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ECOLOGY (Part 1 of 3)   Leave a comment

DEFINITION:1 a) the branch of biology that deals with the relations between living organisms and their environment b) the complex of relations between a specific organism and its environment 2 Sociology the study of the relationship and adjustment of human groups to their geographical and social environments.

1869: Birth of ecology. Most people are unaware that the subdivision of biology called ecology is over a century old. Over the course of its development, ecology has emerged as one of the most significant and studied aspects of biology. Ecology refers to the overall interrelated system of nature and the interdependence of all living things.

The word ecology has been popularized more recently because of the many environmental concerns that have been raised since the 1970s. But as a word, ecology was coined in about 1869 by a German zoologist named Ernst Haeckel. A researcher in evolution and a strong supporter of Charles Darwins theories, Haeckel spent most of his career teaching at the University of Jena.

The study of ecology dates back to the ancient Greek philosophers. An associate of Aristotle named Theophrastus first described the relationships between organisms and their environment. Today the field of ecology has expanded beyond narrow biological studies to include environmental pollution, population growth, and food supplies.

The science that deals with the ways in which plants and animals depend upon one another and upon the physical settings in which they live is called ecology. Ecologists investigate the interactions of organisms in various kinds of environments. In this way they learn how nature establishes orderly patterns among a great variety of living things. The word ecology was coined in 1869. It comes from the Greek oikos, which means “household.” Economics is derived from the same word. However, economics deals with human “housekeeping,” while ecology concerns the “housekeeping” of nature.

Interdependence in Nature

Ecology emphasizes the dependence of every form of life on other living things and on the natural resources in its environment, such as air, soil, and water. Before there was a science of ecology, the great English biologist Charles Darwin noted this interdependence when he wrote: “It is interesting to contemplate a tangled bank, clothed with plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and so dependent upon each other in so complex a manner, have all been produced by laws acting around us.”

Ecology shows that people cannot regard nature as separate and detached something to look at on a visit to a forest preserve or a drive through the country. Any changes made in the environment affect all the organisms in it. When vehicles and factories hurl pollutants into the air, animals and plants as well as humans themselves are harmed. The water they foul with wastes and silt threatens remote streams and lakes. Even ocean fisheries may experience reduced catches because of pollution.

The Balance of Nature

Each kind of life is suited to the physical conditions of its habitat the type of soil, the amount of moisture and light, the quality of air, the annual variations in temperature. Each survives because it can hold its own with its neighbours However, the continued existence of the whole group, or life community, involves a shifting balance among its members, a “dynamic equilibrium.”

Natural balances are disrupted when crops are planted, since ordinarily the crops are not native to the areas in which they are grown. Such disturbances of natural balances make it necessary for man to impose artificial balances that will maintain or increase crop production. For the effective manipulation of these new equilibriums, information on nature’s checks and balances is absolutely essential, and often only a specialist is able to provide it. For example, if a farmer were told that he could increase the red clover in his pasture with the help of domestic cats, he might ridicule the suggestion. Yet the relationship between cats and red clover has been clearly established. Cats kill field mice, thus preventing them from destroying the nests and larvae of bumblebees. As a result, more bumblebees are available to pollinate clover blossoms. The more thoroughly the blossoms are pollinated, the more seed will be produced and the richer the clover crop will be. This cat-mouse-bee-clover relationship is typical of the cause-and-effect chains that ecologists study.

The Wide Scope of Ecology

Long before a separate science of ecology arose, men in all sorts of occupations were guided by what are now regarded as ecological considerations. The primitive hunter who knew that deer had to stop at a salt lick for salt was a practical ecologist. So too was the early fisherman who realized that gulls hovering over the water marked the position of a school of fish. In the absence of calendars, men used ecological facts to guide their seasonal endeavours They planted corn when oak leaves were the size of a squirrel’s ear. They regarded the noise of geese flying south as a warning to prepare for winter.

Natural history, the study of nature in general; forerunner of the sciences of biology and ecology.

Until about 1850, the scientific study of such phenomena was called natural history, and the student of the great outdoors was called a naturalist. Afterwards, natural history became subdivided into special fields, such as geology, zoology, and botany, and the naturalist moved indoors. There he performed laboratory work with the aid of scientific equipment.

While the scientists were at work in their laboratories, other men were continuing to cope with living things in their natural settings on timber lands, on range lands, on crop lands, in streams and seas. Although these men often needed help, many of their problems could not be solved in the laboratory.

The forester, for example, wanted to know why trees do not thrive on the prairie, the desert, and the mountaintop. The rancher wanted to know how to manage his pastures so that his cattle would flourish, and how such creatures as coyotes, hawks, rabbits, gophers, and grasshoppers would affect his efforts.

As for the farmer, almost every part of his work posed problems for which scientific answers were needed. The game manager came to realize that his duties entailed much more than the regulation of hunting. To preserve the animals for which he was responsible, he had to make sure they had the right kinds of food in all seasons, suitable places to live and raise their young, and appropriate cover.

The fisherman learned that most aquatic life fares poorly in muddy and polluted waters. He became interested in land management and waste disposal when he discovered that the silt he found so troublesome came from rural areas where timber, range land, and crop land were mishandled and that the waters he fished were polluted by urban wastes. The ocean fisherman wanted to know why fish were abundant in one place and scarce in another. He needed information on the breeding habits of his catches and of the tiny animals and plants upon which they fed.

These are all ecological problems. To solve them the ecologist must understand biology the science of living things including botany and zoology. He must also understand the sciences that deal with weather, climate, rocks, earth, soil, and water.

An ecologist is concerned with both the past and the future. The present and potential condition of a field, stream, or forest cannot be understood without knowing its earlier history. For example, great stretches of light-green aspen trees may grow in parts of the Rocky Mountains while nearby slopes are covered with dark-green fir and spruce trees. This indicates that a forest fire once destroyed stands of evergreens. Aspens are the first trees capable of growing on the fire-scarred land. After about 40 years spruce and fir seeds begin to germinate in the shade of the aspens. In the course of time the evergreens can be expected to regain their lost territory.


Ecology is a relatively young science. Its laws are still being developed. Nevertheless, some of its principles have already won wide acceptance.

The Special Environmental Needs of Living Things

One of these principles can be stated as follows: life patterns reflect the patterns of the physical environment. In land communities vegetation patterns are influenced by climate and soil. Climate has a marked effect on the height of dominant native plants. For instance, the humid climate of the Eastern United States supports tall forest trees. Westward from Minnesota and Texas the climate changes from sub humid to semiarid. At first the land has squatty, scattered trees and tall grasses or thickets. As the climate becomes drier, tall-grass prairies dominate. Finally, on the dry plains at the eastern base of the Rockies, short-grass steppe appears.

Rocky Mountains (or Rockies), chain of ranges, along e. side of North American Cordilleras from Mexico to Alaska.

Climates and plant varieties change quickly at the various elevations of mountain range. At very high altitudes in the Rockies, alpine range lands exist above the timberline. Here, the climatic factor of cold outweighs that of moisture, and tundra vegetation similar to that of the Arctic regions is nurtured. West of the Rockies, however, in basins between other mountains, the desert scrub vegetation of arid climates prevails. Near the northern Pacific coast may be found lush rain forests typical of extremely humid temperature climates.

Though moisture and temperature determine the overall pattern of a region’s vegetation, unusual soil conditions may promote the growth of un-typical plant species. Thus, even in arid climates cat tails grow near ponds and forests rise along streams or from rocky outcrops where run off water collects in cracks.

Plants and animals flourish only when certain physical conditions are present. In the absence of such conditions, plants and animals cannot survive without artificial help. Domestic plants and animals ordinarily die out within a few generations without the continued protection of man. Of all the forms of life, man seems least bound by environmental limitations. He can create liveable conditions nearly everywhere on the planet by means of fire, shelters, clothing, and tools. Without these aids, man would be as restricted in his choice of habitat as are, for example, such species as the polar bear, the camel, and the beech tree. However, given his capacity to develop artificial environments, man is able to range not only over the entire Earth but also in the heights of outer space and the depths of the ocean bottom.

Communities of Plants and Animals

Community, in biology, a group of organisms living together in a particular environment.

Closely related to the life patterns principle is the principle of biotic communities. According to this principle, the plants and animals of a given area its biota tend to group themselves into loosely organized units known as communities. The community is the natural home of each member-species.

This means that certain types of plants and animals live together in readily identified communities. Pronghorn antelope are associated with dry steppe grasslands; moose inhabit northern spruce forests; and such trees as oak and hickory or beech and maple are found together in forests. By contrast, certain living things cat tail and cactus, for example never share the same natural environment.

Large communities in turn contain smaller ones, each with its own characteristic biota. Bison, coyotes, and jack rabbits are part of the grasslands community. Fox squirrels, wood pigeons, and black bears are part of the forest community. By means of computers, ecologists have simulated communities containing various plants and animals. In this way they have been able to determine optimum populations for each of the species in a community.


ECOLOGY (Part 3 of 3)   Leave a comment

HOW DDT KILLED THE ROBINS. Dutch elm disease threatened to destroy most of the majestic elms that once flourished along residential streets. To eliminate the beetles that carry this fungus disease, many communities sprayed their elms with massive doses of DDT. The pesticide stuck to the leaves even after they fell in the autumn. Earthworms then fed on the leaves and accumulated DDT in their bodies. When spring came, robins returned to the communities to nest. They ate the earthworms and began to die in alarming numbers. Of the females that survived, some took in enough DDT to hamper the production or hatching of eggs. Robin populations were so seriously affected by DDT poisoning that the very survival of the songbird seemed in jeopardy. This experience was a vivid example of the far-ranging effects that flow from upsets in the delicate balances of nature.

Ironically, the DDT did little to prevent the spread of Dutch elm disease.

By the 1970s ecologists had accumulated considerable evidence demonstrating that the widely used pesticide DDT and its metabolites, principally DDE, altered the calcium metabolism of certain birds. The birds laid eggs with such thin shells that they were crushed during incubation. This discovery was one of many that led to the imposition of legal restraints on the use of some agricultural pesticides.

Ecologists know that the well-being of a biotic community may require the preservation of a key member-species. For example, the alligator performs a valuable service in the Florida Everglades by digging “‘gator holes.” These are ponds created by female alligators when they dig up grass and mud for their nests. During extremely dry spells, these holes often retain enough water to meet the needs of bobcats, raccoons and fish until the arrival of rainy weather.

Many birds use the holes for watering. Willow seeds take root along the edges, and fallen willow leaves later add substance to the soil. Thus, many forms of life are sustained by ‘gator holes. But poachers have been hunting the alligators almost to extinction for their valuable hides.

As a result, the number of ‘gator holes can be expected to dwindle, and various forms of Everglades wildlife may be deprived of these refuges. Such ecological findings strengthen the case for the protection of alligators.

Another ecological threat to the Everglades arose in the late 1960s, when plans were made to build a jet airport near the northern end of the national park. The airport would have wiped out part of a large swamp that furnishes the Everglades with much of its surface water. Ecologists and conservationists opposed the project, arguing that it would hamper the flow of surface water through the park and thus endanger the biota of the unique Everglades ecosystem.

Their arguments aroused public concern, and in 1970 plans for the airport were dropped.

An Ecological Mistake

Kaibab National Forest, forest in Arizona, adjoining Grand Canyon National Park; 1,780,475 acres (691,395 hectares); forest headquarters Williams, Ariz.

At times, seemingly practical conservation efforts turn out to be mistakes. Cougars, or mountain lions, and deer were once abundant in Grand Canyon National Park and Kaibab National Forest. Because the cougars preyed on the deer, hunters were allowed to shoot the cougars until only a few were left.

With their chief enemy gone, the deer of the area increased so rapidly that they consumed more forage than the Kaibab could produce. The deer stripped the forest of every leaf and twig they could reach and destroyed large areas of forage in the Grand Canyon National Park as well. The famished deer grew feeble, and many defective fawns were born. Finally, deer hunting in the Kaibab was permitted, in the hope that the size of the deer herd would drop until the range could accommodate it. In addition, the few surviving cougars were protected to allow them to multiply. They then resumed their ecological niche of keeping the herd size down and of killing those deer not vigorous enough to be good breeding stock.

The Ecological Control of Pests

Many of the insects and other pests that have plagued North America originated elsewhere. There these pests were held in check by natural enemies, and the plants and animals they infested had developed a measure of tolerance toward them. However, when they were placed in an environment free of these restraints, the pests often multiplied uncontrollably.

At first, farmers fought the pests with toxic sprays and other powerful chemicals. However, these methods were expensive, sometimes proved unsuccessful, and were often dangerous. After decades of use, some pesticides were banned. In certain instances, pesticide use gave way to an ecological approach.

Research showed that severe damage from certain pests the Mexican beetle and the European corn borer, for example is confined to crops grown on particular types of soil or under certain conditions of moisture. Changes in land use helped control some pests. Others were controlled biologically by importing parasites or predators from their native lands. This important form of pest control proved successful in limiting damage by scale insects.

By destroying birds and other animals, as well as their breeding places, people lose valuable allies in their constant war with insects. Once, when the sportsmen of Ohio supported a proposal to permit quail hunting, the farmers of the state objected. They knew that a single quail killed enough insects to make it worth at least as much to them as a dozen chickens.

In some 3,000 locally organized Resource Conservation Districts ecological principles are being used to guide land use and community maintenance practices. These districts encompass the federal lands of the United States and more than 95 percent of its privately owned farmlands.


Throughout the world man-made communities have been replacing the communities of nature. However, the principles that govern the life of natural communities must be observed if these man-made communities are to thrive. People must think less about conquering nature and more about learning to work with nature.

In addition, each person must realize his interdependence with the rest of nature, including his fellow human beings. To safeguard life on Earth, people must learn to control and adjust the balances in nature that are altered by their activities.

Maintenance of the Environment

Climate cannot be changed except sporadically by cloud seeding, inadvertently by pollution, and on a small scale by making windbreaks or greenhouses. However, human activities can be successfully adapted to the prevailing climatic patterns. Plants and animals, for example, should be raised in the climates best suited to them, and particular attention should be paid to the cold and dry years rather than to average years or exceptionally productive years. In the United States the serious dust storms of the 1930s occurred because land that was ploughed in wet years to grow wheat blew away in dry years. Much of that land should have been kept as range land

Soil is a measure of an environment’s capacity to support life. It forms very slowly but can be lost quickly as much as an inch in a rainstorm. Wise land use ensures its retention and improvement.

For agricultural purposes, land is used principally as timber land, range land, or crop land Timber land and range land are natural communities. Crop land is formed when what was originally timber land or range land is cultivated. To ensure the best possible use of land, it is classified according to its ability to sustain the production of timber, pasture, or crops.

Water, like soil, is a measure of the abundance of life. Usable water depends on the amount and retention of rainfall. An excessive run-off of rainwater, however, may result from human activities for example, the building of roads and drainage ditches; the construction of extensive parking areas and shopping centres; the unwise harvesting of timber; year-round grazing of ranges; and the cultivation of easily eroded lands. Excessive run-off may cause floods. It may also lead to drought, which can occur when too little water is stored underground. Moreover, run-off strips soil from the land. This is deposited in reservoirs, ship channels, and other bodies of water. These silt-laden bodies must then be either dredged or abandoned. Water movements in and out of the soil must be controlled in such a way as to minimize damage and maximize benefits.

The Conservation of Natural Communities

Community, in biology, a group of organisms living together in a particular environment.

The communities of plants and animals established by humans usually consist of only a few varieties, often managed in a way that harms the environment. By contrast, natural communities usually enhance the environment and still yield many products and sources of pleasure to people.

Land once cultivated but now lying idle should be restored to the natural communities that formerly occupied it. In addition, people should use the findings of ecology to improve their artificial communities such as fields, gardens, orchards, and pastures. For example, few man-made agents for the control of pests can outperform the wide variety of insect-eating birds.

The Curtailment of Waste

Modern machines and weapons and the harmful wastes of technology can be used to destroy the environment. At the same time, the wise use of machinery can also enable humans to conserve their surroundings. Just as negotiation rather than warfare can be employed to resolve international disputes, no doubt the means can be devised to curtail the destructive wastes of factories and vehicles. True, ever-growing demands for goods and services, nurtured by increasing human populations and rising expectations, are placing more and more pressure on the environment. An understanding of the causes and consequences of environmental deterioration, however, may bring about a change in the goals that people pursue and the means they use to achieve these goals.

Increases in human material possessions have been accompanied by a potentially dangerous worsening of the natural environment. A central function of ecology is to study human interactions with the natural environment in order to modify them favourably.

Assisted by E.J. Dyksterhuis, Professor of Range Ecology, Texas A & M University.


Books for Children

Jaspersohn, William. How the Forest Grew (Greenwillow, 1980).

Pringle, Laurence. City and Suburb: Exploring an Ecosystem (Macmillan, 1975).

Sabin, Francene. Ecosystems and Food Chains (Troll, 1985).

Selsam, M.E. How Animals Live Together, rev. ed. (Morrow, 1979).

Books for Young Adults

Billington, E.T. Understanding Ecology, rev. ed. (Warne, 1971).

Pringle, Laurence. Lives at Stake: The Science and Politics of Environmental Health (Macmillan, 1980).

Sharpe, G.W. Interpreting the Environment, 2nd ed. (Wiley, 1982).

Sharpe, G.W. and others. Introduction to Forestry, 4th ed. (McGraw, 1976).

CONSERVATION (Part 1 of 5)   Leave a comment

The reasonable use of the Earth’s natural resources water, soil, wildlife, forests, and minerals is a major goal of conservation. Conservation is the preservation and maintenance of the environment to meet human needs for production while insuring that proper consideration is also given to aesthetics and recreation. An effective conservation program results in a continuous production and supply of native plants and animals, and the continued availability of critical mineral resources. Timber, fuels, ores, and other resources are being depleted at such a rapid rate that the need to conserve them has become crucial. The prevention of environmental pollution from industrial, agricultural, urban, and domestic sources, including toxic chemicals, radioactive wastes, and elevated water temperatures, is another concern of conservation. People concerned with conservation seek to prevent the waste of natural resources, to maintain a high-quality environment, and to preserve the natural heritage for future generations.

1869: Birth of ecology. Most people are unaware that the subdivision of biology called ecology is over a century old. Over the course of its development, ecology has emerged as one of the most significant and studied aspects of biology. Ecology refers to the overall interrelated system of nature and the interdependence of all living things.

The word ecology has been popularized more recently because of the many environmental concerns that have been raised since the 1970s. But as a word, ecology was coined in about 1869 by a German zoologist named Ernst Haeckel. A researcher in evolution and a strong supporter of Charles Darwin’s theories, Haeckel spent most of his career teaching at the University of Jena.

The study of ecology dates back to the ancient Greek philosophers. An associate of Aristotle named Theophrastus first described the relationships between organisms and their environment. Today the field of ecology has expanded beyond narrow biological studies to include environmental pollution, population growth, and food supplies.

2300 BC: Invention of paper In ancient Egypt paper was made from the papyrus plant. The stalk was split, sliced, pressed and dried into thin sheets. In China, a government servant named Ts’ai Lun is credited with inventing paper in AD 105. He made the paper from mulberry fibres, hemp waste, rags, fish nets, and other materials. It took many centuries for this invention to travel west: it reached Samarkand, in Central Asia, by 751 and Baghdad by 793. Finally, through Arab contacts, this technology arrived in Europe in about the 12th century. Three hundred years later the invention of printing with moveable type spurred the demand for paper in Europe. Even so, processes for making it were not technologically advanced, and shortages persisted for several hundred years. The use of wood pulp in the early 19th century greatly increased the paper supply. In the 20th century, concern over deforestation led to the growth of recycling processes for paper.

 Soot, car fumes, and acid rain pollute the air.

The world’s rain forests are being destroyed.

Toxic waste and garbage contaminate the water.

Pesticides and chemicals poison our food.

Strip mining ravages the land.

Gas and oil are wasted.

Humans have been slowly destroying the world’s resources for years.

The goal of conservation is to make the environment clean and healthy while continuing to use the Earth’s resources. This goal is gaining popularity throughout the world as all nations begin to see the results of abusing the environment.

Everyone must think seriously about the environment. Humans cannot live happy, healthy lives in an unhealthy world.

Renewable Resources can be maintained with careful planning. Examples include:

wild animals


soil and water


Non-renewable Resources will eventually be used. Examples are:

oil, coal, and gas

gold and silver



Natural resources are sometimes classified as renewable or non-renewable Forests, grasslands, wildlife, and soil are examples of renewable resources. They can be regenerated, and prudent management can maintain them at steady levels. Such resources as coal, petroleum, and iron ore are non-renewable Consumption, wasteful or not, of their limited supply speeds the rate at which they are depleted.

Every creature, large or small, plays a part in the balance of nature.

Balance of nature means the way in which everything in nature depends upon other things in nature in order to live. All of nature works well together, with one creature or plant or mineral supporting others. Sometimes it appears that the elements of nature are not working well together, for example when a volcano erupts or when lightning starts enormous forest fires. However, both of these events that may seem like total disasters are extremely helpful in that they make it possible for new habitats to be created.

In many cases, people have upset this balance of nature. The Earth’s environment can handle some of the bad things done to it, but with so many people living on the Earth, there’s no such thing as “a little bit” of damage. All people on Earth need a healthy, balanced environment.

Natural resources are a vital part of sustaining human life, and conservation measures are designed to control, manage, and preserve them so that they can be used and appreciated to the fullest. Freshwater habitats must be kept clean for drinking and for recreational activities. Soils must be kept fertile, without the accumulation of toxic chemicals from pesticides or herbicides, to provide fruits and vegetables. Forests must be managed in a manner that can provide not only lumber and pulpwood for paper products but also homes for native wildlife. The use of oil, coal, and minerals important for an industrial society must be carefully monitored to be certain that the supply does not dwindle too rapidly. The proper conservation of these natural resources is of key concern in maintaining the balance of nature in a world with a large human population.

The Abuse of Natural Resources

When the first European settlers arrived in North America, they found a continent rich in natural resources. Much of the land was covered with forests where wild animals abounded. Great herds of bison roamed the grasslands. The soil was deep and fertile. Clean lakes and streams, unpolluted with silt and chemical wastes, held a wealth of fish.

In the struggle to obtain food, clothing, and shelter the settlers cut down and burned most of the Eastern forests. As they moved westward, they ploughed up the grasslands to plant corn and wheat. Their growing cities dumped sewage and waste materials from factories into the lakes and streams.

The roots of hundreds of thousands of ground-covering plants and grasses form a sponge-like net that holds the topsoil in place and soaks up rainwater.

If this plant cover is removed:

There is no net to hold the soil down, and nothing for rain to soak into.

The good soil needed for farming and the water needed to fill underground reservoirs wash away into streams and rivers.

Flooding occurs because the rivers and streams can’t hold all of the water and soil that is washing away.

Flooding is a major problem in areas of North America where rain tends to fall quickly in heavy thunderstorms. In Europe rains usually fall slowly and gently enough not to wash away bare topsoil.

The settlers who first came to North America didn’t know that the heavy rains of America would cause so much damage to bare soil. They also had no idea that the methods they used to plough and plant crops were causing soil problems to worsen.

Much of the spring and summer rain in the United States falls in torrential thunderstorms, especially in the vast Missouri, Mississippi, and Ohio river basins. The farmers who settled the country were mainly Europeans who had been used to gentle rains. The methods of tilling and planting which they brought with them were not suited to the new climate. The land’s capacity for water storage was diminished by the loss of the grasses that hold soil in place and prevent the escape of rainwater. With the blotter like plant cover gone, many rivers flooded when the winter snows melted. During natural drought periods, wells ran dry and crops died in the fields. Dust storms blew the topsoil away. Birds and animals that once thrived in the forests and on the prairies became scarce. Some kinds vanished forever. Fish died in the unclean waters.

The Conservation of Natural Resources

The Earth’s environment will continue to become less healthy unless all nations work together to improve it. To protect our world, everyone must understand the need for conservation.

People who worry about the environment have grouped together into organizations that fight for conservation, such as:

the Sierra Club


the Nature Conservancy

the World Wildlife Fund

Many of these groups have succeeded in getting laws passed to protect land, wildlife, and other natural resources. Once laws have been passed, anyone who disobeys them can be punished.

The abuses of the past and even the present have emphasized the need for the wise use of natural resources. Conservation groups have promoted corrective legislation and instituted legal proceedings against violators. People have been made increasingly aware that their continued existence depends on these efforts to stop environmental deterioration.

Individuals have no right to destroy nature’s wealth for profit. The logging company that cuts down too many trees without replanting for the future; the industrial plant that fouls a river or pollutes the air with its wastes; the farmer who neglects his own farm and so damages his neighbour’s land are injuring their whole community. The camper whose carelessness starts a forest fire; the automobile driver who wastes gasoline; the picnickers who tear up armfuls of wild flowers or litter the landscape with their garbage; the hunter who kills more than the legal limit all are abusing natural resources. Conservation is everyone’s responsibility. It is a uniquely human problem. Stringent laws to stop the waste and destruction of natural resources must be supported and effectively enforced.


  1. Rampant streams destroy land and fail to recharge underground water sources.

  2. Bad forestry leaves timber fire-prone and causes soil erosion and flooding.

  3. Poor farming methods drain soil fertility and hasten erosion by wind and water.

  4. Sprawling, monotonous suburbs blight good land and foster obsolescence.

  5. Rural industrial parks create pollution that can affect downstream communities.

  6. Abandoned mining operations poison streams and permanently scar the landscape.

  7. Haphazard placement of industry leads to the pollution of water and air in cities.

  8. Failure to treat garbage and sewage adequately contaminates the surroundings.

  9. Bad industrial zoning downgrades nearby property and produces urban eyesores.

  10. Polluted rivers cannot sustain fish life and need costly purification for drinking.

  11. Poorly managed traffic facilities snarl urban travel and aggravate air pollution.

  12. Densely grouped high-rise apartment buildings wall out air and sunlight.

Conservation can help maintain the natural beauty of a community. When land is mistreated, the countryside can become unattractive. Vacant lots covered with trash, bare roadsides, and garbage-laden streams are ugly. Conservation also helps preserve areas suitable for recreation. As cities grow crowded, natural areas are needed for people enjoying leisure time. People need city parks, county forest preserves, and national parks; grass and trees bordering roads and highways; and sparkling streams.

Posted 2011/12/21 by Stelios in Education

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CONSERVATION (Part 2 of 5)   Leave a comment


Polluted water in one part of the world affects water sources everywhere. This happens because water moves through what is called the hydro logic cycle.

In the hydro logic cycle

1) water moves into the air and clouds as it evaporates from oceans, lakes, and rivers.

2) the winds that blow around the Earth blow the water vapour around until enough builds up inside a cloud to cause rain to fall.

3) wherever that rain falls, sooner or later it will flow into another body of water.

In this way, a water molecule that left the ocean near California may fall as rain in India. Unfortunately, products that pollute the water can also be carried to other parts of the world along with the water molecules.

Water is an essential natural resource. Everyone uses it. It is needed in homes for drinking, cooking, and washing. Communities must have it for fire protection and recreational activities such as swimming, boating, and fishing. Industries use it to produce electricity and to perform a large number of manufacturing processes.

Watersheds and Their Importance

Watershed (or drainage basin), area of land, of any size, from which all precipitation flows to a single stream or set of streams.

A watershed is the area drained by a river or a stream in a region. Such an area slopes toward a common land trough. Some rain runs off, or drains, over the ground surface. Run-off water forms small streams, which flow into larger ones. These eventually join to form rivers.

A natural watershed conserves water. It has clear streams and an ample cover of trees, grasses, and other plants. Plants help contribute to form a part of the topsoil called humus. Humus consists of decaying leaves and wood, bacteria, dead insects, and other plant and animal remains. It provides some of the nutrients for new plant life. Together with a network of roots, it acts as a blotter that soaks up rain. Plants break the force of falling rain and scatter the drops over leaves and branches. Some of the water returns to the air by evaporation. Part of the water used by plants is passed through their leaves into the air again by transpiration. The rest of the water sinks into the earth through countless tiny channels. Some of the spaces in the soil through which water percolates are caused by natural features of the geology or soil itself. Others are made by plant roots and burrowing animals like earthworms, insects, and moles.

The level at which the earth is permanently saturated is known as the water table. This vast underground water supply fluctuates with the seasons and the amount of rainfall. During long, heavy rains the soil may not be able to soak up all the water. Some of it runs off the surface, but in a forested watershed it moves slowly. Deep snow that melts slowly allows water to soak into the soil gradually.

When all the trees in an area have been cut down or burned off due to poor forestry practices, or grasses and other plants have been stripped off by fire, overgrazing, or poor farming practices, the watershed suffers. The water from rainfall flows over the ground’s surface instead of being absorbed by the vegetation and organic materials that would be present on a natural forest floor.

When there are no leaves and branches or grasses to break the force of falling rain and the blotter of roots and humus is gone, mud closes the channels through which water sinks into the soil. If the land is level, the water stands in stagnant pools; if it slopes, the water runs downhill into the rivers. Streams in a mismanaged watershed become brown with silt, or suspended soil, because the racing water carries soil along with it.

A mismanaged watershed can result in destructive floods in the spring because heavy rains and melting snows overflow the riverbanks. In the summer, streams, springs, and wells can dry up because little or no water has sunk into the underground reservoirs.

Water Pollution

Water can be polluted by many things. One of these is the topsoil or silt that washes into streams and rivers. This silt washes into streams and rivers from land that has been badly managed.

When silt washes into streams and rivers, two harmful things may happen.

1) Silt that floats in the water limits the amount of air in the water. Fish need air to breathe. When silt limits the air in the water, the fish die.

2) As the movement of water slows down, silt drops to the bottom of the stream beds

There are ways of controlling erosion of silt from land into streams and reservoirs. Conservationists try to make sure that the right steps are taken to prevent the silting of streams.

The silting of streams is one kind of water pollution. A heavy load of silt kills fish indirectly by reducing the amount of oxygen in the water. Then, as the flowing water slows, silt is deposited on stream beds Reservoirs behind dams also fill with silt unless erosion is stopped in watersheds above.

The main problem with our waterways is that they have been used as a garbage can for every kind of human waste that you might imagine.

Raw, untreated sewage contains:

  • garbage from individuals and businesses

  • waste products from industry

  • run-off from sewers

Raw sewage is unhealthy and can cause outbreaks of disease. It also severely pollutes the environment.

Raw sewage can be treated in special ways to make it less harmful to the environment. For example, poisonous metals and objects that take a long time to break down can be removed from the waste so it can break down faster.

Other kinds of water pollution have created other problems. Many waterways are used as dumps for household and industrial wastes. Some communities dump untreated sewage and garbage into the nearest streams. Industries contaminate the waterways when they discharge acids, chemicals, greases, oils, and organic matter into them. Such materials foul drinking water and endanger public health. They destroy commercial fisheries. They also make waterways unusable for recreational purposes. Leaks and spills from offshore oil wells and wrecked or damaged oil tankers have caused the widespread destruction of marine life.

A food chain is made up of plants and animals linked together like a chain. Each creature depends on the other creatures in the chain for food.

It takes many creatures at the bottom of a food chain to feed just one animal at the top of the chain.

If one link becomes weak, it affects all others in the chain. Here’s an example:

For a period of time humans sprayed a chemical pesticide called DDT on plants to kill bugs.

The DDT washed off the plants and into rivers, lakes, and streams. Fish ate the poison. Many fish died, but many others survived with traces of the poison in their bodies.

Some animals ate the poisoned fish. Still others ate poisoned insects. Finally, other creatures ate the animals that had eaten the poisoned fish and insects.

Since higher animals in the chain eat a large amount of the lower animals, each link was getting more and more DDT.

While large doses of DDT can kill, smaller doses do damage as well. For example, DDT causes the shells of bird eggs to be too thin. Many kinds of birds, such as the American bald eagle, poisoned by DDT, were unable to hatch young, and their numbers became smaller and smaller.

When conservationists and others saw the harm caused by DDT to various creatures such as the bald eagle, they reasoned that other creatures, including humans, were being harmed by the pesticide. Although the spraying of DDT was stopped by passing a law in the United States, it continues in other parts of the world.

The large-scale use of organic insecticides, herbicides, toxic metals, and pesticides, particularly DDT, has polluted streams and destroyed wildlife. Some pesticides tend to concentrate in the tissues of plants and animals in nature’s food chains. Thus organisms at the ends of these chains, including humans, may take in harmful amounts of pesticides deposited in their food supply.


Whenever land is stripped of its plant cover, soil is inevitably lost by erosion, the so-called silent thief. A single rainstorm can wash away centuries-old accumulations of soil from neglected or badly managed fields. Topsoil is an extremely valuable natural resource. Under this thin blanket of rich dirt and humus, in which plants grow best, is a less fertile material called subsoil. If the surface layer of topsoil is blown or washed away, the remaining subsoil cannot support plant life. The submarginal farms must eventually be abandoned.

Types of Soil Erosion

More than 700 million acres (283 million hectares) of agricultural land in the United States are subject to erosion. Some 230 million acres (93 million hectares) of crop land require constant supervision to control erosion caused by wind and water.

Dust storms are the evidence of wind erosion. Soil unprotected by plant cover simply blows away. During the 1930s millions of acres of farmlands were badly damaged by wind. Many fields lost from 2 to 12 inches (5 to 30 centimetres) of vital topsoil during this period. As a result, the entire southern Great Plains area was called the Dust Bowl.

One of the several kinds of water erosion is sheet erosion the wasting away of level land in thin layers. The deterioration may go on for years without being noticed, though the land yields successively smaller crops. A patch of subsoil showing through on some slight rise of ground may be the first sign that the land is nearly finished as a food producer.

Splash erosion is the washing away of soil by the direct battering of rain. Small channels dug in the soil by run-off are called rill erosion. The little rills run together, form a network of larger rills, and then develop into gullies. When gully erosion occurs, the land can become a desert.

Conservationists also recognize that livestock can overgraze a plot of land until severe soil erosion occurs. About 4 million acres (1.6 million hectares) of topsoil are lost every year through erosion, and about 85 percent of this is the result of overgrazing by livestock.

Although major losses of productive agricultural lands occurred in the first half of the 20th century due to erosion, a major concern today is the loss of natural habitats as a result of commercial development. Large tracts of productive land an estimated 1 million acres (400,000 hectares) each year are lost through road building, suburban housing and industrial site developments, and airport expansion. New dams often flood some of the most productive agricultural land and natural forest habitats.

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CONSERVATION (Part 3 of 5)   Leave a comment

How Soil Conservation Works

Groups interested in improving farming practices have been around for many years. But the federal government did not get involved in soil conservation until the early 1930s.

Problems that occurred during the 1930s, such as the Dust Bowl, caused people to recognize the need for government leadership in the areas of soil conservation and farming.

  • Agricultural acts passed by lawmakers in 1929 and 1932 provided money to be used for erosion research.

  • In 1933, during the Great Depression, Congress passed a bill that would allow people without jobs to work in erosion control for the government. In this way, soil conservation could be put into practice and the unemployed would have work.

  • The Soil Erosion Service, later renamed the Soil Conservation Service, was created in 1935 as a result of this bill and has been responsible for managing conservation programs.

In 1933 the Soil Erosion Service (soon renamed the Soil Conservation Service) was created as a major division of the United States Department of Agriculture. The Soil Conservation Service has devised a land classification system that offers guidance in the proper use of land. Such factors as slope, type of soil, amount of rainfall, humidity, and vegetation type are considered when determining land use for maximum productivity. Of the eight government-designated land classifications, classes I, II, III, and IV may be used for cultivated crops; however, classes III and IV require skilful management to avoid serious erosion. Classes V through VII can be used for forests and for grazing. Class VIII land, which includes sandy shores and extremely rocky places, is considered suitable only for wildlife or for scenic and recreational purposes.

Covering the ground with plants is one of the key elements in soil conservation. To prove this, the Department of Agriculture experimented with two steep plots of adjacent land one planted with crops and the other thickly covered with grass. The cultivated plot lost 7 inches (18 centimetres) of topsoil in 11 years. By contrast, it was estimated that it would take 34,000 years to lose the same amount of topsoil from the grass-covered plot.

Plant cover tends to hold rainwater where it falls and thus prevents the soil from blowing or washing away. Gullies can be healed in many cases by planting new plants. They provide a tangle of leaves and stems that trap and hold in place part of the soil carried by run-off Another way to heal gullies is to build brush dams across them at regular intervals. Then soil and water running down the gully are caught behind the dams and held in place.

To help prevent the start of erosion, farmers may use a variety of conservation measures:

Contouring. This practice involves ploughing, planting, and cultivating sloping fields around hillsides, with curving furrows horizontal to the hill, instead of furrows running straight uphill and downhill. The curved furrows catch rainfall and allow much of it to soak into the ground. They also catch soil washing down from higher levels.

Strip-cropping. Strips of close-growing plants, such as grasses or clover, are alternated between strips of clean-tilled row crops, such as corn and soy beans The strips of close-growing plants hold water and keep it from eroding the cultivated strip below. These strips are planted on the contour.

Terrace, in geology, stretch of elevated, level land along banks of a river, lake, or ocean; frequently occur in series, one rising above the other; artificial terraces are used effectively in landscape gardening and in agriculture to hold moisture and prevent erosion.

Terracing. On long slopes a low ridge, or terrace, thrown along the outer side of the slope catches soil and rainwater and retards run-off Encouraging plant growth on a terrace will help hold soil.

Listing. In dry regions a Lister plough can be used to throw a ridge of dirt to each side, creating a trough about 18 inches (46 centimetres) wide and 7 inches deep. Crops are planted in the bottom of the trough.

Shelter belts On treeless plains, belts of trees planted at the edges of fields break the force of winds across the fields and reduce wind erosion.

Deep tillage (also called stubble mulching, or primary tillage), method of ploughing to conserve the land.

Deep tillage,stubble mulching. Instead of turning over the soil with a mouldboard plough, a deep-tillage plough breaks the soil below the surface. It leaves the surface vegetation or harvest remains from the previous crop to act as a cover.

Different crops need different substances, called nutrients, to enable them to grow.

Crops get these needed nutrients from the soil. If the same crop is grown in the same field every year, the soil will soon lose nutrients needed by that crop.

Crop rotation is the practice of planting different crops in a field each year or every few years.

With careful planning, crops can be rotated in a way that builds up nutrients in the soil for the next crop. Here’s an example:

Many crops need nitrogen to grow, and they take it from the soil. Other plants, like legumes, take nitrogen out of the air and put it back into the soil. By rotating legumes with other crops, the nitrogen in the soil can be replaced.

Crop rotation. Planting different crops each year on a piece of land keeps the soil productive. One crop can benefit the next. For example, nitrogen is essential for plant growth and is added to the soil by legumes, such as clover, alfalfa, soy beans, and cow peas These combine nitrogen from the air with other elements and store it in the soil through their roots. In a year or two the plants can be ploughed under. This is called green manuring.

After the roots have rotted, other plants that need nitrogen but cannot use nitrogen in the air for example, corn and potatoes can use the stored nitrogen for growth. Rotations are programmed with strip-cropping by shifting the close-growing strips and the tilled strips at fixed intervals.

Water can be polluted by many things. One of these is the topsoil or silt that washes into streams and rivers. This silt washes into streams and rivers from land that has been badly managed.

When silt washes into streams and rivers, two harmful things may happen.

1) Silt that floats in the water limits the amount of air in the water. Fish need air to breathe. When silt limits the air in the water, the fish die.

2) As the movement of water slows down, silt drops to the bottom of the stream beds

There are ways of controlling erosion of silt from land into streams and reservoirs. Conservationists try to make sure that the right steps are taken to prevent the silting of streams.

Cover crops. Land is kept covered in winter and summer with either a growing crop or the residue, such as corn stalks, from the crop previously grown. When cover crops are ploughed under for green manuring, the plant foods added to the soil improve its water-holding capacity and increase its fertility.

Fertilization. Chemical or natural fertilizers replace the soil substances used up by crops.

Erosion on Urban Land

Crop land is not the only soil subject to erosion. The land on which housing and other urban projects are built is particularly susceptible because its protective cover is generally removed.

Mulch, material such as manure, leaves, pulverized earth, placed on surface of soil to retain moisture and to protect plant roots from frost.

To prevent erosion on construction sites, builders should take corrective action. For example, mulches placed on steeply excavated slopes usually prevent soil from washing or blowing away. Straw or fibre netting may be used as mulches. On sites where erosion control is more difficult, hydro seeding can be used. Grass seed, fertilizer, and mulch are power-sprayed on excavated slopes. The quick-growing grass then stabilizes the soil against erosion.


The preservation of wildlife greatly depends upon water and soil conservation. All native plants and animals constitute the wildlife of a region and are a product of the land resources and habitat conditions. But, like humans, wild animals must have food, water, and shelter. Destroying the forests, marshes, ponds, and grasslands destroys their food and water supplies and the places in which they live.

1872: Yellowstone National Park. Although the concept of national parks was first suggested in 1832 by American artist George Catlin, it was not until March 1, 1872, that the first national park in the United States was established by Congress. Yellowstone Park was the beginning of a large system of 49 parks that today can be found in nearly all parts of the country. These parks, as well as other monuments, are managed by the National Park Service.

Once Yellowstone was opened, other countries began setting aside nature preserves similar to America’s national parks. Canada, for example, established a 10-square-mile area of hot springs at Banff, Alberta, in 1885 as a national park. Today there are national parks on all continents, except Antarctica.

Yellowstone is located in parts of three states: north-western Wyoming, southern Montana, and eastern Idaho; it covers 2,219,823 acres (898,329 hectares). Several sub ranges of the Rocky Mountains are in or around the park’s borders: the Snow Mountains, the Gallatin Range, the Absaroka Range, and the Tetons. Several national forests surround Yellowstone. The Grand Canyon of the Yellowstone River is a 19-mile gorge running through the park. Among Yellowstone’s other distinctive features are 10,000 hot springs, including 200 geysers, many of which erupt to heights of 100 feet (30 meters). The most famous geyser is Old Faithful, named for the regularity of its eruptions.

The park is heavily forested, and in 1988 a series of disastrous fires destroyed much of its vegetation and animal life.

Of the original native wildlife of the United States many species are now extinct. These include the passenger pigeon, the Carolina parakeet, the great auk, the Labrador duck, the Pallas cormorant, the dusky seaside sparrow, and the heath hen. Mammals gone forever include the Eastern elk, the Plains wolf, the sea mink, and the Bad Lands bighorn. Many smaller birds and mammals have also become extinct in the wild. Populations of the ivory-billed woodpecker and the California condor no longer exist in the wild in the United States.

The number of moose, caribou, wild sheep and goats, and grizzly and Alaska brown bears grows smaller every year. Much wildlife is now protected by law from over hunting and overfishing. However, if habitat destruction of their natural homes continues, many will be unable to survive.

The United States Fish and Wildlife Service maintains a list of endangered and threatened species of the United States. Environmental concerns for a variety of reptiles, amphibians, small fishes, insects, and molluscs is reflected in the number of species classed as threatened or endangered.

The Endangered Species Act has been effective for preserving some species that seemed destined for extinction. For example, the American alligator had been reduced to a relatively small number by the early 1960s due to illegal hunting for hides and meat. After 20 years of protection, the species recovered to such a large extent in many parts of its range that it led to a relaxation of the laws in the 1980s so that limited hunting was permitted.

Many events can cause a species of animal to become endangered. For example, some animals are killed because people want trophies or desire to wear clothing made from furs and skins.

However, the main reason many creatures have become endangered is because humans are destroying their habitats. Two such habitats are the Florida Everglades and the rain forests of Brazil. Too often, places that are attractive to animals are just as attractive to people, who want to build various facilities.

Unfortunately, nothing can bring back a species that has been lost. Such extinct creatures will only be seen in museums or pictures.

Worldwide, the International Union for Conservation of Nature and Natural Resources keeps track of species threatened with extinction. Endangered species include many of the world’s great cats, whales, certain species of rhinoceros, tapirs, and many other mammals, birds, and reptiles. Housing and other facilities needed by an expanding human population are encroaching on their habitats.

Many species are the victims of the illegal pet trade and of the trade in exotic pelts and skins; the increasing availability of guns and poisons is responsible for the extermination of other species. The African elephant, once common throughout the sub-Saharan region of the African continent, has been greatly reduced in numbers due to illegal poaching for the ivory trade.

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CONSERVATION (Part 4 of 5)   Leave a comment

Refuges for Wildlife

Some governments have established national wildlife reservations and game refuges. Many refuges are established in places to which animals, especially migratory birds, have long been attracted. In the United States, many of these are administered by the Fish and Wildlife Service. All the national parks and national monuments are wildlife refuges. Individuals can help restore wildlife to the countryside simply by providing birds, fish, and animals with natural breeding sites. They can do even more by encouraging their state and federal governments to provide effective laws for habitat protection.

For a long time, many people believed salt marshes were just worthless land. Salt marshes became dumps for garbage, or they were filled in to make the land more useful to humans.

Now we know that marshes are habitats for many different land and water creatures. They often act as “nurseries,” providing a safe shelter where animals can hide, and their young can grow into adults.

These marshes may produce and protect the greatest numbers and variety of wildlife on Earth.

Brush piles scattered through a wood lot provide retreats for cottontails, weasels, mink, and woodchucks. Fence rows can provide a haven for many kinds of birds. Marshes seldom make good crop lands, but they provide homes for muskrats and certain birds. Unfortunately, many of the salt marshes of the Atlantic coast have become dumping grounds for litter and industry. Others have been filled in to provide land for housing or for boat marinas. The birds and other animals that lived in those marshes, such as marsh hawks and short-eared owls, had to seek other habitats because their food supply and cover were gone. Continued exploitation of the marshes will further reduce the number of wildlife species.


Among the most valuable of nature’s resources are forests. They play a key role in the maintenance of the watersheds that are essential to water and soil conservation. They shelter many forms of wildlife. They supply lumber for construction, cord wood for fuel, and pulp for paper. Forests also provide the raw materials used in many synthetic products considered essential for modern life, including fibres, plastics, and medicines.

Fire can be a major scourge of a forest. Although lightning is sometimes responsible for kindling forest fires, human carelessness is most often the cause. Ground fires can destroy the organic soil of the forest and render it incapable of supporting tree life. When crown fires rage through the leafy tops of trees, they destroy timber and its resident wildlife. However, fire can also be a natural occurrence, and most forests rebound from occasional fires and the wildlife returns.

Insect infestation can also threaten the life of a forest. The Forest Pest Control Act of 1947 authorized surveys of public and private forests so that insect-borne diseases of trees could be detected and suppressed before they became epidemic.

Forests are a renewable resource that can provide us with goods for many years if logging is done carefully.

Most loggers cut small patches of trees out of a forest, leaving mature trees around the cut area. The mature trees …

  • reseed the cut area and produce new trees.

  • form a net with their roots that keeps the soil in place, thus controlling erosion.

  • provide a canopy of leaves that keeps rain from hitting the ground as hard as it would if there were no mature trees. If the rain beats down too hard, it erodes soil and prevents seeds from growing.

A more serious threat than fire or insects is indiscriminate logging. When every tree of a stand is cut without any provision for natural reseeding or manual replanting, no canopy is left to protect the soil against the splash erosion of rainfall. The loose soil soon becomes deposited as silt in nearby streams. Timber must be treated as a renewable crop, carefully harvested to ensure a sustained yield of trees. In this way, a balance is struck between the cutting of mature trees and the growth of saplings.


Minerals are non-renewable resources. Once exhausted, they can never be replaced. The United States has valuable stores of coal, oil, natural gas, and minerals. Until the Mineral Leasing Act was passed in 1920, the resources on public lands were transferred to private individuals, who sometimes exploited them. Government regulation now helps private industry make proper use of these resources.

Coal, gas, and oil are non-renewable resources that we may soon run out of. We have tried to conserve coal, gas, and oil by …

  • making mining processes less wasteful.

  • using other sources, such as nuclear power, for energy.

  • improving the machines that burn coal, oil, and gas so that they don’t need as much fuel to run.

One machine we have improved is the car engine. Today cars travel more miles on one gallon of gasoline than cars of the past did.

While one method of conserving resources may seem to make only a small difference, the use of many different methods can add up to big resource savings.

For years coal was mined as though it were inexhaustible about one ton wasted for each ton mined. The Bureau of Mines and other government agencies have promoted more efficient mining methods. In addition, the use of other sources of energy in home construction and in industry, and to generate electricity, has greatly extended the life of the coal supply. In order to conserve the dwindling supplies of natural gas and petroleum, in 1978 the government established requirements for conversion from these fuels to coal. But coal burning can create pollution problems.

Natural gas and petroleum were once carelessly wasted also. In earlier days, for example, because no use for natural gas had been found, it was burned off or allowed to escape into the air. Several government agencies now carry out programs to conserve these resources by replacing them with more abundant sources of energy. In 1978 the government established restrictions on the use of natural gas and petroleum in new industrial facilities and power plants.

Like other conservation needs, the wise management of mineral resources has become more pressing because of the growing number of consumers. As the human population increases, a need is generated for more consumer goods, such as household appliances and automobiles. Manufacturers must meet these rising demands from already dwindling deposits of metal ore. Under the Office of Fossil Energy Research, a program was set up that is concerned with increasing domestic supplies.

Some mineral resources, particularly metals, may be recycled that is, salvaged and reused. The recycling of waste metals is an important conservation practice that has become a major business. It is known as secondary production.

Throughout most of its history the United States has had ample, inexpensive supplies of fuels to provide energy. During the 20th century the country gradually shifted from reliance on coal as its principal fuel to dependence on natural gas and petroleum. By the late 1970s the United States was consuming more than one third of the world’s supply of these two fuels and was dependent on them for three fourths of its energy.

As it became more apparent during the 1970s that natural gas and petroleum resources might be depleted within the foreseeable future, energy conservation became an important government policy. Conservation measures were also adopted because of political and economic developments. About one half of the petroleum used by the United States was imported, much of it from Middle Eastern countries that opposed certain United States foreign policies. In addition, oil-exporting countries increased oil prices by more than 1,500 percent between 1970 and 1980.

In 1977 President Jimmy Carter established a Cabinet-level Department of Energy and proposed a comprehensive energy program. As passed by Congress in 1978, the program included measures to discourage energy consumption, particularly of natural gas and petroleum, and provided incentives for alternative energy sources. An Energy Security Act, to develop synthetic fuels, was passed in 1980.

Government, industry, and private citizens all took steps to conserve energy. To meet new government standards, smaller and more efficient automobiles were produced. There was renewed emphasis on improving the country’s mass transportation systems.

Grants, loans, and tax credits were offered for the installation of insulation and other energy-saving devices in homes and commercial properties. Efficiency standards for appliances were adopted. The government mandated minimum and maximum temperatures for non-residential buildings and suggested maintenance of similar temperatures in homes.

Until the energy crisis of the 1970s, people did not realize how much oil comes from sources outside the United States.

Many United States citizens don’t want to be dependent on others for energy. They fear such dependence might give foreign nations too much power over the United States.

If the United States can find other sources of energy that will always be available, there will be less worry about using so much foreign oil. This is why the government has supported research to find new ways to get energy from sources such as the wind, the sun, and the ocean.

The energy crisis of the 1970s led to increased emphasis on alternative sources of power. The government supported further development of solar, geothermal, and wind power. Industries and utilities were encouraged, and in certain circumstances required, to use coal as an alternative to natural gas and petroleum. The government encouraged long-range research programs, including the development of economical methods of producing gas and oil from coal and shale. Gasohol a mixture of alcohol produced from grain and gasoline was tried as an alternative fuel for automobiles, and development of a battery-powered automobile continued.

With the election of Ronald Reagan in 1980, the government support for most of these programs was ended. Instead, the government promoted the expansion of nuclear energy and a return to imported petroleum.

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CONSERVATION (Part 5 of 5)   Leave a comment



  1. Good forestry prevents the depletion of timber and the siltation of streams.

  2. Wilderness areas provide shelter for wildlife and a place for people to relax.

  3. Reservoirs control floods, provide plentiful drinking water, and generate power.

  4. Properly ploughed and well-managed farms keep the soil fertile and in place.

  5. Land irrigated with water from diversion dams becomes suitable for crop raising.

  6. Well-planned industrial clusters utilize control devices to lessen pollution.

  7. Hatcheries provide fish to supplement stocks in reservoirs, streams, and lakes.

  8. Self-contained satellite communities maintain the beauty of natural terrain.

  9. Treatment plants help keep rivers clean by processing wastes from city sewers.

  10. Area-wide master plans for work and housing developments enhance city living.

  11. Underground express ways link cities and suburbs without destroying surface land.

  12. Expansive parks provide space and facilities for cultural and recreational activities.

  13. Mass interurban transportation systems move people and goods efficiently.

  14. Footpaths and bicycle trails offer opportunities for stimulating outdoor exercise.

  15. Green spaces established by city zoning hold soil and provide natural beauty.

  16. Rivers kept clean by effective pollution control can be used for recreation.

  17. Scenic easements along riverbanks aid anti-pollution efforts and help stem erosion.

Prepared by the U.S. Department of the Interior

Pinchot, Gifford (1865-1946), U.S. forestry expert, born in Simsbury, Conn.; studied forestry in Europe; president National Conservation Association 1910-25; active supporter of T. Roosevelt; negotiator of coal-strike settlement 1923; governor of Pennsylvania 1923-27, 1931-35.

Conservation in the United States began as a movement to save the country’s vanishing forests, but the concept was soon broadened to include other resources. Gifford Pinchot, the head of the United States Forest Service from 1898 to 1910, was an early conservationist. He strongly influenced President Theodore Roosevelt, who established the National Conservation Commission. Some 234 million acres (95 million hectares) of government-owned timber, coal, oil, and phosphate lands were set apart as public lands, never to be sold to private interests.

During President Franklin D. Roosevelt’s first term, with a severe drought in the Plains states, reforestation and erosion control were undertaken by the Civilian Conservation Corps and the Soil Conservation Service. The government took over abandoned and non-productive farms; many acres were reforested and set aside as game reserves. The Taylor Grazing Act of 1934 regulated livestock grazing on public lands to prevent overgrazing and soil deterioration.

Under President Harry S. Truman a national program was established to control water pollution. Later legislation required states to set and enforce standards to maintain clean natural waters.

The Endangered Species Act of 1966 …

  • was one of the first laws passed in the United States intended to protect endangered animals.

  • provided for the publication of lists that name every endangered plant and animal.

  • was strengthened in 1969, when penalties were set for people who hurt endangered species.

  • was enhanced in 1973 when laws were established to protect animal habitats.

The Endangered Species Act has been a very important law because conservation groups can use it to prevent people from destroying the land that animals must have to live.

Efforts to save native wildlife from extinction were aided by management programs provided in the Endangered Species Preservation Act of 1966. Beginning in 1969 the importation of endangered species and the interstate shipment of illegally captured wildlife were prohibited. Thus the pet, fur, and hide markets for native and foreign species of potentially extinct animals were outlawed.

The National Environmental Policy Act of 1970, a far-reaching conservation measure, was supported by President Richard M. Nixon. It reflected the need for a high-quality environment, emphasized recycling of non-renewable resources, and advocated attempts to equalize population and resource use. In 1970 the Environmental Protection Agency (EPA) was formed to establish standards of environmental quality.

Greenpeace Foundation, international organization for the protection of the environment.

An international organization, the Greenpeace Foundation, was established in 1971 to protect the quality of the Earth’s environment. Its special concerns include protesting against radioactive and toxic waste dumping, the use of nuclear weapons, and acid rain.

Watt, James Gaius (born 1938), U.S. executive and public official, born in Lusk, Wyo.; director U.S. Bureau of Outdoor Recreation 1972-75; member Federal Power Commission 1975-77; president and chief legal officer Mountain States Legal Foundation in Denver 1977-81; U.S. secretary of the interior 1981-83.

The worldwide recession of the early 1980s had an unfavourable effect on national conservation programs because environmental restrictions were viewed as hindrances to economic recovery. The controversial policies of President Ronald Reagan’s Secretary of the Interior, James Watt, who repeatedly favoured land development and exploitation over conservation, were widely opposed, and he resigned in 1983. Public opinion also forced other changes in the personnel and operation of the EPA.

In 1984 Reagan rejected a bill to establish an American Conservation Corps, similar to the Civilian Conservation Corps of the 1930s. However, he supported bills to expand the federal wilderness preservation system by more than 8 million acres (3.2 million hectares).

In 1990, under President George Bush’s administration, legislation was passed that amended the Clean Air Act of 1970 to focus more on reducing acid rain, emissions from fossil fuel burning, and nitrogen oxide emissions. Also passed were a number of new automobile pollution controls, such as stricter tail-pipe emissions standards and installation of vapour-recovery nozzles at gasoline pumps. Also part of Bush’s policies were new legislation to strengthen controls of chemicals that destroy the ozone layer and plans to study radon and other indoor air pollution problems.

Assisted by Herbert A. Smith, Associate Dean for Education, Colorado State University. Also reviewed by J. Whitfield Gibbons, Senior Research Ecologist, Professor of Zoology, Savannah River Ecology Laboratory, University of Georgia.


Baker, Mark and others. The World Environment Handbook (World Environment Center, 1985).

Bittinger, Gayle. Learning and Caring About Our World (Warren, 1990).

Boy Scouts of America. Conservation Skill Book (BSA, 1979).

Curtis, Will. The Nature of Things (Ecco Press, 1988).

Durrell, Lee. State of the Ark (Doubleday, 1986).

Gates, Richard. Conservation (Childrens, 1982).

Graphic Learning International Staff. Concise Earthbook (Graphic Learning, 1987).

Long, R.E., ed. Energy and Conservation (Wilson, 1989).

Middleton, Nick. Atlas of Environmental Issues (Facts on File, 1989).

Owen, O.S. and Chiras, D.D. Natural Resource Conservation: An Ecological Approach, 5th ed. (Macmillan, 1990).

Prescott-Allen, Robert. How to Save the World: Strategy for World Conservation (Littlefield, Adams, 1981).

Schwartz, Linda. Earth Book for Kids: Activities to Help Heal the Environment (Learning Works, 1990).

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