The bryophytes include the liverworts (Hepaticae), the hornworts (Anthocerotae) and the mosses (Musci). All the three sub-groups comprise about 24000 species. On the whole none of these is of direct use to man except the peat mosses, hair cap mosses (polytrichum) and some liverworts (Marchantia). However they influence man through the important role they often play in the economy of nature, as rock builders, as aids in soil conservation and as plants which an important part in the development of vegetation. It is because of this indirect influence of bryophytes on man that they are regarded as of economic importance.
A. Direct use of bryophytes:
1. Sphagnum and the peat.
The pieces of dead vegetables matter partially decomposed by water in the bog and gradually compressed and carbonized under pressure of the overlapping late deposits and water is called the peat. It is a brown or dark colored spongy substance. Sphagnum and other mosses are the chief constituents of peat. Beside these, the peat contains remain of other plants growing in the bog such as the reeds. Sedges, grasses, ferns and shrubs. Some peats however, consist mainly of the remains of Sphagnum. For this moss is often called peat moss. These bog plants grow luxuriantly and in dense stands. Their basal older portions die. Thus large amounts of dead vegetable matter accumulate each year gradually filling the pond or lake. These deposits compressed and hardened by the weight of fresh deposits from above in the course of time, attain considerable thickness. The compacted, partially decomposed and carbonized dead plant deposits are called the peat.
USES OF PEAT:
(i) Peat is used as a fuel: The thick deposits of peat are cut into blocks and dried. Being rich in carbon the dried peat blocks are used as fuel. In Northern Europe, especially the Netherlands peat fuel is still used on a commercial scale. In the recent past the Europeans burned peat in the generation of power and there it existed many factories in finance for making illuminating gas from peat which has now been replaced by coal. Besides fuel, the following other uses of peat have been reported.
(ii) Preparation of ethyl alcohol: Odell and Hood (1926) reported that by chemical treatment cellulose in peat is broken down into sugar which through fermentation is converted into alcohol.
(iii) The Germans evolved a method to obtain Ammonium Sulphate as a by-product in the production of gas from peat.
(iv) Nitrates, brown dye and tanning materials have been produced from peat.
(v) The other products of industrial use of peat tar, ammonia and paraffin.
(vi) Davis (1911) reported that peat has been manufactured into paper, woven fabrics and artificial wood and employed as mattress filler and as bedding material for domesticated animals after cleaning the sticks and other coarse materials.
(vii) Use in horticulture: Sphagnum and peat are also of great use in horticulture. Peat is added to heavy (clayey) soils to improve their texture as it keeps them porous and prevents caking. When added to dry, sandy soils or other humus poor soils, it improves their water holding capacity and serves as a source of organic matter. Duffey (1954) observed that peat is the most important source of humus in the world. Dried sphagna are also used as garden mulch which helps to retain high soli acidity required by certain decorative and economically important plants. Cleansed peat and sphagnum are extensively employed by horticulturists and florists orchids. Sphagnum is also used as a packing for grafting scion to protect them against drying influence of the surrounding air.
(viii) Dried sphagnum and moss peat for their ability to hold water tenaciously are remoistened and used as packing material for shipment of live plants, cut flowers, vegetables, perishable fruits, bulb and tubers. Stokes (1931) observed that it (the packing material) retains enough moisture for a long time and it protects against heat and cold. Peat is as well used as a packing material for fruits, fish, eggs and meat for cold storage.
(ix) Davis (1910) suggested that peat has a certain food value and thus has been used as a stock food in mixture with molasses.
(x) Davis (1946) reported that the various products of industrial use such as acetic acid, methyl alcohol, humic and allied acids, carbonic acids, paraffin, naphtha, montan wax and lignins used in making plastics have been obtained from peat by different methods.
(xi) Dacknowski-stokes (1942) recommended peat moss as suitable material for use in surgical dressing. Because of its great absorbent power employed for guaze to dress wounds and for making absorbent bandages in the treatment of boils and discharging wounds. Properties carefully dries, cleansed and sterilized sphagnum has long been employed for guaze to dress wounds and for making absorbent bandages in the treatment of boils and discharging wounds. Porter (1917) observed that the sphagnum dressings are cooler, softer and less irritating than those made with cotton.
2. Medicinal use of Bryophytes.
Information on medicinal use of bryophytes is scanty watt (1891) had reported to the medicinal use of marachantia polymorpha, Fagetella conica and a few species of jungermannia, Anchoceros and Rriccia. Wren (1956) mentioned only polytrichum juniperinum in this connection. Roig Y. Mesa (1945) mentioned that among liverworts marchanitia polymorpha has been used to cure pulmonary tuberculosis and afflictions of the liver. Hartwell (1971) reported that extracts of M. stellata and polytrichum commune possess antitumout properties. However, the use of mosses in the treatment of ailments is more pronounced. Shiu-ying (1945) reported that dried sphagnum is boiled in water. The decocation is used in the treatments of acute haemorrhage and diseases of the eye. According to rogue (1941) tea made of polytrichum of peat, has to dissolved stones of kidney and gall bladder. Peat tar one of the by-products of peat, has antiseptic and is used as a preservative. According to Grieve (1931), a distillate of peat tar known as sphagnol has been effectively used in the treatment of skin disease, Hotson (1918 a) reported that Alaskan Indians prepared a healing ointment by mixing sphagnum leaves with grease or tallow. It was used in the treatment of wounds and cuts. The use of sphagnum for making absorbent bandages in the treatment of boils and discharging wounds has been described above.
B. Indirect use of bryophytes:
(i) Aids in soil conservation: The mosses prevent sheet corrosion of soil. They grow in dense stands forming a mat or carpet-like structure. This thick moss carpet serves a twofold function. Firstly it bears the impact of the falling rain drops and secondly it holds much of the water that falls. Consequently the amount of run-off is considerably reduced. Besides there is no or little turbidity in the runoff Conard (1935) demonstrated that the turbid water flowing through the moss mat is shorn much of its sediment. The inter-twined moss stems and the underground rhizoids bind the soli particles together to a considerable depth (6-8 inches) so firmly that is no or little erosion even on a steepy hill side. Grout (1912) held that even the moss protonema mat checks soil erosion.
(ii) Formation of soil and development of vegetation cover: The lichens and mosses play an important role formation. Both are slow but efficient soil former. The lichens, however, are the pioneers to colonise barren, bare rocky surfaces where no other plants can grow. The lichen thalli secrete organic acids which gradually dissolve and disintegrate the rock to which they cling. The rock particle together with appearance when sufficient amount of this fertile soil gathers in the crevices of the substratum begun by the lichens. Dust and debris blown by the wind rapidly accumulate between the erect moss stems. Weaver and Clements (1938) reported that in the course of time, the depth of soil under the moss mat may be more than one inch. The moss mat collets sufficient moisture and contains humus to form a suitable substratum for the growth of many rock loving herbaceous plants. In fact schroeter (1926) recorded that saxifrage cotyledon germinates only among the mosses. The other rock loving species which usually appear in the moss mats are sedum, Thymus, Saxifraga aizoon and others. To sum up in the development of vegetation cover over rocky surfaces, the mosses play a vital role. The moss stage follows the lichen stage and precedes the herbs. The latter in turn may be succeeded by shrubs and trees.
(iii) Bog succession: Weaver and Clements (1938) remarked that mosses play an important role in bog succession from open water to climax forest. The mosses especially the peat mosses established on the banks of lakes and other shallow bodies of water extend inwards and grow over the surface of water with their stems intertwined to form thick mats. These surface mats over bodies of water give the appearance of solid soil. Such areas are called quacking bogs. The thick moss mat because of he moisture and humus forms a suitable substratum for the germination of seeds of various species of hydrophytic plants. The older parts of these plants gradually die and settle to the bottom. In the course of time, these lakes and shallow bodies of water become filled up with partially decomposed old parts of mosses and other hydrophytic plants. Thus the areas which originally were sterile sheets of water become converted into solid soil supporting vegetation. The mosses and hydrophytic angiosperms eventually disappear. They are replaced by forest growth of mesophytic type. The mosses thus play a vital role in changing the landscape.
(iv) Role as rock builders: Certain mosses (Bryum, Hypnum, Fisssidens and other) growing in association with other aquatic plants (such as Chara and many other algae) play a remarkable role as rock builders. These plants grow in shallow waters of lakes, streams and springs which contain a large amount of calcium bicarbonate. The plants bring about decomposition of bicarbonic ions by abstracting free carbon dioxide. The insoluble calcium carbonate precipitates. These insoluble minerals, on exposure, harden forming calcareous (lime) rock- like deposits around these plants. These travertine deposits continue to grow by the aid of mosses and algae growing in the water extending over areas of several hundred square feet. The travertine rock deposits are extensively used as a building stone.
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