Conserving our Environment - Use and Reuse

[Music] we all know that fish live in water if they are taken from water they will die water is the natural environment for fish but their environment includes more than just the water the fish's environment includes all of the things and conditions that surround them there are other fish and and snails there are plants that give off oxygen necessary for [Music] life there are even noises sound waves traveling through the water some of them are familiar to the fish but Others May startle them and send them rushing for protection food is also part of the environment and for these particular fish there is even more there is a boy named Dean Dean is interested in ecology ecology is the study of the relationships between living organisms and their environments Dean for instance is interested in the relationship of his fish to their environment he is interested in knowing how one species of fish is affected by another other he knows that if the water gets too hot or too cold the fish will be affected and they might even die he likes to see how they react to food and sometimes to unusual noises as Dean studies the fish he thinks about his own environment in a way he can think of the earth as being in an aquarium that is filled not with water but with air this constitutes man's natural environment it contains all the elements he needs to live man shares the Earth with many other living things and all living things have some effects on the total environment but man more than any other creature has learned to change his environment to use it for his own [Music] demands he has replaced some of the forests and grasslands the original ground cover with roads and cities and these changes have affected other elements of the environment forests and grass help the land to absorb rainwater but water does not soak into concrete or other pavement so when large sections of land are covered with pavement and buildings the rainwater flows off and more often than before the result is flooding the flooding is not always in the city that caused it sometimes it is Downstream where it can damage farmland so when we change part of our environment we should understand how that change will affect other elements of the world about us we have attempted to control our environment so that it can produce the things we want for example we can grow many different types of foods but again this has changed other elements of the environment before the land could be farmed the ground cover of trees or grasses had to be cleared as these disappeared so did many of the birds and animals that depended on them removing the trees and plowing the land left the soil exposed to the Wind and Rain a heavy rainfall might cause erosion wash washing away valuable soil to prevent erosion in a field which is not level the technique of contour plowing is used the rows are plowed across the slope of the land so that each row remains almost level this way each row becomes a small Dyke holding the water in place until it soaks into the ground even as crops are growing changes are taking place the plants are taking minerals from the soil if left alone the plants would eventually die and fall to the ground in time they would Decay and return the minerals to the soil but normally crops such as corn are cut and usually most of the plant is removed from the field as the corn is removed so are the minerals which it contains and if this continues year after year the soil will no longer be able to produce such a wholesome crop as this in order to continue growing useful crops year after year good rich soil must be maintained one way to do this is to replace the Lost minerals with with fertilizers care in applying fertilizer in the right amounts helps keep our Farmland productive but the fertilizer minerals may be washed into other parts of the environment and create new problems everything we use comes from materials in our environment the napkins are paper which of of course comes from wood the dinner table and chairs are also made of wood so are many houses wood is one of our renewable natural resources it is called renewable because as trees are cut down for lumber new trees grow to replace them trees are are useful not only for products such as wood and paper but they affect our environment in other ways along with other green plants they help in removing some of the dust and other particles from the air at the same time trees like other green plants produce oxygen and release it into the air animals need this constant renewal of oxygen one way to use the the wood and still maintain the forest is by selective cutting the selected large trees and also defective ones are marked and then cut this allows more room and sunlight for the smaller trees so they will grow faster and the faster they grow the more trees we can use for chairs and tables and other things to make our environment more comfortable many of the things which affect our lives are made of different types of materials refrigerators are made mostly of metal so are stoves TVs cars and many other things which we use every day it takes a tremendous amount of Steel to make a building this big and even more to make a bridge like this our lives would be very different if there were no Metals before we can enjoy these conveniences made of metal we must first take the metal ore from the earth in some cases The Ore is deep underground requiring a very deep mind to reach it in other cases The Ore may be near the surface where it can be shoveled out metals are among our nonrenewable natural resources they are non-renewable because they cannot be replenished if the Earth's Supply is ever used up there will be no more to replace it there is no immediate danger of this however because the Earth still contains a good Supply but looking ahead for future Generations we should conserve our non-renewable resources make them last as long as possible one way to conserve them is to restrict the amount of ores we take from the earth another way is to reuse the metals whenever possible this machine takes junk cars and chops them up into small pieces the pieces are then sorted according to the type of metal the pieces of Iron and Steel are loaded into railroad cars and carried to foundaries or factories here they are melted down and used for making new products using metals and other resources over and over is called recycling we have seen the importance of metals and Mining but what about the hole in the ground that is left after the ore has been removed deep mines would be dangerous to leave unattended they may cave in at any time trapping animals or even people inside them some mining companies seal off the entrances so that no one can enter them all mines leave scars on the landscape particularly surface mines or strip mines these areas can be restored a few years ago there was a strip mine here but the hole was filled in and grass and trees were planted sometimes the holes are filled with water and stocked with fish a strip mine Lake can actually add to the beauty of the area despite new problems man is constantly learning to use and reuse much of his own natural environment he has not stopped there he is exploring space carrying with him air to breathe and controlling pressure in [Music] temperature mechanical equipment has also opened underwater exploration to him in the future he will continue to learn more about the sea a large part of his environment just as Dean is careful to maintain the proper environment for his fish so we must be careful to conserve our environment the Earth the changes that we make will in the long run determine the kind of world in which we [Music] live