Aim: To evaluate the extent to which ant species richness in Neotropical savannas varies with macrogeographic variables, and to identify the potential climatic drivers of such variation. Location:The Cerrado savanna biome of central Brazil, in a region spanning ca. 20°o f latitude and 18°of longitude.Methods: Standardized sampling of the arboreal and ground-dwelling faunas was performed in 29 well-preserved savanna sites using pitfall traps. Species were classified according to their habitat affinities: open-savanna specialists, forest-associated species or habitat generalists. We used generalized linear models to evaluate the importance of geographic (latitude, longitude and elevation) and climatic (mean temperature and three metrics of rainfall) variables as predictors of species richness.Results: The total number of species recorded at each site varied more than twofold (from 59 to 144), and latitude was the best geographic correlate of overall species richness. However, contrary to the expected pattern, more species were found at higher than lower latitudes. This reversed latitudinal pattern of diversity occurred for both the arboreal and ground-dwelling faunas, and for the habitat generalists and forest specialists. The savanna specialists showed a mid-latitudinal peak in diversity. Overall, there was a significant positive association between rainfall and species richness, but the strength of this relationship varied with ant habitat affinity.Main conclusions: The Cerrado ant fauna shows a reverse latitudinal gradient in species diversity, and this can be explained by increasing rainfall during the warmest months of the year (and therefore in plant productivity) with increasing latitude.The sensitivity of Cerrado ant diversity to declining rainfall contrasts with the high resilience to aridity of the Australian savanna ant fauna, and this reflects the contrasting evolutionary histories of these faunas. Our findings highlight the importance of historical processes as drivers of intercontinental contrasts in macroecological patterns. K E Y W O R D Sant communities, Cerrado, latitudinal diversity gradient, Neotropical arid diagonal, species diversity, tropical savanna

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The conversion of natural habitats into anthropogenic uses is a key driver of global biodiversity loss, but effects can vary among taxa and diversity metrics. This has important implications for the use of bioindicators in land management. We evaluated the local‐scale responses of multiple faunal taxa to land‐use change in the Brazilian Cerrado measuring different aspects (taxonomic and functional) and levels (alpha and beta) of diversity. We compared ant, dung beetle and bird assemblages inhabiting remnants of natural habitat (savanna and semi‐deciduous forest) with those found in cattle pastures, soy fields or Eucalyptus plantations. Species richness was markedly higher in natural habitats for ants and birds but not for dung beetles. Effects on functional alpha diversity were taxon specific and there was not such a contrast between natural and anthropogenic habitats. Patterns of functional beta diversity were correlated with patterns of taxonomic beta diversity and were also taxon specific. For dung beetles, site‐to‐site variation in taxonomic and functional composition was greatest in forests, whereas birds tended to present greater spatial turnover and ants greater nestedeness in the anthropogenic than in the natural habitats. Among the three anthropogenic land uses, tree plantations presented the most similar composition to natural habitat for all taxa. Overall, similarity in taxonomic and functional composition between natural and anthropogenic habitats was greater for savanna than forest. Synthesis and applications. The responses of ant, dung beetle and bird assemblages to land‐use change in the Cerrado were highly variable. Nonetheless, results indicate that the extent of impacts on biodiversity reflects the extent of habitat transformation and that impacts at a landscape scale may be reduced by a mix of land uses. We showed that effects were more severe from a taxonomic than from a functional perspective, for the forest than for the savanna‐associated fauna, for the ant and bird than for the dung beetle fauna, and often in lands devoted to intensive agriculture rather than to pastoralism or plantation forestry. Our findings can help guide the selection and assessment of indicator taxa and the interpretation of exactly what they are indicating.

Although savanna woody encroachment has become a global phenomenon, few studies have simultaneously evaluated its effects on multiple dimensions and levels of savanna biodiversity.We evaluated how the progressive increase in tree cover in a fire-suppressed savanna landscape affects the taxonomic, functional, and phylogenetic diversity of neotropical ant communities. We sampled ants along an extensive tree cover gradient, ranging from open savannas to forests established in former savanna areas due to fire suppression, and found that Leaf Area Index explained much of the observed variation in ant diversity at both the alpha and beta levels.However, ant responses to variation in tree cover were largely non-linear as differences in alpha diversity and in the dissimilarities of the sampled communities were often much more marked at the savanna/forest transition than at any other part of the gradient. The patterns of functional and phylogenetic diversity mirrored those of taxonomic diversity, notably at the beta level. At the alpha level, functional diversity tended to increase, whereas taxonomic and phylogenetic diversity decreased or was unrelated to tree cover. Our results indicate that savanna ant communities switch rapidly to an alternative state once savanna turns into forest. Ant communities in the newly formed forest areas lacked many of the species typical of the open habitats, suggesting that the maintenance of a fire suppression policy, is likely to result in a decrease in ant diversity and in the homogenization of the ant fauna at the landscape level.

ABSTRACT. Richness and composition of Arctiinae (Lepidoptera, Erebidae) in five Conservation Units in the Cerrado biome. The Cerrado biome contains about 50% of the Brazilian Arctiinae moths. However, northern region of the Cerrado is under-sampled for these insects, where there are more preserved areas. Here, we described the richness, composition, abundance, and beta diversity of Arctiinae in different vegetation types in five Protected Areas in the Cerrado northeast. We found 83 species, almost 78% of them occurred in one Protected Area. Less preserved localities had higher species richness. This result can be explained as a response to frequent intermediate disturbances in the landscape of these places. Forested areas were richer in species, supporting the environmental heterogeneity hypothesis. Compositional similarity was low among protected areas and among vegetation types. More complete inventories are required to assess which factors are influencing species richness and composition patterns of Arctiinae moths in these localities and thus guide future conservation actions. KEYWORDS. Protected Areas, inventories, moths.RESUMO. Cerca de 50% da diversidade de mariposas Arctiinae do Brasil está no Cerrado. Contudo, a fauna desses insetos é extremamente subamostrada na região norte do bioma, onde localizam-se as áreas de vegetação mais preservadas. Diante disso, este trabalho teve como objetivos descrever a riqueza, abundância, composição e diversidade beta de Arctiinae em diferentes fitofisionomias de cinco Unidades de Conservação localizadas no nordeste do Cerrado. Foram amostradas 83 espécies, das quais quase 78% ocorreram em apenas uma Unidade de Conservação. As localidades com menor grau de preservação apresentaram maior riqueza de espécies, o que pode ser explicado como uma resposta a distúrbios intermediários na paisagem destes locais. As fitofisionomias florestais foram mais ricas em espécies, corroborando a hipótese da heterogeneidade ambiental. De maneira geral, a similaridade da fauna foi baixa tanto entre as Unidades de Conservação quanto entre as fitofisionomias. Inventários mais completos precisam ser feitos a fim de avaliarmos que fatores estão influenciando os padrões de riqueza e composição de Arctiinae nestas localidades de Cerrado e, assim, subsidiar futuras ações de conservação. PALAVRAS-CHAVE.Áreas protegidas, inventários, mariposas.