AbstrActin Amazonia, nothing is known about the distribution of the invertebrates on a medium-spatial scale pattern. in a trail system of 64 km 2 at ducke reserve, we sampled 72 transects using the hand-sorting method and berlese-tullgren extraction. the reserve possesses ecosystems of "terra-firme" forest and the trail system represents a gradient of topographic soil factors and vegetation, avoiding categorizations. considering the abundance and diversity of pseudoscorpionida, we investigated the relation of the community to environmental factors tested (topography, clay percentage, litter, and soil ph), to the two major drainage basins of the reserve, and if these invertebrates can be used as biological indicators to monitor changes. We registered two species for the first time in the reserve, increasing the known diversity to 17 species. the lack of correlation with the predictor variables and the large home range, indicate that pseudoscorpions are not good biological indicators in the reserve. As the eastern and western watersheds are not separate management units for the community, our results show that they are generalist predators. in spite of our results and lack of knowledge concerning their biology, life history and taxonomy, pseudoscorpions are cosmopolitan and easy to find and measure. compared with previous studies in the reserve, they have a consistent pattern of abundance and diversity throughout the years showing the stability of the community which can be checked mainly by comparison with environmental changes that would occur in the reserve. An investigation on a medium-spatial scale pattern and over a long-term period including other habitats, and also other predictor variables, like humidity, the structure of the vegetation and canopy closure, will be necessary to reinforce the observed tendencies.Keywords: central Amazonia, soil arthropods, medium-spatial scale, biological indicator pseudoscorpionida. na Amazonia, nada é conhecido sobre o padrão de distribuição de invertebrados em escala meso-espacial. em um sistema de trilhas de 64 km 2 na reserva ducke, foram coletados invertebrados em 72 parcelas por meio de coleta manual e método de berlese-tullgren extraction. A reserva possui ecossistemas de florestas terra-firme e as trilhas representam um gradiente de topografia, fatores do solo e vegetação, * part of a master´s degree dissertation of the second author. 792 AguiAr, n. o., guAlberto, t. l. and frAnklin, e. [791][792][793][794][795][796][797][798][799][800][801][802] 2006 evitando categorizações. considerando a abundância e a diversidade de pseudoscorpionida, investigouse a relação da comunidade com os fatores ambientais (topografia, porcentagem de argila, serapilheira e ph do solo), com as duas bacias de drenagem (leste e oeste) da reserva, e se esses invertebrados podem ser usados como indicadores biológicos para monitorar mudanças. foram registradas duas espécies pela primeira vez na reserva, aumentando a diversidade para 17 espécies. A falta de correlação com as variáveis predit...