lord of the files Science 10 ecology project① Extinction of species A species becomes extinct when its last representative dies.  Extinction is forever - Once a species become extinct will never been seen again.  This has happened quite a lot of times on Earth.  Due, in many cases, to colonization and hunting by humans.  People feel that extinction is very sad, and try to protect life-forms on the brink of extinction by naming them 'endangered species' and being nice to them.

 Each living organism which humans force into extinction is a tragedy for nature.  Over fishing or excessive hunting by humans can reduce the populations of certain organisms on Earth.  Animals are hunted for their fur, meat or other valuable parts of their bodies. web lost of habitat Sometimes human activities destroy the habitats of living organisms.

The habitat of an organism is its home: where it lives, feeds, and reproduces.  Many species have become extinct because humans have destroyed or modified their habitats, polluted their environment Human influences on the environment can be considered as being influences on the habitats of living organisms.  Any time humans alter the hydrosphere, lithosphere, atmosphere or biosphere, habitats are modified Survival can become more challenging (or even impossible) for the organisms which live there.  When hunters miss their target, the lead shot which comes out of the gun is left behind in nature. Lead is a toxic metal.  The main component of a panda's diet is bamboo.

Bamboo forests have been cut down by humans for centuries. web lost of biodiversity This collection of vastly varied living organisms is our planet's biodiversity.  The richest parts of the planet's biodiversity are also the least well-known. It is estimated that 97% of all species on Earth live in the oceans below the zone where sunlight penetrates the water.  On the continents, it is estimated that 50% of all land-dwelling species live in tropical rainforest's.  Throughout the history of the Earth, as new species evolve, other species become extinct.

Overall, as time has progressed, there are more and more different kinds of organisms.  Human activities today are exterminating species up to 10 times faster than they would naturally disappear.  As the numbers of people increase, the numbers of species decrease.  web Introduction of exotic species Humans have helped to spread many species across the world.

 More often, however, species are introduced accidentally and have a negative impact.  Plant species used in agriculture, for example, have been deliberately introduced to new areas by humans.  Sometimes wild animals are introduced for hunting as a sport. Exotic plants are grown in gardens and sometimes their seeds escape and colonize the surrounding area.

 Such animals and plants can spread rapidly because they have no natural predators in their new habitat.  They compete with the native flora and fauna or kill them.  In some cases, introduced species completely take over a habitat and eliminate the species that were living there originally.  Sometimes the introduction of species is intentional and beneficial for humans. For example: agricultural species has been introduced by humans to new regions of the globe: tomatoes, rice, wheat, potatoes, and many more.

 As methods of transportation have increased in speed and intensified their traffic, humans have been more careful not to introduce harmful species to new regions.  One group of organisms which people are especially concerned about are micro-organisms. Because bacteria, viruses and other germs are not visible, they can travel without being detected. web Pollution Pollution is caused when a substance is added to the environment to the point where it has a negative effect on the organisms which live there.  In the case of atmospheric pollution, things are added to the air which could make it difficult for organisms to breathe or which might change the temperature.  Some industries make chemicals called chlorofluorocarbons (CFCs).

When CFCs escape into the atmosphere, they rise up and reach the ozone layer. Here the CFCs break down the ozone.  The increase in UV radiation would harm many of the Earth's organisms including humans.  Some industries produce waste products which are pollutants. Industries which burn coal or oil to power their machines produce smoke. When smoke is mixed with the dust and dirt in the air in large cities, smog is produced.

 Chemical industries produce waste gases such as sulphur dioxide and nitrogen dioxide. These gases rise up into the atmosphere and dissolve in the water droplets which make up the clouds. this kinds clouds fall to the earth as acid rain.  Nuclear power does not produce pollutant gases but it does produce nuclear waste. Nuclear waste is made up of radio-active substances.

Radioactivity produces dangerous radiation which can damage living cells, causing cancer and affecting growth.  An oil spill happens when a ship carrying oil has a problem during its journey from the country which produced the oil to the country buying it. The oil is difficult to clean up and poisons the water as well as the fish and birds which live in the region.  Fact: 1 tonne of oil which leaks into the sea covers 12 km 3 of the sea surface.  Industries produce waste products which find their way into river water. One of the most serious pollutants of river water is hot water.

 Chemical wastes from industry and agriculture also find their way into rivers. At one time, even sewage was pumped directly into rivers. web pesticides Farming has become more and more productive because of the use of chemicals and farm machinery. Unfortunately, many of these the chemicals have very bad side-effects.  Many insecticides kill all insects, not just the crop eating insects.  In small quantities the insecticides do not do any serious harm to large animals.

The problem is that as the larger animals continue to eat prey which contain insecticides, the amount of insecticide in the bodies of the predators builds up. In larger amounts, the insecticides can kill even the top carnivores.  The chemicals which are added to the soil and sprayed on the crops can be washed away by rain water. They find their way into stream and rivers and eventually into the sea.

 Many of the insecticides, weed-killers; fungicides and fertilizers which are used to improve the quality of our crops are also pollutants.  When one kind of pesticides used more often on a species of organism the organism will have resistance for that pesticide. And the pesticide will have no effect for that species. web fertilizers Plants need minerals to grow, and fertilizers provide the plants with the minerals Facts Fertilizer given to the plants Amount of wheat harvested / tonnes None 96 Nitrogen only 157 Nitrogen and Phosphorus 166 Nitrogen, Phosphorus and Potassium 212 Plants grow better if they are given fertilizer which contains minerals but it is important to understand that all the minerals must be present to give the best growth. Green plants are special because they need sunlight if they are to grow strong and healthy. A plant growing in the dark grows tall but very thin and weak, with small, yellow leaves.

If you measure its mass you will find that it is a lot less than the mass of a similar plant growing in the light. web Acid rain It is important to notice that the percentage of carbon dioxide gas in the atmosphere is normally very low.  Reason for this is because carbon dioxide gas is quite soluble in water. As rainwater moves through the atmosphere towards the Earth's surface, carbon dioxide gas dissolves in it.

This is the reason why rainwater is slightly acidic. Carbon dioxide dissolves in rainwater to form carbonic acid.  There are other gases, such as sulphur dioxide, which may be found in the Earth's atmosphere. These gases are produced naturally and usually in small quantities from certain areas of the Earth's surface. When larger quantities are produced by cars, airplanes and factories, acid rain becomes a problem.  Fact: Acid rain has severely affected German forests.

In 1983 the German Minister for Agriculture admitted that 34% of German forests were dying from acid rain pollution. In 1988 this percentage had risen to 52, 4% of forestland. At least 70% of the oak trees in these forests are affected. Fact: Acid rain can destroy entire forests and kill entire populations of fish in lakes.

What environmental factor is so drastically changed that it kills organisms? web warming Ever since humans learned to use fire, half a million years ago, they have not only obtained energy from burning things, but they have also produced smoke and gases such as carbon dioxide (C 02) which pollute the atmosphere.  As the demand for energy has increased, so has the demand for new fuel. By burning larger quantities of wood or coal (and more recently petroleum products, such as gasoline and natural gas), humans have created more and more air pollution. One threat this pollution poses is that it might throw off he delicate balance of global temperature, which is regulated by the greenhouse effect.  Gases which have this effect are known as greenhouse gases since the glass around a greenhouse works in the same way. The greenhouse effect is very important for life on Earth.

Without it, much of this planet's surface would be too cold for living things.  Natural event, such as a volcano erupting or a forest burning naturally after a lightning strike. Most atmospheric pollution today, however, is related to human activity. Unlike natural pollution, human-related pollution occurs on a daily basis all over the world. Unfortunately, human-related pollution is often longer-lasting and is increasing as the number of people on Earth continues to grow. web Living organisms prefer certain climatic conditions.

This means that animals and plants are usually found only in regions that suit them.  A biome is a region of the Earth which has a characteristic combination of climatic conditions and living organisms.  Tundra Where the climate is cold and arid and only small plants can grow. Very few animals can survive because of the lack of liquid water.  The Coniferous Forest Can be in a cold, temperate, or mountain climate and is made up of evergreen trees such as fir and cedar trees.

The ground is covered with is covered with needles and mosses.  Temperate Deciduous Forest Ideal for bears and deer because the trees in it are widely spaced apart and the climate is temperate.  The Prairie also called temperate grassland. Where a temperate climate allows grasses to grow and antelope or bison to live.

 The Savannah also called tropical grassland - where a tropical climate allows some trees and bushes to grow among the grasses and where zebras and elephants live.  The Desert Where the climate is hot and arid and where cacti and reptiles live Tropical Rain Forest Where the climate is hot and humid. Perfect for green plants with big leaves, monkeys, parrots and tigers. web closed ecosystem project: terrestrial or aquatic Every ecosystem is home to a community of plants and animals.

All of the organisms in an ecosystem are continually inter-acting with each other, as well as with their non-living environment, such as the atmosphere.  An ecosystem depends upon a supply of energy. All living things need energy for growth, movement and other essential activities. The energy needed by living things comes from the sun. Every ecosystem depends on green plants to trap the energy in sunlight and change it into chemical energy.

 The process by which green plants convert the sun's energy is called photosynthesis. Green plants also take minerals, such as nitrates and phosphates, into their bodies through their roots. These minerals are needed for the healthy growth of the plants.  Some of the animals in an ecosystem gain their energy by feeding on the producers. These animals are the herbivores.  The primary consumers are the food of the secondary consumers.

These carnivores are predators which are adapted to catch and kill their prey.