Peat moss builds its own bogs and fires spores at 36,000 g
Sphagnum does not just live in bogs; it makes them. By soaking up many times its weight in water and souring the ground around it, the moss creeps outward and turns land into peatland. Its spore capsules then blow their lids off, launching spores on tiny vortex rings with an acceleration of about 36,000 g.
Around 380 species make up Sphagnum, also called bog moss. Each plant has two kinds of cells: small green ones that photosynthesise and large, empty, barrel-shaped ones with a pore at one end that fill with water. Depending on the species, a plant holds 16 to 26 times its dry weight in water. The moss also swaps hydrogen ions for calcium and magnesium in the soil, making its surroundings more acidic, and phenolic compounds in its cell walls resist decay. Combined with airless wetland soils, this lets dead moss pile up as peat many metres deep.
Because the moss reshapes whole landscapes, ecologists describe it as an ecosystem engineer. Its peat hosts sedges, heaths, orchids and carnivorous plants, and sphagnum bogs make up several of the world's biggest wetlands, including the West Siberian Lowland and Hudson Bay Lowland, where they lock away large amounts of carbon. The northernmost populations grow on Svalbard at 81 degrees north. On islands such as the Faroes, the Azores and the Galápagos, sphagnum spread noticeably after people settled and began burning and grazing.
Spore capsules sit only about a centimetre above ground, where wind is weak. As a capsule dries, its lid pops off, and high-speed photography shows the burst forms vortex rings that carry spores 10 to 20 centimetres up, higher than simple ballistics would allow. Much of the living moss in a bog, however, comes from fragments breaking off and regrowing. Molecular dating suggests nearly all modern species arose in a burst about 14 million years ago.
As of 2013 Canada supplied up to 80 percent of the peat moss used in the United States, with harvests around a sixtieth of the yearly peat growth. In Chile, large-scale export harvesting began in the 2010s; fears for water supplies in the fjords, which the moss buffers through dry months, led to regulation in 2018 and a ban on peat extraction from April 2024.
Source: Sphagnum
