Wild Side : Fitting in farms
The modern human inclination is to divide the world into "natural" and "human" areas, and to expect little overlap between the two domains. But from the Wild Side perspective, there is no such division. Sure, the mix of species present varies from place to place. But the exact same processes go on everywhere: plants grow; animals eat, reproduce, and die; nutrients cycle through various types of organisms while water filters through the soil.
The whole Vineyard is habitat, and the main business of wildlife is to spend as much time as possible in habitat that offers a favorable balance of resources and risks. Indeed, for some species, "good habitat" may be far removed from anything remotely natural. Martha's Vineyard's breeding population of the familiar American robin, for example, actively prefers artificial habitat, nesting more numerously and probably more successfully among lawns and shrubbery than in natural woodland.
Likewise, there is little that is natural about farmland, a habitat highly engineered to maximize the growth of a small number of plant or animal species that are themselves drastically different from their closest wild relatives. Applications of fertilizer and extra water artificially boost the land's productivity, while weeding and tilling discourage undesired plants. And the annual life cycle of many crop species means that fields oscillate most unnaturally between verdant grown and bare soil during the course of the year.
Unnatural, yes, but some wildlife loves it. Tilled fields at Katama Farm, to take one prominent and publicly-owned example, attract masses of shorebirds during fall migration; black-bellied plovers, especially, love threading elastic earthworms out of the soil. Birds of prey including harriers, red-tailed hawks, and barn and short-eared owls hunt enthusiastically over the farm's hay fields, where voles and other prey items are especially abundant or at least especially easy to catch. Migrant robins, blackbirds, and swallows feast on insects associated with livestock and crops. Certain songbirds that favor open landscapes - horned larks, snow buntings, meadowlarks - find suitable habitat at the farm during winter. And there is nothing like a frosted vegetable patch to attract migrant sparrows in late fall.
Some of the ecological value of farmland stems from the fact that agricultural fields approximate more natural habitat types that are in short supply. A hay field, for instance, has different kinds of grass than a salt marsh, and for some species, especially ones that have evolved to breed in marshes, that difference is critical. But both habitats are flat, open, and grassy, and for some other species, these habitats appear to be essentially interchangeable.
Wildlife using farms also benefits from the intensified flow of nutrients that characterizes farm fields. The whole point of agriculture is to promote the rapid growth of fruit, seed, and other edible plant parts, and many animals and insects cheerfully take advantage of this fecundity. And in addition to the crops deliberately grown, many agricultural weeds that flourish around farms are valued by wildlife (ragweed, the plant everyone loves to hate, is a favored source of seeds for migrant sparrows).
Of course there are limitations on the ecological value of farmland. Deliberately characterized by low plant diversity and a dearth of native vegetation, farms simply can't support many of our native plants and the insects and animals that associate with them. Even the animals that do use farms can rely on this habitat for only a subset of their needs. So wholesale conversion of natural habitat into farm fields would seriously threaten local environmental health.
Moreover, farming done carelessly or too intensively poses a range of ecological risks that extend well beyond the farmland itself. Fertilizer applied excessively or at the wrong time can overwhelm the ability of growing crops to take up nutrients. Surplus nutrients leach into the ground water, ultimately damaging the water quality in ponds and estuaries. Manure runoff from pastures can contaminate surface water with bacteria. Pesticides applied on farms can drift off-site or enter the ecosystem when birds eat poisoned insects. And populations of weeds and non-native insect pests can spill over into nearby natural areas, where they threaten native wildlife populations.
But on the Vineyard, agricultural practice tends increasingly toward responsible, low-impact methods like organic growing and integrated pest management. And while the expansion of agriculture on Martha's Vineyard is a universally welcomed trend, financial realities will probably cap the growth of farming here. It seems unlikely that local agriculture will seriously conflict with protecting the productive natural habitats that are, or ought to be, one of the Vineyard's most valued resources. Meanwhile, for certain species at certain times, our farmland offers an unbeatable resource for wildlife.