Nowadays, people have already notice the problems of the environment. Since people waste too many resources, some kinds of creatures have nothing to eat. Thus, how to protect the biosphere is a serious challenge. Without millions of species, the earth would be a dead planet.
So first of all, it is necessary for us to know about a very important term—biodiversity.
Biodiversity means the magnitude of diversity with different species in a specific region. Every creatures in the nature are dependent on each other. Without plants, animals cannot survive. If there are no insects to deliver the pollen, many angiosperm plants could not be reproductive. Also, dead corpses can’t be dissociated without decomposers, and the cycle of substances will not be existing. Inside rain forest, the growth of a tree mainly due to the absorption of nutrients. Some bears even eat leaves, and lichens are placed on their backs. According to the statement above, we can see that one creature could provide a niche for another one.
As different populations live in the same community, they live together in the same condition. Although ecologists discover that different species have some relationships, but these relationships are still mystery. However, currently, scientists find a very important law that when one species disappears in a region, this region would suffer from some changes. For example, there is one species always eats some kinds of animals or plants, if the animals and plants die out across the food chain or food web, the food chain or food web will be totally broken and the numbers of this individual will be diminished. When predators leave a district, the species being predated will reproduce rapidly and overturn the capacity of the ecosystem. Similarly, if one of the symbiotic species disappears, the other species left along would also be influenced.
Biodiversity makes the structure of ecosystem more stable. If one ecosystem could keep its biodiversity, it is tended to be very steady; but if the species changes, the balance of this ecosystem will be disturbed. Moreover, biodiversity is very important for human’s life. For instance, aerobic respiration needs oxygen, and most of the oxygen comes from some species that could proceed photosynthesis. At the same time, because of biodiversity, human beings get their demanding foods, medicines and so on.
Extinction means one species disappears from the Earth. It is a natural process, during the history of geology, there are many catastrophes that account for extinction. Scientists predict that in every million species, there is about one species dies out annually. However recently, the speed of extinction is greater than any other times before. Hence scientists make a hypothesis which states that because of the demands of human being, the destruction of habitat and the land development, the acceleration of extinction is revealed.
The main factor that affects the decrease of the biodiversity is the disappearance of habitats. From 1970 to 1980, in the Amazon rain forest, thousands of hectares of forest are cultivated into meadow, and trees are cut down for the usage of firewood. This forest has nothing functional after several yeas, because the soil of rain forest is not suitable for cultivating crops. However, the cultivation of land makes the habitats disappear, and it is difficult to reconstruct them. And because of that, some animals and plants are threatened to extinction.
Habitat fragmentation means the large area of the habitat is separated into smaller fragments or islands under the human activities. The fragmentation of habitat will bring these consequences: The acceleration of the extinction of local species, the resistance of ecological process, colonization of exotic species, the insidious danger of fire disaster and the change of local climate. As the habitat is separated into smaller and smaller area, the biodiversity of this region will be simpler and simpler. Because when one species moves out from a region, other species that depends on it has no insurance about foods, so the population would decrease. Finally, the biodiversity of this region diminished rapidly. The habitat fragmentation causes geographical isolation, and then is the genetic isolation. Because if the habitat is very tiny, it is difficult for species to find opportunities to reproduce.
The other factor that threaten biodiversity is the habitat degradation. It is majorly due to the environment pollution. Atmospheric pollution will cause many diseases such as the stimulation of noses and eyes. And aquatic pollution could be fatal to species living in water, especially fishes. Since people fertilize so much phosphorous into the soil and give out so much industrial polluted water, a lot of polluted substances are created. When these substances enter rivers, streams, lakes and oceans, the ability of self-cleaning is decreased. And it strongly affects creatures live in water.
Therefore, we can see that any events that influence the ecosystem could bring negative effects, even though it benefits human beings themselves. But as we can see, the results are unexpected, only the protection of biodiversity could keep the earth evergreen forever. In this place, everyone should has the duty to take actions to do something to save the environment, and even save our planet.