PORTLAND - A huge, largely underground industry has been built on the moss that drapes some forest trees, raising ecological concerns, questions about export of potentially invasive species, and other issues that have scientists, land managers and businesses unsure about how to monitor, regulate or control this market amid so many uncertainties.
A report on this trade in forest moss - sometimes legal, sometimes on the black market - was made today by a botanist from Oregon State University, speaking at the annual meeting of the Ecological Society of America.
"Certain types of mosses and lichens, often those that hang on hardwood trees such as vine maple or big leaf maple, are prized for their use in the floral trade," said Patricia Muir, an OSU professor of botany and plant pathology. "The moss is used in planters, wreaths, hanging baskets, other floral displays. And it has become a big business and big money."
How big? That's part of the problem, no one really knows. The newest studies done by Muir suggests it must be at least $5.5 million a year, but it could also range up to $165 million annually, mostly in the Pacific Northwest and parts of the Appalachian Mountains in the eastern U.S.
Sometimes the moss is harvested legally, by permits on public lands or contractual arrangement on private land, Muir said. But there's strong evidence that the amount taken by permit or private legal arrangements is just the tip of the iceberg of actual harvests.
"Any penalties for illegal taking of moss are usually small and rarely enforced," Muir said. "There also is a lack of record keeping and reporting on many public lands, and clearly some illegal harvesting on both public and private forests."
But legalities aside, millions of pounds of moss are leaving America's forests every year, and that has ecologists concerned.
"When large amounts of moss are taken from an area, we aren't sure what species may grow back in its place," Muir said. "There may be some
inadvertent removal of endangered species. We could be shipping dangerous insect pests overseas in untreated moss samples. And moss may play an important role in nutrient cycling that is not yet fully understood."
Moss also holds about 10 times its weight in water, Muir said, and acts as a natural sponge, a hydrologic buffer to help control the flow of water in forests.
Some threatened species such as the marbled murrelet build their nests in moss mats. And the moss is habitat for hundreds of insect species.
"We don't really know whether the removal of this much moss is a serious problem, because no one has studied it very carefully," Muir said. "Right now it's safe to say that whatever we decide about a reasonable amount of moss to allow harvested is just a seat-of-the-pants guess."
And that assumes, she said, that there is an effective management or enforcement structure in place to control moss harvest, once quotas are decided upon. In fact, there is not.
"Amid land managers, there's a lot of frustration about any type of enforcement of moss regulations," Muir said. "When you consider all the issues relating to timber, streams, fisheries, salmon, endangered species, there is hardly anyone left who has time to worry about moss."
Ideally, Muir said, enlightened managers would know more about their moss resource, how fast it regrows, what amount could be safely removed, and which sensitive habitats should be avoided. Harvesters would be trained, perhaps have a long-term lease on a parcel of forest land, and there would be some enforcement of rules and permits in a system that encouraged trust, respect and responsibility.
The moss industry is unorganized, which is part of what makes it so difficult to regulate. Some of the harvesters are "mom and pop" businesses that are difficult to tell from a couple out for a walk in the woods, Muir said. The moss may bring the harvesters 50 cents to $2 a pound when they sell it to a wholesaler, more often at the low end of that range.
But the pounds can add up. Muir estimates - again, with a huge range of variability - that between 2 and 82 million pounds of moss is used in, or exported from the U.S. each year, with a final market value that could approach $165 million. Domestic sales, which are largely unknown, are estimated based on the value of export sales that are easier to track, an d the known ratio between the amount of moss used locally versus that which is exported. Muir estimated the moss being harvested in the U.S. could fill between 600 and 2,400 semi-trucks per year. In her survey, Muir contacted 361 land managers, 97 botanists and 98 businesses. About 64 percent of botanists felt the volume of moss being removed was of concern.
In the East, the concern about moss harvests in some areas is sufficiently high that the Monongahela National Forest has stopped issuing any harvest permits. In the Pacific Northwest, some business owners are concerned enough about illegal harvests that they have hired private security guards to patrol lands on which they have legally leased the moss rights.
"There's still a lot we don't know here, but there clearly are ecological concerns," Muir said. "Moss harvesting is a big business and it's all around us. We were doing some research up the McKenzie River valley near Eugene and we had a hard time finding a place in the forest, within a reasonable distance from roads, where the moss had not already been picked."