion, drops in water supply, and pollution.
Nongovernmental organizations such as the UK-based
BirdLife International and Royal
Society for the Protection of Birds (RSPB) have been
pushing for better protection for wildlife under the
CAP. The policy was revised in June 2003, when ministers
voted to require farmers to meet environmental objectives,
including habitat protections. But the recent reforms
have yet to impress conservationists because agriculture
ministers postponed full reform and member nations are
not likely to undertake conservation-oriented initiatives
anytime soon. Also, funding for the environmental components
of the CAP remains low. Without adequate protection
measures in place, the CAP will help bring widespread
landscape changes to EU expansion countries such as
Poland, where a lush, expansive network of traditional
small farms currently sustains wildlife long gone from
most Western European countries.
Instead of urging farmers to set aside conservation acreage, a program set up by Dutch biologists offers dairy farmers payments to protect and encourage nesting birds as a farm product. The program began as an experiment conducted between 1993 and 1996, which found that it was cheaper to pay farmers to monitor and manage breeding wild birds as if they were a crop rather than compensate them for restricting farming practices for the sake of bird protection. The project resulted in increased breeding success of meadow-nesting lapwings (Vanellus vanellus), black-tailed godwits (Limosa limosa), ruffs (Philomachus pugnax), and redshanks (Tringa totanus), while not interrupting the dairy business. By 2002, about 89,000 acres of Dutch farmland were enrolled in this program.
Other efforts aim to restore wildlife habitat while composting crop waste. In 1992, the California state government restricted rice growers from burning their stubble in fall. Many Sacramento Valley farmers worked with state and county conservationists to flood their fields, creating wildlife habitat in fall and winter while their stubble biodegraded instead of going up in smoke. From a pilot project in 1993, the program grew to embrace about 137,000 acres during the 2002 to early 2003 growing season. Today, the U.S. Fish & Wildlife Service and the hunting and conservation group Ducks Unlimited share with farmers the cost of fall and winter field flooding. During the 19th and 20th centuries, Sacramento Valley farms replaced much of the area’s wetlands, which lie along the Pacific Flyway and are important to waterfowl, shorebirds, and other wildlife. Today, the flooded-farm acreage augments key but scattered areas set aside as federal and state refuges. The birds are also helping the farmers. The collective trampling of thousands of webbed feet and nibbling bills make the valley’s waterfowl a formidable composting machine. According to a 2003 report by Ducks Unlimited, “Waterfowl use in post-harvest rice fields flooded for decomposition of waste rice straw has proven to enhance the decomposition process.”
As a dominant use of our landscapes, agriculture strongly influences regional biodiversity. Innovative efforts to combine production with conservation as well as to maintain a diverse and environmentally stable mix of small and larger farms appear as important to many wildlife species as would be the setting aside of wildlife preserves. In fact, both efforts should to be combined. “One of my take-home messages is that shade-grown coffee and other eco-friendly agriculture works best if part of a network of small forest reserves interspersed with plantations,” says SMBC’s Greenberg. Perhaps the motto “everything in moderation” is another credo that will drive agriculture as we head into a new millennium in which what we grow and how we grow it affects the survival of many other species besides our own.
—Howard Youth is a ZooGoer contributing editor and environmental writer currently based in Spain.
ZooGoer
32(6) 2003. Copyright 2003 Friends of the National Zoo.
All rights reserved.
