Moss

Compared to other groups of plants, mosses are not very economically important. However, Sphagnum moss has a long history of diverse uses and is certainly the moss of greatest importance to humans. In its natural habitat, sphagnum selectively absorbs certain ions and secretes others. The bogs in which it grows become acidic and anaerobic over time, and the decomposition rate by bacteria is particularly slow in these bogs. Organisms buried in sphagnum bogs remain well-preserved for a very long time.

Currently, the most common use of Sphagnum is by gardeners. They often mix dried sphagnum (peat moss) with soil to improve the water-holding capacity of soil. The American white cedar grows in sphagnum bogs. This tree has been used for a long time to make shingles for houses because its wood resists rotting. In the 1700s, most of America's white cedar came from sphagnum bogs in the Pine Barrens of New Jersey. After all the standing trees were cut down, trees that were buried deep in the bogs for up to 1,000 years were dug up and used. These cedar trees had been preserved by the anaerobic and acidic environment created by sphagnum moss. Cedar was mined from New Jersey's sphagnum bogs until the 1850s.

Sphagnum has antiseptic properties and can hold up to twenty times its weight in water, much more than cotton. Sphagnum was used as a bandage for soldiers wounded in the Russo-Japanese War (1904-05) and World War I. By using sphagnum for bandages, cotton could be saved for making gun powder.

Peat derived largely from sphagnum is important as a fossil fuel, particularly in Scotland and Ireland. In Scotland, sphagnum also has an important role in the making of scotch whiskey. Many scotches are made from grains are steeped in water from a sphagnum bog during the malting procedure. Later, the malted grains are boiled over a fire of burning sphagnum peat. These uses of sphagnum peat impart a characteristic flavor and aroma to scotch whiskey.

Many conservationists have been concerned with the irreversible loss of valuable wetlands due to peat moss harvesting. The process of peat harvesting includes draining the sphagnum bog, after which specialized machines clear the drained bog of large vegetation. Next, ditches are dug that lower the water table, allowing peat to dry. Heavy vacuuming equipment is then used to remove the dried peat. In recent years, peat harvesting has increased because new uses for peat have been discovered. An especially important use is as a natural oil absorbent to clean up oil spills. However, the concerns of environmentalists have created codes of practice for harvesting peat, so that it will remain a sustainable resource.

It is estimated that peat can reform at a rate of about 0.1-0.7 in (1-2 mm) per year. Therefore, it is believed that harvested peatlands can be restored to ecologically balanced systems within twenty years after harvesting. Many efforts have been made to ensure the survival of bogs. In Canada for instance, millions of acres of bogs have been protected by creating natural parks that are not harvested. Also, new understanding of wetland ecology has started to help accelerate the restoration of sphagnum bogs after peat harvest. Some hope to accelerate the process from twenty years to as little as five years by transplanting live sphagnum moss back into harvested areas, and by spreading sphagnum spores to encourage growth.

There are also several vernacular plant names in which the word moss is misused. Spanish moss is a flowering plant and relative of the pineapple. Reindeer moss is a lichen. Moss pink is a garden flower in the Phlox genus. Irish moss is a red alga. Club moss is a simple vascular plant.