A ban on felling of trees for commercial purposes has paid rich dividends in Himachal Pradesh in terms of increased forest cover and a spurt in the number of some of the endangered wildlife. About 20,198 sq km of the State's total geographical area of 55,683 sq km was now under forest cover and the Government wanted to increase it to 50 per cent of the total area by the end of the century, the State Forest Minister,Mr. Roop Singh Thakur, said here today.