What is the value of a tree? Biologist, Professor T M DAS suggests $710,260 over a 50-year life-cycle

The value of a tree was published by the present author in 1979 in the Indian Biologist in Vol. XI, No. 1-2, pp 73.79. For the first time, the intrinsic value of a tree was determined based on various environmental benefits and services derived from a tree during its lifespan of 50 years and its amount was $196,250 calculated at the market rate that prevailed in 1979.

When we estimate the conventional value of a tree we only count the total weight and quality of timber or fruit or biomass it produced and that could be sold in the market.

It was noted in the aforesaid 1979 calculation that all these together hardly make about 0.3% of the real value of a tree. Other benefits that are being derived from the tree in our society are totally overlooked. If we count these items at the prevailing market price in 2012, the value of a tree would be increased more than 20 times.

In 1981 the value of a tree was elaborately presented in the Presidential Address delivered by the present author in the Agricultural Sciences Section in the 68th Session of the Indian Science Congress at Varanasi. It received worldwide attention and the summary of the paper was reprinted and cited in reference books of related subjects including books on accountancy, and journals published by the United Nations Organisation. In those papers Indian Currency was converted in Dollar, Pound and Yen etc. and gave wide publicity through posting permanent exhibitions in forests Reserves. Botanical Gardens, Zoological Gardens, Museums of most of the countries.

In the field of accountancy, a special branch of Social Accountancy and Corporate Social Reporting got incentives from this calculation for determining the social value of natural resources (Chattopadhyay 2000).

In 1983, the Film Division of the Govt. of India made a documentary film entitled ‘Services of a Tree’ which was widely acclaimed and received the First Prize at the International Documentary Film Competition in Spain. In the body of the original paper, it was supposed that the estimated value would not be a constant figure, it may increase with increasing price of oxygen, cost of energy and other inputs in 1991, Australian Horticulturalist Nancy Beckham published a comprehensive review on the subject in the Indian Biologist (1992).

Over three decades subject matter specialists of various disciplines such as Botany (Plant physiology), Zoology, Environmental Sciences and amateur environmental activists have been increasingly urging for updating for the valuation of a tree. Accordingly, all the calculations of the original papers have been revised as per current market rate (accepting the minimal level/rate of 2012 prices).

During 50 years of growth Original (1979) Revised (2011- 12) Production of oxygen $ 31,250 $ 10,500 Conversion to animal flesh & bone $ 3,000 $ 3,000 Controlling of soil erosion & soil fertility $ 31,250 $ 10,000 Recycling of water and controlling humidity and Air temperature $ 37,500 $ 154,560 Sheltering of birch, squirrels & insects $ 31,250 $ 129,700 Removal of SPM. CO2, SO2 from air $ 62,000 $ 402,500 Grand Total $ 196,250 $ 710,260

A Pipul tree which grows luxuriantly with an average weight of 6 tonnes in India and South-East Asia has been chosen as an icon and its various environmental benefits received during its 50 years of growth have been valued at rupees three crores fifty-four lac in this revision work.

This estimation is also applicable to other tree species with identical tonnage.

As in the original paper (and its revised versions), the value of timber has been omitted in this calculation.

The result of the revised figures is depicted in Table 1 including the figures of the original calculation:

Details of Calculation 1. Production of oxygen

Average weight of a full-grown tree of 20 years (e.g. Mango. Aswatha, Jackfruit, Neem and Arjuna trees) Weight of trunk with branches 3.5 Tonnes Weight of root system 0.5 Tonnes Weight of young twigs with leaves 0.5 Tonnes Total Weight 4.5 Tonnes

Fixation of 1 Mol. of CO2 = Release of 1 Mol. of O2 Total weight of oxygen produced = 4.5 Tonnes Cost of oxygen @ $1.40/kg = $6,300

For coming 30 years production of branches

Young twigs and leaves approx. = 100 kg/year would be 3 Tonnes Cost of oxygen production = $4,200 Value of total oxygen production = $10,500 for 50 years Gross weight of the 4.5 + 3 = 7.5 Tonnes Shedding of leaves during 50 years = 5 Tonnes Net weight of tree after 50 years of growth = 6 Tonnes

  1. Conversion to animal flesh and bones

Conversion to 10kg of animal flesh and bones in a pair of goat kids per year. In 50 years the cost of meat @ $6/kg would be as follows the total value of meat would be 50 years x 10kg x $6 = $3000 3. Controlling of soil erosion and soil fertility Annual net benefit (including the value of organic matter) would be $200 per year. In 50 years it would amount to $ 10,000. 4. Water recycling through transpiration Capital expenditure Capital Expenditure

2 pcs. ½ HP pump – $ 120 Cost of land & construction of shade (including installation cost) – $ 3,000 Total – $ 3,120

Maintenance cost

Salary of 2 operators $ 200 p.m. x 12 x 50 (24 hours duty) $ 120,000 Electricity charge

@$ 0.08/unit 1 unit per hour (24 x 30 x 12 x 50 x 0.08) $ 34,560

Total $ 154,560 5. Sheltering of birds, squirrels, insects etc. Capital expenditure

Construction of cages with = $ 2,500 cost of land

Salary of 1 expert @ $ 120 p.m. Salary of 1 helper @ $ 80 p.m. Total salary for 50 years $ 120,000

Food for animals & insects @$ 0.40 /day (0.40x30x 12×50) $ 7,200

Total $ 129,700 6. Removal of SPM, CO2, SO2 from air Capital expenditure

Cost of two mega-size high volume sampler, with installation, along with setting up of a chemical system for removal of CO2, SO2 after filtration of SPM from ambient air.

Two high volume sampler $ 4,000 Installation clunk $ 2,000 Total $ 6,000

Recurring expenditure

for running the system for 24 hours Monthly

Salary of two technicians (@$ 200 p.m.)

Salary of two helpers (@ $ 100 p.m.)

Total $ 600 per month x 12 x 50 = $360,000

Consumption of electricity

Cost of 1 unit per hour @ $ 0.08 for 24 hours the cost is approximately $2

For one year 365 x 2 $ 730 For fifty years $ 36,500 Total of capital and rewiring expenditure: = $ 402,500 ($ 6,000 + $360,000 + $36,500) How much oxygen we consume?

Each adult person inhales about 16 kg of air per day which contain minimum 3 kg of oxygen (20% of air) current market value of this amount is $ 4.2 (@ $ 1.4 per kg). Thus, Indian population of over 120 crores consume 120 x 3 kg crores of oxygen per day cost of which I20 x 3 x 210 = Rupees seventy-five thousand fifty-six hundred crows (75,600 crores) per day corresponding value in West Bengal population (9 crones) would be 9 x 3 x 210 – Rupees five thousand six hundred seventy crores ($ 5,670 crofts) per day.

In the animal world, other than human beings a colossal amount of oxygen is consumed in respiration. During combustion process of fossil fuels in industry and transport, a huge amount of oxygen is consumed along with burning fuel woods for cooking purposes. Nearly 50% of Indian population approximately consumed I ton fuelwood per capita per year; considering the average weight of the tree is 5 tonnes (with small & large trees) hence the total number of trees burnt per year in India is around 12 crams per year.

All such consumptions of oxygen are coupled with productions of carbon dioxide (CO2), carbon monoxide (CO), sulphur- dioxide (S02), oxides of nitrogen (NO2NO) and suspended particulate matter (SPM) etc. and these processes leading to changed composition of air arc silently counterbalanced by green plants in various ways.

During the process of photosynthesis molecules of glucose and other carbohydrates are synthesized, besides the release of free oxygen. Some amount of oxygen is also used up by the tree an amount for greater than the rate of oxygen consumption is released to the atmosphere for the respiration of animals and thus maintaining the oxygen balance of the atmosphere.

According to P. H. Raven, Director, Missouri Botanical Gardens, a disappearing plant species can take with it 10 to 30 dependent species, such as various species of insects, higher animals and even other plants.

When a tree is cut down the damage that inflicted is rather permanent in nature and cannot be recovered immediately. What is more significant, it is not a personal loss. It is a loss to the whole community, every individual of the locality would have to share this loss, the magnitude of which is still unknown to them.

The forest, the natural habitat for trees has been shrinking at an ever-increasing rate. A detailed critical survey indicates that the world’s original tropical rain forest had already been reduced by more than 40 percent in 1970 to the total area of 935 million hectares and that they are shrinking by about 11 million hectares each year. In India, such shrinkage had been more than 60 percent during the last 100 years and unfortunately, the major portion of such destruction was made after their independence.

In future, such process of destruction of the forest will with all probability continue because of the irresistible pressure on land by the ever-increasing abnormal growth of human population. How much green coverage do we require for our survival?

The whole animal world including human beings is totally dependent on the solar energy that is harvested by green plants. It is important as well as alarming to note that of the total amount of solar energy captured by the green plants 80% is consumed by the plants themselves microbial organisms also consume a significant portion of it. Animals do not cat entire plant but only fruits or leaves. Thus, only about 1% of the total energy captured by the green plants would be available to the animal world.

Hence survival ratio of green plant to animals is 99:1 i.e., to survive one part of animals including human beings would require 99 times of their body weight of green coverage in their surroundings. The animal population is increasing all the time. Every day about 3 lacs of human babies are born in the world which would require increasing green coverage 99 times to meet the increasing human population, but, an area of green coverage equivalent to 4 football grounds is vanishing every minute from the face of the Earth. We, therefore are fighting a losing battle. To win this difficult-to-win battle the only option left to us is the total halting of deforestation followed by multifold increasing activities of afforestation programme including the extension of green coverage in every nook and corner in rural and urban areas.

If the situation is allowed to continue, it will be our journey towards the unavoidable calamity of a population crash with the disruption of law and order which would surely be utterly disastrous.