By Dr. R.K. Ranjan Singh
The living organisms are found almost everywhere on earth. Hot desert, extremely cold places, like north and south pole, high mountains, deep oceans, dark caves etc. are all inhabited by one or other kind of organisms. The types of organisms found on different places differ from one another. For example, plants, animals, insects etc. living in pond are different from those on land. Likewise plants, animals and even human beings found in different parts of the world differ in many ways. The planet earth is thus repository of innumerable varieties of living organisms ranging from very small microscope such as bacteria, which cannot be seen by naked eyes, to very large macroscopic like elephants, whales, giant banyan tree etc. The richness of variety of life forms is termed as biological diversity, popularly referred to as biodiversity.
Life has existed on Earth for over 3.5 billion years. Over 95% of the species that ever existed have gone extinct. So why should we be concerned about current extinction rates and conserving biodiversity?
Currently the planet is inhabited by several million species in about 100 different phyla (Dirzo& Raven 2003). About 1.8 million have been described by scientists (Hilton- Taylor 2008), but conservative estimates suggest that there are 5-15 million species alive today (May, 2000), since many groups of organisms remain poorly studied. Over 15,000 new species are described each year (Dirzo& Raven 2003), and new species are evolving during our lifetimes. However, modern extinction rates are high, at 100 to 1000 times greater than background extinction rates calculated over the eras. Although new species appear, existing species go extinct at a rate 1000 times that of species formation (Wilson 2003). Many biologists agree that we are in the midst of a mass extinction, a time when 75% or more of species are lost over a short geological time scale (Raup 1994). The last great mass extinction was 65 million years ago, at the end of the Cretaceous, when the dinosaurs went extinct. The International Union for the Conservation of Nature estimates that 22% of known mammals, 32% of amphibians, 14% of birds, and 32% of gymnosperms (all well-studied groups) are threatened with extinction (Hilton-Taylor 2008). Species that were abundant within the last 200 years have gone extinct. For example, passenger pigeons, which numbered three to five billion in the mid-1800s (Ellsworth &McComb 2003), are now extinct.
Why should we be concerned about this loss of biodiversity? The answer lies in the fact that, for the first time in Earth’s history, single species, HOMO SAPIENS, could cause a mass extinction, precipitating its own demise. The primary cause of today’s loss of biodiversity is habitat alteration caused by human activities. Let’s think about the meaning of biodiversity. Most people understand that biodiversity includes the great heterogeneous assemblage of living organisms. This aspect of biodiversity is also known as species diversity. Biodiversity includes two other components as well- genetic diversity and ecosystem diversity.
Biological resources are those products that we harvest from nature. These resources fall into several categories: food, medicine, fibres, wood products, and more. For example, over 7,000 species of plants are used for food, although we rely heavily on only 12 major food crops. Most of the human population depend on plants for medicines are chemicals produced by pharmaceutical companies, but the original formulas were often derived from plants. For example, opiate pain relievers are derived from poppies, aspirin is derived from willows, and quinine for treating malaria come from the Chinchona tree. The rosy periwinkle (Vincarosea) and Pacific yew (Taxa brevifolia) both provide substances used in chemotherapy to inhibit the cell division of cancerous cells. Fibers for clothing, ropes, sacking, webbing, netting and other materials are provided by a large number of plants, including cotton plants, flax plants (linen), hemp (cordage and sail canvas), Agave plants sisal), Corchorus plants (jute), bamboo and palms. Tress provide the wood products used in making homes, furniture, and paper products.
In addition, living organism provide inspiration for engineers seeking better and more efficient products. The field known as bio-mimicry is the study of natural products that provide solutions to human needs. For example, shark skin provided the model for hydrodynamic swimming suits. The glue used by Sandcastle worms (Phragmatopoma-californica) to cement together their sand particle shells was the inspiration for a glue that mends fractured bones in the aqueous internal environment of the body. Finally, scientists are using the chemical nature of spider’s silk to design strong, lightweight fibers.
Ecosystem services are processes provided by nature that support human life. These services include the decomposition of waster, pollination, water purification, moderation of floods and renewal of soil fertility. Ecosystem processes are often overlooked and are not generally valued as part of the economy until they cease to function. When economic value is assigned to these services, it is often startlingly high. For example, inspect pollinators help produce many commercially important fruits such as almonds, melons, blueberries, and apples. The global economic value of pollination services performed by insects has been value at $ 217 billion per year (Gallai etal. 2009). How does a process like water purification work? Rain water is filtered by soil and by microbes that can break down nutrients and contaminants, and reduced metal ions, slowing their spread into the environment. Wetland and riparian plants absorb nitrogen, and trap sediments that decrease water quality. Human construction and development disrupt natural environments, but most habitats have an extraordinary ability to recover when given the chance. This is because dormant seeds in the soil can germinate, stabilize the soil, and initiate successional events that restore vegetation which provides food and structure for other colonizing organisms. Native plants like fireweed can help re-vegetate an area after fire.
Social and Spiritual Benefits
Throughout most of human history, conservation has involved protecting nature for the spiritual gifts it provides, and protecting sacred places in the local landscape. Stories of indigenous people incorporate detailed knowledge of the animals and plants that make up their world. The heterogeneity of the world’s mythology, folk art and folk dances show the effects of biodiversity on cultural development and contribute to the richness of global arts and literature. Different cultures developed in different landscape that influenced activities, occupations, diet, language and architecture. Cultures adapted to local environmental challenges by growing local domestic crops, developing irrigation and terracing systems, hunting, fishing and gathering. Biodiversity provides a sense of place. Countries and states have flagship animals and plants that are a source of pride and highlight the uniqueness of each habitat. Travel, which provides great pleasure to many people, is motivated by the desire to see this combination of cultural, landscape and biological diversity.
Ecotourism is travel with the desire to view, sustain and support natural ecosystems and local cultures. Support from ecotourism can reduce habitat destruction, preserve species that suffer from poaching and illegal trade in the pet market, plus provide jobs for the local economy. For example, the Wasini Island project in Kenya has been a major ecotourism success story. Coral reefs and mangrove forests were suffering degradation from development, agriculture and from exploitation of reef species. Support from the Biodiversity Conservation Programme made it possible for the local community to build boardwalks and other features that facilitate viewing wildlife. Local people were trained as guides and in administration and they now run a profitable ecotourism operation. Money from tourism helps the local economy, provides incentive to maintain the habitat and provides funds for the local health clinic and scholarships for local students (Peopleandplanet.net2009). In recognition of the aesthetic value of nature, in 1892 the US Congress set aside the first national park “for the benefit and enjoyment of the people” (NPS 2010). Frederick Law Olmstead, who in the 1800s designed and managed park system and urban parks such as Central Park in New York City, believed in the rejuvenating powers of nature. He felt that contemplating nature’s grandeur allowed man to put is life into perspective. In modern times, with increasing urbanization, people seek out local parks, open space and trails, and travel to national parks and wild places where they can enjoy nature. Birding, hiking, fishing, hunting, gardening, and other forms of recreation in nature are popular activities and are economically important.