ESTUDIO PRELIMINAR DE LA MACROFAUNA DEL SUELO EN ÁREAS DE VARILLALES Y CHAMIZALES DE LA AMAZONÍA PERUANA

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

Caracterización de la macrofauna del suelo en fragmentos forestales en el municipio de Leticia, Amazonía colombiana

The characterization and the abundance of the soil macrofauna and its relation with the morphology of the soil, were evaluated in areas of forest fragments of secondary forests in the Center for Biodiversity and Tourism of the Amazon, of the National Service of Learning - SENA, in Leticia, Colombian Amazon. The soil macrofauna (invertebrates greater than or equal to 2 mm in diameter) was evaluated in two seasoning periods (May and October) with different rainfall records. A total abundance of 5995 individuals of the soil macrofauna was found, distributed in 14 taxonomic orders. The conserved forest fragment (FFC) was the area that registered the highest floristic diversity, and presented the highest density of the soil macrofauna in both sampling periods. The groups of insects Isoptera and Formicidae were predominant, especially in the FFC. The soil macrofauna communities did not detect significant correlations with the soil morphology variables in the forest fragments. However, this correlation was significant between the two sampling periods, indicating that the seasonality of the rainfall may affect the density of the soil macrofauna depending on the sampling period. 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.&nbsp

Mesofauna do solo em diferentes sistemas de uso da terra no alto Rio Solimões, AM

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

A“Dirty” Footprint: Macroinvertebrate diversity in Amazonian Anthropic Soils

International audienceAmazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia

Amazonian earthworm biodiversity is heavily impacted by ancient and recent human disturbance

Despite the importance of earthworms for soil formation, more is needed to know about how Pre-Columbian modifications to soils and the landscape. Gaining a deeper understanding is essential for comprehending the historical drivers of earthworm communities and the development of effective conservation strategies in the Amazon rainforest. Human disturbance can significantly impact earthworm diversity, especially in rainforest soils, and in the particular case of the Amazonian rainforest, both recent and ancient anthropic practices may be important. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by sedentary habits and intensification patterns of pre-Colombian societies primarily developed in the second part of the Holocene period. We have sampled earthworm communities in three Brazilian Amazonian (ADEs) and adjacent reference soils (REF) under old and young forests and monocultures. To better assess taxonomic richness, we used morphology and the barcode region of the COI gene to identify juveniles and cocoons and delimit Molecular Operational Taxonomic Units (MOTUs). Here we suggest using Integrated Operational Taxonomical units (IOTUs) which combine both morphological and molecular data and provide a more comprehensive assessment of diversity, while MOTUs only rely on molecular data. A total of 970 individuals were collected, resulting in 51 taxonomic units (IOTUs, MOTUs, and morphospecies combined). From this total, 24 taxonomic units were unique to REF soils, 17 to ADEs, and ten were shared between both soils. The highest richness was found in old forest sites for ADEs (12 taxonomic units) and REFs (21 taxonomic units). The beta-diversity calculations reveal a high species turnover between ADEs and REF soils, providing evidence that ADEs and REFs possess distinct soil biota. Furthermore, results suggest that ADE sites, formed by Pre-Columbian human activities, conserve a high number of native species in the landscape and maintain a high abundance, despite their long-term nature

Macrofauna da liteira em sistemas agroflorestais sobre pastagens abandonadas na Amazônia Central

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

Litter-layer macrofauna in agroforestry systems on abandoned pastures in Central Amazonia

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.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

Carbon and nutrient stocks in the litter layer of agroforestry systems in central Amazonia, Brazil

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. © Springer 2005

COMUNIDADE DE MACRO-INVERTEBRADOS DO SOLO EM PLANTÍOS FLORESTAIS E SISTEMAS NATURAIS NA AMAZÔNIA PERUANA

Avaliou-se a comunidade dos macro-invertebrados do solo e as propriedades químicas do solo em plantios florestais de Cedrelinga catenaeformis e Simarouba amara comparando-as com uma floresta primária e uma floresta secundária em Jenaro Herrera, na Amazônia peruana. Os macro-invertebrados foram coletados pelo método recomendado pelo Programa de Biologia e Fertilidade de Solos Tropicais (TSBF) e o solo com um trado metálico durante o período de maiores precipitações em 2001. Os valores da densidade (expressados em indivíduos/m-2) dos macro-invertebrados foram maiores nos plantios florestais de Simarouba amara (3702 ind.m-2) e de Cedrelinga catenaeformis (2176 ind.m-2) do que na floresta primaria e floresta secundaria respectivamente. Assim, destaca-se que os plantios florestais mesmo em forma de monocultivo, no qual a ciclagem de nutrientes ficou restrito aos compostos da própria espécie, apresentaram um efeito favorável na composição dos macro-invertebrados e nas propriedades químicas do solo, mostrando um efeito positivo na recuperação do sol