Understanding the factors that affect the tolerance of carnivores is critical for proposing strategies for their conservation. A widely known hazard-acceptance model for large carnivores proposes that, unlike cognitive factors, emotional (affective) factors are secondary drivers of tolerance towards these species. The main objective of this article is to compare the effect of affective and cognitive factors on the tolerance of pumas (Puma concolor), using 109 semi-structured interviews conducted in a rural landscape in the state of Bahia (Brazil). Through the use of cumulative link models I found that although the cognitive model explained a considerable amount of variability (gen. R2 = 0.38) in the tolerance of the species, the affective model explained a higher amount of variability (gen. R2 = 0.44). In addition, an integrative model containing cognitive and affective factors explained the highest amount of variability (gen. R2 = 0.51). Contrary to what has been believed for decades, humans may not process information regarding wildlife from a purely analytical viewpoint, and social-based strategies for carnivore conservation should benefit from integrative approaches that consider emotional responses to wildlife.

Interactions between ants and non-myrmecochorous diaspores occur frequently on the forest floor and the results of these interactions (e.g. diaspore cleaning or removal) will often depend on the morpho-chemical characteristics of the diaspores. We conducted two different experiments with seven plant species in the north-eastern Atlantic forest, Brazil. To evaluate whether ant interactions decrease diaspore persistence time on the forest floor, we established sample stations by placing five diaspores of each species spaced every 10 m along a transect and monitored ant interactions over a 24-h period. We also compared diaspore removal by ants and vertebrates through a paired experiment. We monitored removal of the seven plant species in treatments where ants were excluded and treatments where vertebrates were excluded. We recorded 332 ant–diaspore interactions, most resulting in ants cleaning diaspores in situ. Persistence of diaspores on the forest floor varied greatly among studied species and was less than 50% for three species. Ants also removed more diaspores than did vertebrates. Number of diaspores removed by ants was greater for small diaspores and with high lipid concentration. Ant–diaspore interactions may not always exert a positive influence on plant recruitment for diaspores with poor nutrient concentration. Consequently, ants may play a disproportionately important role as secondary dispersers in tropical forests.

Much of the ecological alteration faced by human-modified Neotropical forests can be assigned to edge effects, including the proliferation of some voracious herbivores such as leaf-cutting ants. However, the underlying mechanisms/impacts of tropical forest edge on herbivores performance and their foraging behaviour (e.g. dietary diversity) have rarely been investigated. The goal of this study was, therefore, to determine whether and how the annual diet (i.e. species richness, diversity and the relative proportion of pioneer versus non-pioneer species of plant materials) of Atta cephalotes colonies differs in the forest edge versus the interior zone of a large remnant of Atlantic forest in northeastern Brazil. Among the key results was a strong habitat effect on dietary diversity (explaining ca. 40–50% of the variation), which, in edge colonies, decreased approximately by one fourth compared to interior colonies (inverse of Simpson's index: 3.7±0.84 versus 4.99±0.95). There was a predominance of leaf fragments collected from pioneer species in the diet in both habitat (86% in edge and 80.4% in interior). Edge colonies collected proportionally more fragments from pioneer species than colonies located in the forest interior. Our results are the first to demonstrate an edge-mediated relaxation of dietary restrictions in leaf-cutting ants. These findings render robust support to previous evidence indicating the reduction of bottom-up forces as a key factor explaining both edge-induced hyper-abundance and increased herbivory of leaf-cutting ants in human-modified Neotropical landscapes.

In this paper we examine the number of known populations of 86 bromeliad species recorded in the Atlantic forest of north-east Brazil, to test the following predictions: (1) the current number of populations of most bromeliad species inhabiting the Atlantic forest of north-east Brazil is critically low, (2) the number of extant populations of a particular species is associated with the ecological attributes of the species, and (3) habitat loss determines, at least in part, the current distribution and number of populations of each species. At present there are at least 535 bromeliad populations in this forest but 61.6% of species have <6 populations and 24.4% have only one known population. The mean number of populations per species was significantly lower among species endemic to this part of the Atlantic forest, species recorded in only one vegetation type, forest and inselberg species, and obligatory epiphytic and terrestrial species. We were unable to relocate 41 populations recorded between 1920 and 1996, and populations of 20 species have become locally extinct. For these bromeliads geographic range, habitat specificity and life form appear to determine which species are more vulnerable to extinction. The species that have <6 extant populations include 27 species that are endemic to this forest. These species need to be evaluated for inclusion on both the IUCN and Brazilian Red Lists. Some of these species will only survive if the fragments containing the last populations are declared as protected areas.

Patterns of vertical stratification and canopy utilization by rodents and marsupials were analysed in two contiguous Atlantic forests at different altitudes (100 m and 900 m asl). Twenty-two species were captured using live traps placed at ground level, in the understorey (1.5–2.0 m), and in the canopy (6–15 m) over 2 y; seven species (32%) were mainly or exclusively arboreal. Community composition and relative abundance of species in the different vertical strata were not similar, with a general reduction in the number of species, and in abundance in the upper layers. The following species were captured mainly or exclusively in the canopy: Micoureus demerarae and Gracilinanus microtarsus (Didelphimorphia, Didelphidae); Wilfredomys pictipes, Oecomys aff. concolor, and Rhipidomys aff. macrurus (Rodentia, Muridae); and Nelomys nigrispinus (Rodentia, Echimyidae). Our results indicated that altitudinal changes in Atlantic forest areas may alter the community composition of different forest layers but they do not seem to alter greatly specific patterns of vertical habitat utilization. Similar-sized species tended to differ in their patterns of vertical utilization of habitat with the exception of terrestrial akodontine rodents (genera Akodon, Thaptomys, Oxymycterus and Brucepattersonius). Rodents (mainly Oryzomys russatus) dominated captures at ground level at both sites but Akodontinii were numerous only at the highest site. Unlike other neotropical forests, marsupials did not dominate canopy captures.

The purpose of the present study was to investigate whether variations in tree community structure and soil properties were interrelated in a fragment of semideciduous forest in Martinho Campos, south-eastern Brazil. The forest was sampled by ten plots, each of which was made up of four contiguous 15×15m quadrats (total 0.9ha). Plots were randomly distributed in the fragment with the help of grid-line coordinates. Soil samples were collected from each quadrat for chemical and textural analyses, and the soil of each quadrat was classified in conformity with the US Soil Taxonomy System. All trees with diameter at the base of the stem ≥5cm were identified and measured (circumference and height). Three soil groups were recognized: Ustifluvent, Ustropept, and Dystropept. A principal component analysis independently discriminated the soil groups in terms of their chemical and textural properties, indicating the consistency of the soil classification. Significant differences among the soil groups were also found for most soil properties. Tree community physiognomy was significantly different in Ustropept soil habitat, where trees showed more pronounced slenderness. A detrended correspondence analysis indicated that tree community structure also responded to the three soil habitats. A canonical correspondence analysis, together with Spearman's rank correlations, demonstrated that species' abundance distributions were significantly correlated with the soil properties. Differences in soil nutrient content (particularly Ca2+ and K+) and in ground water regime are apparently the leading factors determining tree species distributions within the fragment.