Mangroves, those ubiquitous and durable plants, are found along the coasts throughout most of tropical Asia. In some áreas, they grow in such profusión that even jungle conquerors like the U.S. Army Corps of Engineers found them impenetrable. But there are also great stretches where they will grow only sparsely. The reason for this lies not just in conditions at the seashore but in the composition of the great inland mountain ranges hundreds or even thousands of miles away. If the mountains are granite, which disintegrates into fertile mud on the long journey to the sea, mangrove jungles are almost certain to be found on the coast. But if they are sandstone, the unfertile silt left at the shore will not support massive mangrove colonies. A classic example is the Malay Peninsula, whose western coast harbors a steaming mangrove jungle while the wave-swept, sandy east coast is virtually barren.
