Both second-growth and agroforestry systems (AFs) have the potential for recovering thousands of abandoned pasturelands in Amazon. The AFs may do it faster and, at the same time, produce direct economic benefits for farmers. Improved nutrient recycling may be expected due to distinctive litter production in AFs, but lacks experimental data yet. The stocks of carbon and nutrients of the litter layer under different agroforestry systems (AFs) were investigated at an abandoned pasture site, 60 km north of Manaus. The experimental design consisted of three blocks, with five treatments: four different types of 5-year-old AFs and a secondary forest (CAP). Litter layer was sampled in the wet and dry seasons, sorted according to the predominant plant species and analysed for carbon and nutrient concentrations. The litter layer in the control plots was much larger than in the AFs, and thus, the carbon stocks in the litter layer of the control (wet = 489 g m 2 ; dry = 783 g m 2 ) were larger than in the AFs. However, due to a clearly higher concentration of nutrients in the litter from the AFs, some nutrient stocks were similar or even greater than in the control. The planted timber species and the green manures were important sources of K and Ca to the litter layer while the peach-palm was an important source of Mg. In general, the litter of AFs had lower C:nutrient ratios than the litter in the secondary forest control, indicating a faster nutrient recycling in the AFs.

-The mesofauna has an important function in the soil and it is represented mainly by Acari Oribatida and Collembola. We report the fi rst 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 identifi ed. 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 infl uenced 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 general patterns of the soil macrofaunal communities in the most common land use types (i.e., primary forests, rice crops, pastures and fallows) of the Brazilian Amazon are summarized. Modifications in the abundance and species diversity of communities according to land use changes and scales are particularly addressed. Also presented are case studies conducted in Benfica and Maraba (Para), Manaus (Amazonas) and Acre-Rondonia, illustrating the large and interregional variations of geological substrate, climate and land use impacts on macroinvertebrate communities.

Amazonian Dark Earths (ADEs) are fertile anthropic soils found throughout Amazonia, resulting from long-term occupation by pre-Columbian societies. Although the chemistry of these soils is well known, their biodiversity, particularly soil invertebrate communities have been neglected. To address this, we characterised soil macroinvertebrate communities and their activities in ADEs, comparing them with adjacent reference soils under forests and agriculture, at nine archaeological sites. We found 667 morphospecies and a tenacious pre-Columbian biodiversity footprint, with 40% of species found exclusively in ADEs. Soil biological activity was higher in ADEs than in adjacent soils, and associated with higher biomass and richness of organisms known to engineer the ecosystem. We show that these habitats have unique species pools, but that contemporary land-use causes nutrient loss and threatens their diversity. Both past and present human activities alter biodiversity and its distribution in Amazonia, and further efforts are needed to recognize and preserve these ADEs and their biodiversity.

La densidad (individuos/m2) y biomasa (g de peso fresco/m2) de la macrofauna del suelo, fueron estudiadas en las áreas de varillales y chamizales de una parte de la Amazonía peruana. El estudio fue desarrollado en el Centro de Investigaciones de Jenaro Herrera (CIJH), 200 km sur oeste de la ciudad de Iquitos, en la margen derecha del río Ucayali, y en la Zona Reservada Allpahuayo-Mishana, situada en el km 29 de la carretera Iquitos-Nauta.El método de muestreo utilizado fue recomendado por el Programa «Tropical oilBiology and Fertility» (TSBF), y se realizó en los meses de marzo (época lluviosa) y setiembre (época de menos lluvias) del 2001. En cada sistema se colectaron 3 muestras, a un intervalo de 5 metros a lo largo de una línea recta cuyo origen y dirección fue escogido al azar, y la macrofauna fue separada en forma manual en monolitos de 25 cm x 25 cm x 30 cm.En los varillales del CIJH se encontró una densidad poblacional de 1 611 a 2 781individuos/m2 y una biomasa de 30.3 a 42.7 g peso fresco/m2 en la época luviosa y menos lluviosa, respectivamente. En la Zona Reservada de Allpahuayo-Mishana, la densidad fue de 10 209 individuos/m2 en la época lluviosa, y 768 individuos/m2 en la época menos lluviosa. La biomasa tuvo un rango de 236.9 a 96.2 g de peso fresco/m2 en las dos épocas de muestreo.La densidad poblacional en los chamizales de Allpahuayo-Mishana fueron de 670a 1 179 individuos/m2 y una biomasa de 31.5 a 100.0 g de peso fresco/m2 en la época lluviosa y menos lluviosa, respectivamente. En el CIJH se encontró una densidad de 1 728 a 4 205 individuos/m2 y la biomasa estuvo en un rango de 31.3 a 42.0 g de peso fresco/m2, en las mismas épocas de muestreo.

The conversion of natural forests into pastures or crops involves a drastic change, damaging in the natural forest succession and leading the systems for the early stages of immaturity, simplicity and instability. The degradation of ecosystems is associated with the loss of biodiversity and the ecosystem services it provides, therefore, it is necessary to know soil biodiversity, in order to generate knowledge and develop more sustainable practices. The goal was to determine the structure of communities of soil organisms and the soil nutrients and identify their contributions to ecosystem services in land use systems Tarumá-Mirim settlement, in the municipality of Manaus, Brazil. The greater abundance of macroinvertebrates soil was found in diversified agroforestry systems, which led to better conditions in the nutrients and the organic matter for to the colonization of soil organisms, mainly termite and earthworms, providing favorable chemical properties for the soil fertility and the increment of the nutrient cycling in the ecosystem.

La caracterización y la abundancia de la macrofauna del suelo y su relación con la morfología del suelo, fueron evaluadas en áreas de fragmentos forestales de bosques secundarios en el Centro para la Biodiversidad y el Turismo del Amazonas, del Servicio Nacional de Aprendizaje - SENA, en Leticia, Amazonía colombiana. La macrofauna del suelo (invertebrados mayores o iguales a 2 mm de diámetro) fue evaluada en dos períodos estacionales (mayo y octubre) con diferentes registros de precipitaciones. Fue encontrado una abundancia total de 5332 individuos de la macrofauna del suelo, distribuidos en 14 órdenes taxonómicas. El fragmento forestal conservado (FFC) fue el área que registró una mayor diversidad florística, y presentó la mayor densidad de la macrofauna del suelo en ambos periodos de muestreo. Los grupos de insectos Isoptera y Formicidae, fueron predominantes, sobre todo, en el FFC. Las comunidades de macrofauna del suelo no detectaron correlaciones significativas con las variables de la morfología del suelo en los fragmentos forestales. Sin embargo, esa correlación se mostró significativa entre los dos periodos de muestreo, indicando que la estacionalidad de la pluviosidad puede afectar la densidad de la macrofauna del suelo dependiendo del periodo de muestreo.