Post-fire succession of small mammals in the Cerrado of central Brazil

In the Cerrado savannas from Brazil fire events are common and strongly influence the vegetation structure and, consequently, the associated small mammals. In this paper, we investigate changes in the structure of small mammal communities related to sites of different post-fire ages. Mammals were captured in similar Cerrado sites that differed in time since the last burn (1 to 26 yr). We sampled six sites in the wet season of 1997 (phase 1) and, three years later, six sites in the wet and dry seasons (phase 2). Six rodent species and four marsupials were captured. Community composition changed drastically as a function of time since fire. The diversity and abundance of small mammals reached maximum values in the early successional stages. The rodent Calomys tener was present only in early seral stages. The rodent Bolomys lasiurus was more frequent in mid-successional stages and decreased in later seral stages, and the rodent Oryzomys subflavus occupied all successional stages. The marsupial Gracilinanus agilis was dominant in the area that did not burn for at least 23 yr. Changes in composition of the community of small mammals were more accelerated in early successional stages, when there are more drastic vegetational changes. The ability of small mammals to cope with Cerrado fires and the great dissimilarity among post-burning seral stages suggest that a mosaic of areas representing different post-fire seral stages could increase the regional diversity of this group.     

DNA barcode and minibarcode identification of freshwater fishes from Cerrado headwater streams in Central Brazil

The extraordinary species diversity of the Neotropical freshwater fish fauna is world renown. Yet, despite rich species diversity, taxonomic and genetic resources for its Cerrado ichthyofauna remain poorly developed. We provide a reference library of 149 DNA barcodes for 39 species/lineages of Cerrado headwater stream fishes from the Brazilian Distrito Federal and nearby areas and test the utility of distance-based criteria, tree-based criteria and minibarcodes for specimen identification. Mean Kimura 2-parameter genetic distances within species to orders ranged 1·8–12·1%. However, mean intraspecific v. congeneric-interspecific distances (0·9–1·3%) overlapped extensively and distance-based barcoding failed to achieve correct identifications due to c. 4–12·1% error rates and 19·5% ambiguous identifications related to the presence of singletons. Overlap was reduced and best-match success rates improved drastically to 83·5% when Characidium barcodes representing potential misidentifications or undescribed species were removed. Tree-based monophyly criteria generally performed similarly to distance methods, correctly differentiating up to c. 85% of species/lineages despite neighbour-joining and Bayesian tree errors (random lineage-branching events, long-branch attraction). Five clusters (Ancistrus aguaboensis, Characidium spp., Eigenmannia trilineata, Hasemania hanseni and Hypostomus sp. 2) exhibited deep intraspecific divergences or para−/polyphyly and multiple Barcode Index Number assignments indicative of putative candidate species needing taxonomic re-examination. Sliding-window analyses also indicated that a 200 bp minibarcode region performed just as well at specimen identification as the entire barcode gene. Future DNA barcoding studies of Distrito Federal–Cerrado freshwater fishes will benefit from increased sampling coverage, as well as consideration of minibarcode targets for degraded samples and next-generation sequencing.     

Soil-vegetation relationships in cerrado (Brazilian savanna) and semideciduous forest, Southeastern Brazil

Several studies pointed out soil properties as the prime determinant ofcerrado (the Brazilian savanna) physiognomies, and a gradient from campocerrado (a shrub savanna) to cerradão (a tallwoodland) has been correlated with a soil fertility gradient. Based on thishypothesis, we investigated soil-vegetation relationships in thePé-de-Gigante Reserve (São Paulo State,SoutheasternBrazil). We randomly distributed 10 quadrats (10 × 10 m) oneach ofthe following physiognomies: campo cerrado, cerradosensu stricto, cerradão, andseasonal semideciduous forest, previously defined by the analysis of satelliteimages (LANDSAT-5). We sampled the woody individuals with stem diameter> 3 cm at soil level, identifying their species. In each quadrat, wecollectedsoil samples at the depths of 0–5, 5–25, 40–60, and80–100 cm, and determined pH, K, Ca, Mg, P, Al, H + Al, basesaturation, aluminium saturation, cation exchange capacity, and percentage ofsand, clay and loam. Obtained data were submitted to a canonical correspondenceanalysis (CCA) and to a detrended correspondence analysis (DCA). Our resultsshowed a clear distinction between semideciduous forest and the cerradophysiognomies, based in soil parameters. The former was related to higherconcentrations of cations and clay in the soil, while the latter was related tohigher concentrations of exchangeable aluminium in the soil surface. The threecerrado physiognomies – campo cerrado, cerradosensu stricto, and cerradão– could not be distinguished considering plant density and the analysedsoil features.     

Taxonomic distinctness and diversity of a hyperseasonal savanna in central Brazil

Savannas are characterized by a sharp seasonality, in which the water shortage defines the community functioning. Hyperseasonal savannas, however, experience additionally waterlogging in the rainy season. Since waterlogging may cause local extinctions of intolerant species, we asked whether waterlogging constricts the phylogenetic structure of a hyperseasonal savanna. We studied a hyperseasonal cerrado, comparing it with a nearby seasonal cerrado, never waterlogged, in Emas National Park, central Brazil. In each vegetation form, we sampled all vascular plants by placing fifty 1-m² quadrats in five surveys. We compared the phylogenetic structure of both vegetation forms, calculating their taxonomic distinctness, taxonomic diversity, expected taxonomic distinctness, and species, genus, and family similarities. The taxonomic distinctness of both cerrados was similar and the values of similarities were high, but taxonomic diversity and expected taxonomic distinctness were lower in the hyperseasonal cerrado than in the seasonal one. Assuming that phenotypic attraction is the major process organizing local communities, the waterlogging in hyperseasonal cerrado assembles phylogenetically unrelated species that have converged on similar habitat use. As a consequence, the habitat use of hyperseasonal cerrado species is a trait widespread in the phylogeny of seasonal cerrado. Waterlogging constrains the phylogenetic structure of the hyperseasonal cerrado, especially by reducing species diversity. In more ecological terms, we can only fully assess the phylogenetic structure of a community if we consider the species abundance.     

Mammal survey at a ranch of the Brazilian Cerrado

The wildlife of the Brazilian Cerrado is threatened by large-scale habitat loss, in particular due to conversion to agricultural land. It is essential to study how the mammal fauna copes with the highly fragmented, human-influenced, non-protected landscape. The paper presents the results of a survey of the large to medium-sized mammals of a typical cattle ranch with a mixture of human-created and natural vegetation types. We recorded 18 species. Surprisingly, several species were found to still thrive in the area, however, many species are rare or have become extinct. We conclude the paper with comments relevant for the conservation of mammals in the Cerrado as a whole.     

Camera-trap studies of maned wolf density in the Cerrado and the Pantanal of Brazil

The maned wolf (Chrysocyon brachyurus) is threatened by large-scale habitat loss, in particular due to conversion to agricultural land. This is the first published study on maned wolf density and the first test of individual identification from camera-trap photographs. We present results from two Brazilian regions: the Cerrado and the Pantanal. Using capture–recapture analysis of camera-trap data, we estimated densities per 100 square kilometers of 3.64 ± 0.77 individuals at the Cerrado site and 1.56 ± 0.77 individuals at the Pantanal site. Parallel radio-telemetry studies at the Pantanal site showed that maned wolves occupied home ranges of 39–58 km² (mean = 50.3 ± 7.67 km²). Our study in the Cerrado took place in a private farm with a mixture of agricultural land and native habitats, representative of the majority of the present-day Cerrado. Whereas many other mammalian species have suffered in the region, our results show that the maned wolf may cope better with this highly fragmented landscape than one might have feared. Finally, the paper briefly compares maned wolf density with density of puma (Puma concolor) in the Pantanal site.     

Biochars from local agricultural waste residues contribute to soil quality and plant growth in a Cerrado region (Brazil) Arenosol

Arenosols (sandy soils) in the Cerrado region of Mato Grosso, Brazil, are increasingly used for maize production, the second most important crop in the region after soybean. Yet, these soils are typically nutrient poor with low soil water retention, requiring high fertilizer inputs that are often lost in surface runoff or leached. The addition of biochar, a more recalcitrant organic amendment, may therefore be beneficial in Cerrado Arenosols, contributing to sustainable crop production in the region. To examine biochar contribution to soil nutrient levels and maize growth in a Cerrado Arenosol, we conducted a greenhouse experiment using biochars made from local agricultural waste feedstocks. These were cotton husks, swine manure, eucalyptus sawmill residue, and sugarcane filtercake, pyrolyzed at 400 °C, and applied to soil at five rates: 0%, 1%, 2%, 3%, and 4% by weight. Maize plants were grown under unstressed conditions (e.g., no nutrient or water limitations) to highlight any possible negative effects of the biochars. After 42 days, soils were analyzed for nutrient levels, and plant physical and physiological measurements were taken. Filtercake biochar had the highest plant biomass and physiological properties (e.g., photosynthesis, respiration, nitrogen use efficiency), while cotton biochar had the lowest. Importantly, maize biomass decreased with increasing application rates of cotton and swine manure biochars, while biomass did not vary in response to biochar application rate for filtercake and eucalyptus biochars. In this study, we found that while each biochar exhibited potential for improving chemical and physical properties of Cerrado Arenosols, filtercake biochar stood out as most promising. Biochar application rate was identified a key factor in ensuring crop productivity. Transforming these agricultural residues readily available in the region into more stable biochar can thus contribute to sustainable crop management and soil conservation, providing an alternative form of waste disposal for these residual materials.     

East-west divergence in central Brazilian Cerrado revealed by cpDNA sequences of a bird-dispersed tree species

Population genetic studies of plant species can contribute to understanding the evolutionary history of the Brazilian Cerrado, a highly threatened hotspot and the richest tropical savanna in the world. Therefore, this study aimed at investigating the diversity and genetic structure of Byrsonima coccolobifolia (Malpighiaceae), one of the most common tree species in the Brazilian Cerrado, focusing mainly on the central area of the biome. This is a bird-dispersed species, and studies targeting species with this seed dispersal syndrome are scarce. First, we performed a careful screening of cpDNA markers to identify regions suitable for intraspecific genetic studies, and then we investigated the diversity and genetic structure in ten populations of B. coccolobifolia. The cpDNA regions selected (trnS-trnG and trnH-trnK) revealed considerable divergence among populations and a striking geographical structure, separating populations in two groups, east and west. Although seed dispersal by birds is expected to reach long distances, our results strongly corroborate studies targeting trees with limited seed dispersal. This suggests that historical fragmentation of Cerrado (possibly during cold and dry periods of the Quaternary) might have limited long distance dispersal events after climate amelioration even in bird-dispersed species, especially while Cerrado was expanding but still fragmented.     

The lizard assemblage from Seasonally Dry Tropical Forest enclaves in the Cerrado biome, Brazil, and its association with the Pleistocenic Arc

Aim  To determine if the distributions of lizard species from Seasonally Dry Tropical Forest (SDTF) enclaves within the Cerrado biome in central Brazil are associated with the Tropical Seasonal Forests Region, a recently proposed phytogeographic unit of South America, corroborating the existence of a Pleistocenic Arc of SDTFs.
Location  SDTF remnants in the Paranã River valley, municipality of São Domingos, Goiás, Brazil.
Methods  Lizards were extensively sampled using haphazard sampling, funnel traps, and pitfall traps with drift fences during four expeditions. The composition of the SDTF lizard assemblage was compared with those from other South American phytogeographic regions (Caatinga, Cerrado, Chaco, Llanos, and the dry forests of Colombia and Bolivia), based on the literature and our own unpublished data.
Results  The SDTF lizard assemblage contained 20 species, including 11 species with extensive distributions among the regions considered, seven species shared exclusively with Cerrado localities, a single species shared exclusively with other SDTFs, and one endemic species. The presence of Lygodactylus klugei (Smith, Martin & Swain, 1977), presumably endemic to the Pleistocenic Arc formed by the Tropical Seasonal Forests Region, considerably extends the known distribution of this species, suggesting historical connections between Caatinga and Cerrado SDTF enclaves.
Main conclusions  The composition of the lizard assemblage in Cerrado SDTF enclaves seems to corroborate the recent proposal that the SDTF should be recognized as a phytogeographic unit (or dominium). The presence of disjunct populations and endemic species highlights the urgency of considering the uniqueness of the Paranã River valley SDTFs and the importance of its conservation.     

Large mammalian herbivores and woody plant species diversity in Zimbabwe

Study sites from various tree savannas and miombo woodland with adjacentareas with different herbivore species (game and cattle) and stocking rates wereselected from around Zimbabwe. Using the fence-lines separating the adjacentareas, 60 m² plots were placed on both sides of thefence at 18 randomly chosen positions. The identity and number of plants of eachwoody species were recorded in paired 60 m² plots. Therewere no significant differences in the woody species richness between pairedplots for any of the fence-line contrasts. For only two of the fence-linecontrasts were there significant differences (P < 0.05)in the relative abundance of woody species. For the first fence-line contrast,the stocking rates were the same, but the herbivore species present weredifferent, while for the second fence-line contrast, the numbers of herbivorespecies present were the same, but the stocking rates differed. Even thoughthere were no differences in the numbers of woody plant species present, therewere differences in the woody plant species and the numbers of plants of eachspecies: the second most common species was different for three fence-linecontrasts and the third most common species was different for four fence-linecontrasts.     

Local richness and distribution of the lizard fauna in natural habitat mosaics of the Brazilian Cerrado

We investigate local lizard richness and distribution in central Brazilian Cerrado, harbouring one of the least studied herpetofaunas in the Neotropical region. Our results are based on standardized samplings at 10 localities, involving 2917 captures of 57 lizard species in 10 families. Local richness values exceeded most presented in earlier studies and varied from 13 to 28 species, with modal values between 19 and 28 species. Most of the Cerrado lizard fauna is composed of habitat‐specialists with patchy distributions in the mosaic of grasslands, savannas and forests, resulting in habitat‐structured lizard assemblages. Faunal overlap between open and forested habitats is limited, and forested and open areas may act as mutual barriers to lizard distribution. Habitat use is influenced by niche conservatism in deep lineages, with iguanians and gekkotans showing higher use of forested habitats, whereas autarchoglossans are richer and more abundant in open habitats. Contrary to trends observed in Cerrado birds and large mammals, lizard richness is significantly higher in open, interfluvial habitats that dominate the Cerrado landscape. Between‐localities variation in lizard richness seems tied to geographical distance, landscape history and phylogenetic constraints, factors operating in other well‐studied lizard faunas in open environments. Higher richness in dominant, open interfluvial habitats may be recurrent in Squamata and other small‐bodied vertebrates, posing a threat to conservation as these habitats are most vulnerable to the fast, widespread and ongoing process of habitat destruction in central Brazil.     

Before it is too late: description of a new genus and species of butterfly from a highly threatened Brazilian biome

A new genus, Nhambikuara Freitas, Barbosa & Zacca gen. nov., and species, Nhambikuara cerradensis Freitas, Barbosa & Zacca sp. nov., of the highly diverse Neotropical butterfly subtribe Euptychiina are described. Nhambikuara cerradensissp. nov. is the type species for the genus, and Euptychia mima Butler, 1867 is also transferred to the new genus, as Nhambikuara mima (Butler, 1867) comb. nov., from the genus Zischkaia Forster, 1964. The taxonomy, phylogenetic relationships, geographic distribution and natural history of species of the genus are also discussed.http://zoobank.org/urn:lsid:zoobank.org:pub:41AD7568-3490-4F63-A019-32D5592A8C44     

Sintopy of two Tropidurus lizard species (Squamata: Tropiduridae) in a rocky Cerrado habitat in central Brazil.

We studied the ecology of Tropidurus itambere and T. oreadicus that occur syntopically in rocky habitats of Cerrado vegetation in central Brazil during the dry season (April to September 2000). The two species are ecologically similar, but somewhat differentiated in vertical microhabitat use. The two species preferred rocky surface microhabitat. Both species demonstrated a unimodal activity pattern, with a peak between 10 and 15 h. Their diets were similar in composition and prey size. The most frequent item used by both species was ants, whereas the most important preys volumetrically were termites and ants. Small morphological differences observed between the two Tropidurus species could explain minor microhabitat divergence: T. itambere is slightly smaller, heavier, and more robust, and uses lower perches. T. oreadicus is larger, lankier, with longer extremities (tail, fore- and hindlegs), and uses a larger vertical microhabitat range. These ecological differences are slight, when compared with those observed between sympatric species of Tropidurus in spatially more heterogeneous landscapes. Considering the slight ecomorphological divergence between the two Tropidurus species and their high abundance in outcrops, we suggest that interspecific territoriality is the mechanism of coexistence.     

Role of mixed‐species flocks in the use of adjacent savannas by forest birds in the central Cerrado,Brazil

Abstract: We examined the role of mixed‐species flocks for forest birds during their breeding and non‐breeding seasons in the use of savannas adjacent to forests in central Cerrado, Brazil. Transect surveys (n = 64) were conducted in eight savanna patches. Distances of birds from forests were estimated. Recorded birds were classified as members or not of mixed‐species flocks. About half of the bird species recorded in savannas were found in at least one mixed‐species flock. As distance from the forest increased, the number of species in mixed‐species flocks tended not to vary, while the number of species foraging alone or in mono‐specific groups decreased. Thus, for some forest species, participation in mixed‐species flocks allowed a greater use of more distant savannas. This tendency of being in mixed‐species flocks at greater distances from forests also can be interpreted as a reluctance to forage alone or in mono‐specific groups due to higher predation risk in less protective vegetation distant from cover. There was strong seasonal variation in the participation of bird species in mixed‐species flocks. There were significantly more species in mixed‐species flocks than out of these associations in the non‐breeding season, while differences in the breeding season were not significant. These patterns occurred, in part because mixed‐species flocks tended to be more frequent, to have more species and to forage at greater distances from forests during the early non‐breeding season than in other periods. This study suggests that the formation of mixed‐species flocks plays an important role in promoting the use of adjacent savannas by forest birds at forest/savanna boundaries in Cerrado. It also pointed out a novel advantage gained by birds with participation in mixed‐species flocks – greater use of adjacent vegetation patches.     

Diversity,floristic and structural patterns of cerrado vegetation in Central Brazil

The cerrado has been identified as one of the richest and most threatened biomes of the world, but few phytogeographical studies have been undertaken in the region. A total of 70 land systems based on climate, landscape and soils have been identified in the region, but it remains to be seen if the distribution and structure of the plant communities support these divisions. The aim of this work was to compare the floristic and structural similarity of cerrado sensu stricto within and between three physiographic units, named Pratinha, Veadeiros and São Francisco, which contain six land systems in central Brazil and cover 10 degrees of latitude and five degrees of longitude. The woody vegetation of 15 selected sites of the cerrado sensu stricto physiognomy was surveyed under a standardized methodology. The number of species per site varied from 55 to 97, with most sites having around 60 to 70 species, and Shannon´s diversity indices ranged from 3.44 to 3.73, with most sites around 3.5 suggesting high alpha diversity. Sørensen´s floristic similarity index was high, with all Figures above 0.5 between the sites in the same land system in each physiographic unit but low between sites in different land systems in the Veadeiros. Czekanowski similarity indices were lower than Sørensen’s in the comparisons due to a high structural differentiation between the sites. There is a large overlap in species occurrence in the sites but the size of their populations is very different at each site. Therefore, the high beta diversity is mostly due to differences in abundance of species between sites. The sites were separated by physiographic units, considering the first three divisions of TWINSPAN classification. The first axis of DCA ordination showed a gradient going from the cerrado on deep soils in Pratinha, through to those on sandy soils in São Francisco and ending on the shallower soils of the Veadeiros. Land systems conformed well with the floristic and structural variations of the vegetation, indicating their potential use in designing a network of conservation areas in the cerrado region and as a basis for decision-making on management.     

Bat species diversity in a lake archipelago in central Sweden

The bat fauna of 35 islands in a large lake in central Sweden were examined using ultrasound detectors. We tested the hypothesis that there is no difference in species number between the mainland and the island fauna. Eight species were found. Species numbers were analysed against island area, area of some habitats (coniferous forest, deciduous forest, semi-open habitats and open habitats), degree of isolation (distance from mainland and from stepping stones) and time spent searching for bats. Species number increased with area of deciduous forest. Presence of houses tended to increase species number. There seems to be a negative relationship between species number and degree of isolation (nearly significant). The results suggest that at least three species, Myotis brandti (Eversmann, 1845), M. mystacinus (Kuhl, 1819) and Plecotus auritus (Linnaeus, 1758), are negatively affected by forest patchiness. These species occurred mainly on large islands. Thus, the results do not support the hypothesis. The reasons why some species avoid open habitats are discussed.