Bt 1008: Plant Resources Lecture 13 PDF

BT 1008: Plant Resources Lecture # 13 Dr. Jinendra Dissanayake Department of Plant Sciences Syllabus ❖ Renewable and non-renewable resources ❖ Traditional uses and potentials of plants as sources of  Food & Beverage plants  Spice & Essential oils  Medicines  Wood...

BT 1008: Plant Resources Lecture # 13 Dr. Jinendra Dissanayake Department of Plant Sciences Syllabus ❖ Renewable and non-renewable resources ❖ Traditional uses and potentials of plants as sources of  Food & Beverage plants  Spice & Essential oils  Medicines  Wood & Fiber products  Natural products and Industrial processing (eg. Latex, narcotics)  Alternative energy resources  Environmental sensors ❖ Sustainable utilization and conservation of plants  ALTERNATIVE ENERGY SOURCE  An energy source Energy source is consumed to produce energy eg. ❖ Fossil fuel ❖ Biomass ❖ Solar power ❖ Wind energy ❖ Nuclear energy  What is an alternative energy source ? ❖ A form of energy, that can replace traditional fossil-fuel sources ❖ Energy generated from non-fossil fuel sources ❖ Sources which are not based on ✓ burning of fossil fuels or ✓ splitting of atoms  Why there is a need for alternative energy sources ? Some energy sources are ❖ costly ❖ polluting the environment & ❖ non-renewable eg. Fossil fuels (petroleum products and coal) Uranium (nuclear energy)  Examples for alternative energy sources ❖ Biomass ❖ Biofuel ❖ Natural gas ❖ Hydrogen gas ❖ Tidal energy ❖ Wind energy ❖ Geothermal energy ❖ Wave ❖ Electricity ❖ Solar energy All of them are not plant based.  Biomass ❖ It is the biological material derived from living, or recently living organisms ❖ Usually, the word refers to plant-based fuel. ❖ Includes all organic material originating from plants, including algae ❖ A store of the sun’s energy through photosynthesis.  Biomass ❖ Biomass energy (= bioenergy) is the conversion of biomass into useful forms of energy such as heat, electricity and liquid fuels. ❖ Can be used directly by combustion (heat) or indirectly by conversion to steam/ gas (then as electricity) or as liquid (then as fuels).  Plant based Biomass ❖ Different sources of plant-based biomass. ✓ Food processing wastes ✓ Wood and agricultural waste (eg. Sawdust, straw, coconut husks & shells, corncobs) ✓ Agro-industrial wastes (eg. Sugarcane bagasse, rice husk) ✓ Alcohol fuels (eg. Ethanol, Methanol) ✓ Landfill gas (eg. Methane) Different ways to generate energy ❖ Directly: ✓Combustion (eg. Solid biomass) ❖ Converted biomass: ✓Bacterial & fungal decaying (eg. Biogas) ✓Fermentation with yeast (eg. Alcohol fuels) ✓Biodiesel  Solid biomass ❖ Wood is the very first source of energy ❖ Still the major energy source, especially in the developing world ❖ Now there are many other sources of biomass  Some plant species used ❖ Gliricidia sepium ❖ Cassia spp. ❖ Cocos nucifera ❖ Saccharum officinarum ❖ Pennisetum purpureum Vishethi gon kaduru Jayapala divi kaduru Val kaduru ruduru Noganu vel devatu dara napuru Mahanuwara suupa sastra potha ed by Punchi Hewa Sannasgala  Biogas (= landfilled gas, LFG) eg. Methane ❖ Generated by breaking down of organic material by bacteria and fungus ❖ Converts cellulose to sugars, methane gas is still produced  Alcohol fuels (= ethyl alcohol) eg. Ethanol ❖ Earlier made by fermenting the sugars & starches found in crops (by yeast) and then distilling them eg. Corn, barley, sugar cane, rice, potato skins. ❖ In addition, now it is made by breaking down the cellulose into cellulosic ethanol eg. trees, grasses, saw dust and also crop waste cellulosic ethanol  Biodiesel ❖ Made by reacting alcohol with vegetable oils, animal fats, or greases ❖ Mostly produced from soybean oil ❖ Can be used alone or blended with normal petroleum products ❖ Non-toxic and biodegradable  Liquid bio fuels ❖ Liquid biofuels (Alcohol fuel and biodiesel) is considered to be carbon-neutral as the plants used to make the fuel, absorb CO2 as they grow and may offset the CO2 produced when the fuel is burnt. ❖ Biodiesel produces fewer air pollutants in comparison to normal diesel fuel (carbon monoxide, sulfur dioxide) Next level of biofuel production PLANTS AS ENVIRONMENTAL SENSORS http://upload.wikimedia.org/wikipedia/commons/thumb/e/ee/Sweetgum-leaf-interveinal-chlorosis.jpg/220px-Sweetgum-leaf-interveinal-chlorosis.jpg soybean vein necrosis  Plants as Biological indicators / Bioindicators (=Phytoindicators) They are the Plants that are used to measure environmental conditions/ pollutants ❖ Plant are sensitive to changing environmental conditions. ❖ They are in direct contact with both the soil and the atmosphere. ❖ They have specific environmental requirements ❖ Plants establish where conditions are favourable & limit distribution  Phytoindicators ❖ Plays an important role in the flow of contaminants through ecosystems. ❖ Distribution, occurrence, and behaviour of a plant are indicator of the factors prevailing in a habitat ❖ Plant act as a measure of environmental conditions ❖Therefore, can use a variety of vascular and lower plants (mosses) as phytoindicators.  An indication of contaminants can be obtained through Visual appearance of plants ❖ Can include leaf colour, vegetative habit and root structure Physiological measurements ❖ Growth rate, photosynthesis, flowering and yield  An indication of contaminants can be obtained through Chemical analysis of plant parts ❖ Provides a measure of the environmental mobility of the contaminant within the environment. ❖ Two methods used:  Naturally growing material can be collected from the field and analyzed  Placement of selected species in a location of interest for a period of time, then harvesting and analysing  Plant indicators for pollution ❖ Use of algae as an indicator of eutrophication. ❖ Increased algal mass in water due to high nutrition (N & P ran off from sewage and agricultural lands) ❖ Heavy metal accumulation in roots and leaves of aquatic plants ❖ Accumulates Cd, Lead, Nickel, Chromium etc. ❖ Plant species: Eichhornia crassipes Glyceria aquatica ❖ Algal species: Ulva ❖ Use of plants as bioindicators of air quality. ❖ The intensity of foliar injury can be used as an index of relative air quality for a particular pollutant ❖ Common symptoms due to air pollutants include ✓ Chlorosis: loss of green colouration in leaves  soybean vein necrosis ✓ Necrosis: death in leaf tissues ✓ Bronzing: leaves turn red- brown to brown ✓ Premature senescence: early loss of leaves ❖ Pollutants that can be detected include O3, SO2, Cl2 ❖ Some of indicating species Pinus ponderosa Nicotiana tabacum cultivars Needle tip browning of Pinus due to high levels of O3, SO2 ❖ Use of lichens (algae and fungi) as a measure of air pollutants such as SO2 and ozone. ✓ some lichens never found in polluted environments eg. Usnea, Evernia ✓ some can thrive little pollution eg. Parmelia ✓ some can thrive best in polluted environments eg. Xanthoria  Plant indicators for global warming ❖ There is a rapid increase in numbers and populations of some species due to warming in the Antarctic region ❖ Indicating species: Colobanthus quitensis  Plant indicators for moisture ❖ Plants indicating the depth of ground water Calotropis, Agave, Opuntia: low water availability Mangrove – water logged areas  Plant indicators for humus ❖ Presence of mushrooms, Strobilanthes and Impatiens indicate presence of humus  Plant indicators for Soil types ❖ Ipomoea pes-caprae in sandy soil ❖ Suaeda fruticosa in salty soil ❖ Shorea robusta (Sal) in calcium rich soil ❖ Vetiveria in clay soil In salty soil  Plant indicators for landmine detection ❖ Scientists have genetically modified the plant Thale Cress (Arabidopsis thaliana) to change its colour from green to red in the presence of high nitrate concentration such as that leached into the soil by landmines  Bioindicators ❖ Advantages Relatively inexpensive method (compared with other specialized technical measuring systems) Can be easily counted, due to their prevalence  Biological impacts can be directly determined  Early recognition of pollutant damage  Bioindicators ❖ Disadvantages  Not accurate always: There can be tolerant/ sensitive individuals in a plant population  Takes a longer time to indicate According to traditional knowledge, do you know any plants that were considered as indicators ? In this session, we have learnt ❖ Traditional uses and potentials In next session, we will learn about ❖ Sustainable utilization and conservation of plants