Many plant eco-systems are ancient. The tropical forests came up some 45 million years ago. They have faced several vicissitudes, expanding and retreating they have faced the nature's vagaries and survived. However, tropical forests whether evergreen rainforests or deciduous mountain forests are being hacked to make room for ever increasing human population. Will they survive the axe of the humans and give us the life supporting oxygen or not is a question that all of us do ponder upon.

William F. Laurance of Smithsonian Tropical Research Institute, Panama, and USA carried out a systematic study of trends of forest loss, population size and corruption within 12 countries that contain bulk o the large Asian tropical forests. He published his findings in a recent issue of Current Science, India. Here is a report.

William takes Southeast Asia, South Asia and island of New Guinea As Tropical Asia. This region he says has the highest biodiversity and species endemism found anywhere in the world. This is a peculiar region, because it has been formed through the geological processes over the past millions of years and witnessed colliding continents resulting to an admixture of biota from distant lands, Laurasia and Gondwana. The dense forests of this region offered one of the best habitats for many of the living beings, including us though initially. It is the variety of fauna and flora that make this region distinct and special from others.

It is unfortunate that the forests of tropical Asia are amongst the most threatened on earth. It is worth mentioning here that during the time of Alexander's reign his soldiers refused to move south beyond Indus River towards the Ganga plains, as they knew that the area is covered by a dense forest. Even as late as 1850 the corridor between Delhi and Kanpur was such a dense forest that people were scared to enter even in the day light. Because hardly day light reached there!

Alas, those lush forests are gone now. Of course we need crops too, but what hurts is that now green agricultural fields are being taken over by concrete roads and forests of concrete.

The scenario had changed so drastically according to the study of William's that by 1990 58% to 25% tropical forests was present in America and Africa respectively against 18% in Asia. The tropical forests of Asia were deforested at a rate of 0.8 to 0.9% per year. On the contrary, America and Africa faced deforestation at a rate o 0.4% to 0.5% respectively. The rate of industrial logging happens to be so high in Southeast Asia that by the end of the century it could lose its entire forest cover, says N.S. Sodhi, as Associate Professor in Museum of comparative Zoology, Harvard University.

Forests are a major 'sink' for the greenhouse gases. Historical records show that vast tracts of forests were hacked to make room for the agriculture. S. Zhao of Institut des sciences de l'environnement, D?partement des sciences biologiques, Universit? du Quebec ? Montr?al, Canada and his co workers from China came out with a publication in 2006 in the Journal, Ecological Research proving that more than 50% of Asian land is under agriculture. Consequently in parts of Southeast Asia has faced highest rate of forest deforestation. Many of the world's large rivers and lakes in Asia have been heavily degraded. Asia has about 11 of 19 mega cities of the world with more than 10 million inhabitants. It is imperative that such vast land use changes have disturbed the ecological balance of the region. Carbon emission had already gone high. In 1995 it had been estimated that 43.5 billion metric tons of atmospheric carbon are being released annually. We know that forests are the largest carbon 'sinks'. The changed land use demanded hacking of the forests. Reducing environmental degradation and maintaining sufficient forest cover are challenging tasks.

William evaluated changes in forest cover of 12 Asian countries, viz. Bangladesh, Cambodia, India, Indonesia, Laos, Malaysia, the Philippines, Papua New Guinea, Sri Lanka, Thailand and Vietnam. In this huge study smaller countries with less than 10, 000 sq km area, and predominantly non-tropical countries like China and Australia were excluded.

A grim picture of changes in the forest cover emerged. It was found that Bangladesh has just a 10.2% of its estimated original cover, whereas Philippines and India have just two-tenths, i.e. 19.4% and 21.6% respectively. Thailand, 28.9%, Sri Lanka 30.0% and Vietnam 30.2% each has about three tenths of their original cover. Forest cover is higher in Myanmar, 52.3%, Cambodia 52.9%, Laos 54.4%, Indonesia, 58.0%, Malaysia 58.7% and Papua New Guinea 67.6% says William.

It is an irony that at present the forest rich nations are losing forests at a faster rate than those with already dwindled cover. For example, Bangladesh, India and Vietnam are experiencing a change in forest cover (either gain or loss) at a rate of +1.3%, +0.1% and +0.5% respectively says William. Comparatively forest rich Indonesia and Malaysia are losing their covers at a rate of -1.2% year-1 and the same is the case of Sri Lanka and Myanmar (-1.6%-1 and -1.4%-1 respectively). Amongst the countries studied by William, Philippines stands apart. Despite being forest poor the rate of loss is on the much higher side, -1.4%-1. Compared to these, Thailand and Cambodia show an intermediate loss of forest at a rate of -0.7% year-1 and -0.6%year-1respectively. Laos and Papua New Guinea stand out in contrast with the lowest rate of forest loss at -0.4% year-1. 

Why these countries show varying rates of forest loss? William attributes this to population density and economics and corruption.

There is a negative relationship between the population density and forest cover. Higher the cover greater is the loss of forest as found by William in his study of 12 Asian countries. He has also established that the forest depletion rate is also directly proportional to population growth rate. Citing UN median projections he says that the present population of 1.87 billion these 12 nations is expected to rise to about 2.4 billion in the year 2030 and to about 2.6 billion in 2050. Countries like Cambodia, Laos, Malaysia and Papua New Guinea are showing fastest. Densely populated Philippines are also growing rapidly but hyper-populous nations like India and Bangladesh have very high growth rates.

Using Corruption Perceptions Index (CPI) and population growth rate during 1990-2000 he says that in Bangladesh, India, Indonesia, Myanmar, the Philippines, Papua New Guinea, Sri Lanka and Vietnam corruption is severe in these countries. Corruption is highest in poorest countries. Outcome is in evitable because forests are a commodity that has been illegally exploited to earn a quick buck. 

A redeeming feature about India and Sri Lanka he has observed that traditional practice has helped the survival of some large wild life species in densely populated areas. In addition good environmental laws and religious practices have helped in felling of trees and killing wild life. In contrast areas of Indonesian Borneo, Sumatra and New Guinea are being colonized via transmigration programme. Such settlements ignore the traditional societal customs and taboos on felling of trees and hunting. In short older and stable cultures have a positive role on floral and faunal conservation.

All to all it's a complex and vicious cycle. More population and less growth rate lead to corruption and the brunt of which is faced by the forests. In order to save the forests of India a multipronged effort on part of the society and government would certainly help. Population control, reducing the gap between employed and unemployed and strict imposition of forest conservation rules will at least help further deterioration of the situation.

If proactive steps are not undertaken to save the forests, it is a big possibility that both oxygen and water may have to be imported to survive! Can we survive such situation?