Biodiversity – Significance, Types and Threats


·                 Biological diversity or biodiversity refers to variability among the living organisms; plants, animals, and microbes from all sources including terrestrial and aquatic ecosystems and ecological complexes of which they are part.
·                 In brief, it refers to the variabilities within species, among the species of plants, animals and micro-organisms and the ecological complexes on the earth.
·                 Biodiversity is the assemblage of different life forms.
·                 It can also be defined as “the number of different organisms and their relative frequency in an ecological system.
·                 Thus the term biodiversity includes variability of genes, varieties, species, population in different ecosystem and their relative abundance.
·                 (BY McNEELY, 1990): “Biological diversity or biodiversity encompasses all species of plants, animals, microorganisms and the ecosystem and ecological process to which they belong.”
·                 It has been estimated that more than 50 million species of plants, animals and microorganisms are existing in the world.
·                 Out of these, about 2 million organisms have been identified so far.
·                 Our planet’s requirements and services depend mainly on the biological resources.





Ø    Values related to biodiversity are three categories:-
i.       Productive use
ii.     Consumptive use
iii.   Indirect use
Ø    Biological resources contribute to social and economic development through:-
i.       Products consumed directly such as firewood, fodder and game meat.
ii.     Products for commercial harvest such as         Timber, Fish and Medicinal Plants.
iii.   Various ecosystems services and functions e.g.
§  Watershed protection,
§  Photosynthesis,
§  Relugation of climate
§  Production of soils
iv.   Intangible values of keeping options open for the future and simply knowing that certain species exist.
Ø    Biodiversity, besides its ecological significance, provides and a socio-economic and monetary asset to the nation.
Ø      Biological resources provide us Nourishment, Clothing, Housing, Fuel, Medicine, Livelihood and Knowledge for Planning.

                   TYPES OF BIODIVERSITY

Ø    It is usually considered at three different levels:-
i.       Genetic Diversity
ii.     Species Diversity
iii.   Ecosystem Diversity 

i.      Genetic Diversity

§  Genetic diversity is the sum total of genetic information contained in the genes of all living organisms.
§  On the earth there are about 30 million insects.
§  Total and identified species are tabulated here under:-
Genetic Diversity
S. No
Total No. of Species
Identified Number
Mammals, Reptiles, and Amphibians
Microbes and Invertebrates

ii.    Species Diversity

§  It refers to the variety of living organisms on earth.
§  It pertains to richness of species of Flora, Fauna and Microorganisms in an ecosystem or biotic community.

iii.  Ecosystem Diversity

§  It releases to the variety of Habitats, Biotic Communities and Ecological Processes in the biosphere as well as the tremendous diversity within ecosystems.

                   VALUES OF BIODIVERSITY

1.              Food

i.       80,000 Edible wild plant species utilized by human.
ii.     Villages in Indonesia use 4000 native plant and animal species for their food and medicine.

2.              Drugs and Medicine

Ø  UNDP estimates the value of pharmaceutical products derived from Plants, Animals and Microbes more than $30 billion per year.

3.              Ecological Benefits

Ø  The organisms are nothing but value of biodiversity. The following services are provided by the organisms:-
i.   Soil Farming
ii.  Air and water purification
iii.  Water disposal
iv. Nutrient cycling
v.  Food production

4.              Aesthetic Benefits

Ø  Million of people enjoy hunting Fishing, Camping, Hilling, Wildlife Watching and other natural activities.
Ø  These activities provide stress relief, good exercise, and contact with nature can be psychologically and emotionally restorative.

5.              Social Values

Ø  The U.S. Fish and Wildlife Services estimated that 40% of all adults enjoy wildlife including 39 million whore hunting or fishing and 76 million who watch, feed or photograph wildlife.
Ø  Local biodiversity can bring cash to remote areas through ecotourism.
Ø  There are nine major ecological or vegetative zone which has further subdivided into 18 habitat types.






Ø    The principal threat to biodiversity in Pakistan comes from the increase pressure on natural resources produced by rapid population growth and demands for increased standards of living.
Ø    Together, these account for doubling of the demand for natural resources every 12 years.
Ø    More specific threats to biodiversity in Pakistan are posed by:-
1.              Deforestation
2.              Overgrazing and browsing
3.              Soil Erosion
4.              Water Pollution
5.              Hunting
6.              Fishing
7.              Agricultural Practices.
8.              Habitat Destruction
9.              Expansion of Agriculture and Industries
10.          Urbanization
11.          Road Construction/ Dam Construction.
12.          Excessive and Uncontrolled Biotic Interference.
13.          Drought.
14.          Land Slides
15.          Floods
16.          Storms
17.          Earthquakes
18.          Diseases
19.          Environmental Pollution i.e.
(Thinning of Ozone Layer, Acid Rains, Global Warming)
Ø    Destruction forest vegetation is the man cause.


loss of biodiversity can be depicted in the following chart:-
Ø    Heavy uncontrolled continuous
§  Grazing, Browsing,
§  Commercial Felling
§  Local use for Fuel wood and Construction
§  Clearance for Cultivation
Rapid growth of population
Food                 Needs Lands         Clearance of Forests
Ø    Livestock numbers in Pakistan are increases by 20% every seven years.
Ø    Serious degradation of Rangelands reduces the diversity of Flora and changes the vegetative composition.
Ø    The causes of water pollution are the discharged of untreated sewage, agricultural and industrial wastes into water courses.
Ø    100,000 Waterfowl are short annually on migration to Chitral.
Ø    Hunting Threatens Musk Deer (Hunting for Musk).
Ø    Markhor, Ibex, Goral in K.P.K.
Ø    Black Bears cubs are caught to be sold for dancing.
Ø    Most Cat species have valuable fur.
Ø    Pheasants and Herons are hunted for their feathers.
Ø    Falcons are sold for the falconry trade and acute problem in K.P.K.
Ø    Cranes are captured in large number to be kept as garden pets.
Ø    Large birds are shot e.g. Storks, Grey/Black partridge, Chakor etc.
Ø    Snakes are hunted for their skins.
Ø    Some plant species may be threatened by their collection or use.


Ø    Conservation of Biodiversity is of two types:
1.    In-Situ Conservation
2.    Ex-Situ Conservation

i.   In Situ Conservation

ü  In-Situ conservation measures are related to the biodiversity of the ecosystem of the original habitats or natural environment.
ü  It is the best, easiest, most advantageous and most feasible method to conserve natural biodiversity.

ii.  Ex-Situ Conservation

     A species can be protected from becoming extinct only through maintaining individuals in artificial conditions under human care and protection. Such measures are included under Ex-Situ or off-situ conservation. e.g.
     Zoos, Sport Forms, Aquaria, Botanical Gardens, Parks, Aroreta Seed Banks, Captive Breading.
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