good news.....
we have holidays up to sunday.
because of YSR'S death ( Bad News?)
SO,
Submit the assignment on MONDAY(7/9/09).
Thursday, September 3, 2009
FIRST MID ASSIGNMENT 2: SUBMIT ON SATUR DAY(5/9/09)
4 a). Zonation of oceans:
FIGURE IS IN NEXT POST. OCEAN ZONES
Oceans cover more than 2/3rd of the earth’s surface. The ocean environment is characterized by its high concentration of salts and minerals. It supplies huge variety of sea-products and drugs. It also provides us iron, magnesium, phosphorous, natural gas.
Zones of oceans:
Intertidal zone: The ocean connect to the land via what is called the inter-tidal zone. Because of rising and falling tides, coastal areas are constantly changing, with various animals and marine plants living at the bottom, and on the seashore. Rocky coastal areas are host to fewer species due to the fact that only the highest of tides will reach the top of the cliffs.
Neritic zone: This is the relatively shallow ocean that extends to the edge of the continental shelf. Primary productivity here depends on planktonic algae growing as deep as the light can reach.
Epipelagic Zone: The surface layer of the ocean is known as the epipelagic zone and extends from the surface to 200 meters. It is also known as the sunlight zone because this is where most of the visible light exists.It is host to many species of fish and marine mammals, plankton ,and some floating seaweed. With the light come heat, responsible for the wide range of temperatures that occur in this zone.
Mesopelagic Zone: Below the epipelagic zone is the mesopelagic zone, extending from 200 meters to 1000 meters. The mesopelagic zone is sometimes referred to as the twilight zone or the midwater zone. The light that penetrates to this depth is extremely faint. It is in this zone that we begin to see the twinkling lights of bioluminescent creatures. A great diversity of strange and bizarre fishes can be found here.
Bathypelagic Zone: The next layer is called the bathypelagic zone. It is sometimes referred to as the midnight zone or the dark zone. This zone extends from 1000 meters down to 4000 meters. Here the only visible light is that produced by the creatures themselves. The water pressure at this depth is immense and temperature is low, In spite of the pressure, a surprisingly large number of creatures can be found here. Sperm whales can dive down to this level in search of food. Most of the animals that live at these depths are black or red in color due to the lack of light.
Abyssopelagic Zone: The next layer is called the abyssopelagic zone, also known as the abyssal zone or simply as the abyss. It extends from 4000 meters to 6000 meters. The name comes from a Greek word meaning "no bottom". The water temperature is near freezing, and there is no light at all. Very few creatures can be found at these crushing depths. Most of these are invertebrates such as basket stars and tiny squids. Three-quarters of the ocean floor lies within this zone. The deepest fish ever discovered was found in the Puerto Rico Trench at a depth of 8,372 meters.
Hadalpelagic Zone: Beyond the abyssopelagic zone lies the forbidding hadalpelagic zone. This layer extends from 6000 meters to the bottom of the deepest parts of the ocean. These areas are mostly found in deep water trenches and canyons. The deepest point in the ocean is located in the Mariana Trench off the coast of Japan at 10,911m. The temperature of the water is just above freezing, and the pressure is an incredible eight tons per square inch. That is approximately the weight of 48 Boeing 747 jets. In spite of the pressure and temperature, life can still be found here. Invertebrates such as starfish and tube worms can thrive at these depths.
Role played by the oceans in terms of providing resources and regulating climate: Oceans represent the largest and most diverse of the ecosystems; The sea has always played an important role in the life of those people who live around its shores. Salt water evaporates and turns to rain which falls on the land regions, while most of the oxygen in our atmosphere is generated by algae. Algae is also responsible for the absorption of large amounts of carbon dioxide from our atmosphere.
The oceans, which cover more than 70% of the earth’s surface, play a fundamental and complex role in regulating climate. The oceans absorb huge amounts of solar energy; ocean currents transport this heat from the equator toward the Poles. In the past, long-term, natural oscillations in the oceans’ capacity to store and transport heat have led to global temperature changes.
As part of a vast planetary cycle of evaporation and rainfall, the oceans are also fundamental to the movement of water around the globe. Measuring changes in precipitation patterns, and understanding how they may lead to droughts in some regions and flooding in others, is a major part of predicting the potential effects of global climate change on human activities and natural ecosystems.
4 b). Define Ecosystem and explain pond ecosystem:
Ecosystem: An ecological community together with its environment, functioning as a unit or Community of living organisms (populations of species) interacting with one another and with the non-living environment.
Simple Pond Ecosystem:
FIGURE IS NEXT POST: SIMPLE POND ECOSYSTEM
Pond ecosystems range in size from just a few square meters to thousands of square kilometers. Scattered throughout the earth. Many ponds are seasonal, lasting just a couple of months (such as sessile pools) while lakes may exist for hundreds of years or more. Ponds and lakes may have limited species diversity since they are often isolated from one another and from other water sources like rivers and oceans. Lakes and ponds are divided into three different “zones” which are usually determined by depth and distance from the shoreline.
Littoral Zone: The topmost zone near the shore of a lake or pond is the littoral zone. This zone is the warmest since it is shallow and can absorb more of the Sun’s heat. It sustains a fairly diverse community, which can include several species of algae (like diatoms), rooted and floating aquatic plants, grazing snails, clams, insects, crustaceans, fishes, and amphibians. In the case of the insects, such as dragonflies and midges, only the egg and larvae stages are found in this zone. The vegetation and animals living in the littoral zone are food for other creatures such as turtles, snakes, and ducks.
Limnetic Zone: The near-surface open water surrounded by the littoral zone is the limnetic zone. The limnetic zone is well-lighted (like the littoral zone) and is dominated by plankton, both phytoplankton and zooplankton. Plankton are small organisms that play a crucial role in the food chain. Without aquatic plankton, there would be few living organisms in the world, and certainly no humans. A variety of freshwater fish also occupy this zone.
Profundal Zone: Plankton have short life spans—when they die, they fall into the deep-water part of the lake/pond, the profundal zone. This zone is much colder and denser than the other two. Little light penetrates all the way through the limnetic zone into the profundal zone. The fauna are heterotrophs, meaning that they eat dead organisms and use oxygen for cellular respiration.
Temperature varies in ponds and lakes seasonally. During the summer, the temperature can range from 4° C near the bottom to 22° C at the top. During the winter, the temperature at the bottom can be 4° C while the top is 0° C (ice). In between the two layers, there is a narrow zone called the thermocline where the temperature of the water changes rapidly. During the spring and fall seasons, there is a mixing of the top and bottom layers, usually due to winds, which results in a uniform water temperature of around 4° C. This mixing also circulates oxygen throughout the lake. Of course there are many lakes and ponds that do not freeze during the winter, thus the top layer would be a little warmer.
5 a). Elements of an ecosystem and their interdependency:
Ecosystem: Community of living organisms (populations of species or biota ) interacting with one another and with the non-living (abiotic) environment.
All living things that inhabit an environment are Biotic Factors. All nonliving things that inhabit an environment are Abiotic Factors.
Abiotic Components:
Water, air, temperature, soil, nutrients, minerals, light levels, moisture, precipitation, salinity.
Biotic Components:
Producers, consumers, decomposers
Plants, animals, bacteria/fungi
Biotic interactions with abiotic components include predation, competition, symbiosis, parasitism, commensalism etc.
FIFURE IS IN NEXT POST:Figure: Relationships within an ecosystem
Figure: Relationships within an ecosystem
Organisms that make up the biotic component of an ecosystem are usually classified as autotrophs and heterotrophs, based on how they get their food or organic nutrients they need to survive.
Autotrophs(producers): are organisms that can manufacture the organic compounds they need as nutrients from simple inorganic compounds obtained from their environment. In most terrestrial ecosystems, green plants are the producers. In aquatic ecosystems, most of the producers are phytoplankton, consisting of various species of of floating and drifting bacteria and protist.
Most producers make their organic nutrients they need through photosynthesis. The overall net chemical change can be summarized as follows:
6 CO2 + 6 H2O + solar energy -----> C6H12O6 + 6 O2
Some producers , mostly specialized bacteria, can extract inorganic compounds from their environment and convert them into organic nutrient compounds without the presence of sunlight. These producers are called chemosynthesis. An example of this is around the hydrothermal vents in some parts of the deep ocean. Bacteria carry out chemosynthesis by converting inorganic hydrogen sulfide to organic nutrients.
Heterotrophs(consumers)-are organisms which cannot synthesize the organic nutrients they need and get their organic nutrients by feeding on the tissues of producers or other consumers. There are several classes of of consumers, depending on there food source.
1.Primary consumers (herbivores) feed directly on plants or other producers.
2.Secondary consumers (carnivores) feed only on primary consumers.
3.Tertiary or higher level consumers feed only on animal-eating animals.
4.Omnivores can eat both plants and animals.Examples are pigs, rats, cockroaches, and humans.
5.Detrtivores (decomposers and detritus feeders) live off of detritus, parts of dead organisms and castoff fragments and waste of living organisms. Decomposers digest detritus by breaking down the complex organic molecules in these materials into simpler, inorganic compounds. Decomposers consist of various bacteria and fungi.
5 b). Bidiversity Types: Genetic Diversity and Species Diversity..
Biodiversity is a modern term which simply means " the variety of life on earth". This variety can be measured on several different levels.
Genetic - variation between individuals of the same species. This includes genetic variation between individuals in a single population , as well as variations between different populations of the same species. Genetic differences can now be measured using increasingly sophisticated techniques. These differences are the raw material of evolution.
Species - species diversity is the variety of species in a given region or area. This can either be determined by counting the number of different species present, or by determining taxonomic diversity. Taxonomic diversity is more precise and considers the relationship of species to each other. It can be measured by counting the number of different taxa (the main categories of classification) present. For example, a pond containing three species of snails and two fish, is more diverse than a pond containing five species of snails, even though they both contain the same number of species. High species biodiversity is not always necessarily a good thing. For example, a habitat may have high species biodiversity because many common and widespread species are invading it at the expense of species restricted to that habitat.
6 a). BIO-DIVERSITY hot-spots:
A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is threatened with destruction.
In 1988, British ecologist Norman Myers developed the concept of biodiversity hotspots to address the dilemma of identifying areas most important for preserving Species. Many areas of global significance face tremendous pressure from logging, agriculture, hunting, and Climate change. The hotspots strategy emphasizes risks of species extinction since species loss is irreversible. Since these species can only be found in specific areas, the loss of such areas would be considered “irreplaceable.” The strategy also emphasizes species endemism.
To qualify as a biodiversity hotspot the regions must support at least 1,500 plant species found nowhere else in the world and Such areas must have lost at least 70 percent of its original Habitat.
It has been estimated that 50,000 endemic plants which comprise 20% of global plant life, probably occur in only 18 ‘hot spots’ in the world. Countries which have a relatively large proportion of these hot spots of diversity arereferred to as ‘megadiversity nations’.
Biodiversity Hotspots in India :
Western Ghats (Sahyadri Hills):
The Western Ghats , also known as the Sahyadri Hills , is a mountain chain running from the north to the South and is isolated by the Arabian Sea to the West, the arid Deccan Plateau to the East, and the Vindhya-Satpura ranges to the North. They have different vegetation types: scrub jungles and grasslands at low altitudes, dry and moist deciduous forests, montane grasslands and shoals, and the precious tropical evergreen and semi evergreen forests. Complex topography, high rainfall and relative inaccessibility have helped the region retain its biodiversity. Of the estimated 17000 species of flowering plants reported from india, about 4780 species are found in the western ghats region, of which 1720 (more than 1/3rd ) are endemic. Of the 372 species of mammals found in india, 63 are in the western Ghats, of which 16 are endemic. in addition 91 species of reptiles and 84(50%) species of amphibians(62%) are also endemic to these region. Some of endemic species in these region are:
Lion-tailed macaque, Nilgiri Hangul, Malabar Civet, Nilgiri marten, Indian gaint sqirrell, small travancore flying squirrel and Nilgiri Tahr.
Indo-Burma ( Eastern Himalayas ) :
Geographhically these area comprises Nepal, Bhutan and neighboring states of Northern India. There are 35000 plant species found in the Himalayas, of which 30% are endemic. Out of the 372 species of mammals found in india, 300 are in the western Ghats, of which 12 are endemic. In addition 48 out of 176 species of reptiles, 42 out of 85 species of amphibians and 15 out of 977 birds are also endemic to these region. The eastern Himalayas are also rich in wild plants of economic value and huge wealth of fungi, insects, mammals and birds.
6 b). In Situ Conservation :- within the natural habitat:
In situ conservation maintains not only the genetic diversity of species, but also the evolutionary adaptations that enable them to adapt continually to shifting environmental conditions, such as changes in pest populations or climate. In situ conservation also ensures that along with target species, a host of other interlinked species are also preserved as a by-product. It is generally cheaper than ex situ methods (although not cheap). It may often be the only conservation option, for example for species with recalcitrant seeds.
In situ conservation measures involve designating specific areas as protected Areas. Protection may be offered at various levels, from complete protection and restriction of access, through various levels of permitted human use. It includes a system of protected areas of different categories, e.g. National Parks, Sanctuaries, Nature Reserves, Natural Monuments, Cultural Landscapes, Biosphere Reserves, etc. protected areas of India cover 156,700 km², roughly 4.95% of the total surface area.
The biosphere reserve concept has been developed through the Man and Biosphere (MAB) Programme of the United Nations Educational, Scientific and Cultural Organization (UNESCO). Biosphere reserves are an attempt to reconcile the problems of conserving biodiversity and biological resources, with sustainable use of natural resources for people.
Seven of the fifteen biosphere reserves in India are a part of the World Network of Biosphere Reserves, based on the UNESCO Man and the Biosphere (MAB) Program list are:
• Nilgiri Biosphere Reserve
• Nanda Devi Biosphere Reserve
• Sundarbans Biosphere Reserve
• Gulf of Mannar Biosphere Reserve
• Pachmarhi Biosphere Reserve
• Nokrek Biosphere Reserve
• Simlipal Biosphere Reserve
There are more than 600 Protected Areas in India of which 96 are National Parks (38,029.18 km², 1.16% of India's total surface area), 15 are biosphere reserves and over 500 are Wildlife Sanctuaries. They include a variety of ecosystems and habitats. Some have been created in order to protect highly endangered species of wild plants and animals found nowhere else in the world.
The Great Himalayan National Park is the largest sanctuary in this ecosystem and is one of the last homes of the beautiful snow leopard.
Dachigam Sanctuary is the only place where the rare Hangul or Kashmir stag is found. There are several Sanctuaries in the Terai region,
Kaziranga National Park is the most famous which has elephant, wild buffalo, gaur, wild boar, swamp deer, and hog deer, in large numbers, as well as tiger and leopard. Its bird life is extremely rich and includes ducks, geese, pelicans and storks.
The Manas Sanctuary, in addition to the above Terai species, also includes the rare golden langur and the very rare pygmy hog, the smallest wild boar in the world. The florican is found only in a few undisturbed grasslands in the Terai sanctuaries.
In the sal forests of Madhya Pradesh, there are several Protected Areas. Kanha offers a wonderful opportunity to observe wild tigers from elephant back. It is the only Protected Area in which a sub species of the Barasingha is found.
Bharatpur is one of the most famous water bird sanctuaries in the world. Thousands of ducks, geese, herons, and other wading birds can be seen here. This is the only home of the very rare Siberian crane which migrates to India every winter. During the last 20 years, the 30 or 40 Siberian cranes have dwindled to only 2 or 3. During 2002-03 no cranes were seen and it is possible that this beautiful bird will never again come to India.
In the Thar desert, the wild life is protected in the Desert National Park. Here large numbers of black buck, neelgai and chinkara can be seen. The Great Indian Bustard lives in these arid lands.
Ranthambor was the most well known sanctuary for observing tigers in the wild till about 3 or 4 years ago. Since then many tigers have been killed by poachers.
The Great and the Little Rann of Kutch have been made into sanctuaries to protect the very rare wild ass, the flamingo, the star tortoise and the desert fox.
In Gujarat, the Gir Sanctuary protects the last population of the majestic Asiatic lion. This thorn and deciduous forest is also the home of large herds of chital, sambhar, and nilgai.
The Sanctuaries of the Western Ghats and associated hill ranges protect some of the most diverse forest types in the country. The few examples of highly threatened species include the Malabar giant squirrel, the flying squirrel and a variety of hill birds, several species of amphibians, reptiles and insects. These regions are also rich in highly endemic plant life. Sanctuaries such as Bhimashankar, Koyana, Chandoli and Radhanagari preserve this rich flora in Maharashtra, Bandipur, Bhadra, Dandeli, Nagarhole, etc. in Karnataka, and Eraviculum, Perambiculum, Periyar, Silent Valley, in Kerala.In the Nilgiri Hills the rich forest Sanctuaries protect some of the last pockets of the Indian elephant in South India. Examples include Bandipur, Madhumalai, Wynad and Bhadra. During the last 10 years, a large number of the great tusker elephants of this region have been ruthlessly killed for their ivory. Now very few of these magnificent animals are left in these jungles.
Two important sanctuaries meant for preservation of coastal ecosystems are the Chilka Lake and Point Calimere. The Sunderbans protect the largest mangrove delta in India. The Marine National Park in Gujarat protects shallow areas in the sea, islands, coral reefs and extensive mudflats.Over a hundred Protected Areas have been created in the Andaman and Nicobar Islands to preserve their very special island ecosystems.
Ex Situ Conservation : - Outside the natural habitat
Conservation of a species is best done by protecting its habitat along with all the other species that live in it in nature. This is known as in-situ conservation, which is conserving a species in its own environment by creating National Parks and Wildlife Sanctuaries. However, there are situations in which an endangered species is so close to extinction that unless alternate methods are instituted, the species may be rapidly driven to extinction. This strategy is known as ex-situ conservation, i.e. outside its natural habitat in a carefully controlled situation such as a botanical garden for plants or a zoological park for animals, where there is expertise to multiply the species under artificially managed conditions. These breeding programs for rare plants and animals are however more expensive than managing a Protected Area.
There is also another form of preserving a plant by preserving its germ plasm in a gene bank so that it can be used if needed in future. This is even more expensive. When an animal is on the brink of extinction, it must be carefully bred so that inbreeding does not lead to the genetic makeup becoming weak. Breeding from the same stock can lead to poorly adapted progeny or even inability to get enough offspring. Modern breeding programs are done in zoos that provide for all the animal’s needs, including enclosures that simulate their wild habitats. In India, successful ex situ conservation programs have been done for all our three species of crocodiles. This has been highly successful. Another recent success has been the breeding of the very rare pygmy hog in Gauhati zoo. Delhi zoo has successfully bred the rare Manipur brow antlered deer. However the most important step of a successful breeding program is the reintroduction of a species into its original wild habitat. This requires rehabilitation of the degraded habitat and removal of the other causes such as poaching, disturbance, or other manmade influences that have been the primary cause of reducing the population of the species.
FIGURE IS IN NEXT POST. OCEAN ZONES
Oceans cover more than 2/3rd of the earth’s surface. The ocean environment is characterized by its high concentration of salts and minerals. It supplies huge variety of sea-products and drugs. It also provides us iron, magnesium, phosphorous, natural gas.
Zones of oceans:
Intertidal zone: The ocean connect to the land via what is called the inter-tidal zone. Because of rising and falling tides, coastal areas are constantly changing, with various animals and marine plants living at the bottom, and on the seashore. Rocky coastal areas are host to fewer species due to the fact that only the highest of tides will reach the top of the cliffs.
Neritic zone: This is the relatively shallow ocean that extends to the edge of the continental shelf. Primary productivity here depends on planktonic algae growing as deep as the light can reach.
Epipelagic Zone: The surface layer of the ocean is known as the epipelagic zone and extends from the surface to 200 meters. It is also known as the sunlight zone because this is where most of the visible light exists.It is host to many species of fish and marine mammals, plankton ,and some floating seaweed. With the light come heat, responsible for the wide range of temperatures that occur in this zone.
Mesopelagic Zone: Below the epipelagic zone is the mesopelagic zone, extending from 200 meters to 1000 meters. The mesopelagic zone is sometimes referred to as the twilight zone or the midwater zone. The light that penetrates to this depth is extremely faint. It is in this zone that we begin to see the twinkling lights of bioluminescent creatures. A great diversity of strange and bizarre fishes can be found here.
Bathypelagic Zone: The next layer is called the bathypelagic zone. It is sometimes referred to as the midnight zone or the dark zone. This zone extends from 1000 meters down to 4000 meters. Here the only visible light is that produced by the creatures themselves. The water pressure at this depth is immense and temperature is low, In spite of the pressure, a surprisingly large number of creatures can be found here. Sperm whales can dive down to this level in search of food. Most of the animals that live at these depths are black or red in color due to the lack of light.
Abyssopelagic Zone: The next layer is called the abyssopelagic zone, also known as the abyssal zone or simply as the abyss. It extends from 4000 meters to 6000 meters. The name comes from a Greek word meaning "no bottom". The water temperature is near freezing, and there is no light at all. Very few creatures can be found at these crushing depths. Most of these are invertebrates such as basket stars and tiny squids. Three-quarters of the ocean floor lies within this zone. The deepest fish ever discovered was found in the Puerto Rico Trench at a depth of 8,372 meters.
Hadalpelagic Zone: Beyond the abyssopelagic zone lies the forbidding hadalpelagic zone. This layer extends from 6000 meters to the bottom of the deepest parts of the ocean. These areas are mostly found in deep water trenches and canyons. The deepest point in the ocean is located in the Mariana Trench off the coast of Japan at 10,911m. The temperature of the water is just above freezing, and the pressure is an incredible eight tons per square inch. That is approximately the weight of 48 Boeing 747 jets. In spite of the pressure and temperature, life can still be found here. Invertebrates such as starfish and tube worms can thrive at these depths.
Role played by the oceans in terms of providing resources and regulating climate: Oceans represent the largest and most diverse of the ecosystems; The sea has always played an important role in the life of those people who live around its shores. Salt water evaporates and turns to rain which falls on the land regions, while most of the oxygen in our atmosphere is generated by algae. Algae is also responsible for the absorption of large amounts of carbon dioxide from our atmosphere.
The oceans, which cover more than 70% of the earth’s surface, play a fundamental and complex role in regulating climate. The oceans absorb huge amounts of solar energy; ocean currents transport this heat from the equator toward the Poles. In the past, long-term, natural oscillations in the oceans’ capacity to store and transport heat have led to global temperature changes.
As part of a vast planetary cycle of evaporation and rainfall, the oceans are also fundamental to the movement of water around the globe. Measuring changes in precipitation patterns, and understanding how they may lead to droughts in some regions and flooding in others, is a major part of predicting the potential effects of global climate change on human activities and natural ecosystems.
4 b). Define Ecosystem and explain pond ecosystem:
Ecosystem: An ecological community together with its environment, functioning as a unit or Community of living organisms (populations of species) interacting with one another and with the non-living environment.
Simple Pond Ecosystem:
FIGURE IS NEXT POST: SIMPLE POND ECOSYSTEM
Pond ecosystems range in size from just a few square meters to thousands of square kilometers. Scattered throughout the earth. Many ponds are seasonal, lasting just a couple of months (such as sessile pools) while lakes may exist for hundreds of years or more. Ponds and lakes may have limited species diversity since they are often isolated from one another and from other water sources like rivers and oceans. Lakes and ponds are divided into three different “zones” which are usually determined by depth and distance from the shoreline.
Littoral Zone: The topmost zone near the shore of a lake or pond is the littoral zone. This zone is the warmest since it is shallow and can absorb more of the Sun’s heat. It sustains a fairly diverse community, which can include several species of algae (like diatoms), rooted and floating aquatic plants, grazing snails, clams, insects, crustaceans, fishes, and amphibians. In the case of the insects, such as dragonflies and midges, only the egg and larvae stages are found in this zone. The vegetation and animals living in the littoral zone are food for other creatures such as turtles, snakes, and ducks.
Limnetic Zone: The near-surface open water surrounded by the littoral zone is the limnetic zone. The limnetic zone is well-lighted (like the littoral zone) and is dominated by plankton, both phytoplankton and zooplankton. Plankton are small organisms that play a crucial role in the food chain. Without aquatic plankton, there would be few living organisms in the world, and certainly no humans. A variety of freshwater fish also occupy this zone.
Profundal Zone: Plankton have short life spans—when they die, they fall into the deep-water part of the lake/pond, the profundal zone. This zone is much colder and denser than the other two. Little light penetrates all the way through the limnetic zone into the profundal zone. The fauna are heterotrophs, meaning that they eat dead organisms and use oxygen for cellular respiration.
Temperature varies in ponds and lakes seasonally. During the summer, the temperature can range from 4° C near the bottom to 22° C at the top. During the winter, the temperature at the bottom can be 4° C while the top is 0° C (ice). In between the two layers, there is a narrow zone called the thermocline where the temperature of the water changes rapidly. During the spring and fall seasons, there is a mixing of the top and bottom layers, usually due to winds, which results in a uniform water temperature of around 4° C. This mixing also circulates oxygen throughout the lake. Of course there are many lakes and ponds that do not freeze during the winter, thus the top layer would be a little warmer.
5 a). Elements of an ecosystem and their interdependency:
Ecosystem: Community of living organisms (populations of species or biota ) interacting with one another and with the non-living (abiotic) environment.
All living things that inhabit an environment are Biotic Factors. All nonliving things that inhabit an environment are Abiotic Factors.
Abiotic Components:
Water, air, temperature, soil, nutrients, minerals, light levels, moisture, precipitation, salinity.
Biotic Components:
Producers, consumers, decomposers
Plants, animals, bacteria/fungi
Biotic interactions with abiotic components include predation, competition, symbiosis, parasitism, commensalism etc.
FIFURE IS IN NEXT POST:Figure: Relationships within an ecosystem
Figure: Relationships within an ecosystem
Organisms that make up the biotic component of an ecosystem are usually classified as autotrophs and heterotrophs, based on how they get their food or organic nutrients they need to survive.
Autotrophs(producers): are organisms that can manufacture the organic compounds they need as nutrients from simple inorganic compounds obtained from their environment. In most terrestrial ecosystems, green plants are the producers. In aquatic ecosystems, most of the producers are phytoplankton, consisting of various species of of floating and drifting bacteria and protist.
Most producers make their organic nutrients they need through photosynthesis. The overall net chemical change can be summarized as follows:
6 CO2 + 6 H2O + solar energy -----> C6H12O6 + 6 O2
Some producers , mostly specialized bacteria, can extract inorganic compounds from their environment and convert them into organic nutrient compounds without the presence of sunlight. These producers are called chemosynthesis. An example of this is around the hydrothermal vents in some parts of the deep ocean. Bacteria carry out chemosynthesis by converting inorganic hydrogen sulfide to organic nutrients.
Heterotrophs(consumers)-are organisms which cannot synthesize the organic nutrients they need and get their organic nutrients by feeding on the tissues of producers or other consumers. There are several classes of of consumers, depending on there food source.
1.Primary consumers (herbivores) feed directly on plants or other producers.
2.Secondary consumers (carnivores) feed only on primary consumers.
3.Tertiary or higher level consumers feed only on animal-eating animals.
4.Omnivores can eat both plants and animals.Examples are pigs, rats, cockroaches, and humans.
5.Detrtivores (decomposers and detritus feeders) live off of detritus, parts of dead organisms and castoff fragments and waste of living organisms. Decomposers digest detritus by breaking down the complex organic molecules in these materials into simpler, inorganic compounds. Decomposers consist of various bacteria and fungi.
5 b). Bidiversity Types: Genetic Diversity and Species Diversity..
Biodiversity is a modern term which simply means " the variety of life on earth". This variety can be measured on several different levels.
Genetic - variation between individuals of the same species. This includes genetic variation between individuals in a single population , as well as variations between different populations of the same species. Genetic differences can now be measured using increasingly sophisticated techniques. These differences are the raw material of evolution.
Species - species diversity is the variety of species in a given region or area. This can either be determined by counting the number of different species present, or by determining taxonomic diversity. Taxonomic diversity is more precise and considers the relationship of species to each other. It can be measured by counting the number of different taxa (the main categories of classification) present. For example, a pond containing three species of snails and two fish, is more diverse than a pond containing five species of snails, even though they both contain the same number of species. High species biodiversity is not always necessarily a good thing. For example, a habitat may have high species biodiversity because many common and widespread species are invading it at the expense of species restricted to that habitat.
6 a). BIO-DIVERSITY hot-spots:
A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is threatened with destruction.
In 1988, British ecologist Norman Myers developed the concept of biodiversity hotspots to address the dilemma of identifying areas most important for preserving Species. Many areas of global significance face tremendous pressure from logging, agriculture, hunting, and Climate change. The hotspots strategy emphasizes risks of species extinction since species loss is irreversible. Since these species can only be found in specific areas, the loss of such areas would be considered “irreplaceable.” The strategy also emphasizes species endemism.
To qualify as a biodiversity hotspot the regions must support at least 1,500 plant species found nowhere else in the world and Such areas must have lost at least 70 percent of its original Habitat.
It has been estimated that 50,000 endemic plants which comprise 20% of global plant life, probably occur in only 18 ‘hot spots’ in the world. Countries which have a relatively large proportion of these hot spots of diversity arereferred to as ‘megadiversity nations’.
Biodiversity Hotspots in India :
Western Ghats (Sahyadri Hills):
The Western Ghats , also known as the Sahyadri Hills , is a mountain chain running from the north to the South and is isolated by the Arabian Sea to the West, the arid Deccan Plateau to the East, and the Vindhya-Satpura ranges to the North. They have different vegetation types: scrub jungles and grasslands at low altitudes, dry and moist deciduous forests, montane grasslands and shoals, and the precious tropical evergreen and semi evergreen forests. Complex topography, high rainfall and relative inaccessibility have helped the region retain its biodiversity. Of the estimated 17000 species of flowering plants reported from india, about 4780 species are found in the western ghats region, of which 1720 (more than 1/3rd ) are endemic. Of the 372 species of mammals found in india, 63 are in the western Ghats, of which 16 are endemic. in addition 91 species of reptiles and 84(50%) species of amphibians(62%) are also endemic to these region. Some of endemic species in these region are:
Lion-tailed macaque, Nilgiri Hangul, Malabar Civet, Nilgiri marten, Indian gaint sqirrell, small travancore flying squirrel and Nilgiri Tahr.
Indo-Burma ( Eastern Himalayas ) :
Geographhically these area comprises Nepal, Bhutan and neighboring states of Northern India. There are 35000 plant species found in the Himalayas, of which 30% are endemic. Out of the 372 species of mammals found in india, 300 are in the western Ghats, of which 12 are endemic. In addition 48 out of 176 species of reptiles, 42 out of 85 species of amphibians and 15 out of 977 birds are also endemic to these region. The eastern Himalayas are also rich in wild plants of economic value and huge wealth of fungi, insects, mammals and birds.
6 b). In Situ Conservation :- within the natural habitat:
In situ conservation maintains not only the genetic diversity of species, but also the evolutionary adaptations that enable them to adapt continually to shifting environmental conditions, such as changes in pest populations or climate. In situ conservation also ensures that along with target species, a host of other interlinked species are also preserved as a by-product. It is generally cheaper than ex situ methods (although not cheap). It may often be the only conservation option, for example for species with recalcitrant seeds.
In situ conservation measures involve designating specific areas as protected Areas. Protection may be offered at various levels, from complete protection and restriction of access, through various levels of permitted human use. It includes a system of protected areas of different categories, e.g. National Parks, Sanctuaries, Nature Reserves, Natural Monuments, Cultural Landscapes, Biosphere Reserves, etc. protected areas of India cover 156,700 km², roughly 4.95% of the total surface area.
The biosphere reserve concept has been developed through the Man and Biosphere (MAB) Programme of the United Nations Educational, Scientific and Cultural Organization (UNESCO). Biosphere reserves are an attempt to reconcile the problems of conserving biodiversity and biological resources, with sustainable use of natural resources for people.
Seven of the fifteen biosphere reserves in India are a part of the World Network of Biosphere Reserves, based on the UNESCO Man and the Biosphere (MAB) Program list are:
• Nilgiri Biosphere Reserve
• Nanda Devi Biosphere Reserve
• Sundarbans Biosphere Reserve
• Gulf of Mannar Biosphere Reserve
• Pachmarhi Biosphere Reserve
• Nokrek Biosphere Reserve
• Simlipal Biosphere Reserve
There are more than 600 Protected Areas in India of which 96 are National Parks (38,029.18 km², 1.16% of India's total surface area), 15 are biosphere reserves and over 500 are Wildlife Sanctuaries. They include a variety of ecosystems and habitats. Some have been created in order to protect highly endangered species of wild plants and animals found nowhere else in the world.
The Great Himalayan National Park is the largest sanctuary in this ecosystem and is one of the last homes of the beautiful snow leopard.
Dachigam Sanctuary is the only place where the rare Hangul or Kashmir stag is found. There are several Sanctuaries in the Terai region,
Kaziranga National Park is the most famous which has elephant, wild buffalo, gaur, wild boar, swamp deer, and hog deer, in large numbers, as well as tiger and leopard. Its bird life is extremely rich and includes ducks, geese, pelicans and storks.
The Manas Sanctuary, in addition to the above Terai species, also includes the rare golden langur and the very rare pygmy hog, the smallest wild boar in the world. The florican is found only in a few undisturbed grasslands in the Terai sanctuaries.
In the sal forests of Madhya Pradesh, there are several Protected Areas. Kanha offers a wonderful opportunity to observe wild tigers from elephant back. It is the only Protected Area in which a sub species of the Barasingha is found.
Bharatpur is one of the most famous water bird sanctuaries in the world. Thousands of ducks, geese, herons, and other wading birds can be seen here. This is the only home of the very rare Siberian crane which migrates to India every winter. During the last 20 years, the 30 or 40 Siberian cranes have dwindled to only 2 or 3. During 2002-03 no cranes were seen and it is possible that this beautiful bird will never again come to India.
In the Thar desert, the wild life is protected in the Desert National Park. Here large numbers of black buck, neelgai and chinkara can be seen. The Great Indian Bustard lives in these arid lands.
Ranthambor was the most well known sanctuary for observing tigers in the wild till about 3 or 4 years ago. Since then many tigers have been killed by poachers.
The Great and the Little Rann of Kutch have been made into sanctuaries to protect the very rare wild ass, the flamingo, the star tortoise and the desert fox.
In Gujarat, the Gir Sanctuary protects the last population of the majestic Asiatic lion. This thorn and deciduous forest is also the home of large herds of chital, sambhar, and nilgai.
The Sanctuaries of the Western Ghats and associated hill ranges protect some of the most diverse forest types in the country. The few examples of highly threatened species include the Malabar giant squirrel, the flying squirrel and a variety of hill birds, several species of amphibians, reptiles and insects. These regions are also rich in highly endemic plant life. Sanctuaries such as Bhimashankar, Koyana, Chandoli and Radhanagari preserve this rich flora in Maharashtra, Bandipur, Bhadra, Dandeli, Nagarhole, etc. in Karnataka, and Eraviculum, Perambiculum, Periyar, Silent Valley, in Kerala.In the Nilgiri Hills the rich forest Sanctuaries protect some of the last pockets of the Indian elephant in South India. Examples include Bandipur, Madhumalai, Wynad and Bhadra. During the last 10 years, a large number of the great tusker elephants of this region have been ruthlessly killed for their ivory. Now very few of these magnificent animals are left in these jungles.
Two important sanctuaries meant for preservation of coastal ecosystems are the Chilka Lake and Point Calimere. The Sunderbans protect the largest mangrove delta in India. The Marine National Park in Gujarat protects shallow areas in the sea, islands, coral reefs and extensive mudflats.Over a hundred Protected Areas have been created in the Andaman and Nicobar Islands to preserve their very special island ecosystems.
Ex Situ Conservation : - Outside the natural habitat
Conservation of a species is best done by protecting its habitat along with all the other species that live in it in nature. This is known as in-situ conservation, which is conserving a species in its own environment by creating National Parks and Wildlife Sanctuaries. However, there are situations in which an endangered species is so close to extinction that unless alternate methods are instituted, the species may be rapidly driven to extinction. This strategy is known as ex-situ conservation, i.e. outside its natural habitat in a carefully controlled situation such as a botanical garden for plants or a zoological park for animals, where there is expertise to multiply the species under artificially managed conditions. These breeding programs for rare plants and animals are however more expensive than managing a Protected Area.
There is also another form of preserving a plant by preserving its germ plasm in a gene bank so that it can be used if needed in future. This is even more expensive. When an animal is on the brink of extinction, it must be carefully bred so that inbreeding does not lead to the genetic makeup becoming weak. Breeding from the same stock can lead to poorly adapted progeny or even inability to get enough offspring. Modern breeding programs are done in zoos that provide for all the animal’s needs, including enclosures that simulate their wild habitats. In India, successful ex situ conservation programs have been done for all our three species of crocodiles. This has been highly successful. Another recent success has been the breeding of the very rare pygmy hog in Gauhati zoo. Delhi zoo has successfully bred the rare Manipur brow antlered deer. However the most important step of a successful breeding program is the reintroduction of a species into its original wild habitat. This requires rehabilitation of the degraded habitat and removal of the other causes such as poaching, disturbance, or other manmade influences that have been the primary cause of reducing the population of the species.
Wednesday, September 2, 2009
ES FIRST MID ANSWERS FOR ASSIGNMENT1
1a). Definition, Scope and importance of Environmental Studies:
Environment is derived from french word envirroner which means to encircle or to surround. All the living and non-living components surrounding an organism form its environment.
Environmental studies is the process of educating the people for preserving quality environment. The main scope of environmental studies includes:
- To get awareness and sensitivity to the total environment and its related problems.
- To motivate the active participation in environmental protection and improvement.
- To develop skills for identifying and solving environmental problems.
- T o know the necessity of conservation of natural resources.
- To evaluate environmental programs in terms of social, economic, ecological and aesthetic factors.
- Environment protection and management, environmental laws, business administration and environmental engineering are emerging as new carrier opportunities.
- Environmental Science will be a growing field for the future with the growing concerns about our global warming and climate changes. Its scope is so wide that it has got relation with every science and scientific aspects in general and biology in particular and other fields such as ecology, botany, and meteorology besides all other major branches of the science, arts and commerce.
The Importance of environmental studies is extremely high in every major discipline, especially in the following aspects:
- Natural resources (flora, fauna, air, water, land, minerals)
- Biological diversity
- Marine life
- Inter-dependence of man and environment
- Environmental degradation
- Environmental problems and hazards
- Environmental pollution _ air, water, soil, noise
- Waste management
- Disaster management
- Protection of human health conditions and quality of life
- Conservation of energy, soil, wildlife, forests, water
- Renewable resources
- Eco-friendly and indigenous technologies
- Water resources management
- Sustainable development
- Sustainable agriculture
- Environmentally sound management of biotechnology
- Environmental policies and programs
- Environmental information resources
- Acts, laws and regulations
- Role of government and non-governmental agencies.
1 b). What are the various employment potential for environmental subject experts?
- There is a need for trained manpower at every level to deal with environmental issues like safe and clean drinking water, hygienic living conditions, clean and fresh air, fertile land, healthy food and sustainable development.
- Environment protection and management, environmental laws, business administration and environmental engineering are emerging as new carrier opportunities.
- Since the pollution control laws becoming more stringent, industries need environment experts to control pollution and disposal of wastes.
- Environmental experts are now in great demand in industries for adopting green technologies to reduce pollution and to cut down the costs of effluent treatment.
- These days, there is huge market world over for waste disposal and pollution control technologists and environmental experts.
- If we want to live in a clean, healthy, aesthetically beautiful, safe and secure environment for a long time and wish to hand over clean and safe earth to our children, we will have to include environmental experts in all developmental and policy making committees.
-
2 a). i. Timber extraction:
Since ancient times, the extraction of timber and the use of wood has been one of man's most fundamental developments. From the implements used in daily life to the buildings that give him shelter and security, man has found wood a uniquely useful utility. Timber production and other wood-based industries still comprise an important part of economy of many countries. Paper production and other industries such as furniture making also important to a nation’s economy.
Commercial logging, a common form of deforestation is cutting trees for sale as timber and pulp. Logging for valuable timber, such as teak and mahogany not only involves a few large trees per hectare but about a dozen more trees since they are strongly interlocked with each other by vines etc., Also road construction for making approach to the trees enable landless people to access the interiors of the forest, which in turn results in further deforestation and poaching. Timber extraction also leads to soil erosion, loss of fertility, landslides, loss of biodiversity, loss of tribal culture and extinction of tribal people.
Classification of timber extraction:
- Clear felling: ..
- Selective logging: ..
- Mechanized logging: …
- Hand logging: ..
- Reduced impact logging: ..
ii. Effects of dams & mining on forests:
Mining, industrial development and Hydro electrical dams also significant causes of deforestation, both in terms of the land they occupy and their influence on degradation of forest and wildlife habitat. The impact of large dams on ecosystems are more negative than positive and in many cases, this has led to serious irrecoverable loss of species and ecosystems. Dams also open up previously inaccessible forest and damage downstream ecosystems. The emission of the greenhouse gases from reservoirs due to rotting vegetation and carbon inflows from the catchment area is a one more recently identified impact. Dams causes water-logging and salinization of the surrounding lands
Mining operations for extracting minerals and fossil fuels such as coal often involves vast forest areas. Mining and its associated activities require removal of vegetation along with underlying soil mantle and overlying rock masses. This results in defacing the topography and destruction of the landscape in the area. The forest area has declined at an average rate of 33% and the increase in non-forest area due to mining activities has resulted in relatively unstable zones leading to landslides. Mining increases access to otherwise remote forest areas and provide an opportunity for further activities, especially in places where population pressures already exist.
2 b). What are the methods of water conservation?
‘CATCH THE RAIN WHERE IT POURS’
Rainwater Harvesting:
Rainwater harvesting is the gathering and collection of water from the rooftop. The traditional method of rain water harvesting is the most effective and simple way to conserve the water. It means utilization of rain water for the domestic as well as agricultural purposes. There are three technical methods of rain water harvesting such as Catchment, Conveyance and storage.
Watershed Management:
Rivers originate in streams that flow down mountains and hill slopes. A group of small streams flow down hillsides to meet larger streams in the valley which forms the tributaries of major rivers. The management of a single unit of land with its water drainage system is called watershed management. It is a technique that has several components. This includes soil and water management and developing vegetative cover. The natural drainage pattern of a watershed unit if managed appropriately can bring about local prosperity by a year round abundance of water that improves the quality of human life in the area.
By constructing a series of long trenches and mounds along contours of the hill to hold the rainwater and allow it to percolate into the ground. This ensures that underground stores of water are fully recharged. This is enhanced by allowing grasses and shrubs to grow and by planting trees (mainly local species) which hold the soil and prevents it from being washed away in the monsoon. Local grass cover can however only increase if free grazing of domestic animals is prevented by stall feeding. The next measure is to make ‘nala’ plugs in the streams so that the water is held in the stream and does not rush down the hillside. In selected sites, several small check dams are built which together hold back larger amounts of water. All these measures constitute sound watershed management. It improves the water table and keeps the streams and nalas flowing throughout the year.
The 3 R’s ( Reduce, Reuse and Recycle )
Reduce:
- Use only as much water as you require.
- Close the tap well after use.
- While brushing your teeth do not leave the tap running, open it only when you require it.
- See that there are no leaking taps. Get a plumber to come in and seal all leaks.
- Use a washing machine that does not consume too much water.
- Do not leave the taps running while washing dishes and clothes.
- Install small showerheads to reduce the flow of water.
- Water in which the vegetables and fruits have been washed can be used to water the flowers and ornamental potted plants.
- Educate the mind of the people in the rural areas to save the water.
- Never throw the water unnecessary on roads which can be used for gardening and cleaning.
- Avoid unnecessary flushing the toilets. Dispose off the tissues, cigarettes and other waste into the bin instead of toilets.
- Water your lawn only when it is needed.
- Use a broom instead of hose to clean the sidewalks or to wash the car.
Recycle:
- Recycle the hot water from industries by using cooling towers etc.,
- Municipalities should equip sewage treatment plants at every level to reduce the water pollution levels and if purified efficiently can be used for the domestic supply once again.
Reuse:
- Never throw the water unnecessary on roads which can be used for gardening and cleaning.
- At the end of the day if you have water left in your water bottle do not throw it away, pour it over some plants.
- Use the remained soap water
- Reuse the water that vegetables are washed in for watering houseplants or for cleaning.
- When washing clothes by hand, the water should not be left running. Fill a laundry tub with water, and reuse wash and rinse water as much as possible. The used soapy water can be used for cleaning your country yard or garage area.
3 a). Explain the need of conservation of mineral resources.
A mineral is a naturally occurring substance of definite chemical composition and identifiable physical properties. An ore is a mineral or combination of minerals from which a useful substance, such as a metal, can be extracted and used to manufacture a useful product. Minerals are formed over a period of millions of years in the earth’s crust. Iron, aluminum, zinc, manganese and copper are important raw materials for industrial use. Important non-metal resources include coal, salt, clay, cement and silica. Stone used for building material, such as granite, marble, limestone, constitute another category of minerals. Minerals with special properties that humans value for their aesthetic and ornamental value are gems such as diamonds, emeralds, rubies. The luster of gold, silver and platinum is used for ornaments. Minerals in the form of oil, gas and coal were formed when ancient plants and animals were converted into underground fossil fuels.
Minerals are a non-renewable resource. It takes thousands of years for the formation and concentration of minerals. The rate of formation is much smaller than the rate at which the humans consume these minerals. Most of the minerals deposits such as fossil fuels may exhaust in near future. Mining causes devegetation and defacing of landscapes, earthquake, subsidence of land, Ground and surface water pollution, lowering water table, air pollution, occupational health hazards so, it is necessary to reduce wastage in the process of mining.
Minerals can be conserved in by the following measures:
• Use of improved technologies to allow use of low grade minerals at low costs.
• Using substitutes for the non-renewable resources.
• Use of scrap metals
• Recycling of metals is good way in which the mineral resources can be conserved efficiently.
• Mining safety.
3 b). Non-Conventional Energy Sources
The sources of energy which are being produced continuously in nature and are in exhaustible are called renewable sources of energy (or) non-conventional energy.
Some of these sources are:
(a) Wind energy
(b) Tidal energy
(c) Solar energy
(d) Geothermal Energy
(e) Ocean thermal energy
(f) Biomass energy
(a) Wind energy:
Winds are caused because of two factors.
1. The absorption of solar energy on the earth’s surface and in the atmosphere.
2. The rotation of the earth about its axis and its motion around the Sun.
A wind mill converts the kinetic energy of moving air into Mechanical energy that can be either used directly to run the Machine or to run the generator to produce electricity.
(b) Tidal energy
Tides are generated primarily by the gravitational attraction between the earth and the Moon. They arise twice a day in Mid-Ocean. The tidal range is only a Meter.
Basically in a tidal power station water at high tide is first trapped in a artificial basin and then allowed to escape at low tide. The escaping water is used to drive water turbines, which in turn drive electrical generators.
(c) Solar energy
Energy from the sun is called solar energy. The Sun’s energy comes from nuclear fusion reaction that take place deep in the Sun. Hydrogen nucleus fuse into helium nucleus. The energy from these reactions flow out from the sun and escape into space.
The solar energy that falls on India in one minute is enough to supply the energy needs of our country for one day. Man has made very little use of this enormous amount of solar energy that reaches the earth.
Solar Energy applications:
1. Heating and cooling of residential building.
2. Solar water heating.
3. Solar drying of agricultural and animal products.
4. Salt production by evaporation of seawater.
5. Solar cookers.
6. Solar engines for water pumping.
7. Solar Refrigeration.
8. Solar electric power generation.
9. Solar photo voltaic cells, which can be used for electricity.
10. Solar furnaces.
(d) Geothermal energy:
Temperature of the earth increases at a rate of 20° to 75°C per km, when we move down the earth surface. High temperature and high pressure steam fields exist below the earth’s surface in many places. The energy harnessed from the high temperature present inside the earth is called geothermal energy.
Natural Geysers and Artificial Geysers.
(e) Ocean thermal energy:
There is often large temperature difference between the surface level and deeper level of the tropical oceans. This temperature difference can be utilized to generate electricity or heating.
The energy due to the difference in temperature (around 20°C ) of water is called ocean thermal energy.
(f) Biomass energy:
Biomas is the organic matter, produced by plants or animals, used as source of energy. Most of the biomass is burned directly for heating, cooling and industrial purposes.
Biogas: is a mixture of methane, CO2 and H2S. Biogas contains 65% of methane gas as a major constituent. Biogas is obtained by the anaerobic fermentation of animal dung or plant wastes in the presence of water
Biofuels: Ethanol, methanol and Gasohol.
Hydrogen fuel: Hydrogen can be produced by thermal dissociation or photosynthesis or electrolysis of water. It posses high calorific value. It is non-polluting, because the combustion product is water.
Environment is derived from french word envirroner which means to encircle or to surround. All the living and non-living components surrounding an organism form its environment.
Environmental studies is the process of educating the people for preserving quality environment. The main scope of environmental studies includes:
- To get awareness and sensitivity to the total environment and its related problems.
- To motivate the active participation in environmental protection and improvement.
- To develop skills for identifying and solving environmental problems.
- T o know the necessity of conservation of natural resources.
- To evaluate environmental programs in terms of social, economic, ecological and aesthetic factors.
- Environment protection and management, environmental laws, business administration and environmental engineering are emerging as new carrier opportunities.
- Environmental Science will be a growing field for the future with the growing concerns about our global warming and climate changes. Its scope is so wide that it has got relation with every science and scientific aspects in general and biology in particular and other fields such as ecology, botany, and meteorology besides all other major branches of the science, arts and commerce.
The Importance of environmental studies is extremely high in every major discipline, especially in the following aspects:
- Natural resources (flora, fauna, air, water, land, minerals)
- Biological diversity
- Marine life
- Inter-dependence of man and environment
- Environmental degradation
- Environmental problems and hazards
- Environmental pollution _ air, water, soil, noise
- Waste management
- Disaster management
- Protection of human health conditions and quality of life
- Conservation of energy, soil, wildlife, forests, water
- Renewable resources
- Eco-friendly and indigenous technologies
- Water resources management
- Sustainable development
- Sustainable agriculture
- Environmentally sound management of biotechnology
- Environmental policies and programs
- Environmental information resources
- Acts, laws and regulations
- Role of government and non-governmental agencies.
1 b). What are the various employment potential for environmental subject experts?
- There is a need for trained manpower at every level to deal with environmental issues like safe and clean drinking water, hygienic living conditions, clean and fresh air, fertile land, healthy food and sustainable development.
- Environment protection and management, environmental laws, business administration and environmental engineering are emerging as new carrier opportunities.
- Since the pollution control laws becoming more stringent, industries need environment experts to control pollution and disposal of wastes.
- Environmental experts are now in great demand in industries for adopting green technologies to reduce pollution and to cut down the costs of effluent treatment.
- These days, there is huge market world over for waste disposal and pollution control technologists and environmental experts.
- If we want to live in a clean, healthy, aesthetically beautiful, safe and secure environment for a long time and wish to hand over clean and safe earth to our children, we will have to include environmental experts in all developmental and policy making committees.
-
2 a). i. Timber extraction:
Since ancient times, the extraction of timber and the use of wood has been one of man's most fundamental developments. From the implements used in daily life to the buildings that give him shelter and security, man has found wood a uniquely useful utility. Timber production and other wood-based industries still comprise an important part of economy of many countries. Paper production and other industries such as furniture making also important to a nation’s economy.
Commercial logging, a common form of deforestation is cutting trees for sale as timber and pulp. Logging for valuable timber, such as teak and mahogany not only involves a few large trees per hectare but about a dozen more trees since they are strongly interlocked with each other by vines etc., Also road construction for making approach to the trees enable landless people to access the interiors of the forest, which in turn results in further deforestation and poaching. Timber extraction also leads to soil erosion, loss of fertility, landslides, loss of biodiversity, loss of tribal culture and extinction of tribal people.
Classification of timber extraction:
- Clear felling: ..
- Selective logging: ..
- Mechanized logging: …
- Hand logging: ..
- Reduced impact logging: ..
ii. Effects of dams & mining on forests:
Mining, industrial development and Hydro electrical dams also significant causes of deforestation, both in terms of the land they occupy and their influence on degradation of forest and wildlife habitat. The impact of large dams on ecosystems are more negative than positive and in many cases, this has led to serious irrecoverable loss of species and ecosystems. Dams also open up previously inaccessible forest and damage downstream ecosystems. The emission of the greenhouse gases from reservoirs due to rotting vegetation and carbon inflows from the catchment area is a one more recently identified impact. Dams causes water-logging and salinization of the surrounding lands
Mining operations for extracting minerals and fossil fuels such as coal often involves vast forest areas. Mining and its associated activities require removal of vegetation along with underlying soil mantle and overlying rock masses. This results in defacing the topography and destruction of the landscape in the area. The forest area has declined at an average rate of 33% and the increase in non-forest area due to mining activities has resulted in relatively unstable zones leading to landslides. Mining increases access to otherwise remote forest areas and provide an opportunity for further activities, especially in places where population pressures already exist.
2 b). What are the methods of water conservation?
‘CATCH THE RAIN WHERE IT POURS’
Rainwater Harvesting:
Rainwater harvesting is the gathering and collection of water from the rooftop. The traditional method of rain water harvesting is the most effective and simple way to conserve the water. It means utilization of rain water for the domestic as well as agricultural purposes. There are three technical methods of rain water harvesting such as Catchment, Conveyance and storage.
Watershed Management:
Rivers originate in streams that flow down mountains and hill slopes. A group of small streams flow down hillsides to meet larger streams in the valley which forms the tributaries of major rivers. The management of a single unit of land with its water drainage system is called watershed management. It is a technique that has several components. This includes soil and water management and developing vegetative cover. The natural drainage pattern of a watershed unit if managed appropriately can bring about local prosperity by a year round abundance of water that improves the quality of human life in the area.
By constructing a series of long trenches and mounds along contours of the hill to hold the rainwater and allow it to percolate into the ground. This ensures that underground stores of water are fully recharged. This is enhanced by allowing grasses and shrubs to grow and by planting trees (mainly local species) which hold the soil and prevents it from being washed away in the monsoon. Local grass cover can however only increase if free grazing of domestic animals is prevented by stall feeding. The next measure is to make ‘nala’ plugs in the streams so that the water is held in the stream and does not rush down the hillside. In selected sites, several small check dams are built which together hold back larger amounts of water. All these measures constitute sound watershed management. It improves the water table and keeps the streams and nalas flowing throughout the year.
The 3 R’s ( Reduce, Reuse and Recycle )
Reduce:
- Use only as much water as you require.
- Close the tap well after use.
- While brushing your teeth do not leave the tap running, open it only when you require it.
- See that there are no leaking taps. Get a plumber to come in and seal all leaks.
- Use a washing machine that does not consume too much water.
- Do not leave the taps running while washing dishes and clothes.
- Install small showerheads to reduce the flow of water.
- Water in which the vegetables and fruits have been washed can be used to water the flowers and ornamental potted plants.
- Educate the mind of the people in the rural areas to save the water.
- Never throw the water unnecessary on roads which can be used for gardening and cleaning.
- Avoid unnecessary flushing the toilets. Dispose off the tissues, cigarettes and other waste into the bin instead of toilets.
- Water your lawn only when it is needed.
- Use a broom instead of hose to clean the sidewalks or to wash the car.
Recycle:
- Recycle the hot water from industries by using cooling towers etc.,
- Municipalities should equip sewage treatment plants at every level to reduce the water pollution levels and if purified efficiently can be used for the domestic supply once again.
Reuse:
- Never throw the water unnecessary on roads which can be used for gardening and cleaning.
- At the end of the day if you have water left in your water bottle do not throw it away, pour it over some plants.
- Use the remained soap water
- Reuse the water that vegetables are washed in for watering houseplants or for cleaning.
- When washing clothes by hand, the water should not be left running. Fill a laundry tub with water, and reuse wash and rinse water as much as possible. The used soapy water can be used for cleaning your country yard or garage area.
3 a). Explain the need of conservation of mineral resources.
A mineral is a naturally occurring substance of definite chemical composition and identifiable physical properties. An ore is a mineral or combination of minerals from which a useful substance, such as a metal, can be extracted and used to manufacture a useful product. Minerals are formed over a period of millions of years in the earth’s crust. Iron, aluminum, zinc, manganese and copper are important raw materials for industrial use. Important non-metal resources include coal, salt, clay, cement and silica. Stone used for building material, such as granite, marble, limestone, constitute another category of minerals. Minerals with special properties that humans value for their aesthetic and ornamental value are gems such as diamonds, emeralds, rubies. The luster of gold, silver and platinum is used for ornaments. Minerals in the form of oil, gas and coal were formed when ancient plants and animals were converted into underground fossil fuels.
Minerals are a non-renewable resource. It takes thousands of years for the formation and concentration of minerals. The rate of formation is much smaller than the rate at which the humans consume these minerals. Most of the minerals deposits such as fossil fuels may exhaust in near future. Mining causes devegetation and defacing of landscapes, earthquake, subsidence of land, Ground and surface water pollution, lowering water table, air pollution, occupational health hazards so, it is necessary to reduce wastage in the process of mining.
Minerals can be conserved in by the following measures:
• Use of improved technologies to allow use of low grade minerals at low costs.
• Using substitutes for the non-renewable resources.
• Use of scrap metals
• Recycling of metals is good way in which the mineral resources can be conserved efficiently.
• Mining safety.
3 b). Non-Conventional Energy Sources
The sources of energy which are being produced continuously in nature and are in exhaustible are called renewable sources of energy (or) non-conventional energy.
Some of these sources are:
(a) Wind energy
(b) Tidal energy
(c) Solar energy
(d) Geothermal Energy
(e) Ocean thermal energy
(f) Biomass energy
(a) Wind energy:
Winds are caused because of two factors.
1. The absorption of solar energy on the earth’s surface and in the atmosphere.
2. The rotation of the earth about its axis and its motion around the Sun.
A wind mill converts the kinetic energy of moving air into Mechanical energy that can be either used directly to run the Machine or to run the generator to produce electricity.
(b) Tidal energy
Tides are generated primarily by the gravitational attraction between the earth and the Moon. They arise twice a day in Mid-Ocean. The tidal range is only a Meter.
Basically in a tidal power station water at high tide is first trapped in a artificial basin and then allowed to escape at low tide. The escaping water is used to drive water turbines, which in turn drive electrical generators.
(c) Solar energy
Energy from the sun is called solar energy. The Sun’s energy comes from nuclear fusion reaction that take place deep in the Sun. Hydrogen nucleus fuse into helium nucleus. The energy from these reactions flow out from the sun and escape into space.
The solar energy that falls on India in one minute is enough to supply the energy needs of our country for one day. Man has made very little use of this enormous amount of solar energy that reaches the earth.
Solar Energy applications:
1. Heating and cooling of residential building.
2. Solar water heating.
3. Solar drying of agricultural and animal products.
4. Salt production by evaporation of seawater.
5. Solar cookers.
6. Solar engines for water pumping.
7. Solar Refrigeration.
8. Solar electric power generation.
9. Solar photo voltaic cells, which can be used for electricity.
10. Solar furnaces.
(d) Geothermal energy:
Temperature of the earth increases at a rate of 20° to 75°C per km, when we move down the earth surface. High temperature and high pressure steam fields exist below the earth’s surface in many places. The energy harnessed from the high temperature present inside the earth is called geothermal energy.
Natural Geysers and Artificial Geysers.
(e) Ocean thermal energy:
There is often large temperature difference between the surface level and deeper level of the tropical oceans. This temperature difference can be utilized to generate electricity or heating.
The energy due to the difference in temperature (around 20°C ) of water is called ocean thermal energy.
(f) Biomass energy:
Biomas is the organic matter, produced by plants or animals, used as source of energy. Most of the biomass is burned directly for heating, cooling and industrial purposes.
Biogas: is a mixture of methane, CO2 and H2S. Biogas contains 65% of methane gas as a major constituent. Biogas is obtained by the anaerobic fermentation of animal dung or plant wastes in the presence of water
Biofuels: Ethanol, methanol and Gasohol.
Hydrogen fuel: Hydrogen can be produced by thermal dissociation or photosynthesis or electrolysis of water. It posses high calorific value. It is non-polluting, because the combustion product is water.
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