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Wednesday 21 December 2011

CONSERVATION (Part 4 of 5)

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.

FOREST CONSERVATION

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.

MINERAL CONSERVATION

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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