ANALYSIS OF GROWTH FROM TYPES AND FLORISTIC COMPOSITION OF THE SPONTANEOUS VEGETATION IN AN AGRICULTURAL TEST AREA NEAR MANAUS, AMAZONAS, BRAZIL

On a terra firme site near Manaus, Amazonas, an experiment in recultiv ating a fallow rubber plantation of 19 ha by establishing mixed planta tions of selected useful plants is being carried out. In 90 plots and 5 blocks (= redundant plots) different combinations of useful plants a re to be tested. This leads - necessarily - to a different management of the spontaneous vegetation, giving an option to study the impact of plot management on the useful plants. On the one hand, the spontaneou s vegetation can constitute competition for the crops (light, nutrient s, space), in which case it must be suppressed. On the other hand, the wild vegetation can be an important store for nutrients. Whether the latter function can be promoted in favour of the crops by appropriate control of the wild vegetation, is a question that is to be examined. Six months and one year after clearance, vegetation analyses were carr ied out to describe growth form structure and floristical composition. The results show vegetation patterns which are mainly dependent on th e pre-use of the sites, but there are still differences to be seen cau sed by recent plot management. Many of the over 300 plant species pres ent in the experimental area show a specific reaction to disturbance. The term ''disturbance'' is used here in accordance with GRIME (1979). The vegetation under study is proposed to fit into Grime's strategy c oncept. A classification of common species due to CSR-theory is theref ore possible and can be helpful to the understanding of vegetation pat terns.