Resumo Na Amazônia, na região do rio Negro, os solos de areia branca dispersos com sua vegetação associada, conhecida como campina amazônica, podem ter influência considerável sobre a ecologia total dos sistemas de rios de água preta. Este trabalho apresenta uma descrição da vegetação lenhosa de uma campina amazônica e de sua campinarana associada. Para que essa vegetação seja melhor interpretada, os autores opinam em considerá-la dividida em dois tipos: campina e campinarana. A campinarana, por sua vez, é subdividida em dois subtipos: campina aberta e campina sombreada. A estrutura e a composição da vegetação de cada tipo ou subtipo foram estudadas com detalhes. Com base no testemunho de sua vegetação, os autores concluem que a campinarana representa uma vegetação em clímax.

Summary Throughout Northern Amazonia, and especially in the Rio Negro region, scattered white sand soils and their associated vegetation, referred to as campinas amazonicas, may have considerable influence on the overall ecology of blackwater river systems. This paper presents a description of the woody vegetation of one campina and its associated campina forest (campinarana), in Central Amazonia at km 62 of the Manaus-Caracaraí road. The term "campina" is here used to describe a vegetational type which occurs in readily discernible clusters, forming islands or peninsulas which are surrounded by or adjacent to relatively open areas of bare sandy soil. The tallest campina trees never reach 10 m in height, and the canopy (where one exists) is rarely continuous over a large area. The authors believe that the campina vegetation is best understood by dividing it into two distinct sub-types: "sun campina" (campina aberta) and "shade campina" (campina sombreada). Sun campina consists of islands of vegetation, each island with an area smaller that 1 m2, over which the canopy cover is less than 50%. Shade campina refers to islands or areas of vegetation larger than 1 m2, over which the canopy cover exceeds 50%. These latter definitions are somewhat arbitrary and, as we lack a quantitative phytosociological, analysis of campina, vegetation, they should be considered tentative. However, within the particular campina under study, they do correspond rather well to areas of vegetation with significantly distinct structure and composition. The term "campina forest" is applied here to a vegetational type which occurs adjacent to the campina and on similar white sandy soil. The vegetation of the campina forest is generally taller than that of the campina, with individuals often exceeding 10 m in height. Within the campina forest, the vegetation is likewise more continuous: isolated clusters of taller trees may still be discernible, but the intervening expanses of sand here become colonized by younger trees and shrubs. The vegetational structure of the sun campina, shade campina, and campina forest are examined in detail. These three vegetational types or subtypes form a successional sequence which proceeds from sun campina to shade campina to campina forest. On the basis of vegetational evidence, the authors conclude that the campina forest represents a successional climax.