Ecological Significance of BRYOPHYTE.pptx

Ecological significance of bryophytes in detail

1. ECOLOGICAL SIGNIFICANCE OF BRYOPHYTES 1

2. Bryophytes are ecologically important as they play an important role in: Soil Conservation Bryophytes form a mats and prevent soil erosion. The intertwined moss stems and rhizoids bind soil particles firmly. Hold large amount of water and reduce run off and checks soil erosion. 2

3. 2. Soil Formation and Growth of Vegetation The lichen and mosses play an important role in soil formation. Both are slow but efficient soil formers. The lichen thallus secrete organic acids which gradually dissolve and disintegrate the rocks to which they cling. The rock particle together with the dead and decaying older parts of the lichen thallus form fertile soil. 3

4. 3. Prevent Soil erosion Bryophytes grow as compact cushions forming a carpet on the forest floor. Actually, their rhizoids bind soil particles together and also interweave with the rhizoids of adjacent plants keeping the whole cushion compact and difficult to detach from the soil. The soil particles thus trapped do not flow along with water during floods. Mosses play a very important role in helping to retain moisture and stabilize dunes. Such mosses can survive even if they get covered by sand. E.g Polytrichum, Atrichum, etc 4

5. 4. Role in Bog Succession Mosses play an important role in bog succession from open water to climax forests. Mosses like Sphagnum grow profusely in open water bodies and cover the whole area. Due to continuous deposition of plant debris, the water body gets converted to a bog, which later colonized by higher plants. 5

6. 5 .Ecological Succession on Rock Liverworts and mosses initially colonize bare rocks where they establish themselves. They initiate soil formation and gradually makes the place ideal for growth of other plants. 6

7. 6. Rock Builders Some mosses in association with some green algae (e.g Chara) grow in water of streams and lakes which contain large amount of calcium bicarbonate. These mosses bring about decomposition of bi-carbonic ions by abstracting free carbon dioxide. The insoluble calcium carbonate precipitates and on exposure hardens, forming calcareous(lime) rock like deposits. 7

8. 7. Formation of Peat Peat is a brown or dark colour substance formed by the gradual compression and carbonization of the partially decomposed pieces of dead vegetative matter in the bogs. Sphagnum is an aquatic moss .While growing in water it secretes certain acids in the water body. This acids makes the conditions unfavourable for the growth of decomposing organisms like bacteria and fungi. Absence of oxygen and decomposing microorganisms slows down the decaying process and large amount of dead material is added yearby year. It is called peat. So Sphagnum is also known as Peat Moss 8

9. Various Uses of Peat are: - Used as Fuel in Ireland, Scotland and Northern Europe. In Production of various products like ethyl alcohol, ammonium sulphate, peat, tar, ammonia, paraffin, dye, tannin materials etc. In horticulture to improve the soil texture. In surgical dressings 9

10. 8. Role in Monitoring and control of Pollution Some mosses like Sphagnum accumulates heavy metal cations and these are used as indicators of aquatic and atmospheric pollution indicators. They are sensitive to air pollution- Bioindicators of air pollution Terricolous ( terrestrial -on soil) species- Most sensitive, then Saxicolous(on rocks) and corticolous(on bark) Thalloid forms are more pollution resistant Fertility of bryophytes decreases with increase in pollution. 10

11. 9. Indicator of Water Pollution Bryophytes can also act as indicator of water pollution. E.g Amblystegium riparium It is found to be absent in the upper part of the river with clean water.However it is appeared at a place where the quality of river water is deteriorated. This species seems to be an indicator of more or less polluted water. Aquatic bryophytes can be used for monitoring heavy metal pollution as they accumulate them in high concentration. Riccia gangetica, Riccia frostii and Funaria hygrometrica. 11

12. 10. Indicators of heavy metal pollution Peat mosses have the ability to accumulate heavy metals. Leafy liverwort Radula complanata is sensitive to SO2 and changes its colour in 10 mins. Chl.a is degraded to Phaeophytin ( colourless chl.a by releasing Mg2+ ions. Atrichum undulatum is also a bio- indicator sensitive to air pollution. Some mosses are indicators of high copper in the substrate called copper mosses. E.g Dryptodon stratus, Mercega ligulata etc….. 12

13. 11. Indicator of soil pH Liverworts and mosses are good indicators of soil pH. Some bryophytes can grow in narrow and specific range of pH so therefore their presence can be used as an indicator of soil pH. The mosses also grow on haematite (iron ore) with alkaline pH(7.3-7.6). Some bryophytes grow only on strongly acidic , highly soluble and iron rich limonitic substrates. Polytrichum is a reliable indicator of acidic conditions. Leucobryum glaucum is the perfect indicator of acidity. Plants like Tortella tortuosa and Neckera crispa are growing well on soils rich in lime or other bases. Campylopus gracilis serves as an example of species that is tolerant to both acidic and basic conditions. 13

14. 12. Water Erosion and Nutrient Cycling Bryophytes on tree trunks absorb rainwater that’s flowing down the trunk and those hanging like curtains will absorb water from rain and help to maintain a humid atmosphere and so greatly influence the microclimate. Bryophytes also trap any nutrients that are dissolved in the rain or mist droplets, in many cases trapping nutrients that would otherwise be washed away . Living bryophytes make use of the nutrients they trap . Dead and decayed bryophytes release nutrients to the surrounding plants. In this way Bryophytes play an important role in nutrient cycling. 14

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16. FOOD AND SHELTER Many animals make use of bryophytes.Numerous invertebrates eat bryophytes, lay their eggs on them or shelter in them. They form a vital part of the construction material of the nest of some birds. In Vertebrates the range of association is much less. Northern Corroboree Frog are found near Sphagnum bogs. These endangered frogs breed in sphagnum bogs in the alpine and subalpine areas but move away from boggy areas outside of the breeding season. 16

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