BIODIVERSITY AND CONSERVATION
Earth has an uneven distribution of soil type and climatic zones. This variation depends on the weathering of the inner layers of the earth.
The internal structure of earth is divided into,
Crust – Rigid, brittle, thin layer of rocks.
Mantle – Semisolid rock.
Core – Metallic, made of iron and nickel.
The process of weathering of the mantel is different in various climatic zones. The action of elements of weather and climate over earth materials is considered as weathering. There are many processes within weathering which act either individually or together which affect the earth's materials in order to reduce them to a fragmental state.
Definition: Mechanical disintegration and chemical decomposition of rocks through the actions of various elements of weather and climate is defined as weathering.
The weathering of mantle is the basis for the diversity of vegetation and biodiversity. The reason for such weathering variations and biodiversity is because of solar energy and water. The areas rich in solar energy and water are the areas of wide spectrum of biodiversity.
Biodiversity is a system of constant evolution from a view point of species and an individual organism. 99% of the species that have ever lived on the earth are extinct today. Biodiversity is unevenly distributed on earth. It is richer in the tropics and poorer in polar regions.
Definition: Biodiversity is the number and variety of organisms found within the specified geographic regions.
Biodiversity is the combination of two words bio meaning life and diversity meaning variety. It refers to the varieties of plants, animals and microorganisms, the genes they contain and the ecosystem they form. Biodiversity is a measure of variation at the genetic, species and ecosystem level. It relates to the variability among the living organisms on earth including variability within and between the species. Biodiversity is result of hundreds of millions of years of evolutionary history and hence is our living wealth. Biodiversity can be studied under three levels,
- Genetic diversity
- Species diversity
- Ecosystem diversity
Genetic diversity
It refers to the range of different inherited traits with in a species. Genes are the basic building blocks of various life form. Genetic biodiversity deals with the variation of genes with in species. Groups of individual organism with similarities in their physical characteristics are called species. Human beings genetically belong to homo-sapiens group differ in many characteristics like height, color, physical appearance etc. This genetic diversity is essential for a healthy breeding of population of species.
Species diversity
It refers to the variety of species in a defined area. Species diversity is the number and the relative abundance of species found in a biological organization. The diversity of species can be measured through its richness, abundance and type. Some areas are more rich in species than others. Areas rich in species diversity are called hotspots of diversity. The biodiversity hotspot is a biogeographic region with significant levels of biodiversity that is threatened by human habitation.
Ecosystem diversity
Ecosystem diversity deals with the variations in ecosystem within a geographical location and its overall impact on human existence and environment. It refers to the number of ecosystems in a certain area. Ecosystem diversity addresses the combined characteristics of biotic and abiotic properties. It is the variation in the ecosystem found in a region or the variation in ecosystems over the whole planet.
It is the largest scale of biodiversity and with in each ecosystem there is a great deal of both species and genetic diversity.
Importance of biodiversity
Biodiversity has contributed in many ways to the development of human culture and in turn, human communities have played a major role in shaping the diversity of nature at genetic, species and ecological levels.
Roles of biodiversity
- Ecological role of biodiversity:
Each species perform a specific function in an ecosystem. Nothing in an ecosystem evolves and sustains without any reason i.e. every organism besides extracting its needs also contribute to something useful to other organisms. Species capture and store energy, produce and decompose organic materials helping to cycle water and nutrients, fix atmospheric gases, regulate climate throughout the ecosystem.
These activities are important for functioning of ecosystem and human survival. The more diverse the ecosystem is the better are the chances for the species to survive through adversities and attacks. Hence the loss of species would decrease the ability of the system to maintain itself. Just like a species with high genetic diversity an ecosystem with high biodiversity may have a greater chance of adapting to environmental change. Simply, the more the variety of species in an ecosystem the more stable the ecosystem is.
- Economic role of biodiversity
One important part of biodiversity is crop diversity which is know as agro-biodiversity. Biodiversity is considered as a reservoir of resources to be drawn for the manufacture of food, pharmaceutical and cosmetic products. This concept of biological resource is responsible for the deterioration of biodiversity. At the same time it is also the origin of new conflicts dealing with rules of divisions and appropriation of natural resources. Some of the important economic products that biodiversity supplies are food crops, live stock, forest, fish, medicinal resources, etc.
- Scientific role of biodiversity
Each species in an ecosystem gives us information about how life evolved and will continue to evolve. Biodiversity also helps in understanding how life functions and the role of each species in sustaining ecosystems of which we are also a species. This fact must be drawn up on every one of us so that we live and let other species live.
It is our ethical responsibility to consider that each and every species including humans have an intrinsic right to exist. Hence, it is morally and ethically wrong to cause extinction of any species. The level of biodiversity indicates our relationship with other living species. In fact the concept of biodiversity is an integral part of many human cultures.
Loss of biodiversity
Since the last few decades growth in human population has increased the rate of consumption of natural resources. Biodiversity, as we have today is the result of 2.5 – 3.5 Billion years of evolution.
Before the existence of human earth supported more diversity. Since the emergence of human, the biodiversity has declined with one species after another bearing the brunt of extinction due to over use.
Tropical regions which occupy one-forth of the total area of the world contain three-fourth of the human population. Over exploitation of resources and deforestation have become common to fulfill the needs of large population. The tropical rainforest contain 50% of the species on earth, destruction of natural habitats have proved disastrous for entire biosphere.
Natural calamities such as earthquakes, volcanic eruptions, floods, forest fires, droughts, etc cause damage to the flora and fauna of the earth, bringing change in the biodiversity. Pesticides and other pollutants such as hydrocarbons and toxic heavy metals destroy the weak and sensitive species. Species which are not the natural inhabitants of the local habitat but are introduced into the ecosystem are called exotic species. A natural biotic community of the ecosystem suffered extensive damage because of the introduction of exotic species. Animals like tiger, elephant, rhinoceros, crocodiles, birds were hunted mercilessly by poachers for their horns, tusks, hides etc. It has resulted in the decline of certain types of organisms and they are called as endangered species.
The International Union of Conservation of Nature and Natural Resources (IUCN) has classified threatened species of plants and animals into three categories for the purpose of their conservation.
- Endangered species
It includes the species which are in danger of extinction. IUCN publishes information about endangered species of the world as the Red list of threatened species. Examples, Tiger, Gorilla, Sea turtle, Rhinoceros, Snow leopard, giant panda, blue whale, polar bear, bald eagle, etc.
- Vulnerable species
The species which are likely to be in danger of extinction in near future, if the factors threatening to their extinction continue. Survival of these species is not assured as their population has reduced greatly. Eg, black spider monkey, black buck, sloth bear, yak, one horn rhinoceros, etc.
- Rare species
Population of these rare species is very small in the world. They are confined to limited areas or thinly scattered over a wider area. Eg, Himalayan brown bear, Wild asiatic buffalo, Hornbill, etc.
Conservation of biodiversity
Biodiversity is important for human existence. All forms of life are closely interlinked that disturbance in one species causes imbalance in others. If species of plants and animals become endangered they cause degradation in the environment which may threaten human being’s existence. It is necessary to educate people to adopt environment friendly practices and develop harmonious relationships with other life forms. 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 the development of institutional structures at local levels is necessary. It is not about the conservation of species or habitat but the continuation of process of conservation.
Government of India have signed the convention of biodiversity at the earth summit held at Rio-De-Janeiro, Brazil in June 1992. The world conservation strategy suggested certain steps for biodiversity conservation.
- Varieties of food crops, forage plants, timber trees, livestock , animals should be preserved.
- International trade in wild plants and animals should be regulated.
- Each country should identify habitats of wild relatives and ensure their protection.
- Efforts should be made to preserve the species that are endangered.
- Habitats where species feed, breed, rest and nest their young ones should be safeguarded and protected.
According to Wild Life (Protection) Act 1972, National Parks, Sanctuaries, Biosphere Reserves are established. These are meant to protect, preserve and propagate the variety of species within natural boundaries.
National Parks:
An area rich in ecology or fauna or flora or geomorphology is protected, propagated for the wildlife or its environment is called National Park. No human activity is permitted inside national parks. There are more than 100 national parks in India. The oldest national park is Corbett National Park established in 1936 in Uttarakhand.
Sanctuary:
It is a protected area of importance of wildlife which is reserved and managed for conservation and to provide opportunities for study of research. There are more than 500 sanctuaries in India and the oldest bird sanctuary is located near Chennai – Vedanthangal Bird Sanctuary established in 1796.
Biosphere Reserves:
The government of India established biosphere reserves to protect natural habitat. It may include one of more national parks or reserves along with buffer zones that are open to some economic uses. There are 18 biosphere reserves in India and oldest is Nilgiri Biosphere Reserve established in 1986.
The countries in tropical region posses a large number of world’s species diversity. These countries are called Mega diversity centers. There are 12 such countries, namely Mexico, Colombia, Ecuador, Peru, Brazil, Democratic Republic of Congo, China, Madagascar, India, Malaysia, Indonesia and Australia. In order to concentrate resources on those areas which are more vulnerable , IUCN identified certain areas as hotspots.
Definition: The hotspot is a biogeography region with significant levels of biodiversity that is threatened by human habitation.
Plants are important because they determine the primary productivity of an ecosystem. Most of the hotspots depend on species rich ecosystems for food, firewood, crop plant, and timber. About 85% of plants and animals are found in Madagascar. Other hotspots are fasting different types of pressures. The islands of Hawaiian have many unique species of flora and fauna that are threatened by alien species and land development.
Biodiversity conservation is the practice of protecting and preventing the wealth and variety of species, habitats, ecosystems, and genetic diversity on the planet, is important for our health, wealth, food, fuel, and services we depend on.It plays an integral role in supporting many sectors of development.
