Central Cerrado Research Articles

The micronucleus test in Ameiva ameiva (Squamata: Teiidae) in riparian forests in the Central Cerrado, Brazil

Free-living species can be used as indicators to estimate the impact of environmental stressors. In this study, the heliophilous lizard Ameiva ameiva was used for the first time for the micronucleus test and other nuclear abnormalities. This biomarker is rapid and reliable in evaluating populations environmentally exposed to genotoxic agents. Thus, two animal populations were collected in the Cerrado Central riparian forests with pasture influence. The results indicated the presence of micronuclei and different nuclear erythrocyte abnormalities: cells with nuclear bud, segmented nucleus, notched nucleus, lobed nucleus, and reniform nucleus. There was no statistical difference in the frequency of DNA damage between the populations in the pasture areas. The inclusion of these species in biomonitoring programs seems relevant to shed light on the susceptibility to expression of genotoxic damage. This species has a wide geographic distribution in the Neotropical region, which makes it promising for research on environmental mutagenesis.

Long‐and short‐term vegetation change and inferred climate dynamics and anthropogenic activity in the central Cerrado during the Holocene

ABSTRACTA paleoecologic analysis of pollen, macrocharcoal and trace elements from a lacustrine sediment core located at Lake Feia, central Cerrado (Goiás State, Brazil), was used to evaluate the relationship between vegetation, fire and climate during the Holocene. The development of cerrado vegetation appears to have begun 6000 years ago, initially with the establishment of an open cerrado, followed from 4800 cal a bp by a change to a woody cerrado driven by an increase in summer insolation. The increases in precipitation levels in the central Cerrado during the last 5000 years are related to the increased influence of the Amazon in central Brazil, which has facilitated biomass burning and anthropogenic activities in the region of Lake Feia. Multi‐centennial‐scale changes in water level‐related and gallery forest pollen assemblages indicate three main dry episodes, at 3440–2760, 2700–1690 and 1330–1150 cal a bp, linked to regional shifts between northern and southern South American summer monsoon boundaries. The presence of low continuous fire activity does not appear to have affected vegetation recovery, whereas two intervals with increased fire activity, at ~3300 and ~1300 cal a bp, indicated a slower recovery.

Response of Conilon coffee cultivars in the central cerrado in irrigated management pivot sprinkler

Coffee cultivation has been growing significantly, since the world demand has increased considerably in recent decades. Among the coffees, conilon coffee has been a good option for cultivation in the Cerrado, as it presents good production in areas of high altitudes, however the study of canefora coffee in irrigated system in the Cerrado is something recent. The work aimed to analyze the productive potential of superior clones of caneflower coffee cultivars through agronomic performance under irrigated conditions in the Central Cerrado and to select the outstanding clones for future use in genetic improvement programs. The experiment was conducted in the experimental area of Embrapa Cerrados in Planaltina - DF, in a randomized block design with three replications. The cultivars evaluated were Diamante ES 8112, ES 8122 - Jequitibá and Centenária ES 8132, each composed of 9 clones totaling 27 conilon coffee genotypes, with different maturation times. The clones were planted with 3.5 x 0.5 m spacing in a center pivot irrigation system. The characteristics evaluated from two harvests (2018 and 2020) were: average grain yield (PMG); percentage of grains retained in sieve 16 (sieve > 16); percentage of mocha grains (GMO); average plant height (AP), crown projection (PC) and number of productive nodes (NNP). Data were submitted to analysis of variance and means were grouped by the Scott-Knott test at 5% significance level. Based on the result of the analysis of variance, there was a significant difference in all maturation cycles for the traits PMG, sieve > 16, GMO, AP, PC and NNP. The averages of grain size percentage in sieve size 16 or larger were distinct in the 3 groups analyzed. It was found that the averages of production of processed grains (PMG) were different in the two years evaluated, due to the environmental conditions imposed from one year to another. Within the clones, clone 207 presented the highest grain yield value in 2020 with 12493 kg ha-1. There was genotypic variability in the behavior of clonal varieties and their respective clones, being able to select clones and use them within breeding programs, for targeted crosses and subsequent development of new cultivars.

Changes in atmospheric circulation and evapotranspiration are reducing rainfall in the Brazilian Cerrado

Here we analyze the trends of rainfall and the frequency of rainy days over the Brazilian Cerrado between 1960 and 2021 in four distinct periods according to the seasonal patterns over the region. We also evaluated trends in evapotranspiration, atmospheric pressure, winds, and atmospheric humidity over the Cerrado to elucidate the possible reasons for the detected trends. We recorded a significant reduction in rainfall and frequency of rainy days in the northern and central Cerrado regions for all periods except at the beginning of the dry season. The most pronounced negative trends were recorded during the dry season and the beginning of the wet season, where we recorded reductions of up to 50% in total rainfall and the number of rainy days. These findings are associated with the intensification of the South Atlantic Subtropical Anticyclone, which has been shifting atmospheric circulation and raising regional subsidence. Moreover, during the dry season and the beginning of the wet season, there was a reduction in regional evapotranspiration, which also potentially contributed to the rainfall reduction. Our results suggest an expansion and intensification of the dry season in the region, potentially bringing broad environmental and social impacts that transcend the Cerrado boundaries.

Planting Date of Cotton in the Brazilian Cerrado Drives Boll Weevil (Coleoptera: Curculionidae) Infestation.

Although the boll weevil (BW), Anthonomus grandis grandis (Coleoptera: Curculionidae) has been attributed to the significant losses caused to cotton yield in the Americas, the categorization as a quarentenary pest in places where it is still not occurring has increased its relevance worldwide. In areas where it is widespread, pest suppression relies on many broad-spectrum insecticide applications. However, other control tactics are sought. Considering that early-flowering cultivars escape from boll weevil infestation, we investigated if three different planting dates (November, December, and January) could alter the plant life cycle, allowing the plants to escape from boll weevil infestation. Field trials were run in two seasons (2014/2015 and 2017/2018), and variables (days required to reach each flowering stage, fruiting plant structures-undamaged and damaged by the BW, and totals-number of boll weevils on plants and that had emerged from fallen structures on the ground) were assessed over 29 and 33 weeks, respectively. Based on the number of days required to initiate and terminate the flowering stage, the time to reach the economic threshold (ET), the number of undamaged, damaged, and the total reproductive structures, we concluded that planting dates in December for the Central Cerrado of Brazil should be preferred over the other two tested dates. Cultivations run at this planting date, anticipating the flowering period initiation and termination, reduced infested flowering structures, and delayed the decision making to control the pest, when compared to the other two planting dates.

Genetic structure of Enyalius capetinga (Squamata, Leiosauridae) in Central Cerrado and transitional areas between the Cerrado and the Atlantic forest, with updated geographic distribution.

The Brazilian Cerrado is considered a biodiversity hotspot highly threatened by human activities. Recently, many studies have demonstrated how underestimated is Cerrado's biodiversity considering squamate species, and the identification of divergent and cryptic lineages is essential for the formulation of effective conservation strategies. The transition areas between the Cerrado and the Atlantic Forest are even less knownand, consequently, often dismissed in conservation policies. As previous studies suggested the presence of cryptic diversity within E. capetinga, we investigated patterns and processes in the geographic distribution of its genealogical lineages. We used DNA sequences from individuals collected in six localities and sequences publicly available from three mitochondrial markers (CYT-B, 16S and ND4) and one nuclear marker (C-Mos). We tested if the core and ecotone regions of the Cerrado show differences in biotic and abiotic characteristics that could promote genetic structure and divergence among lineages within E. capetinga. We found evidence for divergent lineages within the species, but not congruent with our hypothesis. Similar divergent patterns were observed in other Cerrado lizards, including interspecific divergences within the Enyalius genus. Molecular characterization of field-collected individuals (previously identified as E. bilineatus), allowed us to update the geographic distribution of the species to include the ecotone between the Cerrado and the Atlantic Forest, an area where species distribution overlap.

Agronomic, anatomic and physiological characterization of Coffea arabica L. genotypes on irrigated system in the Central Cerrado

Due to climatic conditions and the possibility of using machineries, coffee has a potential to achieve high yields with reduced costs, in the biome of Cerrado. Leaf anatomy and physiology can help in the identification of more adapted cultivars to a given environmental condition. The objective is to verify the behavior of Coffea arabica L. genotypes in the Cerrado of the Brazilian Central Plateau through anatomical and physiological characterization and yield. Ten coffee genotypes from the Active Germplasm Bank located in the municipality of Planaltina, Distrito Federal, were evaluated. The genotypes evaluated were: Araponga MG1, Catiguá MG2, Catiguá MG3 P23, Catiguá MG3 P7, Catiguá MG3 P51, Catiguá MG3 P, Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 15, Paraíso MG1 and Topázio MG 1190. The phenotypic characteristics evaluated were the thickness of: adaxial cuticle surface, adaxial and abaxial epidermis surfaces, the palisade and spongy parenchyma, the mesophyll layer, the phloem, number and diameter of the xylem vessels, stomatal density,relationship between the polar and equatorial diameter of the stoma, specific leaf area, stomatal conductance, transpiration rate, net photosynthetic rate, water use efficiency, intercellular carbon concentration and yield. Genotypes of Coffea arabica L. presented a distinction between the characteristics evaluated when grown under climatic conditions of the Brazilian Central Plateau Cerrado, highlighting the variations in the behavior and distinguished adaptation in this environment. The Araponga MG1 genotype stood out for anatomical and physiological characteristics of higher values, such as net photosynthetic rate, stomatal conductance, intercellular carbon concentration, abaxial and adaxial epidermis thickness, stomatal density and number of xylem vessels. The genotype Paraíso MG1 stands out for higher grain productivity. The genotype Catuaí Vermelho IAC 15 stands out for anatomical and physiological characteristics such as higher stomatal density, greater number of xylem vessels and greater efficiency in water use, resulting in improved productivity.Key words: Adaptability; Coffee tree; Morphology; Grain yield; Gas exchange.

Assessing rainfall spatial variability in the Brazilian savanna region with TMPA rainfall dataset

Rainfall is a major component of the hydrological cycle. The lack of basic information on rainfall spatial variability is a major source of uncertainty in many fields of studies, e.g., meteorology, hydrology, and agriculture. Satellite rainfall measurements are becoming increasingly popular for their extensive database and reliable estimates. The objective of this study was to use the Tropical Rainfall Measuring Mission (TRMM) dataset along with rain gauges to characterize aspects of rainfall spatial variability and discuss the possible impacts from recent trends in the Brazilian savannah biome (Cerrado). Gauge stations were used to assess TRMM bias error and calibrate data for further analyses. Rainfall rates and their spatial variability showed a strong relationship to the transition zones between different biomes. Rainfall showed a decreasing trend for the eastern region of the Cerrado biome, a region characterized by a recent and significant expansion of crop areas. These trends agree with results from different studies which highlight the current drawdown of groundwater levels and reduced discharge, and possible lengthening of the dry season in the long run. As many conflicts have already been documented for this region, these decreasing trends are alarming for urgent and consistent hydroclimatic monitoring, and improved water resources planning and management. Positive trends for rainfall in the central Cerrado are likely a momentary recovery of recent-period drought.

Assessment of agricultural efficiency and yield gap for soybean in the Brazilian Central Cerrado biome

Soybean is the main crop grown in Brazil and is important to quantify the capacity of increase in yield by crop production intensification and management. This study aims to quantify yield gap and agricultural efficiency (AE) for soybean in Central Cerrado biome, Brazil. Yield gap by management (YGMG) and water deficit (YGWD) and AE and climate efficiency (CE) were calculated based on potential (PoY), attainable (AtY) and actual (AcY) yields. Potential yields and AtY were simulated for the main sowing date, ranging from Oct 11 to Nov 01, using the agroecological zone crop model, from 1980/81 to 2016/17 growing seasons. The sites were Rio Verde (GO), Cristalina (GO), Barreiras (BA) and Peixe (TO). Actual yield was obtained from official statistics for each site. Agricultural efficiency rate for this period and its relationship with CE were analyzed. The YGMG were 4,345, 3,446, 4,531 and 2,649 kg·ha–1 for Rio Verde, Cristalina, Peixe and Barreiras, respectively. Barreiras had a higher YGWD when compared with other sites, reaching a mean of 6,526 kg·ha–1. However, Barreiras had a higher AE (51%), indicating that crop management applied in this region can explore the environmental conditions more than other sites. Agricultural efficiency showed an increasing rate from 0.70 to 1.21% per year, while the relation between AE and CE fitted an exponential negative function, by which higher water volume available reduced AE. Thus, it is possible to double soybean yield through improvements in management based on AtY (7,409 kg·ha–1) and AcY (3,260 kg·ha–1) in Central Cerrado biome, Brazil.

Ecological niche modelling and genetic analyses reveal lack of geographic differentiation of Leptolobium dasycarpum (Leguminosae, Papilionoideae) across the Brazilian savannah

Trees from Brazilian savannah (Cerrado), especially species of the family Leguminosae, generally show genetic discontinuity among their populations. This leads to the formation of geographically delimited groups. This study assesses the effects of historical climatic changes during the Quaternary glaciations on the demography, diversification and spatial distribution of Leptolobium dasycarpum, a useful tree species of the Cerrado, using phylogeography and spatial distribution modelling. We sampled freshly collected and herborized individuals throughout L. dasycarpum’s distribution and sequenced two plastid intergenic spacers (133 plants) and the ITS region from the nuclear ribosomal DNA (124 plants). The current study’s framework incorporated statistical phylogeography, coalescent analyses and ecological niche modelling. The species presented significant differentiation among populations, with no geographically differentiated groups along the Cerrado and no signs of recent demographic changes. The species also experienced a moderate reduction of its suitable niche distribution during the Last Glacial Maximum. Moreover, the data suggested that the ancestral distribution area of L. dasycarpum was the central Cerrado and that colonization of adjacent areas occurred only recently. The results suggested that the central region of the Cerrado is the centre of L. dasycarpum lineage diversification and there are no significant barriers to gene flow among populations from the different regions of Cerrado. Historical climate changes did not impact the demographic history of L. dasycarpum probably due to the demographic stability throughout the Quaternary allied to the life history traces of this species.

Vegetation and fire variability in the central Cerrados (Brazil) during the Pleistocene-Holocene transition was influenced by oscillations in the SASM boundary belt

This study investigates historical fire regimes and arboreal cover variability in the Brazilian Cerrados, a large Neotropical savanna ecosystem, during the Pleistocene-Holocene transition and early Holocene, and then tests whether the observed variation is linked to South American Summer Monsoon (SASM) variability. We present high-resolution pollen, XRF and charcoal records from Lagoa Feia, located in central Cerrados, and assess how they compare with other pollen records from the surrounding region to investigate regional trends of vegetation and fire regime variability. Our results show that the Pleistocene-Holocene transition was marked by a wet episode, which included moist forest expansion and rising lake levels, that correlates well with increased monsoon activity in a large area of central South America during the same period. This wet episode chronologically coincides with the Younger Dryas cold episode in the northern hemisphere. Our data revealed moisture declines in central Cerrados after 11.2 kyr BP, along with centennial-scale fluctuations from dry to wet conditions throughout the early Holocene period until around 6 kyr BP. These dry/wet oscillations are associated with weakened SASM activity and repeated shifts of its belt position during this time range. Fire activity increased in central Cerrados just after the onset of drier conditions during the early Holocene, and likely contributed to decreased arboreal cover at that time. A trend of increasing moisture in the region was observed after 6 kyr BP. Our study reveals how centennial and millennial-scale changes in monsoon activity influenced arboreal cover, diversity and fire regimes in the central Cerrados.

Fire management and aspects of the nesting biology of the Red-legged Seriema (Cariama cristata) in woodlands at Parque Nacional das Emas, central Cerrado

In the Brazilian Cerrado Biome, fire management within conservation units is usually restricted to burning grassland and woodland strips during the dry season to stop fires from spreading. Although it is a common practice, the impact of fire management on birds remains poorly investigated. This study aimed to examine the effects of fire management on nest-site selection by the Red-legged Seriema, Cariama cristata, and to describe nest-building characteristics at Parque Nacional das Emas (PNE). Nests were searched and monitored throughout 34 study sites between October and November 2006. These sites were 2.5-km strips of Campo Cerrado woodlands with (firebreaks) and without fire management, located at the interior and boundaries of the park. A total of 13 nests were found, all within firebreaks at the edge of the park. Nine (69%) of them were in fruiting Pouteria torta (Mart.) (Sapotaceae). Two or three white eggs were found in the nests. Nests had eggs and nestlings in October and no nestlings were found in November. Nests were usually in tree canopies and some of them were built nearly over the park’s fence. At PNE, breeding pairs of C. cristata are attracted to firebreaks located at the park’s boundaries. This is probably due to mobility through often burnt vegetation and ease in obtaining food from adjacent unsealed roads, exotic plantations and cleared areas. This study suggests that fire managers should: 1) avoid extinguishing natural fires initiated during the rainy season and 2) rotate controlled burning of patchy areas of Campo Cerrado woodlands. These two procedures should ensure the presence of suitable woodlands with short grasses in interior portions of PNE.

Genotoxic Evaluation in Tadpoles Associated with Agriculture in the Central Cerrado, Brazil.

Many agricultural practices cause environmental degradation that affects the cellular integrity of anurans. In the present study, we provided in situ data of Dendropsophus minutus, Physalaemus cuvieri, and Scinax fuscovarius collected in soybean/corn and conservation units in the Brazilian Cerrado. The in situ data showed no significant variation in the micronucleus frequency between the sites, only the reniform cells had a higher rate for the agricultural environment. A combined analysis of all nuclear erythrocyte abnormalities (ENAs = nuclear buds, reniform nuclei, apoptotic cell, binucleated, and anucleated cells) was recorded higher frequencies in farmland. Overall, Scinax fuscovarius was considered the best potential bioindicator for soybean/corn plantations. Finally, we recommend expanding the micronucleus test for in situ studies to expand our understanding of the sensitivity of native anuran species and provide a more systematic assessment of the adverse effects of environmental pollutants on wildlife.

IDENTITY TEST OF MODELS GENERATED IN NEUTRON PROBE CALIBRATION IN LATOSOL CULTIVATED WITH COFFEE AND SIGNALGRASS

<strong>ABSTRACT: </strong>The sustainability of agricultural production can be improved through the use of cover crops. The objective of this study was to evaluate the Model Identity Method in the verification of equality of linear regressions resulting from the calibration of a neutron probe for different layers, as a function of signalgrass management as a cover crop between rows of soil coffee crop in the Brazilian Central Cerrado. Aluminum tubes were installed to access the probe and two saturation basins were built in a coffee area, irrigated by a central pivot, in an Oxisol, with two management systems, T (Traditional with bare soil) and B (Signalgrass in the row). Samples were taken at depths of 0-0.20; 0.20-0.40; 0.40-0.60; and 0.60-0.80 m for the determination of physical and water properties and monitoring of soil drying; concomitant measurements were taken with the neutron probe in these layers. Two calibration curves were constructed for each layer, which were compared by the above method. It was observed that treatment B yielded differences in soil water storage in the 0.20-0.40 m layer, differing from treatment T. The statistical method allowed the observation of equality of regressions between treatments B and T at depths 0-0.20, 0.40-0.60, and 0.60-0.80 m; it also showed the need for different regression curves per layer, besides justifying the need for neutron probe calibration for each specific local condition.

Evolving in isolation: Genetic tests reject recent connections of Amazonian savannas with the central Cerrado

AbstractAimThe effects of past climatic shifts remain enigmatic for the Amazon region, especially for islands of savanna within the tropical forest known as “Amazonian savannas” (AS). These disjunct savanna areas share many plant and animal species with the Cerrado biome in central Brazil (the CC), fuelling debate over historical connections. We evaluate hypothesized corridors between the CC and the AS, and specifically investigate whether a history of isolation versus recent connections is supported by genetic tests.LocationCerrado and Amazon biomes.TaxonTwo woody plant species: Byrsonima coccolobifolia and B. crassifolia (Malpighiaceae).MethodsAnalyses of genomic data (SNPs from more than 4,500 loci) in 28 populations, as well as chloroplast DNA (cpDNA), were used to test for parallel geographic structuring between the CC and AS—an expected structure if putative corridors provided regional connections between different areas of the CC and AS, and divergence times between the CC and AS were estimated using a composite‐likelihood method based on the site frequency spectrum.ResultsGenomic data, in contrast with cpDNA, generally show strong, concordant genetic structure between the CC and AS in both species, rather than regional grouping of CC with AS populations. In addition, divergence between the CC and AS predates the Last Glacial Maximum.Main conclusionsOur results suggest the AS have remained relatively isolated from the CC even though the strong structure of genomic variation is not shared by cpDNA. We note that past evidence of putative corridors between the CC and AS based solely on cpDNA should be interpreted cautiously since the lack of structure may reflect limited genetic resolution rather than gene flow. As such, the uniqueness of AS may be more pronounced than previously thought, highlighting the importance of protecting these highly threatened areas.

A new species of Apostolepis (Serpentes, Dipsadidae, Elapomorphini) from the Cerrado of Central Brazil.

We describe a new species of the genus Apostolepis found near São Salvador Hydroelectric Power Plant, municipality of São Salvador do Tocantins, in the central Cerrado ecoregion. The new species is distinguished from its congeners by the following combination of characters: presence of eleven dorsolateral stripes, five infralabial scales and the lack of preoculars scales. The new species shares some external characteristics mainly with A. arenaria, A. gaboi and A. nelsonjorgei, with which it is compared.

Spatially-explicit analyses reveal the distribution of genetic diversity and plant conservation status in Cerrado biome

Despite the huge biodiversity of the Cerrado biome, a synthesis on the distribution of genetic diversity across the biome is still wanting. We describe patterns of plant genetic variation across the Cerrado biome, highlighting areas of high diversity and priority areas for conservation. We also analyze the relative importance of environmental characteristics and human footprints on patterns of genetic variation. Raw genetic data comes primarily from central and southeastern Brazil, outside conservation units (CUs). Standardized estimated genetic richness (Gest) decreases in a north–south gradient. Populations with high genetic diversity (He) and allelic richness (AR) are widespread across the biome, but both increase with distance from the center of Cerrado. Environmental variables related to energy, temperature and precipitation are associated with Gest and AR, but not He. Gest is higher in northern Cerrado, in regions with low human development index (HDI). Conversely, southern Cerrado shows higher HDI and lower genetic richness, most likely due to both high habitat fragmentation and loss. CUs in northern Cerrado tend to have higher Gest, whereas those in southeast and central Cerrado have higher He and AR. The high genetic diversity and richness in the few populations studied in northern Cerrado, coupled with the low data availability, reveal the importance of encouraging genetic studies in this region. Moreover, very limited information about population genetic diversity is available from CUs, which may constrain the access of species conservation status and decision-make on management of populations inside CUs.

Unravelling the genetic differentiation among varieties of the Neotropical savanna tree Hancornia speciosa Gomes.

Spatial distribution of species genetic diversity is often driven by geographical distance (isolation by distance) or environmental conditions (isolation by environment), especially under climate change scenarios such as Quaternary glaciations. Here, we used coalescent analyses coupled with ecological niche modelling (ENM), spatially explicit quantile regression analyses and the multiple matrix regression with randomization (MMRR) approach to unravel the patterns of genetic differentiation in the widely distributed Neotropical savanna tree, Hancornia speciosa (Apocynaceae). Due to its high morphological differentiation, the species was originally classified into six botanical varieties by Monachino, and has recently been recognized as only two varieties by Flora do Brasil 2020. Thus, H. speciosa is a good biological model for learning about evolution of phenotypic plasticity under genetic and ecological effects, and predicting their responses to changing environmental conditions. We sampled 28 populations (777 individuals) of Monachino's four varieties of H. speciosa and used seven microsatellite loci to genotype them. Bayesian clustering showed five distinct genetic groups (K = 5) with high admixture among Monachino's varieties, mainly among populations in the central area of the species geographical range. Genetic differentiation among Monachino's varieties was lower than the genetic differentiation among populations within varieties, with higher within-population inbreeding. A high historical connectivity among populations of the central Cerrado shown by coalescent analyses may explain the high admixture among varieties. In addition, areas of higher climatic suitability also presented higher genetic diversity in such a way that the wide historical refugium across central Brazil might have promoted the long-term connectivity among populations. Yet, FST was significantly related to geographic distances, but not to environmental distances, and coalescent analyses and ENM predicted a demographical scenario of quasi-stability through time. Our findings show that demographical history and isolation by distance, but not isolation by environment, drove genetic differentiation of populations. Finally, the genetic clusters do not support the two recently recognized botanical varieties of H. speciosa, but partially support Monachino's classification at least for the four sampled varieties, similar to morphological variation.

Species-specific phylogeographical patterns and Pleistocene east-west divergence inAnnona(Annonaceae) in the Brazilian Cerrado

The Brazilian Cerrado is the most diverse savanna in the world. Phylogeographical patterns for Cerrado tree species are relatively congruent; however, the causes of these patterns are not clear. Ours aims were to investigate phylogeographical patterns in two co-distributed Annona spp. in the Cerrado and identify the factors responsible for their genetic structure. We sequenced non-coding plastid DNA regions and estimated divergence times using a Bayesian Markov chain Monte Carlo method implemented in BEAST. Generalized linear mixed models (GLMMs) were used to relate genetic divergence with spatial, climatic and phytogeographic data. Annona crassiflora possessed only one haplotype, whereas A. coriacea possessed nine haplotypes constituting two groups: western and eastern. Haplotype diversification first occurred in the Pliocene; the split between eastern and western groups was dated to the Early Pleistocene. GLMMs detected a weak association of genetic distance with current climatic factors, represented mainly by precipitation in the warmest months. In A. coriacea, the north of central Cerrado (around Serra Geral de Goias) is suggested as a putative Pleistocene refugium. The current climate and dispersal and local adaptation processes probably contribute to maintaining the east–west genetic structure in A. coriacea. Both Annona spp. show idiosyncratic population histories, reminiscent of the complex biogeography of the Cerrado.

Striped-tailed Yellow-finch nesting success in abandoned mining pits from central Brazilian cerrado.

Suitability of degraded areas as breeding habitats can be tested through assessment of nest predation rates. In this study we estimated nest success in relation to several potential predictors of nest survival in the Stripe-tailed Yellow-finch (Sicalis citrina) breeding in abandoned mining pits at Brasília National Park. We monitored 73 nests during the 2007-breeding season. Predation was the main cause of nest failure (n = 48, 66%); while six nests were abandoned (8%) and 19 nests produced young (26%). Mayfield's daily survival rates and nest success were 0.94 and 23%, respectively. Our results from nest survival models on program MARK indicated that daily survival rates increase linearly towards the end of the breeding season and decrease as nests aged. None of the nest individual covariates we tested - nest height, nest size, nest substrate, and edge effect - were important predictors of nest survival; however, nests placed on the most common plant tended to have higher survival probabilities. Also, there was no observer effect on daily survival rates. Our study suggests that abandoned mining pits may be suitable alternative breeding habitats for Striped-tailed Yellow-finches since nest survival rates were similar to other studies in the central cerrado region.