The mesofauna has an important function in the soil and it is represented mainly by Acari Oribatida and Collembola. We report the first data on the density and diversity of the soil mesofauna in Benjamin Constant, Amazonas State, Brazil. The following systems were evaluated: primary forest, secondary forest, agroforestry system, cultivated areas and pastures. A total of 101 samples were collected 100 m apart from each other and specimens were collected by using Berlese-Tullgren method. The highest density was registered in secondary forest (29,776 specimens.m-2). Acari Oribatida was the dominant group (7.072 specimens.m-2) in the pasture, suggesting that mites show higher capacity of adaptation to disturbed environments and/or due to the presence of gregarious species. The density of Collembola (5,632 specimens.m-2) was higher in secondary forest. Formicidae was the dominant group (27,824 specimens.m-2) and its highest density occurred in the secondary forest (12,336 specimens.m-2). Seven species and ten morphospecies of Isoptera and three species of Symphyla were identified. The highest density and diversity were found in secondary forest. One supposes that the low density of mesofauna found in all of the studied systems is being influenced by soil structure and composition as well as litter volume. For SUT, the composition of taxonomic groups in the cultivated areas is similar to the one found in primary forest, while the groups found in the agroforestry system are similar to those in the pasture, which may help to decide on land use strategies.

As densidades (ind/m2) e biomassas (mg/m2) de grupos selecionados da macrofauna da liteira (isópodos, diplópodos c cupins) foram estudadas sob diferentes sistemas agroflorestais (SAFs) implantados em áreas de pastagens degradadas c abandonadas na Amazônia central. O estudo foi feito na Estação de Pesquisa Agroflorestal da EMBRAPA/CPAA, 70 km ao norte de Manaus, usando-sc três blocos ao acaso, com cinco tratamentos, em quinze parcelas de 3000 m2; cada bloco tinha quatro diferentes tipos de SAFs e uma capoeira (CAP), usada como controle, onde se manteve a regeneração natural existente. Os SAFs eram dois sistemas agrossilviculturais, um com base em palmeiras e outro mais diversificado, denominado multiestrato, e dois sistemas agrossilvipastoris, de altos e baixos insumos. Em cada parcela, foram coletadas 50 amostras da macrofauna da liteira, usando-se um quadro de madeira de 50 x 50 cm, nas estações chuvosa e seca. A densidade e biomassa da macrofauna foram maiores no SAF mais diversificado (multiestrato) e geralmente maiores sob liteiras de cupuaçu e palmeiras, destacando-se o grupo dos isópodos com as maiores densidades c biomassas, seguido pelos diplópodos, nos SAFs, e pelos cupins, na capoeira. Todos os SAFs apresentaram maiores densidades e biomassas da macrofauna do que a capoeira, indicando a formação de micro-sítios favoráveis à sua ação, devido à melhor qualidade da liteira produzida e/ou da abundância localizada de liteiras de menor qualidade produzida pelas diversas espécies plantadas. Os resultados sugerem a melhoria do funcionamento dos processos de reciclagem no solo e, assim, das perspectivas de sustentabilidade da produção.

The densities (ind/m2) and biomasses (mg/m2) of selected groups of the macrofauna in the litter layer (Isopoda, Diplopoda and Isoptera) under different agroforestry systems (SAFs) planted in areas of degraded and abandoned pastures in central Amazonia, were investigated. The study was carried out at the Agroforcstry Research Station of EMBRAPA/ CPAA, located 70 km north of Manaus, using three blocks with five treatments at random in fifteen plots of 3000 m2; each block had four different types of SAFs and a second-growth area (CAP), used as control, where existing natural regeneration was allowed to grow. Of the two agrosilvicultural systems, one was based on palm trees and the other more diversified, so-called multistrata; and of the two agrosilvipastoril systems, one had high and the other low inputs of fertilizer. In each plot, 50 samples of litter macrofauna were collected, using a 50 x 50 cm wooden frame, in the rainy and dry seasons. The density and biomass of the litter macrofauna were higher in the most diversified SAF (multistrata), and generally higher under “cupuaçu” and palm tree litters. Isopoda had the highest densities and biomasses, followed by Diplopoda in the SAFs and by tennites in the second growth. All SAFs presented macrofauna densities and biomasses higher than the second growth, indicating the creation of favorable habitats, due to either a higher quality of the litter produced or a higher abundance of localized litter of lower quality. The results suggest an improved functioning of the nutrient recycling processes in the soil, and sustainable productivity prospects of the agroforestry systems, especially the most diversified ones.