ecosystem class 12 ppt investigatory project

ecosystem defination and other information

1. ECOSYSTEM GUIDED BY: BABITA J SINGH PRESENTED BY: MAYANK TRIVEDI CLASS : 12 th ROLL NO : 35

2. ACKNOWLEDGEMENT I would like to thank my wonderful Biology teacher Babita ma’am for giving me this amazing learning opportunity to work on a topic of my choice.

3. INDEX INTRODUCTION COMPONENTS OF ECOSYSTEM PRODUCTIVITY DECOMPOSITION ENERGY FLOW ECOLOGICAL PYRAMIDS ECOLOGICAL SUCCESSION SUCCESION OF PLANTS NUTIENT CYCLE ECOSYSTEM SERVICES BIBLOGRAPHY

4. Components of ecosystem: Abiotic Components : The abiotic components of an ecosystem are all of the nonliving elements. They include the water, the air, the temperature and the rocks and minerals that make up the soil.   Producers at the Base : Producers are the living organisms in the ecosystem that take in energy from sunlight and use it to transform carbon dioxide and oxygen into sugars. Plants, algae and photosynthetic bacteria are all examples of producers. Consumers in the Chain: Consumers are living organisms in the ecosystem that get their energy from consuming other organisms. Conceptually, consumers are further subdivided by what they eat: Herbivores eat producers, carnivores eat other animals and omnivores eat both. Decomposers and Nutrient Cycling: Decomposers are the living component of the ecosystem that breaks down waste material and dead organisms . They perform a vital recycling function, returning nutrients incorporated into dead organisms to the soil where plants can take them up again

5. Productivity: The rate of synthesis of organic matter (biomass) during a given period of time. It is measured as weight (g-2) or as energy (kcal m-2). It is used to compare productivity of different ecosystems. Primary productivity : It is the amount of biomass produced per unit area in a given time period by Plants during Photosynthesis. Secondary productivity It is the amount of biomass produced at any of the Consumer levels in a given period of time.

6. Decomposition: It is the process of breaking down of dead organic matter into smaller organic molecules and inorganic molecules by Decomposers (bacteria, fungi)   DETRITUS: Dead remains of plants and animals is called detritus.  DETRITIVORES: Animals that feed on decaying organic matter (detritus).   Mechanism of Decomposition:  Fragmentation of Detritus  Leaching: Catabolism: Humification :  

7. Energy Flow: SUN­ Main Source of energy. 50% of incident light is PHOTOSYNTHETICALLY ACTIVE RADIATION (PAR) Only a small fraction of this (stored as organic compounds) is transferred to consumers; the rest is used up in respiration and other life­supporting activities of the plants. As energy is transferred as food, most part is lost as heat at each stage (10% LAW) Unidirectional flow of Energy:

8. Ecological Pyramids: Pyramids are an expression of the relationship between organisms at different tropic levels in terms of their number, biomass or energy.   Pyramid of Number: The relationship between producers and consumers in an ecosystem can be represented in the form of a pyramid in terms of number called pyramid of number. Pyramid of Biomass: The relationship between producers and consumers in an ecosystem can be represented in the form of a pyramid in terms of biomass called pyramid of biomass. It can be of two types: Upright (in case of grassland ecosystem)  Inverted (in case of pond ecosystem) 3. Pyramid of energy: The relationship between producers and consumers in an ecosystem can be represented in terms of flow of energy called pyramid of energy. It is always upright.

9. Ecological succession: Refers to predictable and orderly change in the composition or structure of a community. May be initiated either by formation of new, unoccupied habitat or by some form of disturbance of an existing community. Sere – entire sequence of community that successively change in a given area.

10. Primary Succession : If the development begins on an area that has not been previously occupied by a community. Pioneer species – lichens, phytoplankton, etc. Secondary Succession:  If the community development is proceeding in an area from which a community was removed. Pioneer species – grasses, wildflowers, algae. Examples:an abandoned crop fieid .

11. Succession of plants: Hydrarch succession:It takes place in wetter areas and the successional series progress from hydric to the mesic conditions. Xerarch succession :It takes place in dry areas and the series progress from xeric to mesic condition. Bare rock ­> Lichens and mosses ­> Annual grasses ­> Perennial grasses ­> Shrubs ­> Tall Trees

12. Nutrient Cycle: Also known as biogeochemical cycle. Environmental factors like soil, moisture, temperature, etc. regulate the rate of release of nutrients into the atmosphere. Nutrients are never lost from the ecosystem; they are recycled time an again indefinitely. There are two types: Gaseous cycle Sedimentary cycle  

13. Ecosystem Services: Humankind benefits from a multitude of resources and processes that are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem services. Purify air and water   Decomposition of waste materials Cycle nutrients   Pollinate crops Maintain biodiversity . Researchers have put an average price tag of US $33 trillion a year on these fundamental ecosystems services, which is largely taken for granted because they are free.

14. A Barren Ecosystem: Barren vegetation   describes an area of land where plant growth is sparse, stunted, or possesses little biodiversity. Poor growth may occur due to high winds, climate, salt spray, infertile or toxic soil, or heavy exploitation by humans. Barrens may look poor—with shrubs or moss instead of trees—but they provide good environments for rare plant and animal species that can't compete in nutrient-rich environments. Many serpentine barrens host unique assemblages of plant species. Some barrens, such alpine barrens, are well-wooded with fairly tall trees, though the only smaller plants present are those adapted to a low nutrient supply.

15. Methods Of Desert Greening: Managed intensive rotational grazing Holistic management Landscaping methods to reduce evaporation, erosion, consolidation of topsoil, sandstorms, temperature and more Permaculture in general - harvesting runoff rainwater to grow plant communities polyculture, composting or multitrophic agriculture Planting trees (pioneer species) and salt-loving plants such as Salicornia and Halophytes Regeneration of salty, polluted, or degenerated soils Floodwater retention and infiltration (flood control) [1] Greenhouse agriculture like the Integrated Biotectural System Seawater farming like done by the Seawater Foundation Inland agriculture Prevention of overgrazing and firewood use Training of local residents to care for plantings, water systems etc. Planting trees with dew and rain harvesting technology

16. Modern example: A modern example of desert farming is the Imperial Valley in California, which has high temperatures and average rainfall of just76 mm per year. The economy is heavily based on agriculture and the land is irrigated through a network of canals and pipelines sourced entirely from the Colorado River via the All-American Canal. The soil is deep and fertile, being part of the river's flood plains, and what would otherwise have been desert has been transformed into one of the most productive farming regions in California. Another problem of growing crops in this way is the build-up of salinity in the soil caused by evaporation of river water. The greening of the desert remains an aspiration and was at one time viewed as a future means for increasing food production for the world's growing population. This prospect has proved false as it disregarded the environmental damage caused elsewhere by the diversion of water for desert project irrigation.

17. BIBLOGRAPHY GOOGLE WIKIPEDIA NCERT TEXT BOOK