Economic and Ethnic Uses of Bryophytes Janice M. Glime Introduction Several attempts have been made to persuade geologists to use bryophytes for mineral prospecting. A general lack of commercial value, small size, and R. R. Brooks (1972) recommended bryophytes as guides inconspicuous place in the ecosystem have made the to mineralization, and D. C. Smith (1976) subsequently bryophytes appear to be of no use to most people. found good correlation between metal distribution in However, Stone Age people living in what is now mosses and that of stream sediments. Smith felt that Germany once collected the moss Neckera crispa bryophytes could solve three difficulties that are often (G. Grosse-Brauckmann 1979). Other scattered bits of associated with stream sediment sampling: shortage of evidence suggest a variety of uses by various cultures sediments, shortage of water for wet sieving, and shortage around the world (J. M. Glime and D. Saxena 1991). of time for adequate sampling of areas with difficult Now, contemporary plant scientists are considering access. By using bryophytes as mineral concentrators, bryophytes as sources of genes for modifying crop plants samples from numerous small streams in an area could to withstand the physiological stresses of the modern be pooled to provide sufficient material for analysis. world. This is ironic since numerous secondary compounds Subsequently, H. T. Shacklette (1984) suggested using make bryophytes unpalatable to most discriminating tastes, bryophytes for aquatic prospecting. With the exception and their nutritional value is questionable. of copper mosses (K. G. Limpricht [1885–]1890–1903, vol. 3), there is little evidence of there being good species to serve as indicators for specific minerals. Copper mosses Ecological Uses grow almost exclusively in areas high in copper, particularly in copper sulfate. O. Mårtensson and A. Berggren (1954) and H. Persson (1956) have reported Indicator Species substrate copper values of 30–770 ppm for some of the copper moss taxa, such as Mielichhoferia elongata, Both liverworts and mosses are often good indicators of M. mielichhoferi, and Scopelophila. environmental conditions. In Finland, A. K. Cajander Although no bryophyte seems to be restricted to (1926) used terrestrial bryophytes and other plants to substrates containing iron, photosynthesizing bryophytes characterize forest types. Their value as indicator species have the ability to change soluble reduced iron to its was soon supported by A. H. Brinkman (1929) and insoluble oxidized form and make this molecule visible. P. W. Richards (1932). Yet, bryophytes have a somewhat A. Taylor (1919) discovered that iron compounds different place in ecosystems than their tracheophyte penetrated the tissues of Brachythecium rivulare and neighbors. 14 ECONOMIC AND ETHNIC USES 15 formed a hard tufa; J. M. Glime and R. E. Keen (1984) assemblages. L. F. Klinger et al. (1990) have suggested found a similar response in Fontinalis, where iron oxide that in the Holocene, succession went from woodland to completely enveloped the moss in a hard cover. M. peatland, with peat serving as a wick to draw up water Shiikawa (1956, 1959, 1960, 1962) found that the and raise the water level, causing woodland roots to liverwort Jungermannia vulcanicola and mosses became water-logged. In New England, N. G. Miller Sphagnum and Polytrichum play active roles in deposition (1993) used bryophytes to support conclusions that the of iron ore. Since Japan has few native sources of usable flora during 13,500 to 11,500 BP had been tundra-like iron, S. Ijiri and M. Minato (1965) suggested producing vegetation similar to that presently in the Arctic. limonite ore artificially by cultivation of bryophytes in fields near iron-rich springs. One of the means by which bryophytes sequester both Erosion Control metals and nutrients is to bind them by cation exchange to cell walls of leaves. In this process, Sphagnum places Although legumes with their nitrogen-fixing symbionts hydrogen ions in the water in exchange for cations such are usually planted to secure areas devoid of topsoil, as calcium, magnesium, and sodium (R. S. Clymo 1963). H. S. Conard (1935) suggested that sowing spores and Hydrogen ions make the water more acidic, and most vegetative fragments of bryophytes on bare areas could peatland ecologists argue that this is the primary means help to prevent erosion. In his home state of Iowa, by which bogs and poor fens are made more acidic. Conard found that Barbula, Bryum, and Weissia were While Sphagnum is a reliable indicator of acid important pioneers on new roadbanks, helping to control conditions, K. Dierssen (1973) found that several other erosion there before larger plants became established. The bryophytes successfully indicate other soil conditions. For protonemata that develop from both fragments and example, Ceratodon purpureus suggests good drainage spores form mats that cover and bind exposed substrates and high amounts of nitrogen, whereas Aulacomnium (W. H. Welch 1948). In Japan, Atrichum, Pogonatum, palustre, Pleurozium schreberi, Pogonatum alpinum, and Pohlia, Trematodon, Blasia, and Nardia play a role in Pogonatum urnigerum signal less nitrogen, at least in preventing erosion of banks (H. Ando 1957). Even areas Iceland. Funaria hygrometrica, Leptobryum pyriforme, subject to trampling, such as trails, may be protected from and Pohlia cruda show good base saturation, whereas erosion by trample-resistant bryophyte taxa, and by those Psilopilum laevigatum indicates poor base saturation and with high regenerative ability (S. M. Studlar 1980). poor physical soil condition. On the other hand, when bryophytes such as T. Simon (1975) demonstrated that bryophytes could Sphagnum reach water saturation, they can suddenly be used as indicators of soil quality in steppe forests, but release a great load of water at unexpected times. Because their absorption primarily of rain and atmospheric water of its tremendous water-holding capacity, Sphagnum, makes few of them useful as pH indicators. H. A. Crum along with Calliergon sarmentosum, controls water (1973) considered Polytrichum to be a good acid during spring runoff in the Arctic (W. C. Oechel and indicator; its ability to live on acid soils may be facilitated B. Sveinbjornsson 1978). When Sphagnum is saturated by vascular tissue (hydroids and leptoids) in its stem. The and the layer above the permafrost melts, mosses rhizoids at its base probably enhance uptake of water suddenly permit a vast volume of water to escape all at and nutrients from soil. Leucobryum likewise indicates once, creating problems for road-building engineers. acid soil, usually combined with dry, infertile, deep humus (T. A. Spies and B. V. Barnes 1985). Recently, bryophytes have been used as indicators of Nitrogen Fixation past climate. Although peatlands and their preserved flora and even their fauna have long revealed the past, Nitrogen is often a limiting nutrient for plant growth, we can now use bryophyte assemblages to expose past especially in agriculture. Bryophyte crusts, endowed with climatic and hydrologic regimes. Understanding how nitrogen-fixing Cyanobacteria, can contribute levels of evaporation and precipitation determine considerable soil nitrogen, particularly to dry rangeland composition of Sphagnum communities permits us to use soils. Some of these Cyanobacteria behave symbiotically subfossil Sphagnum and other moss assemblages to in Anthoceros (D. K. Saxena 1981), taking nitrogen from identify past climates (E. A. Romanova 1965; the atmosphere and converting it to ammonia and amino J. A. Janssens 1988). In another example, presence of acids. The excess fixed nitrogen is released to the such drought-tolerant species as Tortella flavovirens in substrate where it can be used by other organisms. subfossils indicates past dry climatic conditions in some K. T. Harper and J. R. Marble (1988) found that areas of the Netherlands (H. Nichols 1969; J. Wiegers bryophyte crusts not only help protect soil from wind and B. Van Geel 1983). and water erosion, and provide homes for nitrogen-fixing Similarly, our understanding of past vegetation is organisms, but they facilitate absorption and retention enhanced by information about past bryophyte of water as well. 16 ECONOMIC AND ETHNIC USES FIGURE 6. Polytrichum juniperinum is an ubiquitous, tall moss that holds soil in place, looks like a small tree in a dish garden, and is strong enough to make brooms, baskets, and door mats. Photo by Janice Glime. U. Granhall and T. Lindberg (1978) reported high to various levels of SO2, he determined that most species nitrogen fixation rates (0.8–3.8 g m-2 y-1) in Sphagnum are injured by 10–40 hours of exposure at 0.8 ppm SO2, communities in a mixed pine and spruce forest in central or at 0.4 ppm after 20–80 hours. Since that time, use of Sweden; thus bryophytes, as substrate for nitrogen-fixing the bryometer has spread around the world, but has been organisms, are important to the forestry industry. In of especial value in Europe, where it has also been known Sphagnum, and probably other taxa as well, three types as a moss bag. In Finland, A. Makinen (unpubl.) used of nitrogen-fixing associations exist: epiphytic Hylocomium splendens moss bags to monitor heavy Cyanobacteria, intracellular Cyanobacteria, and metals around a coal-fired plant. D. R. Crump and nitrogen-fixing bacteria (U. Granhall and H. Selander P. J. Barlow (1980) have likewise used the method to 1973; U. Granhall and A. V. Hofston 1976). Nitrogen- assess lead uptake. fixing Cyanobacteria of bryophyte species also provide growth enhancement for oil-seed rape, the supply plant for canola oil (D. L. N. Rao and R. G. Burns 1990). SO2 and Acid Rain While North Americans have apparently not adopted the Pollution Studies bryometer per se, they began using bryophytes for monitoring relatively early. In 1963, A. G. Gordon and Bryophytes have played a major role in monitoring E. Gorham published what seems to be the first North changes in the Earth’s atmosphere. Working in Japan, American study on the effects of pollutants on mosses, H.