Dimensions Of Environment - Physical Introduction: Earth is the only planet that has shown signs of life. Our planet that was born of fire has undergone change since its evolution and today it has emerged as a perfect system. The natural forces have given rise to an environment that was favorable for growth of life. These forces have gained a perfect of balance and each of the components is dependent on each other. Now the earth looked more like a single living organism. The Greeks called the earth as Gaia or the Goddess Earth that was responsible for the well being of her domain.
Earth’s environment can be divided into four divisions : Atmosphere Biosphere Hydrosphere Lithosphere The names of the four spheres are derived from the Greek words for stone (litho), air (atmo), water (hydro), and life (bio).
Lithosphere : The lithosphere is the solid, rocky crust covering entire planet. The crust is inorganic and is composed of minerals. It covers the entire surface of the earth from the tallest top of Mount Everest (8850 mts) to the deepest bottom of the Mariana Trench (11033 mts). It consists of earth’s crust and upper mantle. Lithosphere is important for rocks, minerals, underground water, soil, etc.
Hydrosphere : The hydrosphere is composed of all of the water on or above the earth’s surface. This includes the oceans, rivers, lakes underground water and even the moisture in the air. 97 % of the earth’s water is in the oceans. The remaining 3 % is fresh water; three-quarters of the fresh water is solid and exists in ice sheets.
Atmosphere: The atmosphere is the body of air that surrounds our earth. Most of our atmosphere is located close to the earth’s surface due to gravitation force of earth. The air comprises of 78% nitrogen and 21% oxygen; the small amount of carbon dioxide and other gasses. 97% of the atmospheric gasses are concentrated upto a height of 29 kms from the earth’s surface.
Biosphere : The biosphere is life supporting arena of the earth. Plants, animals, and even one-celled organisms are part of the biosphere. Most of the planet’s life is found from three meters below the ground to thirty meters above it and in the top 200 meters of the oceans and seas. Life cannot sustain just with the presence of soil, water or air but needs presence of all the three.
Components of Environment : The Physical Components : The Physical components can be classified into two groups : Abiotic Components Biotic components
Abiotic Components :1. Location2. Altitude3. Climate a) Temperature b) Precipitation4. Soil5. Geology
Biotic Components :1. Producers: Oxygen is given out as a by-product of photosynthesis. The process of photosynthesis can be summarized as follows: Carbon dioxide + Water + Solar energy Glucose + Oxygen
Biotic Components :2. Consumers: Organisms that get the nutrients & energy they require by feeding either directly or indirectly on producers are called consumers or heterotrophs (other feeders). Some consumers feed on small fragments of dead plant & animal matter, called detritus. Consumers are divided into different categories depending upon the food they consume. Herbivores (Plant eaters). Carnivores (Flesh eaters). Omnivores (Plant & Flesh eaters). Detritivores.
Biotic Components :3. Food Chain: All ecosystems are made up of food chains that begin with energy. The flesh of the herbivore provides nutrition & energy to the carnivore. Thus, energy is passed on from one organism to another step by step, thus establishing a link. These links together form a food chain.
Biotic Components :4. Food Web : Food chain represents an isolated relationship between the producers & consumers. In reality or in the environment all elements are inter-related & inter-dependent and hence we find that the elements of different food chains are inter-related or inter-dependent on the elements of different food chains. Such a set of intergraded food chains is called as a food web.
Biotic Components :5. Levels of Organisms in Nature : Each food chain consists of different segments or levels known as tropic level. The points of energy transfer in an environment to an organism & then from that organism to another define each level.
Biotic Components :6. Energy flow in the ecosystem : The living organisms need energy for functioning. They use 90% or more of the energy. Thus at every trophic level 90% of the energy is lost & only 10% is passed to next level. So the amount of energy reduces considerably as it passes from one trophic level to another. Hence, the number of consumers at every stage that can survive comfortably is always less than at its previous stage.