A detailed land survey covering both vegetation and soils was carried out in Nicaragua and it was found that the five zonal vegetation formations were closely correlated to the length of the dry season. Numerous swamp and riverine communities were detailed, together with their environmental relationship as well as communities on mangrove areas, beach sands and a large group of salt-meadow communities. Pine and oak forests, pine savannas and two other savanna types were also described and their environmental relations discussed, the conclusion being reached that in each case the community concerned was disclimax. The various pasture types found were described and placed into major pasture groups. The course of plant succession on various volcanic deposits was outlines with the conclusion being reached in two cases that the rate of the succession was largely independent of the effect of vegetation. An outline was also given of the main hydroseres