Biodiversity challenges ahead

Biological estimates suggest that the number of species may be 10 times those described so far. Plant and animal species from major families are still being discovered in rainforests. Photo: K. Murali Kumar  

May 22 marked the International Day for Biological Diversity. It commemorates the adoption of the Convention on Biological Diversity (CBD) that day in 1992. As of December 2009, exactly 192 countries and the European Commission were signatories to it. This year has been declared the International Year of Biodiversity.

The term biodiversity denotes the variability of life forms on earth. It is a vital resource that needs to be assiduously conserved as it holds the key to progress in medicine, agriculture, forestry and other fields.

Globally, 1.4 million life forms have been named and described by science. Biological estimates suggest that the number of species may be 10 times those described so far. Plant and animal species from major families are still being discovered in rainforests. Over 300 new fish species have been described from the Amazon region. Amphibians have recently been reported from the Sathyamangalam forests in Tamil Nadu.

Botanist Alvin Gentry estimates that 15,000-20,000 species of tropical flowering plants are yet to be documented. But then, this diversity is being eroded on an unprecedented scale. During the last 200 million years about 100 species became extinct in each century due to the natural evolutionary process.

At the same time, evolution ushered in new life forms that more than compensated for those that were lost. Today, the extinction rate is approximately 40,000 times higher than this background rate due to human depredations. For the first time an enormous proportion of terrestrial plant species that form the basis of land ecosystems remains threatened. Previous mass extinctions had no palpable effect on terrestrial plants.

But today, one-fifth of all plant species on land face annihilation in the next 20 years. A disappearing plant can take with it 10-30 dependent species such as insects, higher animals and even other plants. According to one estimate, we may already be losing 100 species a day.

Indian scene

India is one of the world's 12 mega-biodiversity centres, and the subcontinent one of the six Vavilovian centres of origin of species. Some 45,000 plant species and over 89,000 species of animals have been documented here, comprising some 6.5 per cent of all known wildlife.

The faunal diversity comprises inter alia 2,500 fishes, 150 amphibians, 450 reptiles, 1,200 birds, 850 mammals and 68,000 insects. Although India is designated as a mega-biodiversity area, it also has two of the world's most threatened ‘hot spots', the Eastern Himalayan region and the Western Ghats. To quote Professor M.S. Swaminathan, both are paradises of valuable genes but are inching towards the status of ‘Paradise Lost.'

At least 10 per cent of India's recorded wild flora and possibly more of its wild fauna are on the list of threatened species; many are on the brink of obliteration. Of the wild fauna, 80 species of mammals, 47 of birds, 15 of reptiles, three of amphibians and a large number of moths, butterflies and beetles are endangered. Out of 19 species of primates, 12 are endangered. The cheetah ( Acinonyx jubatus) and the pink-headed duck ( Rhodonessa caryophyllacea) are among species that have become extinct. There must be many more that have been annihilated, unrecorded either because they were not that spectacular or because their existence remained unknown.

Causes of erosion

The primary cause for this erosion of diversity is human greed. Never before has one species influenced the environmental conditions all over the planet to such a magnitude as today. The human species now uses 40 per cent of the planet's annual net photosynthesis production. The consumption of two-fifths of the planet's net food resources by one species is incompatible with biological diversity and stability. Loss and fragmentation of natural habitats, overexploitation of plant and animal species, the impact of exotics and invasive alien species, industrial effluents, climate change and, above all, the greed of man are causing the erosion.

The introduction of exotic species can pose a threat to indigenous diversity. Invasive alien species include plants, animals and pathogens that are non-native to an ecosystem and that may cause economic or environmental harm or adversely affect human health. According to CBD reports, invasive alien species have contributed to nearly 40 per cent of all animal extinction. Introduced fish species threaten to decimate the diverse fish fauna of big African lakes. Exotic weeds such as lantana and parthenium pose forest management problems.

Global warming

Global warming and climate change pose threats to plant and animal species as many organisms are sensitive to carbon dioxide concentration in the atmosphere that may lead to their disappearance. Pesticide, troposphere ozone, sulphur and nitrogen oxides from industries also contribute to the degradation of natural ecosystems. Poaching puts pressure on wild animals. Elephants are being hunted for their tusks, the tiger is being shot for its skin.

Nature is beautifully balanced; each little thing has its own place, its duty and special utility. Ecosystem stability is a compelling reason for preserving biodiversity. All living organisms are an internal part of the biosphere and provide invaluable services. These include the control of pests, recycling of nutrients, replenishment of local climate and control of floods.

Target 2010

The Conference of the Parties (COP) established under the CBD at its sixth session in 2002 set common global targets to reduce the loss of biodiversity by 2010. These include:

• Conservation of biodiversity at the level of ecosystems, species and genes;

• Addressing risks such as invasive alien species, global warming and developments that threaten the natural environment;

• Maintaining the function of ecological services that support human livelihood;

• Maintaining the rights of the aboriginal people and protecting their traditional knowledge;

• Ensuring equal and equitable distribution of profits from the use of genetic resources.

COP-10 will be held in Nagoya in Japan in October 2010 to review the progress made in biodiversity conservation targets and discuss the establishment of clearer rules for access to and benefit-sharing of genetic resources. The outlook indicates that biodiversity is declining at all levels and on geographical scales. However, targeted response options such as the expansion of protected areas, resource management and pollution prevention can reverse this trend for specific habitats and species. For instance, protected area coverage has doubled over the past 20 years and terrestrial protected area now covers 12 per cent of the earth's surface. In Tamil Nadu, for instance, with the declaration of the Kanyakumari, Sathyamangalam and Megamalai sanctuaries the percentage of protected area in the total forest area has gone up from 14.79 per cent to 20.01 per cent in the last three years. The introduction of a system of joint forest management over 20 million ha in the last two decades has minimised biodiversity losses. Similarly, the implementation of the Tamil Nadu Afforestation Project over the last 15 years with people's participation has helped restore forests and rejuvenate biodiversity over 6.5 lakh ha in Tamil Nadu.

Water quality in Europe, North America and Latin America has improved since 1980. The National River Conservation Plan and the National Lake Conservation Plan of the Union Ministry of Environment and Forests aim to improve water quality in rivers and lakes. But only the active participation of all stakeholders including local bodies, industries and the public at large can bring glory back to rivers and lakes. The experience in other developed countries indicates that such transformation is not impossible. Conservationists are looking to COP-10 to come out with a better strategy to achieve the biodiversity targets.

What Prime Minister Indira Gandhi said in 1980 is relevant even today: “The interest in conservation is not a sentimental one, but the rediscovery of a truth well known to our ancient sages. The Indian tradition teaches us that all forms of life — human, animal and plant — are so closely interlinked that disturbance in one gives rise to imbalance in the other.”

Our welfare is intimately connected with the welfare of wildlife; by saving the lives of wild plants and animals we may be saving our own. Time is running out. We can no longer remain spectators. We need to think globally but act locally, rededicating ourselves to protecting biodiversity in forests, coastal ecosystems and in our own neighbourhood.

(Dr. S. Balaji is an Indian Forest Service officer belonging to the Tamil Nadu cadre and is an expert in biodiversity assessment. He is Chief Conservator of Forests, Chennai. He is at balajisrinivasagopalan@gmail.com)

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Printable version | May 15, 2021 9:35:29 PM | https://www.thehindu.com/opinion/lead/Biodiversity-challenges-ahead/article16303691.ece

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