Here is your essay on Essay on the Biosphere!
The entire world basically can be broadly classified into abiotic world and biotic world. The abiotic world can be further divided into three packages: the atmosphere (air), the lithosphere (earth) and the hydrosphere (water). To these three ecological components we can add the biological world or biotic world, the biosphere.
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All four subdivisions thus represent four major global components of the world ecosystem. These four spheres continuously exchange matter with one another, but obviously there are differences in the relative and total amounts of the natural elements in each organisms take in inorganic nutrients from the soil, water and air; they eliminate their wastes, and their bodies are rendered into inorganic molecules once again. Water and minerals shuttle among the air, land and water with an occasional pause in an organism.
Thus, the biosphere is that part of the earth in which life exists (Hutchinson, 1970). More specifically, the sum of those portions of the hydrosphere, lithosphere and atmosphere into which life penetrates is the biosphere. However, together with the geological, chemical features of the totality of our habitats, these (air, water and earth, and organisms) are sometimes grouped under the term ecosphere (Cole, 1958).
Biosphere or ecosphere may be thought of as a biochemical system capable of capturing, converting, storing, and utilizing the energy of the sun. Approximately three hundred thousand species of green plants and micro-organisms are recognised as primary producers which utilize inorganic elements and compounds to synthesize the organic materials of life.
Their productivity is consumed by more than a million other species of organisms which convert this organic storehouse into animal form, adding to the beauty, and value of the biosphere as well as its complexity.
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Still other species, primarily bacteria and fungi, accomplish the recycling process by returning plant and animal wastes and residues to inorganic form so the process may be renewed. In this cyclic process of life, many elements are shared from a common global pool and are converted from inorganic to organic form and back again.
Examples of such elements which commonly shuttle among the air, water, earth and organism are carbon, oxygen, hydrogen, nitrogen, phosphorus, sulphur, sodium, potassium, calcium, magnesium, iron, manganese, cobalt, copper, and zinc.
The oldest known photosynthetic organisms are at least two billion years old, and throughout this vast period of time, the entire biosphere has matured and evolved as a self-regulatory system with internal checks and balances.
It has developed a remarkable degree of homeostasis and ecological control within its various components. In forthcoming chapters; we will consider in more detail the process of photosynthesis or primary production, the cyclic passage of elements, the flow of energy through living organisms, the growth and development of populations, and the diversity and maturation of communities and ecosystems.
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In physical terms, the biosphere is a relatively thin and incomplete envelope covering most of the world. It represents b mosaic of different biotic communities from simple to complex, aquatic to terrestrial, and tropical to polar. It does not exist in the extremities of the Polar Regions, the highest mountains, the deepest ocean troughs, the most extreme deserts, or the most highly polluted areas of land and water.
Its total thickness, including all portions of the earth where living organisms can exist, is less than 26 kilometres. Its zone of active biological production, in terms of photosynthesis, is much narrower, and varies from a few centimeters to over 100 metres.
This zone would, for instance, be only a few centimeters in muddy or turbid water, whereas in very clear ocean water, it could be more than 100 metres in thickness. On land, the zone of biological production might be only a few millimeters in a desert or rock environment, whereas it might again be more than 100 metres in a sequoia or tropical rain forest.
Living organisms can exist, of course, beyond the range of active biological production; some insects or birds may be airborne to altitudes above 20,000 feet, and viable spores, seeds of plants, and microorganisms may be found in the atmosphere and mountain tops above 25,000 feet.
In the ocean depths, many animals cam exist well below a thousand feet—one hydra-like animal has been photographed at a depth of 15,900 feet in the south Atlantic. However, in both extreme altitude and extreme depth, the organisms depend upon the much thinner zone of active biological production, that portion of the system which converts the energy of sunlight into the chemical and physical energy of living organisms.