Imagine a planet that has only one species. The concept is hard to imagine specially for us as our planet is endowed with a diverse and magnificient array of species which have come to live and coexist both symbiotically and asymbiotically. Earth has a evolved over millions of years which has created many interdependent ecosystems and habitats on which we all depend directly or indirectly for our survival and flourishing. However this can change if we keep destroying our habitats thus eliminating the species that survive on these. Exponential growth of human population, increasing consumption levels, and excessive usage of natural resources are some of the critical causes that have led to the overexploitation and manipulation of ecosystems. Trade in wildlife, like rhino horn and elephant tusk has led to the extinction of several species. Disturbance caused to one species' population affects the interdependent species within the ecosystems and this can put stress on the neighboring ecosystems as well.
What is Biodiversity?
The term “Biodiversity” refers to the variety and differences among living organisms (both flora and fauna) found in aquatic, terrestrial and marine ecosystems. It also deals with the ecological complexes that co-exist between different species of plants and animals. Thus, in a nutshell, biodiversity represents “all the varieties of life on earth”. Both managed and unmanaged ecosystems come under biodiversity. Unmanaged ecosystems include nature preserves, wild lands, or national parks. A managed ecosystem refers to farmlands, plantations, croplands, aquaculture sites, rangelands, urban parks and urban settlements.
Why is Biodiversity important?
Biologists contend that each species, irrespective of its size, plays an important role in boosting the ecosystem’s productivity. Biodiversity helps the planet as a whole. It helps in climate control, breakdown of pollution, protecting the soil ecosystem which is very crucial for the crops to be healthy, in the maintenence of ecosystems, to breed stocks and to have a greater diversity in the species and genes. When species get extinct the population that depends on it also suffers endangerment within an ecosystem. Biodiversity contributes to the general health of the planet without which there will not be enough diversity to exchange genetic material and absorb the shocks from different natural events.
Economical and Medical Importance: More than 90% of today’s food grains have been cultivated from wild tropical plants. Genetic engineers and agricultural scientists derived many crop strains from wild varieties. Several wild plants have been domesticated to supply oils, latex, lumber, dyes, and many other useful products. Nitrogen-fixing microbes are used to enhance the soil’s fertility. More than 80% of the world's population depends on medicines made form plant or animal extracts. It has been estimated that plant-derived oncology drugs save more than 30,000 people per year in India. Over 3000 antibiotics including tetracycline and penicillin are derived by cultivating micro-organisms. Imagine the pencillin mold getting extinct. This would result in huge numbers of human and animal populations suffer as we use pencillin to treat an umpteen number of infections.
Ecological Importance: Environmentalists advocate that each species plays a pivotal role in the ongoing evolution of life on this planet until it becomes extinct without human interference. Study of the species helps the scientists understand the evolution of life and how it will continue to evolve on this planet. Old-growth forests are regarded as global "carbon sinks". Plants absorb greenhouse gases and produce oxygen; regulate local climates and water levels; trap solar energy and reduce the probability of soil erosion. Additionally, wild species make a vast gene pool necessary for sustaining the earth's ecological and biodiversity integrity. The introduction of the mexican tree, Prosposis juliflora in the Thar desert by foreigners resulted in it adapting to the local environment and taking over the land making survival very difficult for the local flora and fauna. By introducing new species to an already established ecosystem can wipe out the local species entirely and result in a whole biodiversity chain being destroyed.
Recreational Importance: With many animals and plants getting on the endangered list due to destruction of their natural habitats, it has become harder to see many of the local flora and fauna resulting in people going to sanctuaries and forests to watch them to the effect that watching wild plants and animals has developed into a new entertainment, "Wildlife tourism" which is gaining popularity in the global travel industry.
Ethical Importance: Some environmental crusaders contend that each species has natural right to exist. They have an inherent right to struggle which is irrespective of its usefulness to human society.
What are the factors that are a threat to Biodiversity?
Destruction of Habitats: It is one of the biggest threats to biodiversity on Earth. Dynamite fishing, boat anchorages and oil spills has severely destroyed coral reefs in some parts of the world. This has badly affected the freshwater and marine ecosystems. Lately, deforestation has led to habitat destruction of many terrestrial species. Singapore in Southeast Asia has lost 95% of its lowland rainforests due to excessive logging. During 1949-1998, over 35 wild species have become extinct.
Overexploitation: Due to over hunting/harvesting of vast numbers of exotic fishes and marine animals, their populations is getting smaller each year and facing the risk of extinction.
Pollution: Excessive release of toxic fumes, chemicals and wastes over extended time periods destroys the biological fabric of aquatic and terrestrial systems. Pollutants have the tendency to spread into food chains.
Climate Change: The earth’s climate is rapidly changing. With global warming on the increase, chances for ecosystems to acclimatize naturally are diminishing.
Introduction of invasive species: It has been seen thatnon-native species can cause extinctions of native species. Earlier, Lake Victoria in Africa was famous for its great diversity of endemic species, of cichlid fishes. Later, with the introduction of the single, exotic species, the Nile Perch, most of the native species became extinct. Exotic species was introduced for subsistence and sports fishing, however, it became a disaster.
How can we protect Biodiversity?
There are three approaches to manage and conserve biodiversity.
The ecosystem approach aims to safeguard existing populations of species in their native habitats. It emphasizes to establish legally protected wildlife reserves and wilderness areas. Moreover, it focuses on the elimination or reduction of the populations of non-native species. Many biologists support this approach by stating that the protection and conservation of ecosystems is the best way to conserve biological diversity and ecological integrity. The only drawback is that fully or partially protected wildlife sanctuaries will require more than 6% of the world's land area which seems to be unfeasible as human population is expected to double in the next 40 years.
The species approach aims to legally protect endangered species by identifying them, preserving their habitats, propagate them in captivity, and reintroduce them into sustainable habitats.
The wildlife management approach aimsto use laws to regulate hunting, reinforce harvest quotas and develop species population management plans. It also emphasis on the introduction of international treaties to protect migrating species such as waterfowl.