Valuing the forest ecosystem

September 17, 2016 12:00 am | Updated November 01, 2016 07:06 pm IST

A new study by scientists K. Ninan and Andreas Kontoleon reveals that the Nagarhole National Parkprovides millions of dollars worth of ecosystem services to the country, says M.A. Siraj

the parkis home to 32 species of large mammals and 252 species of birds

the parkis home to 32 species of large mammals and 252 species of birds

The contribution and value of forests has been fairly well-known. But the evaluation of forests in economic and financial terms is a recent discipline that has come to the fore. It can enable policy planners to weigh the pros and cons of diverting a forest land for non-forest uses. Beginning from the Silent Valley in Kerala (1972), the nation has witnessed a series of debates and conflicts over preserving or clearing a particular piece of forested land while envisioning development projects. While the government/s try to relax laws pertaining to forests in such areas, green activists are seen contesting the official plan. Most such debates, however, were reduced to two monologues (instead of a dialogue). This is because there was a lack of definite yardsticks for measuring intangible benefits of, say, carbon sequestration or nutrient fixation. Similar hurdles were faced in evaluating disservices such as damage caused by wild animals or forest fires.

In a unique exercise, two environmentalists, Dr. K. Ninan of the Bengaluru-based Centre for Economics, Environment and Society (CEES), and Prof. Andreas Kontoleon of Cambridge University have computed the economic value of the services (as well as the disservices) rendered by the Nagarhole National Park to the ecosystem that serves a vast mass of population inhabiting the Western Ghats.

The authors have employed varying parameters, benchmarks, and yardsticks to arrive at the economic value of land, water, soil, carbon and nutrition fixations and have used all alternative methods to assess their value, leaving little scope for contestations.

Biodiversity hotspot

India is home to two of the 34 biodiversity hotspots in the world, namely the Western Ghats and the Eastern Himalayas. Statistics by the India’s State of Forest Report-2015 reveal that over 70 million hectares are classified under ‘forests’ that constitute 21 per cent of the geographical area of the country. The Nagarhole Park sprawling over 544 sq. km. is home to about 32 species of large mammals, 252 species of birds, 32 species of reptiles, 13 species of amphibians and 10 species of fish, several of them being on the list of endangered animals.

The economic value of the water stored in Nagarhole Park (at the rate of Rs. 0.03 per cubic metre) is calculated to be Rs. 12 million (or $ 0.20 million) per annum. Soil protection is an important function of the forests. The study estimates the Park’s soil protection value to be Rs. 8,108 million ($ 132.33 million) per annum. The duo have attempted an alternative assessment through estimation of avoided soil erosion in the event of the land not being under forests. Usually, a non-wooded land loses 3.5 tonnes of soil per hectare due to wind and rain erosion. Going by this yardstick, the Park conserves 225,187 tonnes of soil annually, the value of which is estimated to be Rs. 4.2 million ($ 0.07 million).

Carbon sequestration

Forests are known to store carbon and release oxygen and thereby harmonise the environment and render it habitable for living beings. Deforestation is a major contributor to greenhouse gas (GHG) emissions. It is estimated that between 12 to 20 per cent of GHG emissions are caused by deforestation across the world. The authors estimate that the Park helps to fix 37,934 tonnes of carbon annually whose economic values computed through three alternative methods works out to be $ 0.38 million, $ 0.76 million and $1.25 million a year.

The study, however, took into account carbon fixed above the ground biomass and left out the below the ground biomass and the forest soil due to practical difficulties.

Nutrient fixation

The study of litter, biomass, and forest soils reveal that they contain Nitrogen, Phosphorous, and Potash. Trees absorb mineral nutrients from the soil which they accumulate in their bodies which return to the soil through trees that wither, leaves that fall and branches that fall off.

The nutrient value accumulated by the Park is thus assessed at Rs. 24.41 million ($ 0.41 million) in a typical year, going by the rate of the green fertiliser (leaf manure) in nearby towns. The Park is stated to be cycling nutrient at a rate of 1,130 tonnes a year.

Purification of the air is perhaps the most notable contribution of trees to the environment. The two scientists estimate that the Park absorbs 695 tonnes of sulphur dioxide gas (S0 2 ) and 1,004 tonnes of Nitrogen Dioxide (N0 2 ), both of which are pollutants. It thus saves Rs. 116.93 million ($1.91 million) which is the cost of purification of air if it had been attempted through engineering abatement.

The villages in and around Nagarhole host a cattle population of nearly 60,000 heads of cattle. Each head consumes about 1,779 kg of green fodder or natural herbage a year through free grazing. By this yardstick, the Park offers free grazing opportunity whose value could be fixed at Rs. 195.76 million ($ 3.19 million).

The damages caused by wildlife and the forest fires and pests unleashed by the forests have been categorised under disservice by the Park.

Similarly, the fires that raged on 2080 hectares in three years (2011-14), led to emission of GHGs to the tune of 409 tonnes of carbon on an average in each of the three-year period.

The damage to the environment on this score is computed at $ 8,018 each year. Ninan Says that accumulated benefits accruing to the environment from the Nagarhole Park (value of services minus the disservice) total up to $ 80.5 million per annum or $ 1,248 per hectare per annum. Ninan suggests levying of an environment cess on those who benefit from the ecosystem services rendered by the Park.

The Report has been published in the August 2016 issue of the Ecosystem Services journal published by Elsevier, London.

Theauthor can be reached at maqsiraj@ gmail.com

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