New Delhi, Feb. 12: Dams in central India, bamboo flowering in the Northeast, crops and the tsunami of 2004 combined to shrink India’s forest cover by about the size of Bangalore, the latest national forest survey has revealed.

India’s forest cover declined by 728sqkm between 2003 and 2005, all of the loss being in the moderately dense forests while areas under very dense forest and open forest actually increased, the Forest Survey of India (FSI) said today. Bangalore covers about 740sqkm.

The loss of forests observed in the latest biannual survey follows an FSI claim of a 23,000sqkm increase between 2001 and 2003. But some ecologists had earlier criticised the FSI for underestimating forest loss from degradation because of faulty interpretation of satellite images.

The new survey also revealed discrepancies between government-recorded forest areas and actual cover. In Andhra Pradesh, Kerala, Meghalaya and Dadra and Nagar Haveli, 36 per cent of the forest area lay outside the government-recorded forest land.

Only 64 per cent of the 76,000sqkm of recorded forest land in these three states and the Union territory is actually under forest cover.

India’s forest cover stood at 677,088sqkm, or about 20.6 per cent of the country’s geographic area, during 2005, according to a survey based on analysis of satellite imagery and ground studies. “But if you exclude areas not available for forests, the forest cover is 21.8 per cent,” said Devendra Pandey, the FSI’s director-general.

Madhya Pradesh, Arunachal Pradesh and Chhattisgarh have the largest areas under forest cover, accounting for nearly one-third of total forests.

Nagaland recorded the largest loss of forest — 296sqkm — since the last survey. This loss is because of the flowering of bamboo in Nagaland and Manipur which caused the loss of 176sqkm. Dams caused the loss of about 120sqkm of forest in Madhya Pradesh and Chhattisgarh, while the sea claimed 196sqkm during the tsunami of December 2004.

Two years ago, ecologists from Delhi and Bangalore had published a research paper pointing out what they claimed were discrepancies in FSI figures and interpretations of satellite imagery.

But the FSI today said the accuracy of the assessment was more than 92 per cent.