快猫短视频

BOUGHT a classy Christmas wreath this year? Then chances are that tucked away amidst the boughs and the berries you will find the desiccated remains of a moss 鈥� harvested, perhaps, on the other sideof the planet.

鈥淥nce you start noticing, you see wild-harvested moss everywhere,鈥� says Patricia Muir from Oregon State University in Corvallis. Even that green carpeting under the nativity scene could be 鈥渟heet moss鈥�, sold by the yard and rolled up like bolts of cloth. The moss鈥檚 feathery fronds have been glued to a fabric backing, dyed a lurid green and sprayed with fire retardant. And this stuff doesn鈥檛 just turn up in Christmas decorations; it can be found everywhere from funeral parlours to airports, motor shows and the lobbies of elegant hotels.

In the past decade, consumers with an eye for the 鈥渘atural鈥� have unwittingly fuelled a fast-growing trade in mosses. As moss is not yet grown commercially, this demand can only be met by plundering nature鈥檚 store. And no one really knows how big the industry is. 鈥淭hat鈥檚 part of the problem,鈥� says Muir. Her latest study shows that it must be worth at least $5.5 million a year in the US, and could be as much as 30 times that amount, given that harvesting carried out under permit is just the tip of the iceberg. Mosses have always been put to good use (see 鈥淣ot just for Christmas鈥�), but a recent boom in demand threatens woodlands and moorlands worldwide.

New Zealand was one of the first countries to cash in. The decorative moss industry took off almost by chance in the 1980s, when a Kiwi promoting his native goods in Tokyo covered his stand with dried sphagnum moss. To his surprise, he soon received a NZ$400,000 (about US$230,000) order 鈥� for 12 container loads of moss for the Japanese floral trade, particularly for orchid growers. Overnight, sphagnum became a major export. By 1990 some 700 tonnes of dried sphagnum, worth NZ$10 million, was being shipped abroad every year. In recent years the export trade has been valued at NZ$18 million annually. And some New Zealanders have recently teamed up with Chilean entrepreneurs to begin sphagnum harvesting at Puerto Varas in southern Chile.

It takes 15 wet tonnes to produce 1 tonne of dry moss, so harvesting it is a major operation. Helicopters have even been drafted in to lift sphagnum from swamps in the southern and western parts of the South Island. The moss is harvested from private land or from swamps leased by the Department of Conservation and deemed to be of low conservation value. However, the ecological importance of moss is a moot point. A recent report by the Ministry of Agriculture and Forestry concluded that 鈥渢he level of harvest of sphagnum moss determined to be sustainable is unknown鈥�.

Home-grown bounty

Today dried moss from New Zealand is imported to the UK preformed into liners for hanging baskets. But the UK home-grown trade is expanding quickly, according to Alison Dyke of the non-governmental organisation Reforesting Scotland. What was once a cottage industry is becoming commercialised. Wild moss is proving to be a lucrative forest product which, along with pheasant shooting, rivals the value of the timber itself. On a good site a 鈥渕osser鈥� can fill 400 bags in a day, with bags selling at 拢1 each. One Welsh firm shifts around 50 truckloads of moss and foliage each year. In the UK, most of the legal collecting tends to be restricted to the parts of conifer plantations earmarked for clear-felling. Much harvesting is on a modest scale and supplements the livelihoods of local farmers and forestry workers, says Helen Sanderson from the Royal Botanic Gardens at Kew, London. 鈥淏ut illicit collecting on moorland and in mixed semi-natural woodlands is worrying,鈥� she says.

In the US, alarm bells are already ringing. Here, the burgeoning trade in wild moss is concentrated in the deciduous woodlands of the Appalachian mountains in the east and the temperate rainforests of the Pacific north-west. The moss in the rainforests is epiphytic, meaning it grows on trees, and the area boasts luxuriant mats of moss and liverworts dripping from the branches of huge old trees. Twenty years ago this bryological bounty was exploited modestly, mostly by self-employed locals who collected moss as a stopgap between logging or fisheries work. Since the early 1990s, however, the locals have been sidelined by labour contractors who bring in crews of poorly paid immigrant workers to strip whole sections of forest. Up to 40,000 tonnes of moss are now being removed from US forests every year, Muir says.

鈥淢arkets are driving what is happening on the ground,鈥� says Rebecca McLain, a policy analyst at the Institute for Culture and Ecology in Portland, Oregon. A few controlling companies buy up most of the harvesting leases then sublease to labour contractors. 鈥淵ou can鈥檛 blame any individual, they are all trying to make a living,鈥� says McLain. 鈥淭he problem lies in the way the system is structured.鈥� Big, short-term leases encourage over-exploitation, and the supply chain exacerbates the situation. The gang-harvested moss is sold on to garden centres and florists, which tend not to ask where it came from or how it was collected. 鈥淯ntil the floral industry starts to worry about its green credentials and consumers become more discerning, things are not going to change,鈥� Dyke says.

Collectors do target common mosses, but they can鈥檛 help gathering up rarer species too, says Susan Studler of the West Virginia University in Morgantown. In one typical 100-kilogram load, along with the two or three common species of feather moss that were the collector鈥檚 quarry, she found 75 different species of moss and lichen as well as several rare ferns. Hundreds of invertebrate species and even young salamanders are also scooped up. 鈥淭his high 鈥榠ncidental take鈥� of species is what particularly concerns me,鈥� Studler says.

In an attempt to control the trade, forest managers have banned collecting in some places, but government authorities don鈥檛 have the manpower to enforce their own rules. Besides, tighter regulations on public land seem to have intensified harvesting in the remaining forests, worsening the ecological impact, according to JeriLynn Peck of the University of Minnesota, St Paul, a pioneering researcher on the US moss trade. She believes that not all moss harvesting is unsustainable, but that exploitation at present rates could destroy natural ecosystems that have taken years to evolve. 鈥淓xperimentally harvested plots suggest that some mosses need at least 10 years and probably as many as 30 years to regrow,鈥� she says. Worse, epiphytic mosses may only be able to colonise the rough young twigs of saplings, not the smooth branches of veteran trees. If that is true, these moss mats are as old as the trees themselves 鈥� hundreds of years old in many cases. 鈥淏y definition this is an unsustainable harvest,鈥� says Robin Hall Kimmerer from the State University of New York at Syracuse, 鈥渁nd the loss will have consequences we cannot foresee.鈥�

Mosses can hold 10 times their weight of water. In the forest they act as slow-release sponges, buffering the flow of water and nutrients. They are the forest鈥檚 seedbeds, form insulating and antiseptic nest liners for birds and mammals, and provide sources of food and shelter for thousands of creatures. Salamanders breed and feed in moss mats, for example, and in turn become food for animals higher up the food chain. Remove the moss 鈥� a major link in a web of interactions 鈥� and the whole ecosystem could be disrupted.

No one knows whether it will prove possible to regulate moss harvesting. One telling case study reveals that even small-scale removal may cause damage. Researchers accompanied an extended family of 10 people living in the mountains of Mexico as they gathered moss destined for Christmas nativity scenes. In the 1996 season the collectors removed 50 tonnes wet weight of moss from the forest floor. They harvested the moss patchily, only taking about 2 per cent of the total surface area. That may be sustainable, but with the moss they inadvertently gathered the seedlings of fir trees (Bryologist, vol 104, p 517). As a result, the researchers conclude, the harvest could threaten the long-term regeneration of the forest. Worse still, it jeopardises a flagship protected species, because these are the very trees that provide the winter resting place for monarch butterflies after their famous annual transcontinental migration.

Green-nosed reindeer

With enough ecological knowledge and plenty of determination on the part of governments and conservationists, it may be possible to control the excesses of big industrial harvesters and balance forest conservation with local livelihoods. But that will inevitably take time. In the meantime, we the consumers should consider our responsibilities. Mosses may look good in Christmas decorations, but is it worth it? Kimmerer is certain it is not. This is like witnessing 鈥渁n antique tapestry ripped to shreds and stuffed in a bag鈥�, she says. 鈥淎ll this destruction 鈥� and for what?鈥� Kimmerer is horrified to find that in upstate New York you can buy green teddy bears and life-sized reindeer made of wire frames stuffed with Oregon moss. 鈥淭he time to be a bystander has passed,鈥� she says.