Biodiversity

In this chapter, Biodiversity we are going to learn what is biodiversity, its importance and ways to conserve biodiversity. If you are interested to learn via video lecture, click the lecture tab.

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Biodiversity

The vast variety of animals and plants have provided for man’s needs for thousands of years. This diversity of living organisms has been used by each civilization for its growth and development. Animals and plants helped the humanity in using the biological resources for the benefit of humanity and have been integral to the process of development. The diversity of life on this biosphere is so great that if we use it sustainably the resources can be used for many generations. It is possible only when we manage the resources as a precious resource.

There are many organisms that live all around you but we cannot see with our eyes. The total number of species that are known to us are between 1.7 to 1.8 million. This biological diversity of living organisms is called as biodiversity and generally refers to the variety of life on Earth.

Out of all living organism in this world, about 70% is of animals, 22% is of plants. India is one among the 12 megadiversity countries having around 45,000 plants and 90,000 animals.  Insects constitute roughly around 70% of the animals present in the earth. It is interesting to note that Insects population is more and have occupied almost all habitats are available in the earth. Therefore, present era is not the human era. This is actually insect’s era.

There are more than 5 million species present on earth. But so far Scientist have discovered and named only 1.75 million species. Though Scientists are describing several new species and adding to this list. Study of all organisms is not possible. Therefore, they are classified into groups for your convenience so that we can study them easily by associating them based on similarity in their characteristics.

What is biodiversity?

Biological diversity deals with the degree of nature’s variety in the biosphere. Otherwise, the sum total of all the variety of living organisms makes biodiversity. The term biodiversity was first coined by E.O. Wilson in the year 1985. The biodiversity includes different kinds of plants, animals, organisms and their genes, terrestrial ecosystem, water ecosystem and marine ecosystem.

Biodiversity may be defined as “the variety and variability of living organisms and the ecological complexes in which they exist.” This variety in the biosphere can be observed at three levels; they are genetic diversity, species diversity, and ecosystem diversity.

Genetic diversity

Each and every member of animal and plant species differ from one individual to other in this genetic makeup because of the vast number of combinations of the genes that give every individual specific characteristic. For example, no individual in the human being is alike another individual. This genetic diversity is important for a healthy breeding population of a species. The diversity in wild species forms the gene pool from which variety of crops and animals have been developed over thousands of years.

Species diversity

The variety of plants and animal species that are present in a region constitute its species diversity. This kind of diversity is seen both in natural ecosystems and in agricultural ecosystem. Natural undisturbed tropical forests have a much greater species richness and it provides a large number of non-wood products that local people depend on such as fruit, resin, gum fuelwood, fodder, and medicines.

Ecosystem diversity

Variety of ecosystems is on this earth. Each one has its own complement of distinctive interlinked species based on the differences in the habitat. Ecosystem diversity can be described for a specific geographical region. Distinctive ecosystems include landscapes such as forest, Grasslands Mountains and deserts.

An ecosystem is referred to as natural when it is relatively undisturbed by human activities or modified when it is changed to other types of uses such as farmland or urban areas.

Ecosystems are most natural in wilderness areas. Ecosystems are most natural in wilderness areas. This natural ecosystem is overused or misused their productivity will decrease. Based on the famous taxonomists Whittaker (1965), the community diversities are of three types.

• α-diversity – This gives the detail on the species diversity in a given community. This α-diversity depending on species richness and evenness.
• β-diversity – This gives a detail on a range of communities due to the replacement of species which is due to the presence of different microhabitats, niches, and environmental conditions.
• ϒ-diversity – This gives a detail on the diversity of habitat over a total landscape or geographical area.

Biodiversity in India

Among the world’s mega-diversity countries, India is one among them. In terms of higher plant species richness, India is in ninth position in the world. According to Wildlife Institute of India, the biogeographical regions are divided into ten different regions.

Biogeographical regions in India

1. Gangetic plain
2. Dessert
3. Semiarid zone
4. Deccan Peninsula
5. Western Ghats
6. Northeastern zone
7. Himalayas
8. Trans Himalayas
9. Islands

Reasons for India as the megadiversity nation

1. India is having 7.3% of the world fauna and 10.88% of world flora.
2. India is having 45,000 plant species, 350 different mammals, 1200 bird species, 453 kinds of reptiles, 182 amphibians
3. There are 13,000 butterflies and moths out of 50,000 species of insects.
4. There are 10 biogeographical regions and 25 biotic provinces having varieties of lands and species.
5. India is the origin for many crops and it has been spread throughout the world.
6. India is having many numbers domestic animals such as cows, buffaloes, goats sheep, horses, and pigs.
7. The marine biota includes seaweeds, fishes, molluses, crustaceans, reptiles, corals etc.
8. The hot spots in India are Eastern Ghats, Western Ghats, North Eastern hills

Importance of biodiversity:

The biodiversity has productive value, legal value, ethical value, ecological value and economic value

Benefits of Biodiversity

The following are the benefits of biodiversity. They are as follows:

1. Biodiversity is the source of all types of food
2. It is giving the variety of oil seeds for the production of oils.
3. It is providing fibers for the production of cloths.
4. Biodiversity provides the number of varieties of rice, potato etc. Through the method of hybridization
5. Biodiversity is the source of different drugs and medicines
6. Biodiversity is having high commercial value aspects. Like pollination by insects and birds, pest control, conservation of water, the formation of soil and so on.
7. Biodiversity helps in controlling the extinction of species and providing vast genetic pools
8. Biodiversity is helping in regulating the weather pattern of earth
9. It is helping in maintaining equilibrium in the environment.

The eco-balance is threatened by climatic change, over-exploitation, habitat loss and pollution.

The following could be the reasons for biodiversity loss.

1. Habitat destruction – The primary cause of loss of biodiversity is habitat loss or destruction which is resulted due to the large industrial and commercial activities.
2. Habitat Fragmentation – When population increased the living habitats are fragmented by fields, roads, canals, towns etc. The fragmented habitats prevent the potential of species for dispersal and colonization.
3. Pollution – Pollution is the major factor inducing loss of biodiversity is environmental pollution which includes air pollution, industrial pollution, water pollution, pesticides and radioactive materials.
4. Overexploitation – Due to overpopulation the natural resources are overexploited to meet growing rural poverty, intensive technological growth, and globalization of the economy. All these factors together may be responsible for the extinction of a number of species.
5. Introduction of exotic species – The introduction of exotic species is due to 1)horticulture 2) agriculture 3) European colonization and 4) accidental transport. It is seen that some exotic species may kill or eat the native species thereby causing its extinction
6. Diseases – Since the animals are more vulnerable to infection, the anthropological activities may increase the incidence of diseases in wild species leading to their extinction.
7. Shifting or Jhum cultivation – The shifting or jhum cultivation by poor tribal people greatly affects the forest structure which is a storehouse of biodiversity
8. Poaching of wildlife-A number of wildlife species are becoming extinct due to poaching and hunting

Conservation of Biodiversity

There are two types of biodiversity conservation. In situ conservation and ex situ conservation.

In situ Conservation:

In this conservation system, the conservation of organisms in their natural habitats is called In situ conservation. This is considered to be the most suitable way of conserving biodiversity. In This areas the population of species exists naturally is an underlying condition for the conservation of biodiversity, therefore the protected areas form a central element of any national strategy for conserving biodiversity such as

1. National parks
2. Biosphere reserve
3. Wildlife sanctuaries
4. Sacred groves and lakes
5. Several wetlands, mangroves, and coral reefs

Ex-situ conservation:

Ex-situ conservation is the preservation of components of biological diversity outside their natural habitats. This involves conservation of genetic resources and cultivated species by using different techniques and facilities. Some of them are

1. Setting up of gene banks e.g., seed banks, sperm and ova banks
2. Plant tissue culture and microbial culture condition
3. Breeding of animals in captivity and artificial propagation of plants, with possible reintroduction into the wild.
4. Collecting and preserving of living organisms for Zoos, aquaria and botanical garden for research and public awareness.

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Concepts in Biodiversity Chapter

Species Diversity

Ecosystem diversity

Genetic Diversity

Habitat Fragmentation

Exotic Species

In-situ Conservation

Ex-situ Conservation

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