INFLUENCE OF DIFFERENT CROPPING SYSTEMS ON THE DENSITY OF TERRESTRIAL INVERTEBRATES IN VARZEA SOIL OF CENTRAL AMAZONIA

The possible effects of cropping systems on terrestrial invertebrates and on soil physical characteristics (temperature and humidity) have been studied in varzea areas of the Terra Nova region. The habitats studied included: monoculture of cacao (Theobroma cacao) and of quiabo (Hibiscus esculentus); mixed cultures of manga (Mangifera indica), jambo (Eugenia malaccencis), acai (Euterpe oleracea), seringueira (Hevea brasiliensis), and banana (Musa sapientum) and a pasture; using a ''forest'' as control area. The methodology of Berlese-Tullgren was used with samples taken between March 1987 and March 1988. The analysis of the different biotopes indicated a dominance by Acari in the five habitats, with a greater percentage in the H. esculentus monoculture (86.52 %) and in pasture (80.50 %). Collembola is the second group, with an expressive density in the ''forest'' (27.52 %). The presence of Diplopoda and Isopoda in the T. cacao and H. esculentus monocultures (1.46 % and 0.64 %, respectively) is particularly important due to their role as primary decomposers in forest habitats.