140 ENVIRONMENTAL SCIENCE
Beta Diversity
It indicates the degree to which species composition changes along an environmental
gradient.
Gamma Diversity
It indicates the rate at which additional species are encountered as geographical
replacements within a habitat type in different localities.
- Rio-geographic Classification of India
India has been classified into ten bio geographic zones by the Wildlife Institute of India
under the Government’s Bio-geographic Project Table 3.
Table 4.3: Bio-geographic Zones of India
S.No. Bio-geographic Zones Distribution- Trans- Himalaya Ladakh Mountains, Tibetan plateau.
- Himalaya North-Western, Central, Western and Eastern
Himalayas - Desert Thar, Kachchh
- Semi-arid Punjab plains
- Arid Gujarat, Rajputana
- Deccan Peninsula Central Highlands, Chhota Nagpur, Eastern Highlands,
Central Plateau, Deccan south - Gangetic Plain Upper and lower Gangetic plain
- Coast West coast, East coast
- North-East Brahmputra valley, North east hills
- Island Andamans and Nicobar Group of Islands, Lakshwadeep
- The Value of Biodiversity
Ecosystems and species provide an enormous range of goods and other services -
immediate as well as long term, material as well as spiritual and psychological - which are
vital to our well being. The values of the earth’s biological resources can broadly be classified
into-
Direct Values
Consumptive and productive uses.
Food Resources: Grains, vegetables, fruits, nuts, condiments, tea-coffee, tobacco, liquor,
oil from plant resources; and meat, fish, egg, milk (and milk products), honey, etc. from
animal resources.
Other Resources: Medicine, fuel, timber, household accessories, fodder, fiber, fertilizer,
wool, leather, paint, resin, wax, thatch. Ornamental plants, rubber, creams, silk, feathers,
decorative items, etc.