Humans depend for their sustenance, health, wellbeing and cultural growth on nature. The enormous diversity of life is of immense value, imparting resilience to ecosystems and natural processes.

The various benefits of biological diversity can be grouped under the following categories:

I . Ecosystem services
II . Biological resources
III . Social benefits
IV . Research , education and monitoring

I . ECOSYSTEM SERVICES

Living organisms provide many ecological services that are responsible for maintaining ecosystem health

1 . Protection of water resources:

Natural vegetation cover helps in maintaining hydrological cycles, regulating and stabilizing water run-off and acting as a buffer against extreme events such as floods and droughts. Vegetation removal results in siltation of dams and waterways. Wetlands and forests act as water purifying systems, while mangroves trap silt thereby reducing impacts on marine ecosystems.

2 . Soil protection:

Biological diversity helps in the conservation of soil and retention of moisture and nutrients. Clearing large areas of vegetation cover has been often seen to accelerate soil erosion, reduce its productivity and often result in flash floods. Root systems allows penetration of water to the sub soil layer. Root system also brings mineral nutrients to the surface by nutrient uptake.

3 . Nutrient storage and cycling:

Ecosystem perform the vital function of recycling nutrients found in the atmosphere as well as in the soil. Plants are able to take up nutrients, and these nutrients then can form the basis of food chains, to be used by a wide range of life forms. Nutrients in the soil, in turn, is replenished by dead or waste matter which is transformed by micro-organisms; this may then feed others such as earthworms which also mix and aerate the soil and make nutrients more readily available.

4 . Pollution reduction:

Ecosystems and ecological processes play an important role in maintenance of gaseous composition of the atmosphere, breakdown of wastes and removal of pollutants. Some ecosystems, especially wetlands have the ability to breaking down and absorb pollutants. Natural and artificial wetlands are being used to filter effluents to remove nutrients, heavy metals, suspended solids; reduce the BOD (Biological Oxygen Demand) and destroy harmful micro-organisms.

5 . Climate stability:

Vegetation influences climate at macro as well as micro levels. Forests help to maintain the rainfall in the vicinity by recycling water vapor at a steady rate back into the atmosphere. Vegetation also exerts moderating influence on micro climate. Cooling effect of vegetation is a common experience which makes living comfortable.

6 . Maintenance of ecological processes:

Different species of birds and predators help to control insect pests, thus reduce the need and cost of artificial control measures. Birds and nectar–loving insects which roost and breed in natural habitats are important pollinating agents of crop and wild plants.

Thus without ecological services provided by biodiversity it would not be possible to get food, pure air to breathe and would be submerged in the waste produced.

II . BIOLOGICAL RESOURCES

1 . Food, fibre, medicines, fuel wood and ornamental plants:

Five thousand plant species are known to have been used as food by humans. A large number of plants and animals materials are used for the treatment of various ailments. The therapeutic values of herbal medicines led to evolution of Ayurveda .

Wood is a basic commodity used worldwide for making furniture and for building purposes. Fire wood is the primary source of fuel widely used in third world countries.Wood and bamboo are used for making paper. Plants are the traditional source of fibre such as coir, hemp, flax, cotton, jute.

2 . Breeding material for crop improvement:

Wild relatives of cultivated crop plants contain valuable genes that are of immense genetic value in crop improvement programmes. Genetic material or genes of wild crop plants are used to develop new varieties of cultivated crop plants for restructuring of the existing ones for improving yield or resistance of crops plants.

3 . Future resources:

There is a clear relationship between the conservation of biological diversity and the discovery of new biological resources. The relatively few developed plant species currently cultivated have had a large amount of research and selective breeding applied to them. Many presently under-utilised food crops have the potential to become important crops in the future.

III . SOCIAL BENEFITS

1 . Recreation:

Forests, wildlife, national parks and sanctuaries, garden and aquaria have high entertainment and recreation value. Ecotourism, photography, painting, film making and literary activities are closely related.

2 . Cultural values:

Plants and animals are important part of the cultural life of humans. Human cultures have co-evolved with their environment and biological diversity can impart a distinct cultural identity to different communities.
The natural environment serves the inspirational, aesthetic, spiritual and educational needs of the people, of all cultures.

IV . RESEARCH , EDUCATION AND MONITORING

There is still much to learn on how to get better use from biological resources, how to maintain the genetic base of harvested biological resources, and how to rehabilitate degraded ecosystems. Natural areas provide excellent living laboratories for such studies, for comparison with other areas under systems of use and for valuable research in ecology and evolution.

PRACTICE QUESTIONS

QUES . Biodiversity forms the basis for human existence in the following ways : UPSC 2011

1 . Soil formation

2 . Prevention of soil erosion

3 . Recycling of waste

4 . Pollination of crops

Select the correct answer using the codes given below:

(a) 1, 2 and 3 only

(b) 2, 3 and 4 only

(c) 1 and 4 only

(d) 1, 2, 3 and 4

Ans (d)