Bio-Diversity & Its Convervation - Part 4

BIO – DIVERSITY & ITS CONSERVATION

PART 4

CONSERVATION OF BIODIVERSITY :
•    Conservation of biodiversity is protection, uplift and scientific management of biodiversity so as to maintain it at its optimum level and derive suitainable benefit for the present as well as future strategies.
•    Conservation strategies : There are two basic strategies of biodiversity conservation
            1.    in-situ (on site)
            2.    ex-situ (off site)

1.    In-situ conservation : It is protection and management of important components of biological diversity through a network of protected areas.

A.    Protected areas :
•    They are ecological/biogeographical areas where biological diversity alongwith natural and cultural resources are protected, maintained and managed through legal or other effective measures. National Parks and Wild life Sactuaries are the examples of protected areas.
•    The World Conservation Monitoring Centre (WCMC) has recognised 37,000 protected areas around the world.
•    As of September 2002, India has 581 protected areas (89 National parks and 492 Wildlife Sanctuaries).
•    These areas cover 4.7 per cent of the land surface as against 10 per cent internationally suggested norm. The protected areas provide following benefits.
            a.    Maintain viable populations of all native species and sub-species.
          b.    Maintain the number and distribution of communities and habitats, and conserve the genetic diversity of all the present species.
            c.    Prevent man made introduction of alien species.
        d.    Make it possible for species/habitats to shift in response to environmental changes.

B.    Biosphere reserves :
•    The Man and Biosphere (MAB) programme of UNESCO formulated the concept of Biosphere in 1975, which deals with conservation of ecosystems and genetic resources contained therein.
•    "The Biosphere Reserves are a special category of protected areas of land/or coastal environments, wherein people are an integral component of the system'.
•    These are representative examples of natural biomes and contain unique biological communities.
A biosphere reserve has three zones :
         a.    Core or natural zone : It comprises an undisturbed and legally protected ecosystem.
        b.    Buffer zone : It surrounds the core area, and is managed to accommodate a greater variety of resource use strategies, and research and educational activities.
           c.    Transitional zone or manipulation zone : It is the outer most part of the biosphere reserve. It serves as an area of active cooperation between reserve management and the local people, wherein activities like settlements, cropping, forestry and recreation and other economic uses continue in harmony with conservation goals.

Importance of biosphere reserve
I.    Restoration : Biosphere reserves help in restoration of degraded ecosystems and habitats.
II.    Conservation : Biosphere reserves ensure the conservation of landscapes, ecosystems, species and genetic resources. These reserves also encourage the traditional resource use.
III.    Development : The biosphere reserves promote culturally, socially and ecologically sustainable economic development.
IV.    Scientific research, monitoring and education : The biosphere reserves provide support for research monitoring, education and information exchange related to local, national and global issues of conservation and development.

C.    Sacred forests and Scared lakes :
•    Sacred forests are forest patches around places of worship which are held in high esteem by tribal communities.
•    They are the most undisturbed forest patches (Island of pristine forests) which are often surrounded by highly degraded landscapes.
•    They are found in several parts of India, e.g., Karnataka, Maharashtra, Kerala, Meghalaya, Temples built by tribals are found surrounded by Deodar forests in Kumaon region, Jaintias and Khasias in Meghalaya.
•    Not a single branch is allowed to be cut from these forests. As a result many endemic species which are rare or have become extinct elsewhere can be seen to flourish here.
•    Similarly aquatic flora and fauna is also protected in sacred water bodies. e.g. Khaeheopalri lake in Sikkim.

2.    Ex-situ conservation : It is conservation of selected rare plants/animals in places outside their natural homes. Ex situ conservation includes offsite collections and gene banks.

A.    Offsite collections :
      •    They are live collections of wild and domesticated species in botanical gardens, zoos, arboreta, etc.
      •    Currently, there are more than 1500 botanical gardens and arboreta (Gardens with trees and shrubs) having more than 80,000 species.
       •    Many of them have seed banks, tissue culture facilities and other ex-situ technologies. The number of zoos/zoological parks is more than 800.
      •    They have about 3000 species of mammals, birds, reptiles and amphibians. Most of them have well managed captive breeding programmes.

Therefore, offsite collections can be used to restock depleted populations, reintroduce species in the wild and restore degraded habitats.

B.    Gene banks :
       •    A gene bank or germ plasm bank is an institution where valuable plant material is preserved in a viable condition.
      •    These are stored either in the form of seeds or dormant vegetative organs or in the form of frozen gametes.
Seed banks :
      •    Plant germplasm in live state is the viable seed. In a seed the embryo is present in a dormant state. The moisture contents of seeds is kept low (5-15%) and they are stored at low temperature (10oC
     •    to20oC) with supply of little oxygen.
    •    With these conditions there is reduced enzyme activity and reduced respiration.
    •    From time to time at definite intervals these seeds are sown to produce new plants and fresh seeds are obtained.
    •    Such seeds are called Orthodox seeds as they can withstand the reduction in moisture and prolonged exposure to low temperature.
    •    Seeds of trees and shrubs usually get killed on drying and freezing. Such seeds are called Recalcitrant seeds e.g., tea, litchi.
    •    In such cases plants are kept in orchards and maintained through in-situ conservation.
   
Orchards :
    •    Plants with recalcitrant seeds are grown in orchards where all possible strains   and varieties are maintained, e.g., litchi, oil Palm, rubber tree, etc.

Tissue Culture :
    •    It is carried out through callus formation, embryoids, pollen grain culture and shoot tip culture for those plants which are either seedless, have recalcitrant seeds, variable seed progeny or where clone is to be maintained.
    •    The method is useful in maintaining a large number of genotypes in small area, rapid multiplication of even endangered species and for hybrid rescue. Shoot tip culture maintains virus free plants.
    •    It is used for international exchange of germplasm in vegetatively multiplied cultivars, e.g., banana, potato.

Cryopreservation :
   •    Preservation at 196oC (liquid nitrogen) can maintain tissue culture, embryos, animal cells/tissues, spermatozoa indefinitely. The cryopreserved material is revived through special technique when required.

To be Continued in Part 5