Cerrado Of Central Brazil Research Articles

Territorial system and adult dispersal in a cooperative-breeding tanager

ABSTRACT Latitudinal differences in territorial behavior are considered to have great influence on differences in life-history strategies of Nearctic and Neotropical birds. Most territorial behavior of tropical birds has particularities that cannot be explained only by theories from studies of birds in temperate regions. We evaluated the territorial system of the cooperative-breeding White-banded Tanager (Neothraupis fasciata) in central Brazil's savanna and present results on stability of territory site occupation, relationship between territory size and group size, and dispersal patterns. Territories (n = 27, mean per season) were monitored for 3 yr in a protected area in the cerrado of central Brazil and were defined by the minimum convex polygon method. Territory size averaged 3.7 ± 0.6 ha, and was defended by all individuals of groups of 2–8 individuals (mean = 3.4 ± 1.2). We recorded 44 dispersal events between territories, and most individuals dispersed distances equal to one territory in length. M...

Morphological and acoustic characterization of Proceratophrys goyana (Lissamphibia: Anura: Odontophrynidae), with the description of a sympatric and related new species

Proceratophrys goyana was until recently the only species of the genus described from central Brazil. In this paper we characterize the adult morphology and advertisement call of this species, based on data collected at its type-locality (Chapada dos Veadeiros, Goiás, Brazil). These new data allowed us to recognize a new species of Proceratophrys, sympatric to P. goyana, which is described herein. Proceratophrys goyana is mainly characterized by the male SVL = 38.8-46.5 mm; a well-developed and continuous pair of dorsal sagittal ridges; upper eyelids triangular; developed frontoparietal crests, delimiting a shallow depression between them; overall color pattern browned, with the symmetrical dorsal ridges bordered laterally by dark brown undulations. Proceratophrys rotundipalpebra sp. nov. is characterized by the male SVL = 30.4-39.3 mm; the pair of symmetrical dorsal ridges well-developed anteriorly and somewhat interrupted in the sacral region; upper eyelids short and rounded; frontoparietal crests not well-developed; overall color pattern stained by 3-4 tonalities of gray, without a clear background color. The advertisement calls of both species are emitted in a multi-note pattern, each note pulsed, the first and last notes differing from each other and from those amidst the call in temporal features. The description of this new species is another example of the underestimated diversity of Proceratophrys in the Cerrado of central Brazil.

Self-sterility and self-fertility of Passiflora L. (Passifloraceae) in the Cerrado of Central Brazil

Many species of wild passion fruit are used for the genetic breeding of passion fruit crop and kept in germplasm banks. This study investigated floral biology, breeding system, and chromosome number of Passiflora species that occur in areas of Cerrado in Uberlândia, Minas Gerais, from 2008 to 2010. In general, the species bloomed in the rainy season, the anthesis was diurnal, except for P. tricuspis, and flowers were open from 6 to 12 h. At the time of flower opening, the nectar was already accumulated in the nectariferous chamber. Protandry occurred only in P. tenuifila. Bees were the main flower visitors of these species. There were significant differences in the diameter and length of the floral androgynophore among species. Passiflora amethystina, P. tenuifila (both subgenus Passiflora), and P. suberosa (subgenus Decaloba) were self-fertile, while P. cincinnata (subgenus Passiflora) and P. tricuspis (subgenus Decaloba) were self-sterile, which contrasted with the usual trends in the group. The chromosome number for P. tricuspis was 2n = 12, P. amethystina and P. tenuifila were 2n = 18 chromosomes, and P. suberosa was 2n = 24 chromosomes, which conformed to the recorded results for the group. Overall conservative chromosome numbers, and self-fertility in P. amethystina are interesting results for breeding programs and basic information for conservation.

Cladocerans (Crustacea, Anomopoda and Ctenopoda) from Cerrado of Central Brazil: Inventory of phytophilous community in natural wetlands

The aim of this study was to inventory the cladoceran fauna in wetlands located in two large areas that protect fragments of Cerrado. Located in the Brasília National Park-DF and Campo de Instrução de Formosa-GO, these wetlands are formed by upwelling groundwater, with extensive vegetation cover. We found 24 species in the Brasília National Park and 30 in the Campo de Instrução de Formosa. The observed richness reached approximately 80% of the estimated values for both protected areas. Moreover, the community of cladocerans in the kind of environment studied appears to be influenced by depth, with higher values of richness and similarity in wetlands of higher average depths. However, shallow wetlands contributed to the total richness with exclusive species, which shows the importance of these habitats for species richness.

Deforestation causes different subregional effects on the Amazon bioclimatic equilibrium

AbstractDeforestation on Amazonia and central Brazil Cerrado could change regional climate, possibly shifting forest equilibrium into a bioclimatic envelope typical of savannas. Although impacts of climate change induced by deforestation are likely to vary subregionally, the potential geographic variation of these effects and the thresholds of rainforest and Cerrado removal that will affect Amazonian bioclimatic equilibrium remain unknown. We evaluate the effects of deforestation scenarios of increasing severity on the bioclimatic equilibrium of Amazon subregions. Results indicate that subregional precipitation responds in three distinct ways to progressive deforestation: a near‐constant rate of reduction, a rapid drop for low deforestation levels, and a decrease after intermediate deforestation levels. Additionally, while inner forest regions remain inside rainforest bioclimatic envelope, outer forest regions may cross forest‐savanna bioclimatic threshold even at low deforestation levels. We argue that at least 90% of Amazonia and 40% of Cerrado should be sustained to avoid subregional bioclimatic savannization.

Diet of the gracile mouse opossum Gracilinanus agilis (Didelphimorphia: Didelphidae) in a neotropical savanna: intraspecific variation and resource selection

Investigation of the effect of endogenous and exogenous factors on the diet of animals is necessary for a better understanding of their feeding habits. This approach can provide relevant information on the autoecology of a species and its ecological interactions. We investigated the composition and intraspecific variation in the diet of the marsupial Gracilinanus agilis in areas of dry woodland forests (i.e., cerradao) in the Cerrado of Central Brazil, taking into consideration the availability of prey (arthropods) in the environment. We found insects, spiders, birds, and fruits in the scats of G. agilis. Insects (orders Hymenoptera, Isoptera, Hemiptera, and Coleoptera) and fruits were the most frequently consumed resources. Males fed more heavily on insects than females did, whereas during the warm–wet season (October to April), the reproductive females fed on insects more than the nonreproductive females did. On the other hand, the consumption of fruits and vertebrates did not vary between seasons, sexes, or according to female reproductive condition. Moreover, reproductive females fed more frequently on ants and beetles than nonreproductive females did. We also detected both positive (for Isoptera and Hemiptera) and negative (for Hymenoptera) selection of insects during the cool–dry season, whereas in the warm–wet season, these resources were consumed according to their availability in the environment. Our study revealed that G. agilis is an insectivore–omnivore species, but fruits also are a relevant part of its diet. This marsupial seemed to select their prey qualitatively according to its energy demands and nutritional requirements.

Cryptic diversity in South American Teiinae (Squamata, Teiidae) lizards

Based on phylogenetic and molecular dating analyses of several species of Cnemidophorus and Ameiva, representing major groups of species of these two genera, we uncover a previously unrecognized Ameiva lineage, which includes described Cnemidophorus parecis from south‐western Amazonia. We discuss the diagnosis of Ameiva and Cnemidophorus and the implications of the new taxonomic rearrangement of genera from Teiidae for the monophyly of Ameiva. Based on the conclusion of our analyses, we provide description of a new species named Ameiva jacuba from the central Brazilian Cerrado and a detailed diagnosis for the relocation of C. parecis to Ameiva. We do not adopt here recent taxonomic changes proposed for Teiidae and provide a discussion about them. Finally, based on molecular dating and the distribution of living species, we propose an evolutionary scenario for the origins of South American cis‐Andean Ameiva lineages, associated with the topographic subdivision of the Cerrado region during Miocene marine introgressions.

Two sympatric Byrsonima species (Malpighiaceae) differ in phenological and reproductive patterns

Sympatric and taxonomically related species may present pre- and/or postzygotic mechanisms for reproductive isolation. We compared the phenology and reproductive biology of Byrsonima intermedia and B. pachyphylla, two sympatric Malpighiaceae species, growing in a remnant of Cerrado in Central Brazil. Both species are evergreens and do not have an overlapping flowering period. In both species, dispersal occurs during the rainy season with low and intermediate overlap in the production of immature and mature fruits, respectively. Both species exhibit self-incompatibility (SI), or, in the case of B. intermedia, facultative SI, and, hence, depend on pollinators to compensate for the lack of spontaneous self-pollination. The flowers of the Byrsonima species were visited by fifteen species of bees that collected pollen and/or oil. Based on their more appropriate intrafloral posture, Epicharis flava and Centris varia were the main pollinators of both species, presenting more frequent visits and/or exhibiting trapline foraging behavior, tending to promote outcrossing. Temporal variation in flowering period and total or partial self-incompatibility seem to function as prezygotic isolation mechanisms that form barriers to gene flow between the studied species and probably avoid competition among pollinators. Both species make oil and pollen available to flower visitors and pollinators almost the entire year, but since Byrsonima intermedia has a long flowering time and is very abundant in the study area, it seems to be more important in maintaining flower-visiting bees.

Chemical variability in the essential oils from leaves of Syzygium jambos

Syzygium jambos (L.) Alston, Myrtaceae, occurs in tropical regions and is a widespread medicinal plant used to treat several diseases, such as hemorrhage, dysentery, diabetes, inflammation, diabetes and gastrointestinal disorders. Leaf essential oils of ten specimens of S. jambos collected from two localities of Central Brazilian Cerrado were investigated by GC-MS. Soil and foliar nutrients were analyzed to determine the mineral compositions. The aims of this study was to evaluate the influence of environmental factors on chemical composition of leaf essential oils of S. jambos. Studies on the influence of environmental factors over composition of essential oils are important because they contribute data for its cultivation, harvest and establish parameters to essential oil components. The data were analyzed using stepwise Multiple Regression and Cluster Analysis, and the results suggest that the main factor capable to influence the chemical composition of leaf essential oils was the collection period and the collection site had a minor effect. The results also suggest that the leaf essential oils composition was influenced mainly by foliar nutrients (N, Mn, Co, Fe, S and Mg) and soil nutrients (Na, Al, S and H+Al). The compound with the best model obtained was the (E)-caryophyllene, with a coefficient of determination equal 0.8113.

Assessing the spatio-temporal rates and patterns of land-use and land-cover changes in the Cerrados of southeastern Mato Grosso, Brazil

The Cerrados of central Brazil have undergone profound landscape transformation in recent decades due to agricultural expansion, and this remains poorly assessed. The present research investigates the spatial-temporal rates and patterns of land-use and land-cover (LULC) changes in one of the main areas of agricultural production in Mato Grosso State (Brazil), the region of Primavera do Leste. To quantify the different aspects of LULC changes (e.g. rates, types, and spatial patterns) in this region, we applied a post-classification change detection method, complemented with landscape metrics, for three dates (1985, 1995, and 2005). LULC maps were obtained from an object-based classification approach, using the nearest neighbour (NN) classifier and a multi-source data set for image object classification (e.g. seasonal Thematic Mapper (TM) bands, digital elevation model (DEM), and a Moderate Resolution Imaging Spectroradiometer (MODIS)-derived index), strategically chosen to increase class separability. The results provided an improved mapping of the Cerrados natural vegetation conversion into crops and pasture once auxiliary data were incorporated into the classification data set. Moreover, image segmentation was crucial for LULC map quality, in particular because of crop size and shape. The changes detected point towards increasing loss and fragmentation of natural vegetation and high rates of crop expansion. Between 1985 and 2005, approximately 42% (6491 km2) of Cerrados in the study area were converted to agricultural land uses. In addition, it was verified that cultivated areas are encroaching into fragile environments such as wetlands, which indicates the intense pressure of agricultural expansion on the environment.

Environmental factors affecting the concentration of phenolic compounds in Myrcia tomentosa leaves

Myrcia tomentosa (Aubl.) DC., Myrtaceae, found in Central Brazilian Cerrado and popularly known as “goiaba-brava”, belongs to the Myrcia genus, which has several species with medicinal properties such as: hypoglycemic, diuretic, hypotensive, antidiarrheal, antimicrobial and antitumor. The present study aimed to analyzed the environmental infl uence on concentrations of phenolic metabolites in M. tomentosa leaves. Compounds assayed in the leaves were: total phenols, tannins by protein precipitation, hydrolysable tannins and total fl avonoids and mineral nutrients, while soil fertility was also analyzed, all over during one year. The results were submitted to Pearson Correlation Analysis and stepwise Multiple Regression Analysis to investigate the relationship between phenolics and environment data. Analysis of variance and Cluster Analysis allowed indicated a high variability in samples from different sites. The results obtained suggests that content of phenolics from M. tomentosa leaves are infl uenced by environmental factors, particularly some foliar nutrients (Nl, Cal and Mnl), soil nutrients (Cas and Ks) and Rainfall.

Spatial Chemometric Analyses of Essential Oil Variability inEugenia dysenterica

Chemovariations in essential oils were used for studying the spatial chemical structure of eight E. dysenterica populations in Central Brazilian Cerrado. Previously, multivariate Mantel autocorrelogram and chemical matrix variation partitioning, using the spatial and environmental data sets as predictors, have suggested a highly significant spatial variation in essential oils. In the present study, spatial chemometric methods using variograms and probability maps detected and characterized the spatial chemical structure among populations, as well as the environmental factors responsible for them. All these strategies indicated that the populations differ chemically whenever the geographical distance exceeds 120 km, an indicator of the minimal distance between samples required for conserving the genetic diversity of populations. Although being scarcely used with secondary metabolites, these methodologies may be used in a wide range of applications in species management and may lead to an effective integration of genetic, chemical and ecological perspectives.

Use of habitats by non-volant small mammals in Cerrado in Central Brazil

Non-volant small mammals are organisms capable of yielding precise information on richness, abundance and species composition variations related to the use of habitats. The aim of this research was to compare these variations in Cerrado sensu stricto, Palm Forest, Gallery Forest and Rocky Field. From May 1999 to February 2000, we surveyed non-volant small mammals (hence small mammals) in Serra das Araras Ecological Station. We captured 218 individuals and recaptured 62 individuals, belonging to 21 taxa, 13 rodents and eight marsupials, in a total of 13200 trap-nights. Capture success was 1.7%. We observed higher richness of small mammals in forested areas (Gallery Forest and Palm Forest) than in open areas (Rocky Field and Cerrado sensu stricto). The Palm Forest had the highest richness of marsupials, possibly due to the quality of a specific niche. The Rocky Field had the smallest richness, but with very high abundance of few species, mainly Thrichomys pachyurus and Monodelphis domestica. Forest habitats had similar species composition. The open habitats, Cerrado sensu stricto and Rocky Field, had a distinct species composition between them, and also when compared to forested areas. Different species are exclusive or showed preference for specific habitats. The protection of horizontally heterogeneous biomes, such as Cerrado, has a fundamental importance to the maintenance of the regional diversity of the small mammal community of Central Brazil.

Spatial structure of Eugenia dysenterica based on essential oil chemovariations and implications for conservation and management of the genetic diversity of its populations

The chemical composition of essential oils was used to study the spatial structure of eight Eugenia dysenterica populations in central Brazilian Cerrado. Variation partitioning using spatial and environmental data sets as predictors was highly significant and explained 7.8 and 8.1% of oil chemovariations, respectively. Results suggested that essential oil polymorphism was genetically rather than environmentally determined. Furthermore, the intercept of the multivariate Mantel autocorrelogram between the distance matrices of oil constituents and sampling sites suggested that the populations differ chemically whenever geographical distance exceeds 120 km. It stands, therefore, as an alternative indicator of the minimal distance between samples required for conserving the genetic diversity of populations.

Chemotaxonomic markers in essential oils of Hypenia (Mart. ex Benth.) R. Harley

Central Brazilian Cerrado is regarded as the center of origin and dispersion of Hypenia (Lamiaceae: subtribe Hyptidineae) in South America. The genus has either remained undivided or been divided into two or seven taxonomic sections, based almost exclusively on a limited range of floral features. Interspecific chemical delimitation to complement analyses of botanical traits is described. Multivariate analysis of essential oils of ten species in the vegetative stage supports the taxonomic division in two sections. Cluster I included four species belonging to section Laxiflorae in addition to H. irregularis, which were characterized by the highest percentages of spathulenol and caryophyllene oxide. Cluster II contained five species belonging to section Densiflorae with α-cadinol, α-muurolene and a-muurolol as major constituents. Cadinanes and germacranes/ aromadendranes seem to be chemotaxonomic markers of sections Densiflorae and Laxiflorae, respectively. Furthermore, redundancy analysis revealed no significant correlation between edaphic factors and oil chemovariations, suggesting that Hypenia oils consist of constitutive rather than induced compounds.

Estudo fitoquímico de folhas de Solanum lycocarpum A. St.-Hil (Solanaceae) e sua aplicação na alelopatia

Solanum lycocarpum A.St.-Hil (Solanaceae) é um arbusto típico da região central do Brasil (Cerrado). A atividade alelopática do extrato aquoso de folhas e frutos dessa espécie já foi verificada em estudos anteriores. O objetivo desse trabalho foi avaliar a atividade alelopática de diferentes extratos de S. lycocarpum na germinação e crescimento de quatro espécies-alvo. As folhas foram coletadas, secas e trituradas e submetidas a dois métodos distintos de extração: 1- líquido-líquido (acetato de etila e diclorometano) do extrato aquoso das folhas e 2- com solventes em polaridade crescente (hexano, diclorometano, acetato de etila, acetona, metanol e água) diretamente das folhas. Cada extração foi realizada com equipamento de ultrassom durante uma hora, filtrado e evaporado. Desses extratos, soluções de 800, 400 e 200 ppm foram preparadas, e água e Logran® foram usados como controle positivo e negativo, respectivamente. Cada solução, bem como os controles, foi dissolvida em DMSO para os bioensaios. As espécies alvo usadas foram: alface, agrião, tomate e cebola. Cada placa era composta de 20 sementes e foi adicionado 1 mL de solução teste com 4 repetições. As placas foram incubadas a 25 ºC no escuro. Posteriormente, as plântulas tiveram suas partes aéreas e raízes medidas e a porcentagem de germinação e inibição calculada para cada extrato. Tomate foi a espécie que mostrou maior sensibilidade para todos os extratos, seguido de agrião, cebola e alface. Os extratos que tiveram maior atividade foram o acetato de etila, acetona e as extrações líquido-líquido, indicando as frações que devem conter os princípios ativos da folha dessa espécie.

Chewing lice (Insecta, Phthiraptera) and feather mites (Acari, Astigmata) associated with birds of the Cerrado in Central Brazil

The association of chewing lice and feather mites with wild birds of riparian forest was investigated in the Cerrado biome, Tocantins State, Brazil. The birds were captured with mist nets between July 2008 and March 2009. Ectoparasites were collected by the dust-ruffling technique. Infestation rates were determined by the sampling prevalence, abundance, and mean intensity of ectoparasites. A total of 1,479 chewing lice were collected that were distributed in 3 families and 18 genera, of which 15 taxa were identified to the species level. Sixteen genera of feather mites were found, and 10 species were identified. A high prevalence rate of chewing lice and feather mites was found in non-Passeriformes (66.7 and 50.0%) and Passeriformes (57.8 and 75.6%) birds. New host-parasite associations were registered for two species of chewing lice and for four species of feather mites, thus expanding the geographical distribution in Brazil of six chewing lice species. This is the first study of the ectoparasites of wild birds to be conducted in this region of Brazil.

Occurrence of Metarhizium spp. in Central Brazilian soils

The biodiversity of entomopathogenic fungi in tropical ecosystems is still little investigated, and the objective of this study was to isolate and identify fungi of the entomopathogenic genus Metarhizium (Hypocreales: Clavicipitaceae) present in undisturbed soils of the Central Brazilian Cerrado. A total of 107 Metarhizium isolates was obtained from soils collected from Cerrado sites in the state of Goiás; gene sequences from 63 of these were obtained and compared. Among these, one was confirmed to be M. anisopliae sensu stricto; 53 were very closely allied to M. anisopliae but require more extensive genetic characterization to determine if they might represent a new taxon in the M. anisopliae species complex. Eight of these Cerrado isolates were referable to M. robertsii, and the remaining isolate is the first South American (and Southern Hemisphere) collection of M. flavoviride var. pemphigi. These findings underline the need for better characterization of the diversity of these widely distributed fungi in Brazil.

Taxonomic and conservation status of the elusive Oecomys cleberi (Rodentia, Sigmodontinae) from central Brazil

The arboreal mouse Oecomys cleberi was described in 1981 based on just one specimen from Distrito Federal in central Brazil, and it has not been recorded ever since. Its taxonomic status as a valid species has been questioned and it is currently listed as Data Deficient in terms of conservation status. Here we used ancient DNA methods to obtain a partial mitochondrial cytochrome b gene sequence from the holotype of Oecomys cleberi. Very low levels of genetic divergence (0.6% on average) allowed us to associate sequences from specimens previously identified as O. bicolor to O. cleberi. Comparative analyses of morphological and molecular data confirmed the taxonomic status of O. cleberi as a valid species, and increased our knowledge on its geographic distribution to at least three additional localities in the Cerrado of central Brazil. Cytochrome b sequences of O. cleberi formed a well-supported monophyletic group and diverged 6.8% on average from those of O. bicolor, its sister species from the Amazon. We refined and improved the morphological description of O. cleberi based on the examination of 15 museum specimens, including the holotype, and suggest that other field and museum records of this species may have also been misidentified as O. bicolor. Considering that O. cleberi may be more common and widespread than previously suspected, we suggest the conservation status of Least Concern for this species. However, further studies are needed to understand population trends of O. cleberi, given that it is apparently endemic to the Cerrado biodiversity hotspot.

Frugivory and seed dispersal of Miconia theaezans (Bonpl.) Cogniaux (Melastomataceae) by birds in a transition palm swamp: gallery forest in Central Brazil

The objective of this study was to evaluate potential avian dispersers of Miconia theaezans by dietary habits in the Cerrado of Central Brazil. Forty-two hours and 40 minutes of focal tree observation were conducted between 7:00 AM and 5:00 PM. For each bird species that consumed the fruit, we registered: the time they remained on the plant, the total amount of fruit they consumed, foraging tactics and strategies to consume the fruit. Five-hundred and fifty-nine units of fruit were consumed in 47 visits by seven bird species. Thraupidae was the most frequent and representative family and Tangara cayana was the main consumer. The Tachyphonus rufus had the highest rate of intake of the entire fruit, however the rates were not significantly different among the visitors. The most-used foraging tactic by all species was to consume the fruit while "perched" (95.74% of the visits). The most commonly-used consumption strategy was to mandibulate the fruit and swallow all the contents (65.12%). Omnivores were the predominant visitors (71.43%) and made most of the visits (89.36%). All visiting species could act as potential dispersers of M. theaezans, which demonstrates the low selectiveness of this pioneer plant towards its frugivorous.