ENVIRONMENT-INDIA: Experts Question Satellite Data On Forests

By Neena Bhandari Reprint | | Print |

Neena Bhandari

NEW DELHI, Apr 18 1998 (IPS) - Environmentalists say depleting forest cover over India may have less to do with grazing and population pressure than with new policies linked to liberalisation.

The Forest Survey of India (FSI) conducts biennial surveys through remote sensing and prepares reports on which planning for sustainable development can be done. But the accuracy of the imagery is now under question.

The sixth, “State of the Forest Report-1997” released recently, reveals a loss of 5500 sq km of forest cover since the 1995 assessment with major losses recorded in the states of southern Andhra Pradesh (3822 sq km) and central Madhya Pradesh (3969 sq km).

While the losses have been attributed by the report to growing human population, grazing pressure and greed for minerals, eminent environmentalists like Ashish Kothari think otherwise.

“In my assessment I have found no clear corelation between high population density, high incidence of grazing and high rate of forest loss. The simplistic assumption that population rise and grazing are the primary factors for forest loss, simply do not hold up to scrutiny,” he said.

The North- Eastern states, which have 67 per cet forest cover, have lost 316 sq km compared to the 783 sq km loss recorded in the 1995 assessment. The loss in the North-East is mainly attributed to the felling of trees and shifting cultivation.

Since liberalisation began in the early 1990s, there has been an increasing demand to relax the Forest Conservation Act or otherwise make easier the clearance of forest land for ‘developmental’ activities.

The land released for non-forestry purposes show an upward curve. In addition, a lot of forest is probably being taken over without reference to the Central government, due to the new policies and to the increasing power of state governments in centrally-ruling coalitions.

While the National Forest Policy of 1988 aims to have a minimum of one-third of the geographic area of the country under forest/tree cover, only 19.27 per cent of the country can be so described.

There has been a net decrease of 17,777 sq km in dense forest cover over the country while open forests and mangroves have increased by 12,001 sq km and 294 sq km respectively in 1997 as compared to the previous assessment.

Even in Maharashtra which shows a significant 2300 sq km increase in forest cover, the figures are no cause for celebrain and are, in fact, alarming, says Kothari.

“The analysis seems to suggest that the major loss has been in the dense forest category, which means that the situation is worse – it is not the degraded forests we are losing, but the good ones,” he said.

” Also, the trend towards decreasing forest loss (and even increasing forest cover), which had been shown in the two or three previous assessments, has been halted, and we are back to major forest losses.”

The report defines dense forests as forests with a canopy density of 40 per cent and above and open forests as those with a canopy density of between 10-40 per cent.

Scrub forests are lands with poor tree-growth consisting chiefly of small or stunted trees with a canopy density of less than 10 per cent while mangroves are salt-tolerant forest ecosystems found mainly in tropical and sub-tropical inter-tidal regions.

The report covers 437 out of 540 districts using data procured from the National Remote Sensing Agency in the form of False Colour Composites, which are interpreted visually/digitally and then followed up by extensive ground verification.

Leading environmentalist, Shekhar Singh says the methodology is faulty on several points starting with th fact that canopy is not the best indication of the health of forests.

Old trees may have good canopies, but if there are no new plants or grasses then it is considered a dead forest, though remote-sensing will show it to be a perfect forest.

Remote sensing imagery also does not distinguish plantations from natural forests. “Since the data does not match reality on the ground, the accuracy of statistics is questionable,” Singh said.

Programme officers at the Forests and Wildife division of the World Wide Fund for Nature-India say it is not easy to decipher the data and that increase, decrease or stability in statistics may not reflect the true picture.

The growing stock assessment of forest resources cannot be done without intensive field inventory. Since assessment of forest cover is based on satellite data, it is difficult to differentiate between natural forests and plantations.

Also, considerable detail may be obscured in areas having clouds and shadows. The SFR report for the first time provides information on the forest cover situation in the hill and tribal districts of the country.

The National Forest Policy says two-thirds of the area in the hills should be under forest cover in order to prevent erosion and land degradation. But out of the 98 hill districts in the country, only 19 districts have the stipulated cover.

The tribals constitute 8 per cent of the total population spread across 149 tribal districts but the report furnishes forest cover information for only 137 districts.

It is revealed that the total forest cover in the tribal districts as per 1997 assessment is 417,174 sq km which constitutes 65.86 per cent of the total forest cover. The average forest cover is about 35 per cent of the area of the tribal districts.

The FSI, in the recent past, has started surveys of plantations outside conventional forest areas keeping in view the important role played by social forestry in meeting fuelwood, timber and raw material for wood- based industries.

Kothari feels the report suffers the same shortcomings that all aggregate national surveys do such as the fact that it is not site-specific.

For instance, he says, if forest area has been increasing prior to the current estimate (or at least if the rate of loss has been decreasing), then is it because of good protection of standing forests or regeneration of degraded lands and plantations?

“I suspect that a substantial part of the gain is due to plantations, but then most plantations in India are not multi- species, and can in no way compensate for the loss of natural forests,” he said.

Even if they were multi-species, they would not be able to fully compensate for the loss of forests. In other words, It is time the government stopped all further logging or diversion of good, standing forests.

“At least phase it out within the next 4-5 years – If Thailand could take such a decision, why can’t we?’

The FSI could render a more valuable service by making raw data available and involving NGOs working at the local level in random sampling, he said adding that satellite imagery without ground truthing cannot tell how or why forests are destroyed.