Gland, Switzerland – Wildlife conservation experts raised the alarm on Monday about an Indonesian forest where a record number of plant species are under threat from logging.

WWF International called for the tropical forest of Tesso Nilo, one of Sumatra island's single largest remaining areas of lowland forest, to be designated a protected area.

According to a field survey by the organisation, the forest harbours the "highest level of lowland forest plant biodiversity known to science". However, WWF warned it could be lost in less than four years.

The 1,800 square kilometre forest was found to have nearly twice as many species of vascular plants, visible plants with stems and leaves, than elsewhere in Sumatra. It is also home to elephants, tigers and gibbons among other wildlife.

Logging in Tesso Nilo is part of a pattern across Indonesia where companies are removing forests for a small fraction of their economic potential and without regard to their biological value, WWF said.

Illegal, small-scale logging is also going on, and the Indonesian authorities have pledged a crack down on the trend, WWF pointed out. Illegal logging is a complex issue, involving a number of parties, including communities, bureaucrats, military personnel and global market interests, it added,

"Indonesia has a rare opportunity to make an invaluable contribution to conservation, which the global community would certainly welcome," Claude Martin, WWF's director-general, said in the statement.