Development of Ecological systems- Surn

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Eco-systems : 

Eco-systems Home is where we are . Planet earth or mother earth with all her life-support systems - Atmosphere Hydrosphere Lithosphere Solar Energy Eco-system with bio-diversity of fauna and flora.

Eco-balance Health,Happiness,Prosperity : 

Eco-balance Health,Happiness,Prosperity Early man was in harmony with nature. Hunting and agriculture activities were seldom a threat to the environment. Less population pressures produced less eco-strain. Eco-systems balances intact barring natural catastrophes. Sustainable human development– need of the hour (i) New eco-threats emerging due to industrial growth and development in the post-industrial age scenario- (ii) Pollution effects on environment upsetting ecological systems. (iii)Increased energy demands of human civilization- depletion of non-renewable energy resources and environment degrading effects.

What is ECOLOGY? : 

What is ECOLOGY? 1.Ecology – from Greek word ‘oikos’,meaning house (or households of planet earth.) 2.It is the sum total of abiotic and biotic interactions of organisms in the bio-sphere. 3. Addresses the survival (adaptation) and population growth dynamics & existence of the species. [Abiotic environment of an organism includes atmosphere,hydrosphere& lithosphere. Also physical & chemical factors like temperature,rainfall, pressure,pH,oxygen,carbon-dioxide, etc. Biotic environment includes all living organisms with their interactions and also with the abiotic environment.]

Bio-sphere : 

Bio-sphere Part of the earth where eco-systems operate. (ie. lithosphere,hydrosphere & atmosphere) Grasslands- plains,prairies,steppes. Tropical forests- eg. in Asian and South American continents. Mountain forests- deciduous,coniferous . Natural wetlands-ponds,lakes etc. Constructed wetlands.

Importance of man in the world eco-system : 

Importance of man in the world eco-system Development of man and his dependence on the eco-system. From struggle with nature to use and control of nature. Mans food,fuel,medicines derived from the environment . Interactions with own and other species.

Purpose and beauty of eco-studies : 

Purpose and beauty of eco-studies Understanding the natural order that consists of dynamic interplay of countless organisms. How do chemicals & nutrients circulate between environment and organisms? Water cycle,oxygen cycle,carbon cycle,carbon-dioxide cycle,nitrogen cycle,sulphur cycle in bio-sphere.

How is energy utilised and transferred? Knowledge of land ,air and water and how to better manage and utilise these precious natural resources. Handling wastes,& pollution threats to the environment. Natural and artificial eco-systems. Improved food and fuel production. Safeguarding the earth.

The Bio-sphere : 

The Bio-sphere Atmosphere consists of Troposphere –(10-18 Km.) contains 4/5 th of the atmospheric air-mass .Also collects moisture from oceans .Suns heat produces changing hot/cold wind currents which may carry evaporated water in the air towards or away from land masses- thus changing climate and ecology/bio-diversity. Stratosphere- (10-50Km.)free from clouds/vapour but rich in ozone.Protects the bio-sphere from deadly UV radiation from sun. Mesosphere- (50-85 Km.)less ozone,but oxygen and nitrogen oxide.

Stratosphere : 

Stratosphere Stratosphere heating prevents heating of the bio-sphere and UV radiation from sun harming living organisms on terra firma (earth) Photo-chemical reactions in stratosphere. O2 + hv ? O + O (?< 242 nm.) O2 + O + N2 (or O2 ) ? O3 + N2 (or O2 ) O3 + hv ? O2 = O (?< 400 nm.) O + O3 ? 2O2

Ionosphere -several layers containing oxygen,nitrogen oxide,ionised by solar radiation –used in radio communication. Exosphere- (>500 Km.) low air density,outer space begins. Lithosphere- formed 5-6 billion years ago. Earth’s crust – 16-50 Km.deep with soil several inches to many feet deep .Many organisms of the bio-sphere survive,grow and reproduce here. bacteria.virus,fungi,algae,protozoa,molluscs, arthropods etc.

Mantle- 2880 Km. Of hard rocks Mg. And Fe. 84% earths volume ,67% of earths weight. Core - Ni. and Fe. In solid/molten form. Soils- sandy - 30% pore space clay - 50% pore space. Different particle sizes and porosity.

Land Resource/Utility : 

Land Resource/Utility India has 1.3 mln. – 44% - agriculture(~ 2% GDP growth contr.) 23% - forest 8% - industry( ~ 2% of GDP growth contr.) 4% - grazing 14% - barren 7% - misc. Indian successes Green revolution- >200 mln. tonnes food-grain production, self-sufficient for 1 bln. people. White revolution . Worlds 2nd largest fruit producer. Worlds 2nd largest vegetable producer.

Organism and environment interactions : 

Organism and environment interactions Organism not static – in dynamic equilibrium with the environment. Organism must adapt to environment changes for its survival,growth and reproduction. External environment changes –eg. of temperature,humidity,pressure,pH,oxygen etc. must be first be counter-acted by the outer shell or skin of the organism.

Capacity or extent of the organisation to adapt to environment changes determines its evolutionary success or survivability. eg. virus or bacteria strains resistant to anti-biotics. Salamander reared in oxygen deficient water developes larger gills. Bacteria are known to have survival mechanisms to endure harsh environments-eg. 100 degrees C , several atmospheres pressure ,excessive acidity/alkinity etc. Beaks & tails of birds vary depending on the local adaptation eg for mountain birds,water-birds,and birds on plains. Body sizing of mammals in colder environments.

Homeostasis mechanisms that result in stabilisation of the organism’s internal environment when there are external environmental changes. Different species(genotypes) adapt in different ways to environmental changes.Within a genotype (with its genetic structure,physiology morphology,behavior,etc) there may be several pheno-types – ie. based on local populations of same species adaptating in different ways to environment stresses.

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