Gather no moss?
The bale of peat moss my father used on our lawn always stood in a corner of the garden like a burlap refrigerator, holding a rich, dark substance smelling of the swamp. The sharp, vinegary reek of decaying vegetable matter seemed to me an essential part of gardening.
But as wetlands around the world have been drained and filled and cut away, some environmentally minded gardeners have begun to wonder if they are building up their lawns and flowerbeds at the expense of fragile ecosystems elsewhere.
Peat moss is the partially decomposed remains of sphagnum moss, a plant that defines the bogland ecosystems where it is found. As it grows, the lower parts of sphagnum die and are buried beneath the new growth; eventually, the dead moss is compacted and deprived of oxygen by the weight above it and forms peat, a dense vegetable mud. This mat of dead and living sphagnum literally supports the plant life of the bog. If sphagnum moss is not cut out completely, it will slowly grow back. But since it is the keystone of bog ecosystems, cutting it results in the destruction of many other plants as well as wildlife habitat.
In Ireland and Great Britain, peat bogs are in danger of disappearing. The problem is exacerbated by the relatively small acreage of peatlands, and by development, agricultural use, and the commercial harvesting of peat for fuel. Many conservationists, gardeners, and wetlands scientists in these countries have recommended a boycott of horticultural peat.
In the United States, peat moss is harvested in Indiana, Florida, Maine, Michigan, and Minnesota, but most of the peat Americans use comes from Canada, which boasts 270 million acres of peatlands. Canada harvests some 40,000 acres of sphagnum and exports 90 percent of it to the United States for lawn and garden use.
Producers in both Canada and the United States maintain that they never cut sphagnum faster than it grows, and leave behind enough peat to ensure regeneration. "Harvesting peat bogs actually helps preserve them," says Gerry Hood of the Canadian Sphagnum Peat Moss Association, who claims that peat-moss operations keep the bogs from being drained for development. Five to ten years after harvesting, Hood says, the bog will be a "functioning wetland" again. He admits that it will take up to 25 years for a bog to return to its preharvested state, but says that 90 percent of the original flora will eventually grow back.
Some wetlands scientists, however, point out that a managed bog bears little resemblance to a natural one. Like tree farms, these peatlands tend toward monoculture, lacking the biodiversity of an unharvested bog.
Though gardeners may have a nostalgic attachment to peat moss, there's no real need to use it. Fallen leaves and grass clippings make a better mulch; though it won't last as long as peat moss, compost from yard clippings is a suitable soil conditioner. Leaf mulch in particular will help soil hold water.
Lawns are big absorbers of peat moss and other resources as well: perhaps we should reconsider the whole concept of putting-green perfection and allow distant ecosystems - such as peat bogs - to flourish unmolested.
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|Title Annotation:||peat moss and the environment|
|Date:||May 1, 1993|
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