cerere referat

[z3r0_barat]

as vrea un referat pe engleza , care sa fie despre un animal pe cale de disparitie...va rog mult. multumesc !

[AlFa]

poftim :)

Code: Select all

Over 19,000 species of plants and 5,000 species of animals on earth are classified as being in danger of extinction. Several thousand speciii reach the threshold of extinction every year before that biology can identify them. 
The main causes of extinction of species of plants and animals are habitat destruction, commercial exploitation (collection of plants, hunting and poaching irrational), the damage caused by pollution and species aclimatizate. Of these cases, habitat destruction is the greatest threat to these species. 
Up erelor geological different species of plants and animals have evolved slowly and have disappeared because of climate change and radical inability to adapt to competition for survival. However, during 1600, the rate of extinction has increased progressively with increasing human population and consumption of natural resources. 
Many scientists believe that the disappearance of the dinosaurs, after 65 million years, today we are in the middle of the biggest critical period, the irreversible destruction of many species of plants and animals. 
Maintaining current ecosystems such as forests, coral or recifurile of marshes, depends largely on their biodiversity. Disappearance of a species that make up this food chain can lead to decline in the ecosystem concerned. 
Dropping irreversible biodiversity has a serious impact on living standards of people. 
Healthy ecosystems provide food, clean air, water and fertile soil for agriculture. Also, 40% of modern medicines come from plants and animals. 

The causes of species extinction are diverse: 
- Destruction of habitats by human activities is the primary cause of extinction of species of plants and animals. As vietuitoarele evolve, they can adapt to specific habitats that provide the best life that they need. Pollution, draining marshes, clearing forests, urbanization and the construction of roads (Transamazonianul, trans-Siberian) are leading to destruction or fragmentation of the media life. Thus, the species lose contact with other populations, thereby reducing genetic diversity and adapting to the more difficult to changing climate conditions. In some cases, fragmented habitat becomes too restrânsa area to support a large population. 
- In the last 400 years, worldwide commercial exploitation of animals for food and other products has increased significantly. Many species of whales reached the threshold of extinction after they were simply macelarite oil and meat. Another example is conclusive African black rhino, killed on a large scale or the horn, which is valued as medicine and aphrodisiac. Also, whole families of orchids and cacti are endangered because their irrational collection. 
- Species aclimatizate introduced a new ecosystem has caused in many cases, the decline of native species. In 1959, British colonists introduced bibanul the Nile in Lake Victoria in East Africa. The loot from the drastically reduced populations of native fish and caused the disappearance of no less than 200 endemic species, which feed on algae. Thus, aquatic vegetation in Lake Victoria has increased very much and the natural balance has been cranky, irreversible till nowadays. 
- Another major reason which has led and leads to drastic fauna and flora is environmental pollution. Different toxic chemicals were spread more and more into the food in the ecosystem. Water pollution and high water temperatures have made away many species of fish endemic. Acid rain destroyed, until the end sec.XX, 118 million m3 of timber in Europe. Also, chemical discharges have affected for long and ocean bottom. 
List of species of plants and animals recognized as endangered on is pretty high. 

May conclusive examples are: 
- Dovel passenger ever had absolute supremacy in number of copies between birds and mammals. In the year 1813, there were over 1 billion pigeons in the U.S. Kentucky, more than a century, in the same state of life has ceased last copy of this species. 
- Bird "Dodo" similar dove`s, but can`t fly, was first spotted in 1598, on the island of Mauritius in the Indian Ocean, the last copy disappeared around 1681. 
- Condorilor Californian, considered the largest bird in danger of extinction, has become the attention of specialists who have taken the last copies of their natural environment and have been in special reserves, which are trying their înmultirea. 
- Eagle plesuv, head and covered with white feathers, despite the name, was declared the year 1782 as a symbol of U.S. poultry Its existence was made in great difficulty because of excessive pollution, but the energetic measures taken by specialists, the number of its recovered significantly. 

Many parrot are seriously threatened by the destruction of forests nemiloasa their habitats in tropical and subtropical, and the demand for large bird cage. Among the species is endangered Spix's country, in north-eastern Brazil, which believed that only one male still alive in the wilderness. Kakapo of New Zealand is another parrot threatened, pushed nearly to extinction by predators as hermeline, cats, rats placed in their habitat of European colonists. 
Of the 4600 known mammal species are considered as over 1,000 species are affected, many are in danger of extinction, including: 
- Tasmanian wolf, whose final copy died in captivity in 1936. 
- Bear giant panda from China has become the symbol of world animal endangered and efforts are being made to preserve it. 
- Irbis (snow`s lepard) with habitat in the Himalayas and neighboring areas, their existence is put in danger because of excessive hunting for its valuable fur. 
- Tibetan Yakul, once the large number has been reduced significantly as the number of copies due to extensive hunting

DAR VEZI CA SUNT UNELE GRESELI DEOARECE AM FOLOSIT GOOGLE TRANSLATE DECI VERIFICA-TE!