Negative effects of human disturbance and increased aridity on root biomass and nutrients along the regeneration of a tropical dry forest in the context of slash-and-burn agriculture.

Biomass is an important indicator of the ability of tropical forests to deliver ecosystem services, but little attention has been given to belowground biomass and its drivers in human-modified landscapes. Here, we investigated the belowground biomass and nutrient concentration/stocks (C, P, and N) across regenerating forest stands with varying ages (10-76 years old) and old-growth forests in the Caatinga dry forest (northeastern Brazil) in the context of slash-and-burn agriculture. Belowground biomass ranged from 1.89 ± 0.33 Mg ha-1 to 17.53 ± 2.28 Mg ha-1 (mean ± SE) across regenerating forest stands and averaged 8.33 ± 1.59 Mg ha-1, with no differences compared to old-growth stands. However, regenerating stands exhibited a higher root/shoot ratio with biomass concentrated in the superficial soil layer and in large-sized roots, regardless of the successional stage. Root nutrient concentration and stocks were highly variable across forest stands with fine roots supporting a higher concentration of N and P, while regenerating stands supported lower nutrient stocks as compared to old-growth forests. Finally, precipitation and chronic disturbance emerged as the most important drivers of belowground biomass and nutrient concentrations/stocks, while aboveground biomass played a negligible role. Our results indicate that, in human-modified landscapes of tropical dry forests, belowground biomass and nutrients play important roles in ecosystem functions in regenerated forests after slash-and-burn agriculture. Forest resilience and provision of ecosystem services (e.g., nutrient cycling) appear to be very sensitive to increased aridity and exploitation of forest resources.

ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America.

Ants, an ecologically successful and numerically dominant group of animals, play key ecological roles as soil engineers, predators, nutrient recyclers, and regulators of plant growth and reproduction in most terrestrial ecosystems. Further, ants are widely used as bioindicators of the ecological impact of land use. We gathered information of ant species in the Atlantic Forest of South America. The ATLANTIC ANTS data set, which is part of the ATLANTIC SERIES data papers, is a compilation of ant records from collections (18,713 records), unpublished data (29,651 records), and published sources (106,910 records; 1,059 references), including papers, theses, dissertations, and book chapters published from 1886 to 2020. In total, the data set contains 153,818 ant records from 7,636 study locations in the Atlantic Forest, representing 10 subfamilies, 99 genera, 1,114 ant species identified with updated taxonomic certainty, and 2,235 morphospecies codes. Our data set reflects the heterogeneity in ant records, which include ants sampled at the beginning of the taxonomic history of myrmecology (the 19th and 20th centuries) and more recent ant surveys designed to address specific questions in ecology and biology. The data set can be used by researchers to develop strategies to deal with different macroecological and region-wide questions, focusing on assemblages, species occurrences, and distribution patterns. Furthermore, the data can be used to assess the consequences of changes in land use in the Atlantic Forest on different ecological processes. No copyright restrictions apply to the use of this data set, but we request that authors cite this data paper when using these data in publications or teaching events.

Winner-Loser Species Replacements in Human-Modified Landscapes.

Community assembly arguably drives the provision of ecosystem services because they critically depend on which and how species coexist. We examine conspicuous cases of 'winner and loser' replacements (WLRs) in tropical forests to provide a framework integrating drivers, impacts on ecological organization, and reconfiguration of ecosystem service provisioning. Most WLRs involve native species and result from changes in resource availability rather than from altered competition among species. In this context, species dispersal is a powerful force controlling community (re)assembly. Furthermore, replacements imply a nearly complete functional reorganization of assemblages and new 'packages' of ecosystem services and disservices provided by winners. WLRs can thus elucidate the multiple transitions experienced by tropical forests, and have theoretical/applied implications, including the role that human-modified landscapes may play in global-scale sustainability.

What is the importance of open habitat in a predominantly closed forest area to the dung beetle (Coleoptera, Scarabaeinae) assemblage?

What is the importance of open habitat in a predominantly closed forest to the dung beetle assemblage? The Atlantic Forest in Brazil is one of the most highly disturbed ecosystems and is mainly represented by fragmented areas. However, in places where human disturbances have ceased, certain areas are showing a natural regeneration pattern. The aim of the present study was to determine how the dung beetle assemblage responds to distinct habitat structures in a fragment of Atlantic Forest. For such, open and closed forest areas were sampled in a fragment of the Atlantic Forest in the northeastern region of Brazil. Pitfall traps baited with excrement and carrion were used to collect the beetles. A total of 7,267 individuals belonging to 35 species were captured. Canthon chalybaeus and C. mutabilis were restricted to open areas. Nearly 90% of the individuals of C. aff. simulans and Deltochilum aff. irroratum were identified in these areas. A higher percentage (> 50%) of Canthon staigi, Dichotomius aff. depressicolis and D. aff. sericeus occurred in closed areas. Abundance differed between areas, with higher values in closed areas. Richness was not influenced by the habitat structure. NMDS ordination exhibited the segregation of areas and ANOSIM confirmed that this variable explained the assemblage of dung beetle species. The findings of the present study validate that open areas are associated to more restrictive conditions, limiting a higher abundance of dung beetle. Although situated near preserved fragments, the studied open areas increase the heterogeneity of the general landscape.

First report of Oxysternon silenus Castelnau (Scarabaeidae, Scarabaeinae, Phanaeini) in the Brazilian Atlantic Forest

First report of Oxysternon silenus Castelnau (Scarabaeidae, Scarabaeinae, Phanaeini) in the Brazilian Atlantic Forest. This is the first record of Oxysternon silenus in the Brazilian Atlantic Forest. Specimens were collected in the Serra Grande landscape, municipality of Ibateguara, in Alagoas State. The samples were done from August 17 to 19, 2007 with pitfall traps. Before the present study, Oxysternon silenus had been reported predominantly in Amazonian region. The finding of this species corroborates the hypothesis of the biogeographical relationships between the Amazon Rainforest and the Atlantic Forest.

Primeiro relato de Oxysternon silenus Castelnau (Scarabaeidae, Scarabaeinae, Phanaeini) na Mata Atlântica brasileira. Esse é o primeiro registro de Oxysternon silenus na Mata Atlântica brasileira. Os espécimes foram coletados em Serra Grande, município de Ibateguara, Alagoas. As coletas foram realizadas de 17 a 19 de agosto de 2007 com a utilização de armadilhas do tipo pitfall. Antes do presente estudo, Oxysternon silenus tinha sido reportada apenas na região Amazônica. O encontro dessa espécie reforça a hipótese das relações biogeográficas entre a Amazônia e a Mata Atlântica.

How habitat change and rainfall affect dung beetle diversity in Caatinga, a Brazilian semi-arid ecosystem.

The aim of the present study was to evaluate how dung beetle communities respond to both environment and rainfall in the Caatinga, a semi-arid ecosystem in northeastern Brazil. The communities were sampled monthly from May 2006 to April 2007 using pitfall traps baited with human feces in two environments denominated "land use area" and "undisturbed area." Abundance and species richness were compared between the two environments and two seasons (dry and wet season) using a generalized linear model with a Poisson error distribution. Diversity was compared between the two environments (land use area and undisturbed area) and seasons (dry and wet) using the Two-Way ANOVA test. Non-metric multidimensional scaling was performed on the resemblance matrix of Bray-Curtis distances (with 1000 random restarts) to determine whether disturbance affected the abundance and species composition of the dung beetle communities. Spearman's correlation coefficient was used to determine whether rainfall was correlated with abundance and species richness. A total of 1097 specimens belonging to 13 species were collected. The most abundant and frequent species was Dichotomius geminatus Arrow (Coleoptera: Scarabaeidae). The environment exerted an influence over abundance. Abundance and diversity were affected by season, with an increase in abundance at the beginning of the wet season. The correlation coefficient values were high and significant for abundance and species richness, which were both correlated to rainfall. In conclusion, the restriction of species to some environments demonstrates the need to preserve these areas in order to avoid possible local extinction. Therefore, in extremely seasonable environments, such as the Caatinga, seasonal variation strongly affects dung beetle communities.

Attractivity of omnivore, carnivore and herbivore mammalian dung to Scarabaeinae (Coleoptera, Scarabaeidae) in a tropical Atlantic rainforest remnant / Atratividade de Scarabaeinae (Coleoptera: Scarabaeidae) por fezes de mamíferos onívoros, carnívoros e herbívoros em um remanescente de Floresta Tropical Atlântica

In this study, performed in a remnant of Brazilian Atlantic Forest, three types of dung from animals with distinct alimentary habits were utilized, in order to verify possible differences of attractivity of these dungs to the Scarabaeinae and the influence of seasonality in the attractivity. Three habitats were sampled: edge, clearing and forest core, each with 40 pitfall traps. A total of 2,137 beetles were collected from August 2005 to July 2006. Canthidium sp. 1 (43 percent) and Dichotomius sericeus (41 percent) were the most abundant species. From the total number of beetles collected, 80.5 percent were attracted to human dung, 11 percent to jaguar dung, 7.8 percent to waterbuck dung and 0.7 percent to the control. The species Canthidium sp.1, Canthidium sp. 2, Ateuchus sp., Canthon nigripenne, Canthonella sp. and D. sericeus came to all three bait types. Eight species were found in the baits with human dung, where Canthidium sp.1 (49 percent) and D. sericeus (39 percent) were the most common. A significant difference in attractiveness of the different baits was observed; the highest abundance found in traps baited with human dung (F = 36.59; g.l. = 3; p < 0.0001). A significant difference in richness was observed between rainy and dry seasons (F = 12.29; g.l. = 1; p < 0.001), the highest richness found in the dry season.

Nesse estudo, realizado em um remanescente de Floresta Atlântica Brasileira, três tipos de fezes de animais com distintos hábitos alimentares foram utilizados para verificar possíveis diferenças de atratividade dessas fezes por Scarabaeinae e a influência da sazonalidade nessa atratividade. Três habitats foram amostrados: borda, clareira e núcleo da floresta, cada um com 40 armadilhas de queda ("pitfall"). Um total de 2137 besouros foi coletado de agosto de 2005 a julho de 2006. Canthidium sp. 1 (43 por cento) e Dichotomius sericeus (41 por cento) foram as espécies mais abundantes. Do número total de besouros coletados, 80,5 por cento foram atraídos para fezes humanas, 11 por cento para fezes de jaguar, 7,8 por cento para fezes de cobo e 0,7 por cento para o controle. As espécies Canthidium sp.1, Canthidium sp. 2, Ateuchus sp., Canthon nigripenne, Canthonella sp. e D. sericeus foram aos três tipos de isca. Oito espécies foram encontradas nas iscas com fezes humanas, onde Canthidium sp.1 (49 por cento) e D. sericeus (39 por cento) foram as mais abundantes. Diferença significativa de atratividade por diferentes iscas foi observada; a maior abundância foi evidenciada em armadilhas iscadas com fezes humanas (F = 36.59; g.l. = 3; p < 0.0001). Diferença significativa foi observada na riqueza entre as estações chuvosa e seca (F = 12.29; g.l. = 1; p < 0.001) sendo a maior riqueza verificada na estação seca.