Lord Of The Files

lord of the files

Science 10 ecology project

① 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.

http://www.galactic-guide.com/articles/2R84.html

http://www.saburchill.com/hfns02/chapters/chap019.html

1. 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.

http://www.saburchill.com/hfns02/chapters/chap020.html

http://www.saburchill.com/hfns02/chapters/chap021.html

2. 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 rainforests.

 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.



http://www.saburchill.com/hfns02/chapters/chap024f.html

3. 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.

http://www.saburchill.com/hfns02/chapters/chap022f.html

② 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