Sphagnum a sustainable substitute in growing media. Coir has also been touted as a sustainable alternative to peat moss in growing media. Another peat moss alternative is manufactured in California from sustainably harvested redwood fiber. Semi-open cell polyurethane materials available in flaked and sheet stock are also finding application as sphagnum replacements with typical usage in green wall and roof garden substrates. Europe has a long history of the exploitation of peatlands. The Netherlands, for example, once had large areas of peatland, both fen and bog. Between 100 AD and the present, they were drained and converted to agricultural land. The
Sphagnum all other land plants, has an alternation of generations; like other bryophytes, the haploid gametophyte generation is dominant and persistent. Unlike other mosses, the long-lived gametophytes do not rely upon rhizoids to assist in water uptake. "Sphagnum" species can be unisexual (male or female, dioecious) or bisexual (male and female gametes produced from the same plant; monoecious); In North America, 80% of "Sphagnum" species are unisexual. Gametophytes have substantial asexual reproduction by fragmentation, producing much of the living material in sphagnum peatlands. Swimming sperm fertilize eggs contained in archegonia that remain attached to the female gametophyte. The sporophyte is relatively