Biological diversity’ means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems. The word Biodiversity means Gk. Bios- Life, diversity- forms. The occurrence of difference species of organisms with the whole range of their variants (Biotypes) & genes adapted to different climates, environments along with their interactions & processes. This term was coined by Walter G. Rosen- 1985. Biodiversity refers to the numbers, variety and variability of living organisms and ecosystem. It includes all terrestrial, marine and other aquatic organisms. Also covers diversity within species, between species as well as variations among ecosystems.
Biodiversity has contributed in many ways to the development of human culture, and, in turn, human communities have played a major role in shaping the diversity of nature at the genetic, species, and ecological levels.
Types of Biodiversity
- Genetic diversity – Diversity of genes within a species. i.e. genetic variability among the populations and the individuals of the same species. Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species. Ex. Domestic Dogs. Humans have created distinct breeds of dogs within the species by selectively breeding individuals.
- Species diversity – Diversity among species in an ecosystem. “Biodiversity hotspots” are excellent examples of species diversity. Species diversity is defined as the number of species and abundance of each species that live in a particular location. Each species is distinct from other species in form & character such as cow & goat. Species diversity is the most common level to describe biodiversity of any area.
- Ecosystem diversity – Diversity at a higher level of organization, the ecosystem. To do with the variety of ecosystems on Earth. Ecosystem diversity deals with the variations in ecosystems within a geographical location and its overall impact on human existence and the environment. EX. deserts, forests, grasslands, wetlands and oceans. Ecological diversity is the largest scale of biodiversity, and within each ecosystem, there is a great deal of both species and genetic diversity.
VALUES OF BIODIVERSITY
1. Consumptive value : The most important point of consumptive use is that some rural communities closets to the forests or other natural areas can prosper through the sustainable harvesting of wildlife species. Hunting, Direct consumption-herbs, plants, mushrooms are all consumptive uses.
2. Productive Value : Products that are commercially harvested for exchange in formal markets. Each species is valuable to human. The global collection of genes, species, habitat & ecosystems is a resource that provides for human needs. It is also essential for human survival in the future. This is often then only value of biological resources that is reflected in the income accounts.
3. Social Value : Social value of biodiversity refers to religious and cultural importance. Trees are worshiped as God. ex. Banyan tree, Peepal Tree. Flowers, Tulsi leaves are offered during pooja.
4. Ethical Value : ‘All life must be preserved’ based on ‘Live & let live’. This means we don’t use the species directly or indirectly, but we feel sorry about the loss of species. They have a existence value.
5. Aesthetic Value : It is related to the beauty of biodiversity. The pleasure, excitement & visual peace of any area. Concept of Eco- tourism & willingness to pay are gaining grounds, leading to monetary estimate for aesthetic value of biodiversity.
6. Option Value : The option values of biodiversity suggests that any species may be proved to be a valuable after someday. At present the potentials/ uses/ values are unknown. Ex. Growing technology field is searching new species for causing the diseases of cancer & AIDS.
HOT SPOTS OF BIODIVERSITY
A biodiversity hotspot is a bio-geographic region that is both a significant reservoir of biodiversity and is threatened with destruction. The term biodiversity hotspot specifically refers to 25 biologically rich areas around the world that have lost at least 70 percent of their original habitat. The original 25 hotspots covered 11.8% of the land surface area of the Earth.