Lec-4

  • November 2019
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Biodiversity Variation of the living organisms is called Biodiversity.  Sometimes habitat diversity (the variety of places where organisms live) and genetic diversity (the variety of traits expressed within a species) are also considered types of Biodiversity. 

Significance of Biodiversity Biodiversity, besides its ecological significance provides a socioeconomic and monetary asset to the nation. Human society depends on biological resource, Their diversity and the ecosystems that sustain them provide essential goods and service. Values related to biodiversity can be grouped in to three categories as following.

Significance of Biodiversity.  Productive use: Products that are commercially harvested for exchange in formal markets and it is the only value of biological resources that is concerned in national income. It provides us many products, such as fuel, timber, fish fodder, skin, fruits, cereals and medicinal plants.  Consumptive use: Consumption value is related to natural products that are consumed directly, i.e. the goods which do not come under normal circulation of trade. eg. Honey collection from own garden.  Indirect use: This use provide us indirect benefits as non-consumptive values. maintenance of ecological balance, conservation of natural resources and

Types of Biodiversity



Ecological diversity: It refers to the variability among the living organisms in different ecosystems. It also refers to the variability within the species and variability among the species of plants, animals an micro-organisms. It pertains to richness of species of flora and fauna and micro-organisms in an ecosystem or biotic community



Genetic diversity: Range of diversity in plant and animal genetic resource. So that, diversity among individuals of a species as well as variability among

Depletion of Biodiversity Natural causes of biodiversity depletion: Drought, Land slides, Flood, Strom, Earthquakes, Disease etc. Artificial causes of biodiversity depletion:  Grazing,  scientific and educational research,  road and dam construction all leading to destruction of habitat.  Due to habitat destruction  Over-exploitation of biological resources  Pollution and introduction of exotic plants and animals which causes qualitative as well as quantitative changes in biodiversity.  Expansion of agriculture and industries, urbanizations, road construction and large scale developmental projects. *Excessive and uncontrolled biotic interference.

Artificial destruction of the Biodiversity: eg. Deforestation and habitat loss.

Human are destroying the plant and it causes the loss of habitat of others animals and birds.

Industrialization causes the destruction of environment by destroying plants and emitting many kinds of harmful gases



Remember, it's not just the trees that are lost but all the animals whose home it was like monkeys, tigers or parrots.

Toxic chemicals are dangerous for the creature.

Destroying the natural world by cutting and burning rainforests, covering the ground with more houses, office blocks, factories and roads or using life-destroying farming methods

Over exploitation of the environment is one of the cause of destruction of biodiversity.

Over-hunting for food, for fur or, nowadays,

fun. Thousands of creatures have been wiped out by people. Some of the most famous are the dodo, the passenger pigeon and the great auk

Introducing alien species. Sometimes people do this by accident but often it's deliberate. Cats and rats in Australia have driven many once common creatures almost to extinction by hunting them

Conservation of Biological Diversity Increasing population, urbanization and industrialization, however, have led depletion of natural resources. In this case the immediate task is not only to manage and conserve the existing natural resources and ecosystems through cooperation and support of people. Conservation of bio-wealth and genetic resources is essential for providing security of food to the nation.

In-situ conservation: In-situ conservation means a conservation process by which we can conserve natural resources in their own habitat. e.g. 1. The conservation of ecosystem and biogeographic units. 2. Establishing new protected areas based on utility, distinctiveness and endangerment of species.

Ex-situ conservation: A conservation

process by which we can conserve natural resource artificially. Sometimes the populations of species may decline or may become extinct due to genetic of environmental factors such as genetic drift, inbreeding , habitat loss, competition with exotic species, diseases and over-exploitation. In such cases In-situ conservation may not proves to be effective and a species can be protected from becoming extinct only through maintaining individuals in artificial conditions under Exsitu or Off-situ conservation. e.g. 1. Collection and maintenance of microbial cultures. 2. Encouraging the establishment of seed

What we have to do?



Start composting waste food, vegetable peelings and stuff.



wear your clothes more than once before you wash them.

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