The forests are composed of the birch, oak and other deciduous trees, the soil is dry, and the woodlands are divided by green prairies.
The war in Achin did not materially retard the development of Sumatra, and although the titular sultan of Achin continued a desultory guerrilla warfare against the Dutch in the mountainous woodlands of the interior, the almost inaccessible Pasei country, really active warfare has long ceased.
Its chapadas are covered with extensive campos, its shallow valleys with open woodlands, and its deeper valleys with heavy forests.
The Paraguay basin is covered with extensive marshy tracts and open woodlands, the palms being the conspicuous feature.
A very beautiful stag (shika), with eight-branched antlers, inhabits the remote woodlands, and there are five species of antelope (kamo-shika) which are found in the highest and least accessible parts of the mountains.