Economic Importance of Bryophytes - Evolution of Plants - Lecture Slides - Document's extract

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Description: Economic Importance of Bryophytes, Liverworts and Hornworts, Glomeromycota, Sphagnidae, Sphagnum Dressings, Important in Hydrodynamics, Bog Formation, Sphagnum Ion-Exchange Mechanism are the important key points of lecture slides of Evolution of Plants.

Economic Importance of Bryophytes I. Liverworts and hornworts: not much! (but many contain Nfixing cyanobacteria, important in ecosystem nutrient availability; some are mycorrhizal with Glomeromycota) II. SPHAGNIDAE: "economic" importance • 1. Important in hydrodynamics of large areas of especially northern hemisphere - bogs and “muskeg”. • 2. Sphagnum dressings, in medicine, shoes and diapers • III. Other mosses, various other uses BOG FORMATION • a) open pond, slow-moving stream: margins with floating aquatics, especially Carex spp. with roots anchored in Sphagnum • b) Sphagnum builds above (growth) and below (death and deposition) water-line; enables margin to grow inwards • c) increased Sphagnum growth allows colonization of mat by bog shrubs, and eventually conifers such as black spruce & tamarack Bog Formation II • d) continued encroachment of water surface by floating bog mat may eventually cover surface if disturbance is slight. Waves or stream-flow erode edges • e) amelioration of water table by increased Sphagnum mat away from water-line allows development of forest; hummocks may have white pine or white birch • f) in permafrost areas, forest lowers summer temperature of forest floor, permafrost moves upward, water is trapped, and trees are drowned, so open Sphagnum bog cycles with forest SPHAGNUM ION-EXCHANGE MECHANISM • Metal2+ + 2HA ---> MA+ + A- + 2H+ • Gives off H+, lowering pH and eliminating competing mosses (and many vascular plants) • Metal ions can be displaced by shaking in H+ (e.g., dilute HCl) to assay metal content BOG SIDE-BENEFITS a) b) Bog fossils PEAT (1.5m = 6,000y): for fuel and horticulture c) Conservation aspects: exploitations and emissions d) Carbon sink – unless climate warms! Sphagnum dressings, in medicine, shoes and diapers • Absorbs 16-20 X dry weight in water (cotton 4-6); comfortable; mildly antiseptic (vs diaper rash, g

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angrene) • Sphagnum dressing used greatly in wars: Russo-Japanese (19045); WW I (both sides). Millions of dressings made by thousands of volunteers a) crude sphagnum collected, partially air-dried, cleaned of debris, and sorted. b) wrapped in sewn gauze c) sterilized before use by autoclaving or with antiseptics d) preferred species was S. papillosum; also used were S. palustre, S. imbricatum & S. magellanicum III. Other Mosses, Other Uses: 1. Housing 2. Boat-building 3. Fibre for baskets 4. Bedding and pillows 5. Cultivation 6. Mosses as living mulch in nurseries and orchards 7. Problem mosses in lawns and roofs

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University: Shree Ram Swarup College of Engineering & Management
Subject: Evolution
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