Biodiversity

Biodiversity represents the variety and variability of all animals, plants and organisms.

The term biological diversity or refers to the variety of life forms and habitats found in a defined area. Biodiversity can be defined “as the variety and variability of all animals, plants and micro­organisms and the ecological complexes of which they are a part”.

Diversity characterizes most living organisms, the our earth supports something like 5 to 10 million species of plants and animals (IUCN, 1980) which have been the result of 3 billion years of evolution involving mutation, recombination and natural selection.

LEVELS OR COMPONENTS OR FORM OF BIODIVERSITY

Biodiversity is said ions in the sequence of four base pairs in DNA.

Ecosystem. Indian ecosystem diversity is described at each of the three levels (biogeographical region, biotic province and biome). Largest of identified ecosystems has been the biogeographical zone. The vast area covered by biogeographical zone contains a wide diversity of smaller units called bioticprovinces. Finally, within each biotic province, various kinds of biomes are distinguished. Biome dassification broadly follows commonly used terminology distinguishing between forests, grasslands, wetlands, deserts and other such ecosystem on the basis of their physical appearance and dominant biotic or biotic element.

Species. Species are the most commonly used unit describing biodiversity. Comparisons of the diversity found in different countries or ecosystems, for instance, are almost always based on species number. According to investigations into Amazonian rainforest canopy (Wilson, 1988), worldwide, some 5 to 30 million species are believed to exist. Nearly 1.7 million have so far been described (Myers, 1993). Species diversity has frequently been used as an indicator of the conservation significance of an area.

Genes. The genetic diversity within a species is expressed by many terms, subspecies, breeds, races, varieties and forms. This diversity arises from ‘‘variations in the sequence of four base pairs inDNA’’.

PRESENT STATUS OF BIODIVERSITY

India is one of the 12 megadiversity countries of the world for its great diversity of plant life, especially the angiospenns.

India’s biological diversity is one of the most significant in the world. About 48,000 species of plants (about 11% of worlds flora) and 81,000 species of animals (about 6.4% of world’s fauna) are estimated to occur in the country.

The floral diversity includes about 17,000 species of angiosperms; 64 of gymnosperms, 1022 of pteridophytes, 2,843 of bryophytes, 1,940 of lichens, 13,000 of fungi and 12,480 of algae. While about 35% of the flowering plants and about 18% of the total flora is endemic to the country, the endemism amongst the animals is as high as 62% in groups like amphibia.

Some of the biological rich areas of India are either unexplored or under-explored, the recorded biodiversity may be first only a part of the biological wealth that might actually exist.

Range of diversity in plants and animals genetic resources is highly significant. The Indian subcontinent is known as “Hindustan Centre” - one of the 12 centres of origin and diversity of crop plants.

About 166 species of domesticated agri-horticultural crop plants, and over 320 species of wild progenitors of these, occur in India. This rich diversity of living resources notwithstanding, about 10% of the country’s recorded higher group of plants and a large segment of its wild fauna today belong to different “Red data” categories.

•  Expansion of industry and agriculture on prime forest lands.
•  Urbanisation and large scale developmental projects.
•  Pollution.
• Overutilisation of biological resources.

LIVING RESOURCES CONSERVATION HAS THREE SPECIFIC OBJECTIVES

To maintain essential ecological processes and life support system.

To preserve biological diversity.

To ensure that any utihsation of species and ecosystems is sustainable.

CONSERVATION OF BIO-DIVERSITY

There is an urgent need to arrest species extinction. Equally important is the need to prevent the loss of thousands of years of human selection in crop species and domesticated animals for posterity.

In-situ CONSERVATION

In-situ conservation measures are primarily related to the natural, biodiversity within the evolutionary dynamic ecosystems of the original habitat or natural environment. It is the best, easiest, most advantageous, besides being most feasible method to conserve biological diversity.

In-situ conservation includes a comprehensive system of protective areas. These include National parks, Sanctuaries, Nature Reserves, Natural Monuments, Cultural Landscapes, Biosphere reserves and several others.

Geography and Biodiversity

Strong equations have been suggested between various geographical factors and the extent of biodiversity. For instance, as a general rule, the larger the size of an area, the greater the number of species found in it. Indeed, even in the case of the population of a single species, a larger spread is more likely to lead to diverse adaptations among different populations and thereby to speciation.

This is one overwhelming justification for larger-sized conservation areas though of course it is also true that a number of smaller protected areas in more diverse areas could help to conserve a larger biodiversity Other geographical variables include latitude, elevation, and precipitation. Elevation is inversely related, with higher diversities found at lower heights, and very poor diversity at the upper extreme of altitude.

Ex-situ CONSERVATION

Ex-situ conservation is conservation outside their habitats by perpetuating sample population in genetic resource centres, zoos, botanical gardens, culture collections etc., or in the form of gene pools and gamete storage for fish, germplasm banks for seeds, pollen, semen, ova, cells etc.

Plants are more readily maintained than animals, yet zoos have recorded success with captive breeding of animals. e.g., the Pere David’s Deer and the European Bison have lost their wildland habitats many decades ago, have been kept alive solely through zoos and similar facilities.

Ex-situ conservation measures for restoration of biodiversity should aim at consolidating the public network of zoological parks and botanical gardens, herbaria, aquaria, gene/seed/embryo banks, in-vitro and cryopreservation facilities.