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ContextThe role of protected areas as biodiversity repositories has become increasingly important in face of increased deforestation. By adding free-living exotic mammals, removing forest-dependent native ones, isolating forest patches from large protected areas and reducing landscape forest cover, human activities may drive mammal communities towards regional biotic homogenization.ObjectivesWe assessed how landscape forest cover and proximity to the largest and best-preserved area of the Catimbau National Park—one of the largest protected areas of the Brazilian Caatinga—affect α- and β-diversity of medium- and large-sized mammals, considering native and exotic species.MethodsUsing camera traps (total effort of 2340 cameras/day), we obtained 823 records of 15 species (8 natives and 7 exotics) in 18 landscapes of 1-km radius. We estimated diversity metrics within and among landscapes and used generalized linear models to assess the effect of forest loss and isolation on diversity metrics.ResultsAs expected, forest loss decreased α-diversity of native species and increased the diversity and relative abundance of exotics. However, proximity to the preserved area showed weak effect on α-diversity, suggesting that this area does not work regionally as source for natives neither as ecological trap for exotics. Supporting the biotic homogenization hypothesis, β-diversity of natives decreased and β-diversity of exotics increased in more deforested landscapes. Yet, species composition was weakly related to forest cover and isolation.ConclusionsOur findings demonstrate that deforestation jeopardizes native species, favors exotics, and drives mammal communities towards biotic homogenization. Protected areas should be properly implemented to safeguard mammal diversity.

The deep reef refugia hypothesis (DRRH) predicts that deep reef ecosystems may act as refugium for the biota of disturbed shallow waters. Because deep reefs are among the most understudied habitats on Earth, formal tests of the DRRH remain scarce. If the DRRH is valid at the community level, the diversity of species, functions, and lineages of fish communities of shallow reefs should be encapsulated in deep reefs. We tested the DRRH by assessing the taxonomic, functional, and phylogenetic diversity of 22 Brazilian fish communities between 2 and 62 m depth. We partitioned the gamma diversity of shallow (<30 m) and deep reefs (>30 m) into independent alpha and beta components, accounted for species’ abundance, and assessed whether beta patterns were mostly driven by spatial turnover or nestedness. We recorded 3,821 fishes belonging to 85 species and 36 families. Contrary to DRRH expectations, only 48% of the species occurred in both shallow and deep reefs. Alpha diversity of rare species was higher in deep reefs as expected, but alpha diversity of typical and dominant species did not vary with depth. Alpha functional diversity was higher in deep reefs only for rare and typical species, but not for dominant species. Alpha phylogenetic diversity was consistently higher in deep reefs, supporting DRRH expectations. Profiles of taxonomic, functional, and phylogenetic beta diversity indicated that deep reefs were not more heterogeneous than shallow reefs, contradicting expectations of biotic homogenization near sea surface. Furthermore, pairwise beta‐diversity analyses revealed that the patterns were mostly driven by spatial turnover rather than nestedness at any depth. Conclusions. Although some results support the DRRH, most indicate that the shallow‐water reef fish diversity is not fully encapsulated in deep reefs. Every reef contributes significantly to the regional diversity and must be managed and protected accordingly. The taxonomic, functional, and phylogenetic diversity of shallow‐water reef fish communities is not fully encapsulated in deep reefs. Every reef contributes significantly to the regional fish diversity. Deep and shallow reefs complement each other and must be managed and protected accordingly.

β-diversity has been under continuous debate, with a current need to better understand the way in which a new wave of measures work. We assessed the results of 12 incidence-based β-diversity indices. Our results of gradual species composition overlap between paired assemblages considering progressive differences in species richness show the following: (i) four indices (β-2, β-3, β-3.s, and βr) should be used cautiously given that results with no shared species retrieve results that could be misinterpreted; (ii) all measures conceived specifically as partitioned components of species compositional dissimilarities ought to be used as such and not as independent measures per se; (iii) the non-linear response of some indices to gradual species composition overlap should be interpreted carefully, and further analysis using their results as dependent variables should be performed cautiously; and (iv) two metrics (βsim and βsor) behave predictably and linearly to gradual species composition overlap. We encourage ecologists using measures of β-diversity to fully understand their mathematical nature and type of results under the scenario to be used in order to avoid inappropriate and misleading inferences.

1. As tropical cattle ranching continues to expand, successful conservation will require an improved understanding of the relative impacts of different livestock systems and landscape structure on biodiversity. Here, we provide the first empirical and multi-scale assessment of the relative effects of livestock intensification and landscape structure on biodiversity in the threatened tropical dry forests of Mesoamerica. 2. We used a dataset of dung beetles (169,372 individuals from 33 species) collected from 201-km² landscapes, ranging from zero-yielding forest sites to high-yield cattle ranches and maize farms, to investigate the relative effect of livestock intensification (net cattle production; macrocyclic lactone use; annual dung production) landscape structure (landscape composition and configuration) at multiple spatial scales on different attributes of dung beetle communities using a multi-model averaging approach. 3. Dung beetle species richness, biomass and composition were more strongly related to landscape structure than to livestock intensification. 4. Forest cover was the best predictor of dung beetle assemblages, being positively related to species diversity and biomass across multiple spatial scales. The use of macrocyclic lactones was strong and negatively related to dung beetle communities at the local scale. 5. Synthesis and applications: Maximising forest protection through a \"land sparing\" strategy is likely to be the best strategy for reducing negative impacts of cattle farming on Neotropical dung beetle communities. However, increasing or maintaining yields while reducing agrochemical inputs will be important for conserving onfarm biodiversity and the ecosystem services that dung beetles provide in livestock-dominated landscapes.

Humans are promoting drastic changes in biological communities that result in ‘winner-loser’ species replacements across multiple spatial scales. In tropical regions, such replacements can be particularly driven by deforestation, especially in landscapes devoted to free-ranging livestock production in which mixing native and exotic species can create species-poor and homogenized communities. We tested this hypothesis assessing medium- and large-bodied non-volant mammals in four 16-km2 landscapes with varying deforestation levels (5%, 30%, 70%, and 95% forest cover), where exotic mammals (e.g., cows and goats) have free access to the remaining Caatinga dry forest. Using camera traps, we obtained 2808 independent records of 17 species, most of them (2054 records, 73%) corresponding to seven exotic species. Native Cerdocyon thous (crab-eating fox) and exotic Capra hircus (goat) accounted for almost half of the records and 60–80% of the records in the two most deforested landscapes. Alpha diversity did not differ significantly among landscapes, but the two more forested landscapes tended to have more native species than exotic ones. Beta diversity patterns among and within landscapes were relatively low regardless of species abundance, indicating biotic homogenization at multiple spatial scales. We conclude that a novel mammal community full of exotic mammals and a few generalist natives has been established in the study region. To promote environmental-friendly livestock farming in the largest tropical dry forest of South America, we should avoid deforestation, especially in sites that concentrate native species, segregate lands for livestock and conservation, and boost inspection against illegal hunting.

Resumen: A lo largo de las últimas décadas, la historia contemporánea ha estado marcada por tres crisis sucesivas —los totalitarismos del siglo XX, el relativismo posmoderno y la globalización indiferente— que encontraron respuesta en los pontificados de Juan Pablo II, Benedicto XVI y Francisco. Cada uno, desde su contexto histórico y sensibilidad pastoral, afrontó los desafíos de su tiempo iluminándolos con la fuerza del Evangelio: la libertad frente al miedo, la verdad frente a la duda, y la fraternidad frente a la exclusión. Su acción conjunta revela una continuidad providencial en la misión de la Iglesia, capaz de dialogar con la historia sin perder su identidad.

The Brazilian Amazon has undergone an intense process of urbanization responsible for changes in the land use and land cover patterns in the last decades. Therefore, understanding the impacts resulting from the urbanization of Amazon become urgent, both to preserve biodiversity and associated ecosystem functions and services, since Amazon region comprise a key ecosystem regarding biodiversity and ecological dynamics. We studied, for the first time, the impact of urbanization on dung beetles, a recognized bioindicator group, in an Amazonian landscape. For this, we assessed the dung beetle taxonomic and functional responses along a preserved-rural-urban habitat gradient in an Amazonian city, and how landscape predictors affect dung beetle diversity. We found a consistent shift in species composition and reduction of both taxonomic and functional diversity from forest patches located outside the city towards those located in the city core. In addition, forest cover was the main driver of dung beetle responses at the landscape scale, where the increase of forest cover positively affected dung beetle diversity. Our results provide evidence that urbanization negatively impacts the dung beetle taxonomic and functional diversity in Amazonian cities, and reinforce the importance of maintaining forest cover to conserve dung beetles in tropical forests. Finally, the development of sustainable initiatives for the conservation of biodiversity in urban landscapes, such as public policies aimed at the maintenance of urban forest fragments, can help to maintain biodiversity and ecosystem processes within cities and to mitigate the urbanization impacts.

Ecosystem services provided by insects are threatened by recent increasing global temperatures, particularly in the tropics, where insects live close to their thermal limits. Given that tolerance to high temperatures depends on individual metabolism and physiological stress response, it may also be sensitive to other stressors that are common in natural and human-modified environments, such as pollution and parasite pressure. The effects of multiple stressors could be synergistic and can be particularly relevant in insects that provide highly valuable ecosystem services, such as dung beetles in cattle pastures. Here we measured heat tolerance (critical thermal maximum, CTmax) in dung beetles exposed to ivermectin, a toxic parasiticide excreted in cattle dung, with known negative effects on coprophagous fauna, and in beetles exposed to an immune challenge. We also exposed a group of beetles to a combination of both ivermectin and immune challenge to test for potential synergistic effects of both stressors. Contrary to our predictions, CTmax did not change with ivermectin exposure, but increased in immune-challenged beetles. As found in other insects, CTmax was higher in larger beetles, highlighting the importance of body size on thermal tolerance in ectotherms. We discuss potential mechanisms responsible of increased heat tolerance in immune-challenged beetles and highlight the importance of natural and human-induced environmental pressures that now interact with global warming and threaten ecosystem services provided by wild animals.

Studies on elevation diversity gradients have covered a large number of taxa and regions throughout the world; however, studies of freshwater fish are scarce and restricted to examining their changes along a specific gradient. These studies have reported a monotonic decrease in species richness with increasing elevation, but ignore the high taxonomic differentiation of each headwater assemblage that may generate high β‐diversity among them. Here, we analyzed how fish assemblages vary with elevation among regional elevation bands, and how these changes are related to four environmental clines and to changes in the distribution, habitat use, and the morphology of fish species. Using a standardized field sampling technique, we assessed three different diversity and two structural assemblage measures across six regional elevation bands located in the northern Andes (Colombia). Each species was assigned to a functional group based on its body shape, habitat use, morphological, and/or behavioral adaptations. Additionally, at each sampling site, we measured four environmental variables. Our analyses showed: (1) After a monotonic decrease in species richness, we detected an increase in richness in the upper part of the gradient; (2) diversity patterns vary depending on the diversity measure used; (3) diversity patterns can be attributed to changes in species distribution and in the richness and proportions of functional groups along the regional elevation gradient; and (4) diversity patterns and changes in functional groups are highly correlated with variations in environmental variables, which also vary with elevation. These results suggest a novel pattern of variation in species richness with elevation: Species richness increases at the headwaters of the northern Andes owing to the cumulative number of endemic species there. This highlights the need for large‐scale studies and has important implications for the aquatic conservation of the region. We perform the first regional analysis of elevation diversity gradients in freshwater fish. For this we used 141 localities between 250 and 2533 m a.s.l. from seven sub‐regions in the Northern Andes, Colombia. The results of our study suggest a novel pattern of variation in species richness with elevation: species richness increases at the headwaters of the Northern Andes owing to the cumulative number of endemic species there.

Seasonally Dry Tropical Forests (SDTFs) have long suffered from chronic, intensive and extensive landscape transformations due to human activities, challenging biodiversity conservation in this biome. The Caatinga is the largest Neotropical SDTF, serving as an excellent model to understand how land use changes modulate ecological communities. In this study, we assessed the effects of landscape configuration and composition on the abundance and diversity of Chrysomeloidea in a region of Caatinga. We sampled beetles in 10 landscape units, in which we measured landscape configuration (patch size, edge density) and composition (landscape diversity, patch richness). Hill numbers (q0, q1, q2) were used to analyze the diversities of Chrysomeloidea. A total of 484 individuals belonging to 82 species were collected. Landscape configuration affected Chrysomeloidea assemblages with a positive correlation between edge density and Chrysomeloidea diversity. We provide a new perspective regarding the spatial distribution of Chrysomeloidea in Caatinga and conclude that landscape configuration, but not composition, directly affects Chrysomeloidea assemblages.