Biodiversity: Types, Importance, Biodiversity in India | Biology Class 12 - NEET PDF Download

What is Biodiversity?

Biodiversity is the variation among living organisms from different sources including terrestrial, marine and desert ecosystems, and the ecological complexes of which they are a part.

• Biodiversity describes the richness and variety of life on earth. It is the most complex and important feature of our planet. Without biodiversity, life would not sustain
• The term biodiversity was coined in 1985. It is important in natural as well as artificial ecosystems. It deals with nature’s variety, the biosphere. It refers to variabilities among plants, animals, and microorganism species.
• Biodiversity includes the number of different organisms and their relative frequencies in an ecosystem. It also reflects the organization of organisms at different levels.
• Biodiversity holds ecological and economic significance. It provides us with nourishment, housing, fuel, clothing, and several other resources. It also extracts monetary benefits through tourism. Therefore, it is very important to have a good knowledge of biodiversity for a sustainable livelihood.

Types of Biodiversity

There are the following three different types of biodiversity:

• Genetic Biodiversity
• Species Biodiversity
• Ecological Biodiversity

Genetic Diversity

• It refers to the variations among the genetic resources of the organisms. 
• Every individual of a particular species differs from others in their genetic constitution. That is why every human looks different from the other. 
• Similarly, there are different varieties in the same species of rice, wheat, maize, barley, etc.

Species Diversity 

• Species diversity refers to the variety of different types of species found in a particular area. 
• It is biodiversity at the most basic level. It includes all the species ranging from plants to different microorganisms.
• No two individuals of the same species are exactly similar. For example, humans show a lot of diversity among themselves. 

Ecological Diversity

• An ecosystem is a collection of living and non-living organisms and their interaction with each other. Ecological biodiversity refers to the variations in the plant and animal species living together and connected by food chains and food webs.
• It is the diversity observed among the different ecosystems in a region. Diversity in different ecosystems like deserts, rainforests, mangroves, etc., include ecological diversity.

Importance of Biodiversity

Biodiversity and its maintenance are very important for sustaining life on earth. A few of the reasons explaining the importance of biodiversity are:

Ecological Stability

• Every species has a specific role in an ecosystem. They capture and store energy and also produce and decompose organic matter. 
• The ecosystem supports the services without which humans cannot survive. A diverse ecosystem is more productive and can withstand environmental stress.

Economic Importance

• Biodiversity is a reservoir of resources for the manufacture of food, cosmetic products and pharmaceuticals.
• Crops livestock, fishery, and forests are a rich source of food.
• Wild plants such as Cinchona and Foxglove plant are used for medicinal purposes.
• Wood, fibres, perfumes, lubricants, rubber, resins, poison and cork are all derived from different plant species.
• The national parks and sanctuaries are a source of tourism. They are a source of beauty and joy for many people.

Ethical Importance

• All the species have a right to exist. 
• Humans should not cause their voluntary extinction. Biodiversity preserves different cultures and spiritual heritage. Therefore, it is very important to conserve biodiversity.

Loss of Biodiversity

• Loss of biodiversity is the decrease in the number of a particular species in a certain habitat. Loss of biodiversity also leads to the extinction of the plant and animal species and this loss can be either reversible or permanent.
• Human activities have been the major cause of the loss of biodiversity which has led to sudden changes in climate causing a big threat to biodiversity. 
• There has also been an increased demand for natural resources along with the growing population leading to greater waste generation.

Causes of Loss of Biodiversity

• The natural habitat of the ecosystem plays a major role in maintaining the ecological balance. Several trees are cut down every year for the construction of industries, highways, settlements,s and so on to fulfill human demands. As a result, the species become the target of predation and eventually dies.
• Hunting of wild animals for the commercialization of their products has been a major reason for the loss of biodiversity. Since the year 2013, more than 90 rhinos were killed by the poachers for their horns and as per the records of 2016, 9 Indian Rhinos have been killed in Kaziranga National Park of Assam.
• The exploitation of medicinal plants for several laboratory purposes has resulted in the extinction of these species. Also, several animals are sacrificed for various research in science and medicine.
• Natural calamities like floods, earthquakes, forest fires also lead to the loss of biodiversity.
• Air pollution has a major role in the loss of biodiversity. Rapid cutting down of the trees has resulted in the increase of carbon dioxide in the atmosphere leading to climate change. As a result, there has been an increase in the land and ocean temperature leaving an inimical impact on species.

Biodiversity in India

• India is one of the most diverse nations in the world. It ranks ninth in terms of plant species richness. Two of the world’s 25 biodiversity hotspots are found in India. 
• It is the origin of important crop species such as pigeon pea, eggplant, cucumber, cotton, and sesame. India is also a center of various domesticated species such as millets, cereals, legumes, vegetables, medicinal and aromatic crops, etc.
• India is equally diverse in its faunal wealth. There are about 91000 animal species found here.
• However, diversity is depleting at a drastic rate and various programs on biodiversity conservation are being launched to conserve nature.