Campo Sujo Research Articles

A comprehensive checklist of the angiosperms of a Cerrado fragment reveals outstanding species richness in the state of Maranhão, Brazil

The Morros Garapenses Environmental Protection Area (EPA) is home to significant biodiversity and an important paleobotanical site, with Permian fossil records, being a strategic area for studies in Maranhão. The objective of this study was to provide a list of species of phanerogams from the Morros Garapenses EPA. The material was collected through the walking method on pre-existing trails at different elevations and phytophysiognomies. The collection, herborization, identification, and classification of species followed the usual methodology for this type of research. A total of 297 species distributed in 196 genera and 70 families were cataloged. The families with highest specific richness were Fabaceae (60 species), Malvaceae (20 spp.), Rubiaceae (18 spp.), Cyperaceae (16 spp.), Euphorbiacae (14 spp.), and Bignoniaceae (13 spp.). Forty-nine species were endemic to Brazil, fifteen are being reported for the first time from Maranhão, and five from Cerrado. Several phytophysiognomies were found in the area, namely, Cerradão (33 species), Campo sujo (7 spp.), typical Cerrado (154 spp.), veredas (10 spp.), riparian forest (5 spp.), and anthropized areas (5 spp.). The study revealed a significant number of species in the Morros Garapenses EPA, stressing the urgent need to create a management plan for the sustainable use of natural resources and recovery of degraded areas.

Groundwater Level Variation Analysis Using Hydrogeophysical Methods in an Area of Campo Sujo in Cerrado, Chapada dos Veadeiros Region, Goiás

Cerrado’s campo sujo areas have been one of the main focuses of anthropic occupation in the Chapada dos Veadeiros region, Brazil’s Central Plateau, as they are easily accessible flattened areas with less dense vegetation. They are usually associated with wetlands representing excellent water reservoirs and groundwater recharge zones. The environmental characterization and analysis of water level variation are essential to investigate the impacts of human occupation. Hydrogeophysics represents one of the main subsurface research tools due to its easy application and efficiency in identifying the water level, with emphasis on Ground-penetrating radar (GPR), and electrical resistivity tomography (ERT). An analysis of GPR sections with 200, 400, and 900 MHz frequency antennas associated with the resistivity model was carried out to identify structures, and map the groundwater level. The overlapping data compose a hydrogeophysical model with good correlation to direct measurements of water level in a monitoring well, and soil horizons mapped in a trench. The GPR proved to be efficient in mapping the water level, mainly about to the survey with a 400 MHz antenna, shown as a horizontal reflector associated with attenuation portions of the reflection signal, registering in profile the lowering of the water level from 1.68 m in May to 3.35 m in August. The resistivity model showed a good correlation with the variations between the mapped soil horizons. The analysis shows that constructing a hydrogeophysical model is an excellent alternative for identifying the water level, and characterizing the shallow subsurface by applying non-invasive techniques. The study area represents a preserved area of campo sujo, and the research data can be used for comparison with future surveys, in addition to representing a base hydrogeophysics methodology that showed promising results for the physiographic characteristics of the area, which can be replicated in regions of similar geoenvironmental aspects.

Nitrogen and phosphorus pools and fluxes in upland and seasonally flooded forests and woodlands of the Cerrado-Pantanal transition of Brazil

Brazilian tropical savanna (referred to as Cerrado) has enormous structural variability ranging from tree- and shrub-free grasslands to tall, dense forests that are found in both well-drained upland and seasonally flooded (hyperseasonal) landforms. These structural and hydrological variations cause variations in aboveground carbon (C) storage, and presumably nitrogen (N) and phosphorus (P) storage and fluxes; however, the effects of these structural and hydrological variations on ecosystem N and P pools and fluxes are less well-known. Thus, our objective was to analyze N and P pools and fluxes for a spectrum of Cerrado physiognomies in both upland and hyperseasonal landforms. N and P pools and fluxes were compiled over an 8-10 year period in structurally different forms of Cerrado, including both upland and hyperseasonal grass dominated (campo sujo), typical wooded (sensu stricto) and dense wooded cerrado, and forested Cerrado stands located in the Cuiaba Basin and Northern Pantanal of southern Mato Grosso, Brazil. We found that aboveground N and P storage was generally higher in forested Cerrado than in non-forest landcover types, regardless of hydrology; however, these patterns were not consistent as wood N and P storage was just as high in typical- and dense-wooded savanna as in forested savannas. Wood typically made up the largest aboveground vegetation N and P reservoir, even for woody-grass savanna (campo sujo) which had a substantially lower tree density than wooded or forested savanna, followed by litter and roots, and then foliage. However, the vast majority of N and P was found in the upper 50 cm soil layer, accounting for 82-98% and 72-98% of the total ecosystem N and P, respectively, and even if only the 0-10 cm soil layer is considered, more than half of the ecosystem N and P was found in soil. Nutrient return via litter production was the largest flux followed by mineralization and root uptake, and nutrient cycling in litter production tended to be higher for forests than for wooded and woody-grass savannas. Savanna woodlands and forests in the Pantanal had higher N and P storage than comparable woodlands and forests in the Cuiaba Basin, presumably because of the shallower and stonier soils of the Cuiaba Basin. However, while the vegetation types studied here had large differences in structure (vegetation height, leaf area index, and density), the forested and wooded savannas had comparable belowground and wood N and P pools.

The Ground-Dwelling Ant Fauna from a Cerrado Reserve in Southeastern Brazil: Vegetation Heterogeneity as a Promoter of Ant Diversity.

Ants represent one of the most diverse and ecologically important group of insects in tropical ecosystems, including in highly threatened ones such as the Brazilian Cerrado. Yet, a detailed understanding of the species diversity and composition of local Cerrado ant assemblages is lacking in many cases. Here we present the results of a comprehensive ant inventory performed within a region of the Cerrado (in São Paulo state) where most of the original vegetation has already been lost and where few conservation units exist. We performed consecutive surveys of the ant fauna that forage on the ground in replicated plots established in open savanna (campo sujo), dense savanna (cerrado sensu stricto), and forest (cerradão). Our surveys, with an estimated sample coverage of 99.4%, revealed a total of 219 species of ants from 60 genera, of which 36.1% were found in all the three vegetation types and 29.7% in just one. Rarefied species richness did not differ between vegetation types, but species composition differed markedly, especially between the two savannas in one hand and the forest in the other. Several species (60.1% of the 128 species analyzed) were significant "indicator" species due to their strong association with a given vegetation type. Overall, our findings reinforce the idea that habitat heterogeneity enhances ant diversity and that the mosaic of vegetation types that characterizes the Cerrado biome is one of the main factors explaining the elevated number of species that can be found at relatively small scales.

Taxonomic, functional, and phylogenetic diversity of lizard assemblages across habitats and seasons in a Brazilian Cerrado area

AbstractOne of the core issues in community ecology is the understanding of mechanisms that determine community structure. In this study, we examine how two structurally distinct habitats (campo sujo – a grassy savanna habitat with low shrubby cover – and seasonal semi‐deciduous forest) and distinct hydrological seasons (dry and rainy) influence the taxonomic, functional and phylogenetic diversity of lizard assemblages in a savanna area in the Brazilian Cerrado. We used pitfall traps to sample lizards from May 2000 to February 2002. To quantify spatio‐temporal changes in the lizard assemblages, we used parameters of taxonomic (species richness – SR), functional (functional diversity – SES.FD, functional redundancy – FR and functional dispersion – FDis), and phylogenetic diversity (phylogenetic species richness – PSR and phylogenetic species variability – PSV). We also estimate functional and phylogenetic structure of the assemblages in each habitat during dry and rainy seasons. We recorded 182 lizards distributed among 14 species. Species composition differed among habitat types, but did not differ seasonally within habitats. SES.FD, FDis, and FR also differed among habitat types but not among seasons, with SES.FD and FDis being greater in seasonal semi‐deciduous forest, while FR was greater in campo sujo. SR, PSR, and PSV were not influenced by the factors analysed. The lizard assemblage of campo sujo was functionally clustered in the dry season and phylogenetically clustered in the rainy season. These results demonstrate that differences among habitat types and seasons are important in shaping the taxonomic, functional, phylogenetic diversity and structure of lizard assemblages in the savanna area studied. Our study also demonstrates the importance of using different measures of diversity to obtain a better understanding on the mechanisms that influence the lizard assemblages in a highly seasonal environment.

Fire stimulates grass flowering in the Cerrado independent of season

AbstractQuestionsPost‐fire flowering is an underestimated plant trait of many fire‐prone ecosystems and is rarely considered for tropical savannas. Therefore, we analyzed the effects of fire season and history on post‐fire flowering of grass species in a tropical savanna (Cerrado), by evaluating the number of species, frequency of individuals and number of reproductive tillers after wet‐ and dry‐season fires, and under different fire histories.LocationsOpen savannas (campo sujo) of the Cerrado in central Brazil (Reserva Natural Serra do Tombador [RNST], 13°35–13°38′ S, 47°45′–47°51′ W).MethodsWe sampled flowering individuals in 10 Poaceae species and counted flowering/vegetative tillers of grass species in 1 m × 1 m plots after wet‐ and dry‐season fires and under different fire histories (3, 18 and 72 months post fire).ResultsSome of the studied species responded differently to fire according to season but most flowered after fire events. Moreover, the exclusion of fire led to a decrease in the number of flowering individuals and reproductive tillers of grass species.ConclusionsWe describe a unique event for tropical savannas: beside rapid resprout after fire events, grasses can allocate resources for both vegetative and reproductive tiller production, even during the dry season. If fire is excluded from the system, fewer grass species and individuals will flower and there will be a lower percentage of reproductive tillers, showing the importance of fire for grass flowering in these tropical savannas, independently of fire season.

Can an invasive African grass affect carbon and nitrogen stocks in open habitats of the Brazilian Cerrado?

Considering the emergence of ecosystems dominated by invasive species, there is growing interest in estimating the effect of biological invasions on ecosystem processes and provision of services. African grasses are the most invasive plants in the Cerrado (Brazilian savanna), but their impact on C and N stocks is poorly known. We compared patterns of C and N stocks in the aboveground biomass, root biomass and soil in open Cerrado (campo sujo) sites, both uninvaded and invaded by the African grass Urochloa decumbens. In both sites we estimated the aboveground biomass of U. decumbens and native grasses, as well as the root biomass up to 50 cm. We obtained C and N soil content and soil bulk density up to 1 m depth, which were used to obtain the overall soil C and N stocks; we also assessed the variation in soil δ13C and δ15N. Although invasion did not affect the aboveground biomass, it did affect belowground biomass, leading to more C stocked in fine roots and soil, higher N concentration close to soil surface, and also more C along the soil profile. C and N soil stocks, soil δ13C and δ15N values did not significantly differ between invaded and uninvaded site. Even a relatively low level of invasion by U. decumbens changed the root distribution pattern and increased C and N contents in the upper soil, which may promote ecosystem changes by altering nutrient dynamics. Although our study was conducted at a single site, it clearly shows effects of the invasive species on the belowground environment, and indicates the necessity of further studies.

Variation in biomass allocation and root functional parameters in response to fire history in Brazilian savannas

Abstract Fire is a fundamental ecological factor in savannas because it affects vegetation dynamics and ecosystem functioning. However, the effects of fire on below‐ground compartments, including biomass and root traits, and their regeneration remain poorly understood. In this study, we assess the variation of above‐ and below‐ground plant components along fire‐history gradients in Brazilian open savannas and investigate whether changes in vegetation and soil properties are associated with the responses of below‐ground biomass and root traits. The study was conducted in eight sampling areas of open savanna (campo sujo, i.e. vegetation having low woody cover) within the Cerrado (Brazilian savannas), located along a gradient of time since the last fire (1–34 years); the number of fires that occurred within the past 34 years (0–9 fires) varied by sampling area. In each sampling area, we measured above‐ and below‐ground biomass, root depth distribution, root functional parameters and nutrient levels in the upper soil layers (0–10 cm). Rapid recovery of above‐ground live biomass after a fire was primarily due to resprouting of graminoids. This recovery was associated with an increase in absorptive root biomass in the upper soil layer in the most recently burnt sites, whereas root biomass was unaffected in deeper layers. Root parameters remained constant regardless of fire history but responded to variations in vegetation structure and soil properties. Specific root length (SRL) decreased with K, Mg2+, Al3+, N and C and increased with P concentration. In contrast, root tissue density (RTD) and absorptive root proportion were negatively correlated with soil P. RTD was strongly associated with the above‐ground biomass of graminoids. Soil texture impacted the root system: the proportion of absorptive roots increased with fine sand content in the soil, inversely to transport root biomass. The relationship between fire and soil properties was insignificant. Synthesis. In savannas, fire stimulates absorptive root biomass in response to the higher demand for below‐ground resources. This response is correlated with shoot regrowth after a fire. Variations in morphological root parameters are not directly associated with fire history; instead, they reflect differences in soil chemistry, especially soil P and graminoid biomass changes.

Composition and natural history of a snake community from the southern Cerrado, southeastern Brazil.

The natural history of a cerrado snake community in a protected area in southeastern Brazil (Santa Bárbara Ecological Station; SBES) is described. A visual guide and an identification key are also provided to assist researchers and local people in identifying snakes in that region.Sampling was performed through pitfall traps, time-constrained search, accidental encounters, and observations by local people for two years, which corresponded to 240 days of sampling. Among the 388 individuals found in the field, 33 snake species belonging to 21 genera of seven families were recorded. Most species were restricted or found at least once in non-forest vegetation types (campo sujo, campo cerrado, and cerrado sensu stricto) and a few were restricted to forest habitats (cerradão). Our results show that most species (1) occupy open areas; (2) present both diurnal and nocturnal activity; (3) are primarily terrestrial; (4) include lizards, mammals and/or anurans in the diet; (5) present seasonal reproductive activity; and (6) use mainly visually oriented defensive tactics. Despite its small size (3,154 ha), the SBES harbours preserved habitats and a rich and typical Cerrado snake fauna, including threatened species. Furthermore, most of the SBES snakes occur in non-forest environments (54%) and some species are sensitive to habitat disturbance.

Fire‐triggered flowering is the dominant post‐fire strategy in a tropical savanna

AbstractQuestionsIn fire‐prone ecosystems, fire can enhance the flowering and fruiting of many species, a strategy assumed to be well represented in savanna. Despite this, there are surprisingly few studies assessing how prevalent fire‐stimulated flowering is. Thus, we asked: (a) are there differences in the reproductive phenology of Cerrado plants between recently burned and unburned areas; (b) how does fire affect the speed of flowering and how does this differ between growth forms; and (c) what are the post‐fire flowering (PFF) strategies of Cerrado species and is there evidence for high proportions of obligate PFF?LocationOpen savannas (campo sujo in the Cerrado) in Central Brazil (Reserva Natural Serra do Tombador — RNST, 13°35–13°38' S and 47°45'–47°51' W).MethodsWe established six plots, three recently and frequently burned (FB) and three excluded from fire for six years (E). In all treatments, the number of species flowering and fruiting was counted every 15 days for three months, and then at six, nine and 12 months after fire. We also counted the number of reproductive and vegetative shoots in 10 subplots (1 m × 1 m) per plot.ResultsApproximately 66% of species studied were fire‐stimulated, with half of these only flowering after fire (obligate PFF). Fire‐enhanced flowering was rapid, with the clearest differences between burned and unburned plots seen in the first 30 days, and up to three months after fire, where there were up to two times more species flowering in the FB than E areas.ConclusionsThe extremely high proportion of PFF species, at least five times that reported for heathlands and other shrub communities, highlights the role that short‐interval fire regimes have in savanna ecosystems, selecting for resprouting life forms and PFF dominance, particularly in herbaceous species. Rapid post‐fire reproduction may be a strategy to disperse large quantities of seed into an environment with a small recruitment window.

Higher Diversity in Open Cerrado Supports the Role of Regional Processes in Shaping an Anuran Assemblage in Southeastern Brazil

In this study, we evaluate the role of local and regional factors in shaping the anuran assemblages in the Cerrado biome by contributing to the knowledge on the diversity patterns of different Cerrado vegetation types in southeastern Brazil. We measured richness and abundance of ground dwelling frogs in a gradient of vegetation structural complexity, varying from grassland (campo sujo) to forest (cerradao), using pitfall traps with drift fences and standardized efforts. We also measured vegetation structure by directly counting its components in the field. We found differences in richness and abundance among vegetation types, with richness being higher at more open vegetation types, and abundance being higher at the forest due to the extremely high number of captures of Rhinella ornata, a species from the Atlantic Forest biome. A concordant pattern in anuran diversity and vegetation structure suggests an important role of the habitat in structuring diversity in this group, with open vegetation types sharing both more similar anuran assemblages and vegetation. The higher diversity of Cerrado anurans observed in the open vegetation types in southeastern Brazil is in phase with diversity accounts for other groups of the herpetofauna throughout the biome, and it supports a prevalence of the regional processes over local determinism, a hypothesis that should be formally tested for amphibians with large-scale standardized sampling.

Effect of substrates on the emergence of a Cerrado grass

Large-scale seedlings production of non-tree species is an obstacle for the advance of ecological restoration of grasslands and savannas ecosystems worldwide. We tested different substrates to verify the germination and emergence of seeds of the species Aristida jubata (Arechav.) Herter - Poaceae. We collected seeds in a “campo sujo” site – a phytophysiognomy of the Cerrado biome in Sao Paulo state, Brazil. Four substrates were tested: sand; sand + vermiculite; vermiculite and clayey soil (collected in a rut) in a random blocks experimental design with four replicates of 25 seeds –100 seeds per treatment. The ANOVA variance test was used for statistical analyses followed by post hoc tests to compare treatments (Tukey test, p=0.05). We found significant substrates effect in vermiculite; sand + vermiculite, sand and clayey soil presented a tendency of lower germination rates.

OCCUPATION STRATEGY OF THE ARBOREAL SPECIES Tachigali rubiginosa (MART. EX TUL.) OLIVEIRA-FILHO: EVIDENCE OF FOREST EXPANSION OVER GRASSLAND AREAS.

ABSTRACT Understanding the dynamics of forest species occupation in savanna and grasslands environments allows us to assess how forest expansion operates over time. For eleven years, the population dynamics of Tachigali rubiginosa (Mart. ex. Tul.) Oliveira-Filho was registered to evaluate the occupation strategy of this species in the ecotone between forest (Mata de Galeria) and grassland (Campo Sujo), located within the Capetinga stream basin, at Fazenda Água Limpa, Federal District. This area has been protected from wildfires since 1987. This study allocated thirty-one transects of 5 m x 100 m perpendicularly to the Capetinga stream, covering forest and grassland environments. The measurements were taken from adult trees (DBH ≥ 5 cm), young trees (height > 1 m and DBH < 5 cm) and seedlings (height ≤ 1 m and DBH < 5 cm). The results indicated that, in the studied period, the population of T. rubiginosa increased from 179.5 to 262.8 ind / ha. In 2007, of the total of 280 individuals in 1.56 ha, 96 of them were in the forest (0.22 ha), 103 in the ecotone (0.16 ha), and 81 in the grassland (1.18 ha). In 2018, this proportion changed when the number of individuals decreased in the forest (83 individuals), while the number increased in the ecotone (135 individuals) and in the grassland (194 individuals). In 2007, the young trees dominated with 71% of the total, followed by the adults trees (28.5%) and the seedlings (20.7%). In 2018, the young trees represented most individuals (39.2%), but there was a balance between the three size categories, as the seedlings represented 30.0% and adults trees 30.7%. Over the period of the study, there was an increase in the population of T. rubiginosa, especially of young individuals, which indicates persistence over time and an expansion of this forest species into grassland environments.

Post‐fire regeneration strategies in a frequently burned Cerrado community

AbstractAimFire is a natural disturbance in many ecosystems throughout the world where plant populations can persist by the resprouting of individuals and/or by recruiting from seeds. We evaluated the post‐fire regeneration response for 41 coexisting species, including grasses, forbs, and shrubs, from an open Cerrado community (campo sujo) in Central Brazil.LocationThe study was conducted at the Reserva Natural Serra do Tombador (RNST) in Central Brazil. The vegetation of the study area is characterized by a continuous herbaceous layer dominated by grasses and scattered shrubs, which produces fine fuel loads that can burn frequently.MethodsWe examined both resprouting ability after experimental fires, accounting for bud location, and seed response to heat shocks caused by fire, where seeds were subjected to heat shocks of 100°C for one and three minutes, 200°C for one minute, and a control (untreated seeds).ResultsAll species were able to resprout (R+) after fire, mainly from buds located in underground structures, but also from aerial and basal buds. Seeds of most species tolerated heat shocks of 100°C for one and three minutes, but heat treatments of 200°C decreased seed viability of nearly 50% of species. Seven species, all of which had dormant seeds, showed heat‐stimulated germination. In sum, 81% of the community was classified as R+PT (resprouters with heat‐tolerant propagules) and 17% was R+PS (resprouters with heat‐stimulated propagules). The remaining 2% (one species) was classified as R+P−, showing heat‐sensitive seeds.ConclusionsResprouting is the main post‐fire regeneration strategy in Cerrado open savannas, while fire‐stimulated germination, although possible, is less common in comparison to the frequency in other fire‐prone ecosystems. However, in Cerrado open savannas, heat tolerance is an important trait that enables germination when favorable conditions arise.

Seasonal Variation in Mycorrhizal Community of Different Cerrado Phytophysiomies.

Purpose: Understanding the dynamics of mycorrhizal fungi in the Cerrado is fundamental for the adoption of conservation practices and for understanding the resilience of this biome in relation to long periods of drought. Thus, this work aimed to verify the dynamics of the mycorrhizal population in five phytophysiognomies of the Cerrado biome.Methods: The samples were taken from the Chapada dos Veadeiros National Park, a permanent preservation with native Cerrado vegetation without any anthropic influence. The five main phytophysiognomies of the Cerrado biome were chosen: the Campo Limpo, Campo Sujo, Cerrado Strictu Sensu, Cerradão, and Veredas. Rhizospherical soil samples were collected in both the wet and dry seasons. Spore density, mycorrhizal colonization rate, easily extractable glomalin, and associated mycorrhizal fungi genera were identified.Results: The values of spore density, mycorrhizal colonization rate, and glomalin were higher in the samples performed during the dry season compared to the samples performed in the rainy season. The same behavior was observed when comparing the different phytophysionomies.Conclusion: Mycorrhizal activity is higher in dry periods when compared to rainy periods. There is no specificity of genera of arbuscular mycorrhizal fungi within the Cerrado phytophysiognomies.

Species composition and frequency of habitat use by medium and large-sized mammals in the Brazilian Cerrado Biome, State of Tocantins

The Cerrado biome is the second largest natural vegetation type existing in Brazil after the Amazon, covering 91% of the State of Tocantins, with 30% of the territory changed as a result of the expansion of economic development areas. The substitution of natural vegetation means habitat loss on species, and may put the survival of medium and large-sized mammal species under extinction risk. These species represent significant energy demands and high requirements of area within the habitat. This study aims to assess the species composition and the frequency of use of physiognomic types of vegetation by medium and large-sized mammals. The study was conducted from 2001 to 2011 using a set of complementary and alternative techniques in fragments of seven different physiognomic types of vegetation. Fourth-seven medium and large-sized mammals were registered. This record corresponds to 92% of species already described within the biome, and five additional species to those registered in the data base of the State of Tocantins. Fourteen of these species are at certain degree of threat of extinction. The most used physiognomic types of vegetation in terms of canopy cover were Cerradao, Typical Cerrado, Riparian Forest and Dense Cerrado, and the less used were Gallery Forest, Campo Sujo and Vereda.

Home ranges and aspects of the natural history of the Black-masked Finch Coryphaspiza melanotis (Gray, 1840) (Aves, Thraupidae) in central Cerrado, Brazil

ABSTRACTIn the Cerrado, native grasslands have been dramatically lost, leading to an alarming decline in populations of bird species that require these vegetation physiognomies. Species such as the Black-masked Finch Coryphaspiza melanotis (Gray, 1840) are vulnerable to extinction and remain poorly studied. The objective of this study was to examine home ranges of the Black-masked Finch at the Parque Nacional da Chapada dos Veadeiros, central Brazil. Ten males were studied in a patch of shrubby grassland (campo sujo) between February and December 2008. The mean sizes of home ranges were 4.47 ± 1.49 ha (Minimum Convex Polygon) and 3.48 ± 1.44 ha (Kernel 95%), and this varied significantly between seasons. Home ranges were significantly larger in the non-breeding dry season than during other periods, and significantly smaller in the breeding season than during other periods. Core areas (Kernel 50%) had a mean of 0.46 ± 0.26 ha. A large overlap of home ranges was observed. The home ranges of all banded males overlapped those of at least three co-specifics, and most had an area overlap of more than 50%. A nest containing an egg and a nestling was found in November. Small and largely overlapped home ranges can be considered as positive for the conservation of the Black-masked Finch. This is because both small grassland fragments and conservation units can substantially contribute to the conservation of its populations through the Cerrado extension.

Increases in local richness (α-diversity) following invasion are offset by biotic homogenization in a biodiversity hotspot.

The world's ecosystems are experiencing unparalleled rates of biodiversity change, with invasive species implicated as one of the drivers that restructure local assemblages. Here we focus on the processes leading to biodiversity change in a biodiversity hotspot, the Brazilian Cerrado. The null expectation that invasion leads to increase in local species richness is supported by our investigation of the grass layer in two key habitats (campo sujo and campo úmido). Our analysis uncovered a linear relationship between total richness and invasive richness at the plot level. However, because the invasive species-even though few in number-are widespread, their contribution to local richness (α-diversity) is offset by their homogenizing influence on composition (β-diversity). We thus identify a mechanism that can help explain the paradox that species richness is not declining in many local assemblages, yet compositional change is exceeding the predictions of ecological theory. As such, our results emphasize the importance of quantifying both α-diversity and β-diversity in assessments of biodiversity change in the contemporary world.

Space use patterns of the burrowing echimyid rodent, Clyomys laticeps

AbstractSpace use patterns of a population are a result of the set of movements of its individuals, which are directly influenced by their attributes and environmental conditions. Understanding space use patterns and its determinants may give us insights about a species’ ecology, social and mating systems. Although echimyid rodents display a variety of mating and social systems, movements of burrowing species are poorly studied due to their cryptic habits. Hence, in this study, we evaluated the effects of body mass, sex, and palm fruit availability on space use patterns of the burrowing echimyid Clyomys laticeps, by measuring their daily home range (DHR) and intensity of habitat use. In 9 months of study in a “cerrado campo sujo” site, we tracked 14 adults with the spool‐and‐line in a backpack method. Adult males had larger DHR size than females, probably as a response to greater body mass and reproductive behavior. Furthermore, adult females had greater intensity of habitat use, presenting site fidelity, which can be due to offspring care as a response to non‐seasonal reproduction observed in our study and/or due to nest site defense strategy to avoid energetic costs associated with burrow construction. Differently from expected, food availability (i.e., Allagoptera campestris palm fruits) had no influence on the space use patterns of C. laticeps. As in other herbivorous rodents, shifts in proportion of consumed food items according to their availability may explain the lack of this influence in our study. Our findings suggest that space use patterns of C. laticeps are mainly explained by behavioral and physiological differences between sexes, including body mass and reproductive strategies. Additionally, larger male movements and female site fidelity suggest a solitary behavior and a polygynous mating system, although further studies regarding spatial organization and genetic structure are necessary to support these suggestions.

From individuals to communities: How singleton invasive pine saplings lead to biodiversity change in the Brazilian Cerrado hotspot

AbstractQuestionsHow do newly established species interact with existing assemblage members to alter local biodiversity? This question is especially topical given growing concerns about increased temporal turnover levels relative to background rates. Pine (Pinus spp.), a major invasive taxon in the Southern Hemisphere, is progressively dominating remaining fragments of the Brazilian savanna (Cerrado), a biodiversity hotspot. Because the Cerrado's diversity is linked to habitat heterogeneity we argue that the impact of these invasive singleton pines will be mediated by differences in local habitat structure. Here we use isolated invasive pines (Pinus elliottii) in the Cerrado as a study system to test the prediction that changes in the diversity of native communities, in the presence of newly established exotic individuals, will be greatest in the dominant vegetation layer of a habitat.LocationItirapina Ecological Station, southeast of Brazil.MethodsWe used a stratified random survey in 5 m × 5 m pairs of plots invaded by a single pine individual, each matched by control uninvaded plots; both shrub and grass vegetation layers were sampled in both habitats. In total, 300 plots were sampled, 114 in the shrub‐dominated campo sujo and 186 in the grass‐dominated campo úmido.ResultsOver 400 plant species were recorded. In both habitats, we detect marked shifts in species richness of the dominant vegetation layer. In line with our prediction, the nature of these changes is mediated by local habitat structure. We find significantly reduced species richness in the shrub layer of the shrub‐dominated habitat, but elevated species richness in the grass layer of the grass‐dominated habitat in invaded sites (vs. control). In the grass layer of campo úmido, pine initially decreases dominance thus allowing more species to colonize the plots.ConclusionsThe shape of the diversity vs. establishment time relationship is layer‐dependent, with a significant relationship between dominance/evenness and pine size in the grass layer but no relationship in the shrub layer. Our results show that, although complex, the consequences for local biodiversity of non‐native species establishment are not haphazard and thus contribute to the understanding of species co‐existence.