Light and temperature of an ecosystem
Download as PPTX, PDF12 likes15,026 views
This document discusses the factors of light and temperature in an ecosystem. It notes that light is essential for photosynthesis and plant growth. Light intensity is measured in units like foot candles and lux. Temperature also affects plant growth, reproduction, and metabolism. Temperature influences processes like vernalization and thermoperiodism. Plants are classified based on their temperature requirements, such as megatherms, mesotherms, and microtherms. Both light intensity and temperature are measured using instruments like photometers, lux meters, maximum–minimum thermometers, and thermocouples.
Light and temperature of an ecosystem
- 1. I am Ali Raza Roll no.2122
- 2. Light and temperature of an ecosystem The light factor Light is a form of radiant energy. It is an essential factor for the production of the plant materials upon which all other living organisms depend directly or indirectly.
- 3. The visible range of light is between 380 to 720 nm. The chloroplast absorb radiation from 330 to 740 nm. Only 39% of total radiation reaching the earth from the sun is visible light. 60% is infrared and 1%is ultraviolet.
- 5. Effects of light on plants 1. Photosynthesis. 2. Transpiration. 3. Seed germination. 4. Photoperiodism. 5. Reproduction and growth. 6. Influence upon number and position of chloroplast. 7. Changes in leaf structure.
- 6. Sun leaf Shade leaf
- 8. Ecological Classification • Heliophytes • Sciophytes • Facultative Sciophytes • Facultative Heliophytes
- 9. Measurement of light intensity The intensity of light is usually measured by an instrument called photometer or lux meter.
- 10. Unit of Measurement The intensity or brightness of light is measured in terms of candle power. The light intensity from standard candle at one foot distance is called foot candle (F.C) and at one meter distance is called lux (L) or meter candle (M.C) Radiometer
- 11. The Temperature Factor Temperature is a measurement of the degree of hotness. The radiant energy received from the sun is converted to heat energy. Heat is measured in calories.
- 12. Vernalization The flower production under the effect of low temperature is called vernalization.
- 13. Thermoperiodism A phenomenon in which growth or development is promoted by alternating day and night temperatures.
- 14. Importance of temperature to plant 1. Temperature and metabolism 2. Temperature growth and reproduction 3. Temperature favourable and unfavourable to plants Optimum temperature Maximum temperature Minimum temperature
- 15. Ecological classes of plants based on temperature 1. Megatherms 2. Mesotherms 3. Microtherms 4. Hekistotherms
- 16. Measurement of temperature Maximum minimum thermometer Thermograph Thermocouples and thermistors (water)