What is Biodiversity?
Biodiversity is the geographical distribution of all species of plants, animals, insects and the microorganisms inhabiting the earth either in the aquatic or the terrestrial habitats.
Biodiversity is a term that combines two words, Bio (life) and diversity (variety). However, biodiversity is defined as the number and variety of organisms found within a particular geographic region. It refers to the varieties of plants, animals and micro-organisms, the genes they contain and the ecosystems they form. This relates to the variability among living organisms on the earth, including the variability within and between the species and that within and between the ecosystems.
Human civilization basically depends directly or indirectly upon this biodiversity for their essential needs of survival which include food, fodder, fuel, fertilizer, timber, liquor, rubber, leather, medicines and several raw materials. This diversity is the condition for the long-term sustainability of the environment, continuity of life on earth and the maintenance of its integrity. Although our understanding of the earths organisms, its biological resources is still imperfect, there is no doubt that the abundance and diversity of living organisms provide many benefits and make our world a beautiful and interestingly habitable for us to live.
Based on historical result of hundreds of millions of years of evolutionary, biodiversity is a system in constant evolution, from a view point of species, as well as from view point of an individual organism. The average half-life of a species is estimated at between one and four million years, and 99% of the species that have ever lived on the earth are today extinct.
Some areas on earth are richer in species than others; areas rich in species diversity are called hotspots of diversity. Biodiversity is not evenly distributed on the earth rather it varies greatly across the globe as well as within regions. Species are consistently richer in the tropics. As one moves towards the polar regions, he will find larger and larger populations of fewer and fewer species. Generally, diversity tends to measure higher in thetropicsand in other localized regions such as theCape Floristic Regionand lower in polar regions. 12 hotspots of diversity identified in the world over represent 14% of worlds plant species in only 0.2% of its total land surface. 12 mega diversity nations include Mexico, Ecuador, China, Peru, Columbia, Brazil, Zaire, Madagascar, , India, Malaysia, Indonesia and Australia contain 60-70 % of the worlds biodiversity.
Rain forestswhich have had wet climates for a long time have particularly high biodiversity. Terrestrial biodiversity is usually greater near theequatorwhich is as the result of the warmclimateand highprimary productivity. Certain factors are responsible for the diversity of all living things such as temperature, precipitation,altitude,soils,geographyand the presence of other species.
Examples of Species
Blue whales, white-tailed deer, blue butterflies, Red eyed tree frogs, orangutans, lemurs, flying squirrels, spider monkeys, Red foxes, civets, one-horned rhino, the spiny mice, white pine trees, sunflowers, Lichens and microscopic bacteriaetc.
Types/Levels of Biodiversity
- Genetic diversity
- Species diversity
- Ecosystem diversity
Genetic diversity: Genes are the basic building blocks of various life forms. Genetic diversity refers to the variation of genes within species, both among geographically separated populations and among individuals within single population. Groups of individual organisms that have certain similarities in their physical characteristics are called species. Human beings genetically belong to the homo sapiens group and also have physical characteristics such as height, colour, physical appearance for instance. This is as a result of genetic diversity. This genetic diversity is very important for a healthy breeding of population of species.
Species diversity: Species diversity refers to the variety of species; including the number of species in a specified area; this usually includes full range of species from micro-organisms to giants and mammoth varieties of plants and animals, for example single celled viruses and bacteria etc. and multi-cellular plants, animals and fungi. The diversity of species can be measured through its richness, abundance and types.
Ecosystems diversity: This studies variation in the biological communities in which species live, exist and interact. The great differences between ecosystem types and the diversity of habitats and ecological processes occurring within each ecosystem type constitute the ecosystem diversity. The boundaries of communities (associations of species) and ecosystems are not very rigidly defined. Thus, the demarcation of ecosystem boundaries is difficult and complex.
Why is Biodiversity Important?
- Some of the important economic commodities that biodiversity supplies to humankind are: food crops, livestock, forestry, fish, medicinal resources, etc.
- Biodiversity has played so many roles in the human communities especially in the development of human culture; however, the human communities have played a major role in shaping the diversity of nature at the genetic, species and ecological levels.
- Biodiversity is an important resource in a day-to-day life of all individuals. One important part of biodiversity is in the area of crop diversity, which is also referred to agro-biodiversity. Biodiversity is seen as a reservoir of resources to be drawn upon for the production of food, pharmaceutical, and cosmetic products.
- Trade and commerce industry is largely dependent on forest products apart from firewood, timber, paper pulp, and other wood products, we derive many valuable commercial products from forests such as gums, cane, sisal, rubber, pectin, resins, tannins, vegetable oils, waxes, and essential oils.
- Humans are mostly dependent on plant and animal resources for dietary requirements. A major part of our food comes from domesticated crops and animals. Still we derive major of food from wild species. A large section of human population is dependent on food, which we gather from seas, and oceans that is harvested from free roaming wild organisms.
- Biodiversity helps to regulate climate both at micro and macro level. Trees provide shade whilst forests influence rainfall and water availability both locally and regionally. For example, trees play an important role in regulating air quality by removing pollutants from the atmosphere; these plants also work by converting carbon dioxide to oxygen through photosynthesis.
- It helps in intercepting particulate pollutants (dust, ash, pollen and smoke) and absorbing toxic gases such as ozone, sulphur dioxide, and nitrogen dioxide from penetrating into the atmosphere.
- Biodiversity (living organisms) creates buffers against climate extremes. It reduces damages caused by floods, tsunamis , storms, landslides, droughts and avalanches.
- Biodiversity also helps us to understanding how life functions and the role of each species in sustaining ecosystems of which we are also a species. Each of these species can give us some clue as to how life evolved and will continue to evolve.
- Wild species of plants and animals have always appealed mans psyche hence a lot enjoy hunting, fishing and other adventurous outdoor activities that involve wild species, However, thousands of tourists visit national parks, zoos, and forests throughout the world and especially in mountainous areas. A glance at the temperate grasslands is perhaps one of the most beautiful landscape to attract and comfort man.
- Species of many kinds perform one function or the other in an ecosystem. Nothing evolves and sustains in our ecosystem without any reason. For this reason, every organism, aside extracting its needs, also contributes something very useful to other organisms.
The rapid growth in human population since the last few decades has increased the rate at which natural resources are consumed. This has accelerated the loss of species and habitation in different parts of the world. Tropical regions which occupy only about one-fourth of the total area of the world, contain about th of the world human population.
Biodiversity is diminished or destroyed in a number of ways either through natural changes or by human disruption. The loss of just a single species can alter a the interrelationship in the food chain or food web, i.e. ecosystem disruption and upset the delicate balance between one species that depends upon another. Some of the major causes of loss in biodiversity are due to natural occurrences however, it is considered that man has also disturbed his own life support system through ignorance or careless practices. Humans have reduced biological abundance and driven species into extinction through.
Causes of Species Extinction
- Deforestation: this has been one of the major causes of depletion of wildlife. With the increasing human population and the growing need for natural resources, forests are continuously cleared for agricultural operations, human habitation and for grazing of livestock. The tress are constantly removed for timber, housing construction, for making furniture and for collecting wood as fuel.
- Overexploitation– large industries make a heavy demand on forest resources such as wood for paper and building materials, exploitation of gums and resins, mining of forestland for mineral ores. Apart from forest resources, food resources are not left out, the coral reefs, estuaries marshes, and other biologically rich ecosystems are massively harvested from time to time. Overexploitation of food species is another way in which humans directly destroy biological resources.
- Hunting and Poaching– illegal hunting of wildlife for food, skins, furs, horns, tusks, and pleasure etc. has posed a serious threat to the survival of wildlife and has resulted in the rendering of certain types of organisms as endangered species.
- Natural calamities– (earthquakes, floods, volcanic eruptions, wild fires, droughts, etc.). All these natural calamities cause severe damages to the flora and fauna of the earth thus bringing changes in the biodiversity of respective affected regions.
- Pollution– Pesticides and other pollutants such as hydrocarbons and toxic heavy metals are not only harmful to human health but have also destroyed the air, water and soil thereby affecting the health and well-being of animal population. Oil spillage is another serious problem affecting the seas through leakage from cargo ships or accidents, this has severely destroyed the weak and sensitive species in many parts of the world.
These are species in danger of extinction and whose survival is unlikely especially if the casual factors is still in operation, included are species whose numbers have been reduced to a critical level or whose habitats have been destroyed they are deemed to be in immediate danger of extinction.
These are the species in which their populations are still in abundant but are under threat from serious adverse factors throughout their range these species are likely to be in danger of extinction in the near future if the factors threatening to their extinction continue. Survival of these species is not guaranteed as their population has reduced immensely due to over-exploitation, extensive destruction of habitat or other environmental disturbances.
These are Species with small populations that are not presently endangered or vulnerable, but are at risk. The population of these species is very small in the world; they are confined to limited areas or thinly scattered over a wider area.
Out of Danger Species
These species formerly includes one of the above categories, but are now considered relatively secure as a result of effective conservation measures being taken or the previous threat to their survival has been prevented.
Conservation of Biodiversity
Biodiversity is important for human existence. All forms of life are so closely interrelated that a little disturbance in one gives rise to imbalance in the others. If species of plants and animals become endangered, they cause degradation in the environment, which may threaten human beings own existence. There is an urgent need to educate people to adopt environment-friendly practices and reorient their activities in such a way that our development is harmonious with other life forms and is sustainable. There is an increasing consciousness of the fact that such conservation with sustainable use is possible only with the involvement and cooperation of local communities and individuals. For this reason, the development of institutional structures at local levels is necessary.
However, the hope for conservation of natural biodiversity however rests on preservation of selected ecosystems and representative areas of different vegetation types as well as on preserving some of the extinction-prone species. The number of endangered species of plants and animals is continuously rising, which has prompted government and non-governmental organizations to take certain steps in this direction. The main issue is not merely the conservation of species nor the habitat but the continuation of process of conservation. The following steps are the suggested strategy for biodiversity conservation:
- Prevention of extinction needs proper planning and management.
- Varieties of food crops, forage plants, timber trees, livestock, animals and their wild relatives should be preserved.
- Effort should be made to preserve the species that are endangered.
- Every country should identify habitats of wild species relatives and ensure their protection.
- Habitats where species feed, breed, rest and nurse their young should be safeguarded and protected from danger.
- International trade in wild plants and animals should be regulated.