Alexandre A Oliveira

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The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations(More)
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under(More)
Amazonian rainforests are some of the most species-rich tree communities on earth. Here we show that, over the past two decades, forests in a central Amazonian landscape have experienced highly nonrandom changes in dynamics and composition. Our analyses are based on a network of 18 permanent plots unaffected by any detectable disturbance. Within these(More)
1. Litter decomposition recycles nutrients and causes large fluxes of carbon dioxide into the atmosphere. It is typically assumed that climate, litter quality and decomposer communities determine litter decay rates, yet few comparative studies have examined their relative contributions in tropical forests. 2. We used a short-term litterbag experiment to(More)
The structure of the Atlantic Forest (AF) has been studied for almost 70 years. However, the related existing knowledge is spread over hundreds of documents, many of them unpublished and/or difficult to access. Synthesis initiatives are available, but they are restricted to only a few parts or types of the AF or are focused on species occurrence. Here, we(More)
The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are five times(More)
The Camponotus Mayr genus of carpenter ants is one of the largest in species number and widely represented in the Neotropical Region. Most species are generalists and capable of exploiting diverse habitats including urban environments. Urban green areas can act as a repository of regional biodiversity, thus we investigated whether this is valid for the(More)
The stress gradient hypothesis (SGH) postulates how the balance between plant competition and facilitation shifts along environmental gradients. Early formulations of the SGH predicted that facilitation should increase monotonically with stress. However, a recent theoretical refinement of the SGH postulates stronger facilitation under moderate stress,(More)
We examined the effects of soil mesofauna and the litter decomposition environment (above and belowground) on leaf decomposition rates in three forest types in southeastern Brazil. To estimate decomposition experimentally, we used litterbags with a standard substrate in a full-factorial experimental design. We used model selection to compare three(More)
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