The forest reserves of the temperate zone in Eurasia and Nothern America as well as the tropical forests in South-East Asia and Africa re being reduced so strongly that within some time they wil be used up. Therefore the importance of the South-American forests enhances rapidly as these are till now hardly exploited at all, except for the Auraucaria-forests in Brasil and Argentina, the forests of the Chaco and few other types. The present work divides the South-American half-continent into 40 different forest regions. The rain forests of the Amazonas and Orinoco basins alone already are divided into 14 different regions. The boundaries of each region are shown and a short description of the climatic and the soil conditions is given. Maps and diagrams of the climate help to make it easier to understand these facts.