The civil war in Sri Lanka has taken its toll on the environment also. Millions of palmyrah trees have been destroyed in Sri Lanka's war-shattered northern province. Government officials say that about 2.5 million palmyrah trees have been felled by the army and the Liberation Tigers of Tamil Eelam, mainly to build bunkers and checkpoints. The trees are valuable because they prevent soil erosion and their fibre is considered harder than that of coconut trees, giving the trees a foreign exchange potential.