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Stil om biologisk mangfold. Her tar jeg for meg hva biologisk mangfold er, hvilke trusler det har og hvorfor det bør bevares.
Biological diversity is the sum of all diversity within species, genes and ecosystems. It is an expression which include all variations of life which exists on earth; millions of plants, animals and microorganisms, their genes and the interaction they are a part of.
The biodiversity consists of millions of different species, which is a result a development stretching more than 4 billion year back time. Only a small part of all species are known to men. Experts estimate that not more than two thirds of all species in the world are identified.
The biodiversity is unevenly distributed and is depend on the climate, altitude above sea level, soil and the presence of other species. It is greatest in tropical rainforest which contain more than two thirds of all know species.
Generally we split the biodiversity in three:
- species diversity is the sum of all species or all variations of species in an area. For example; an island with two bird species and one mammal has a great biodiversity than an island with three bird species and no mammals.
- genetic diversity is the genetic variation in the DNA within a specie - either variations between populations or within one population. All individuals has its own qualities, and no lion or no elephant is the same. This genetic variation is vital to the species` ability to survive and adapt to changes in the environments.
- ecosystem diversity is variation in the number of ecosystem in an area and within the ecosystems. An ecosystem can for example be big lakes or a forest, or a smaller limited area.
The fact that species die is a result of a natural development. However, nowadays species disappear much faster than what is considered natural. An estimate of more than 140 species disappear from tropical areas mainly due to deforestation ever day. The destruction of the biodiversity is now stronger than ever before.
Threats to the biodiversity
The global issues is that as we interfere with nature the biodiversity is reduced, which is a big problem. A varied biodiversity is vital for the human existence. However, as we interfere with nature the biodiversity is put under threat, by for example physical interference, foreign species, overexploitation and pollution.
One of the main reasons for the extinction of species is destruction of their territories. If the small ponds or old trees in the forest disappear, the species dependent on this in their life cycle also disappear. A number of species are dependent on others to survive, and if one species disappear others will most likely follow, and the ecosystem loses its stability, which can have global effects.
A great diversity of unique species exist only because it is separate by barriers such as rivers, oceans and mountains. However, today we use plane and boats to mix animals which have not had anything to do with each other, and the species are reduced. When exotic animals are introduced into new areas, the already existing species might not be able to adapt and die out.
In the future climate changes will probably be the greatest threat to biodiversity. Scientists fear that between 15-37 present of all landliving species might be extinct because of climate changes within 2050. As the temperatures and sea levels are expected to rise a huge amount of species are threatened. Animals which for example are adapted to a colder climate, such as the polar bear, might die out, and others will take its place.
As I have already said the introduction of foreign species cause a serious threat to a good biodiversity. In addition to suppressing already existing species, they can strongly damage the territories. A good example of a specie which has made huge damages to the ecosystems are the red king crab. Most foreign species are introduced by humans; either willingly or as a stowaway. Some species also spread dangerous diseases and parasites which kill already existing species.
Some species, especial marine animal, are taken up quicker than the population can renew, which puts a serious threat in the long-term survival of certain populations. Some fish populations are taken up faster than advised by scientists, and if this happens over a long period of time the population might collapse, and not be able to get back to its former state.
Pollution is a serious threat to biodiversity. It occurs when substances are realized into an area where they can have dangerous effects. Human activates can pollute both locally and globally, and might affect water, soil and air. Pollution can for example occur through acid rain, oil spills and sewage disposal. The increased production and use of fossil fuels can lead for example air pollution and oil spills. The rupture of the oil well in the Golf of Mexico in April 2010 is a good example of consequences of human activities. This oil spill while probably kill a huge amount of species, and strongly affect the ecosystems in this area for a long period of time.
Fertilizers used in agriculture causes a serious threat when it is washed into rivers, and affect the environment. An increased consumption also increase the huge amount of domestic waste we produce every single day and this creates a dangerous threat to biodiversity. When domestic waste is left to rot it gives off a mixture of gasses and a poisonous liquid, which can pollute both air and soil. Also industrial waste pollute the environment.
This is only some of the challenges the global biodiversity is faced with, and it is the fight against these threats which is a global issue. So why is it important to fight the destruction of the biodiversity. What good does it really do us?
There is actually a huge amount of reason for conserving the world`s biodiversity. The truth is that it is the very foundation of our existence. Without a great biodiversity the possibility for the species on earth to survive would be minimal.
By preserving a rich biodiversity with for example many different variations of species, the species can mix together and create a better and stronger specie. A great biodiversity is also necessary for nature to be able to save species from extinction. If there is multiple varieties of one specie the specie is more sustainable.
A good example of this is the potato famine in Ireland in 1846. At this time the potato was the most important food source, and because they only had two types of potato, which both were destroyed, millions of people died. If they had planted more than two types the changes that one would have survived would have been better, because a greater biodiversity slows down the spread of diseases because the bacteria has to infect different varieties.
Agriculture is an important part of the life of all of us and has an economic importance. To keep a health and livable crop it is important for it to receive constant input of new genetic codes from the wild. Some wild organisms have more taste or have greater power to resist diseases, and to sustain changes in soil or climate. The biodiversity of insects is also important for the pollination of plants.
Biodiversity is an important measure of a sustainable development, because it is extremely important that we do not let our urge to develop destroy the quality of life of future generations. In addition, nature provide us with many services that is essential for our existence. For example the Amazonas rainforest recycle the oxygen that we breath. Other ecosystem services benefit us with for example purification of water and prevention of erosion.
As you might know the biodiversity provides food for humans. Even though 80 percent of our food supply comes from just 20 kinds of plants, humans use at least 40 000 species of plants and animals a day. Also a lot of people use this species for shelter and clothing. Also a number of industrial materials are taken directly from nature.
Biodiversity has an important significance to the human health. It is essential to ensure many of our vital necessaries such as fresh water, food resources and the limitation of diseases. Medical science and prevention of natural disasters are dependent on biodiversity. Even though we can produces more and more medicines syntactically, biodiversity is an endless source of lifesaving drugs. About 80% of world's population depend on medicine from nature for primary health care. Also, only a small part of the total biodiversity on earth have been discovered and investigated as a possible source of drugs, which renders great opportunities for future finds.
It is true that we have inherited the earth from our ancestors and for that reason it should be important to us to preserve it. Some species do only exist in some parts of the world and is extremely rare. Even though we might not ever see a kangaroo or a great white whale in the wild, it is nice knowing they are out there and that we might have the opportunity to see them one day.
The most visible value of biodiversity is the leisure, cultural and aesthetic values. The opportunities to wander through beautiful, wild and untouched nature with a variety of plants and animals has a great significance to our well-being and happiness. As nature has inspired a number of painters, writers and musicians, some people see themselves as central part of nature and respect their surroundings greatly. Also popular outdoor activities are strongly dependent on biodiversity.
To sustain a varied biodiversity is as an important opportunity to gain knowledge about the history of the species and the earth. As more and more species disappear the opportunity to preserve our roots vanishes. Some also argue that biodiversity has spiritual and aesthetical value to humans. This becomes quite clear when you see the importance nature has to some of the worlds native populations.
Humans do not rule over nature, but is a part of it, and for that reason have no right to exterminate other species. All life has its own value, regardless if they benefits us or not. The biodiversity we have today has developed over millions of years, and we have a ethical and moral responsibility to preserve it for future generations.
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