Climate change and Agricultural Biodiversity

সেউজী ধৰণী

অতিথী চ’ৰা

Climate change and Agricultural Biodiversity

Dr. D.N. Chakravarty

Biodiversity is the source of the plants and animals that forms the basis of agriculture and the immense variety within each crop and livestock species. Countless other species contribute to the essential ecological functions upon which agriculture depends. Worldwide there is now a huge diversity of agricultural system ranging from paddy varieties of Asia to dryland pastoralsystems of Africa and hill farms in the mountain of South America. Of the 27,000 species of higher plants, about 7000 are used in Agriculture. Animal and insects pollinate approximately 80% of angiosperms which amount to about 300,000 flower visiting species.

However, the Earth’s biodiversity is being lost at an alarming rate, putting in jeopardy the sustainability of ecosystem services and agriculture and their ability to adapt to changing conditions. As custodians of land and natural resources, including biodiversity, farmers and agricultural scientist manage agricultural biodiversity and their landscapes. They are allies in global effort to manage biodiversity better.

According to FAO about 7000 species of plants have been cultivated since human first began farming. To-day, only 30 crops provide an estimated 90% of the world population’s dietary energy requirements, with wheat, rice and maize alone providing about half the dietary energy consumed globally. Of the estimated 15,000 species of mammals and birds, only some 30 to 40 have been domesticated for food production and less than 14 species including cattle, goats, sheep, buffalo and chickens accounts for 90% of global livestock production. FAO data indicate that during the past six years, a breed has been lost each month.

Many modern practices and approaches to intensification aimed at achieving high yields include use of monocultures with reduction in cropping diversity and elimination of rotation, use of HYV and hybrids with loss of traditional varieties and diversity together with the need for high inputs or inorganic fertilizers, control of weeds, pests and diseases with chemical pesticide than mechanical or biological methods.

Land and habitat conversion to large scale agricultural production, including drainage of land and conversion of wetlands has also caused significant loss of biodiversity. The homogenization of farming landscape with elimination of natural areas to achieve large scale mechanized production has also lead to decline in biodiversity and ecological spots.

The increased demand for animal feed puts increased pressures on cultivated systems, with consequently an increased demand for water and nitrogen, other fertilizers and chemical pesticides inputs. Emphasis on modern system on quantity of yield has led to selection and breeding for high production and loss of traditional breeds that held other traits, qualities and adaptation, now lost.

Thus human activities are driving the loss of biodiversity at an unprecedented rate, up to 1000 times than natural rate of species loss. All the achievements on higher productivity are being done without major regards to the erosion of biodiversity.

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Writer is Retd. Dean (Agri.) AAU and presently      Director, NEOLAND Technologies, Guwahati-24;                       Cell-94351 16605; E-mail: neoland123@gmail.com