I know from many years of personal experience in the Malaysian rainforest (Sarawak, Sabah and Peninsular Malaya) that it is not inflammable. Dayaks and aborigines cultivate small patches of shifting cultivation called ladangs, but the trees have to be felled and dried in the sun before they can be burned. No precautions are necessary to prevent the surrounding rainforest from catching fire.
Yet, I often hear of rainforest being burned on a vast scale, particularly in Brazil, and wonder how it can be rainforest if it burns so easily. Are these inflammable forests really rainforests, or are they being confused with monsoon forests which are dry for a large part of the year?
Another type of vegetation in Malaysia is what we call secondary jungle and Malays call belukar. It is a kind of thorny scrub which soon springs up on abandoned ladangs, and is probably easier to slash and burn than primary rainforest. Left for about 60 years, belukar becomes primary rainforest again.