爱尔兰及澳大利亚的独特地理特征与生物多样性(英文)

The relationship between Unique geographic features of Ireland , Australia and their Biodiversity(生物多样性) There are two interesting major english-speaking countries, Ireland and Australia.
Ireland is very different from either Great Britain or mainland Europe.It surrounded by blue, covered with green, in the top view. It is a separate island, not connected with other continent. It has less biological species. And to my surprise, red deer (Cervus elaphus) is Ireland's largest wild mammal. That's so weird. Deer are eating plants, but there often exist an animal who eat meats in the top of food chain.
Australia is a distinctive land with many miracles. It have complex kinds of landscape and climate. It also has the world's largest coral reef. The kangaroo, the koala, the wombat and the platypus are very unique. If we put them on somewhere else, they can't survive with no suitable food, many hunter and different climate.
I wondered to know why the two islands have such special biodiversities. So I research some references and give my answer.
To Ireland, I found just because of the unique feature, the genes of biological materials on Island have less chance to exchange with others, formed close breeding(近亲繁殖), so that the gene pool(基因库)do not improve and become weak, making less and unique biodiversity of Ireland.
To Australia, I think, to some extent, the geographical isolation(地理隔离) protect the adventitious mutations(不定项基因突变). Effected by the extremely variable weather patterns, through a long long term of selection and accumulation, gene frequency change makes evolution, there produce many new species.
1. Geography of Ireland
Ireland has a unique geography feature.
1.1 Unique geography of Ireland
We all know Ireland is an island, it surrounded by seas. To the west is the northern Atlantic Ocean and to the south is the Celtic Sea. It makes Ireland separate with other areas, so that the gene of biological materials on Ireland has less chance to communicate with others.
1.2Geology of Ireland
A ring of coastal mountains surround low plains at the centre of the island. We usually call it Basin. We could consider it as a bowl or a tea saucer. With large central lowland comprised of limestone. This kind of geology has typical advantages.
1.3Climate of Ireland
Ireland has a mild but changeable oceanic climate with few extremes. The climate is typically insular and is temperate avoiding the extremes in temperature of many other areas in the world at similar latitudes. This kind of climate provides a no survival threat environmental for living things.
Because of the above, Ireland has lush vegetation, a product of mild climate and frequent rainfall, thus Ireland also known as the Emerald Isle.
2. Flora and fauna of Ireland
In terms of native flora and fauna, Ireland has a smaller range than is found elsewhere in Europe. There are less diverse animal and plant species than either Great Britain or mainland Europe.
It is believed that this occurred as a result of the Ireland becoming separated from the European mainland in the period following the last Ice Age. As Ireland was isolated from mainland Europe by rising sea levels after the ice age, there are 55 mammal species in Ireland and of them only 26 land mammal species are native to Ireland.
3.Geography of Australia
Australia has a very distinctive geography.
3.1 Distinctive geography of Australia
Australia's landmass surrounded by the Indian and Pacific oceans, is a island continent or a largest island. The landscape of the country is extremely variable. In the north are tropical rain-forests; snowfields occupy the plateau landscapes of the southeast whist, in the centre and the western areas of the continent, two third of the land is desert or semi desert. In one word, complex. These produced a condition to
variety biodiversity.
3.2 Climate of Australia
We know, the climate of Australia is very complex. The living place in Australia is under the Mediterranean and temperate climates. The climate is significantly influenced by ocean currents, the period drought, the seasonal tropical low pressure system and etc. These complex factors forms distinctive environment for human and wildlife. This a reason why there are so many distinctive animals, such as the kangaroo, the koala and the wombat.
4. Flora and fauna of Australia
Isolated from other major land masses, Australia's distinctive flora and fauna evolved through its long period as an island continent.
When refer Australia, we know the koala and the eucalyptus form a pair as Australian iconic.
Australia exist two kind of marsupial---the kangaroo and the wombat.
Australia has the greatest number of reptiles of any country, is home to many dangerous animals including some of the most venomous snakes in the world.
5. The meaning of biodiversity
The meaning of biodiversity embodies the value of it.
To us humans, living things provide us foods, fibre, materials of building and furniture and other industry. The various living things also have aesthetic values, could mould persons temperament, beautify the living environment. If there are not different colors of plants and variety expression faunas in the boundless universe, how about touring or taking a rest？Absolutely, boring. It is the plants in significant mountains and fishes in great rivers build the moving environment. By the way, biodiversity can stir up the inspiration of creating literature and art works.
Biodiversity is also contribute to Ecological(生态). In all kinds of ecosystem(生态系统), wildlife is an indispensable part. In the ecosystem, the relationship among wildlife is both interdependent and restrict each other. All the wildlife hold together the
structure and function. When the number of wildlife decreases, the stability of ecosystem destroyed and this will truly effected on human.
In the field of pharmacy and science, wildlife offers many to humans. As we all know, traditional Chinese medicine use more than 10,000 kind of plants, people get inspiration of plane from birds. The majority wildlife have studied well or even realized by man, they will provide huge potential value if they continue existing. Many plant and animal species became extinct soon after first human settlement Above all, biodiversity has great value and we should protect wildlife, it is kind of protect ourselves.
6. What is Geographical isolation
Geological processes can fragment a population through such events as emergence of mountain ranges, canyon formation, glacial processes, the formation or destruction of land bridges, or the subsidence of large bodies of water. On a global scale, plate tectonics are major geological factors leading to separation of populations and the resulting distribution of species.
Geographical isolation（地理隔离）is the geographic reason interfere genetic exchange（基因交流）. Geographical isolation makes gene isolation（基因隔离）.
For instant, we can consider all the sheep living in an island as a big group, other sheep populations can't join in so they only can give birth with the same group. In other words, they share a close common ancestor. Then forms in-and-in breading, the weak gene frequency(基因频率) becomes higher. When the gene pool been adapted in this way for a lasting time, without survival threat, but this sheep population is easy to catch disease and their living capability die away.
In general, geographical isolation makes new species or makes some species die away and even die out.
7. The conclusions
So we can explain why Ireland have less mammals and plants.
As Ireland was isolated from mainland Europe by rising sea levels after the ice
age, it isolate the connecting, make the gene pool of Ireland separated and weaken, adopt to its particular pool.
Because of the continent's great age, extremely variable weather patterns, and long-term geographic isolation, much of Australia's flora and fauna is unique and diverse. Australians are proud of their rare animals so as we Chinese consider panda and tiger as a pride.
Although Australia has diversity wildlife, we also should know many species has been extinct. Biodiversity is a treasure to humans, we should protect them, pay attention when run the car, don't buy fur of rare animals and even all the clever animals, refuse to eat wildlife.
8.References
1) 英语国家社会与文化入门，高等教育出版社
2）高中理科生物教材，高等教育出版社
3）/wiki/Ireland
4) /wiki/Australia。