The Assam forest department is fighting a "losing battle" against the fast depleting forest cover in the state. The Principal Chief Conservator of Forest, Mr P Lahon, told the Statesman today that the state had lost 147 sq km of forest cover in the last two years. Assam has nearly 18,000 sq km of reserved forest area. While "unclassed state forest" comprise a little over 9,000 sq km , "proposed reserved forest" covers an area of nearly 4,000 sq km.