Brazilian Ecosystems Research Articles

Productivity and morphological composition of Xaraés palisade grass under three light intensities

The adaptation of Urochloa brizantha to Brazilian ecosystems and the use of artificial shading in low light production studies are important tools to obtain productive responses and to know the behavior of plants when used in integration with arboreal components. The experiment was conducted at the FMVZ - UNESP in Botucatu city, São Paulo state, Brazil. The study aimed to evaluate the yield of U. brizantha (syn Brachiaria brizantha) cv. Xaraés (Xaraés palisade grass) under three light intensities and four cuts. The experimental design was a randomized block with three treatments (natural luminosity, 30% light reduction, and 60% light reduction), three replicates and four cuts. The following morphological components were determined: leaf area index (LAI), forage accumulation rate (FAR), total forage mass (TFM), stem yield (SY), leaf yield (LY), and dead material yield (DMY). Light intensity influenced grass productivity, and the best performance was reached under 60% shading, which had higher values of TFM, LY, SY, LAI, and FAR if compared to natural luminosity. Thus, a reduction of 60% in light intensity showed to be the most productive and the best alternative under those conditions.

Condições para coprodução e inovação aberta: um estudo no ecossistema brasileiro de dados governamentais abertos

Os desafios impostos pelas sociedades atuais superam a capacidade dos governos que, com diversas restrições, devem descobrir formas inovadoras de oferecer serviços e/ou produtos de melhor qualidade. Entre as principais soluções apontadas destaca-se a possibilidade da utilização das Tecnologias de Informação e Comunicação, destacando-se iniciativas de governo aberto e dados abertos, promovendo maiores possibilidades de inovação aberta. Assim, este trabalho teve como objetivos identificar fatores capazes de promover a coprodução em iniciativas de dados abertos e os elementos necessários para o processo de inovação aberta. Para atender estes objetivos foram realizadas entrevistas com atores do ecossistema brasileiro de dados abertos. Os resultados demonstram que existem alguns fatores, como aproveitamento da inteligência coletiva e a participação social, que podem motivar a coprodução, fator essencial para o processo de inovação aberta. Também foram identificados incentivos expressivos e solidários, que podem motivar o cidadão (sociedade) a promover maior interação com os governos.

Complementarity among otter trawl, cast net, and encircling gill net improves the characterization of a subtropical subtidal fish assemblage

We investigated the combined use of cast net (CN), otter trawl (OT), and encircling gill net (EG) to characterize the richness, composition, and abundance of species and functional groups of the subtidal fish assemblage in a subtropical shallow ecosystem in Brazil. Our hypothesis, that this combination would improve faunal characterization, was supported. The CN best sampled small pelagic planktivores (e.g., juvenile sardines) and detritivores (e.g., juvenile mullets); OT, small and large demersal benthivores (e.g., mojarras and croakers); and EG, large fast-swimming species, such as piscivores (e.g., snooks and weakfishes) and large detritivores (adult mullets). The mean and total richness were best sampled with the OT. The most accurate richness estimate using non-parametric estimators was reached by combining all three types of gear. Our findings emphasize that the careful sampling gear selection and the use of multiple gears are indispensable for solid characterizations of coastal fish fauna, and consequently, for the success of monitoring and research programs.

Quantitative variations of Constrictotermes cyphergaster (Isoptera) instars over time in a Neotropical semiarid ecosystem

The presence and relative proportion of termite castes can vary according to both intrinsic characteristics of the colony and in response to external stimuli. Constrictotermes cyphergaster is a Neotropical termite that demonstrates high densities of arboreal nests in open vegetation ecosystems in Brazil. Numerical variations of the instars in 30 nests of this specie were analyzed over 1 year in the semiarid Caatinga vegetation of northeastern Brazil. The number of individuals per instar was estimated from five subsamples (5 ml) taken from each colony. The abundance of most instars varied significantly among the nests sampled within the same month. Between months, there was significant numerical variation in the numbers of second instar larvae, workers, presoldiers, soldiers and fifth instar nymphs. In the nymphal line, only the fourth instar was found in all months, whereas alates were only found in February, the month with the highest recorded rainfall. With increasing proximity of the swarming event, there was an increase in the differentiation of last two nymphal instars, with subsequent investment in the differentiation of apterous instars and the emergence of early nymphal instars. These results indicate that differentiation of the instars of C. cyphergaster is synchronized with the regional climatic cycle and the annual production of alates. However, there was substantial numerical variation between the instars of the colonies sampled at the same time points, suggesting that factors intrinsic to the colony can generate heterogeneous feedback along with responses to environmental factors.

Integrating zooarchaeology in the conservation of coastal-marine ecosystems in Brazil

Sambaquis are archaeological shell mounds and middens formed by pre-Columbian populations inhabiting the Atlantic Forest coast of Brazil between the Middle and Late Holocene. Beyond their recognized cultural values, sambaquis are valuable biological archives for tracking changes in past biodiversity and informing modern conservation studies and management. In this contribution we reviewed the published record of faunal remains from archaeological sites located in Babitonga Bay, in the state of Santa Catarina, southern Brazil. Through a literature review covering 110 sites, we assembled a comprehensive survey of terrestrial and marine taxa exploited by human groups in this area between ca. 5500 and 370 years ago. A total of 244 species were recorded, of which 14 are currently endangered and 12 are no longer present in Babitonga Bay. This zooarchaeological synthesis provides snapshots of past biodiversity, adding a novel contribution to current debates around the conservation biology of one of the world's most threatened tropical biomes.

Environment and Bioeconomics: An Analysis of the Brazilian Ecosystem in Bioproducts Development

Environment and Bioeconomics: An Analysis of the Brazilian Ecosystem in Bioproducts Development

Specialized roots of Velloziaceae weather quartzite rock while mobilizing phosphorus using carboxylates

Abstract Campos rupestres is an extremely phosphorus (P)‐impoverished rocky ecosystem in Brazil. Velloziaceae is an important plant family in this environment, and some species colonize exposed quartzite rock. However, we know virtually nothing about their root development and nutrient acquisition within the rock outcrops and their possible role in rock weathering and landscape formation. We tested the hypothesis that Velloziaceae dissolve P from the rock, enhancing rock weathering. The study was carried out with two Barbacenia species (Velloziaceae) that colonize quartzite rocks. We assessed the root specializations and exudates, and determined the mineralogical composition of the rocks. The quartzite rocks contained a low concentration of total P in a matrix composed predominantly of silica. Using transmission electron microscopy, we show root growth perpendicular to the rock‐bedding planes. A micro‐XRF set‐up at the XRF beamline of a synchrotron evidenced root‐associated rock dissolution. The investigated roots show novel morphological and physiological specializations, coined vellozioid roots, which are highly effective at P acquisition. These carboxylate‐releasing roots function like other specialized roots in nutrient‐depleted soils. The rocks represent a barrier for most species, but due to their chemical and physical actions inside the rocks, vellozioid roots play a pivotal role in rock weathering, contributing to shaping the campos rupestres landscapes. A plain language summary is available for this article.

Aerial plant biomass and litterfall as local determinants of leaf litter and fine root decomposition in a semiarid ecosystem of the Neotropical region

The rate of litter decomposition can vary within ecosystems that have high spatial heterogeneity, and many uncertainties remain regarding the abiotic and biotic factors that act as determinants of decomposition rates at small spatial scales. This study investigated the decomposition rates of leaves and fine roots of Croton sonderianus Mull. Arg., Poincianella pyramidalis Tul., and Aspidosperma pyrifolium Mart. over 12 months in a semiarid ecosystem in Brazil. Twelve biotic and abiotic factors were also evaluated as local determinants of decomposition rates. A 2000 × 500 m grid was delimited within which thirty 20 × 20 m plots were established. Two sets of litterbags were installed in each plot, one containing a mixture of leaves and the other a mixture of roots. The approximate mean lost mass was 90% for leaf material and 47% for roots after 10 and 12 months, respectively. Due to the litterbag incubation sites being distributed in a heterogeneous area, values for the intrinsic decay coefficient (k) (through month) varied widely from a minimum of 0.073 to a maximum of 0.458 for leaf litter and from 0.045 to 0.077 for roots. Variation in the decay coefficients for leaves and roots was significantly explained by aerial plant biomass and litterfall production, respectively; more open areas exhibited the highest rates of decomposition. Vegetation structure that favors the exposure of soil to solar radiation can influence the decomposition process, promoting an increase in leaf, and fine root decomposition rates at small spatial scales in tropical semiarid ecosystems.

Pouteria torta is a remarkable native plant for biomonitoring the glyphosate effects on Cerrado vegetation

Cerrado is a Brazilian savannah ecosystem that has a high diversity of flora and fauna and originally covered 2 million km2, but in recent years more than 50% of its area has been converted to grain crops and pastures. The intensive grain production in Cerrado has been accompanied by an increase in pesticide and herbicide use, glyphosate is the most common. This may have implications for biodiversity loss that are still unknown. Seeking this understanding, we assessed biochemical changes in two native Cerrado plants species subjected to glyphosate. The aim of this study was to identify biomarkers in Pouteria torta and Alibertia edulis treated with glyphosate and evaluate their use as phytoindicators of the herbicide on the Cerrado vegetation. The plants were challenged with glyphosate [Roundup Transorb®, containing 480 g L−1 acid equivalent (a. e.)] in two independent experiments. In both, glyphosate was used at 0, 200, 400, and 800 g a. e. ha−1. The activities of the enzymes phenylalanine ammonia lyase (PAL), peroxidase (POX), polyphenol oxidase (PPO), and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), as well as the concentrations of shikimic acid, phenolic compounds, amino acids, proteins, and malondialdehyde (MDA) were evaluated at 1 and 13 and at 1 and 72 days post-application in P. torta and A. edulis leaves, respectively. Glyphosate had reduced EPSPS activity and blocks the shikimate pathway in P. torta and A. edulis. Thus, this biochemical changes can be biomarkers of glyphosate in both native Cerrado plants. The activity of the PAL and PPO enzymes also showed this potential. Glyphosate caused leaf chlorosis and necrosis in P. torta, in addition, the concentrations of phenolic compounds, proteins, and amino acids were altered only in this species. Thus, concentrations of these cell compounds can be biomarkers of glyphosate stress in susceptible plants. The herbicide did not have the same effects on A. edulis. The changes in P. torta leaves occurred more quickly than in A. edulis. Thus, A. edulis plants may be used as a glyphosate biosensor. P. torta were susceptible and can be a phytoindicator of the herbicide. Its high sensitivity is useful for monitoring the initial effects of glyphosate on native Cerrado vegetation.

Species diversity, community structure and ecological traits of trees in an upper montane forest, southern Brazil

ABSTRACT Upper montane ecosystems in Brazil are little known, and their structural and functional aspects poorly understood. Our goals were to describe tree species diversity and community structure, and to characterize tree species in relation to their ecological traits, phytogeographic history and conservation status in an upper montane araucaria forest remnant. A total of 26 species belonging to 18 families were found in a 1-hectare permanent plot. The tree community mainly comprised trees with diameters of less than 20 cm and heights of between 6.5 and 9.5 m. Drimys angustifolia and Myrceugenia regnelliana had the highest importance values. Most species were shade tolerant while most individuals were pioneers. Most species and individuals presented zoophily and zoochory. Most sampled species and individuals were related to araucaria forests. Seven species are threatened to some degree while one species, Crinodendron brasiliensis, besides threatened, is also endemic to the region. The presence of endemic and endangered species demonstrates that the studied area serves important conservation purposes. Furthermore, the present study demonstrates the important role that upper montane regions have for conservation and describes the structural patterns of still poorly studied habitats, reinforcing the importance such systems have in maintaining species diversity at high elevations.

DIVERSITY OF ARBUSCULAR MYCORRHIZAL FUNGI IN FOREST ECOSYSTEMS OF BRAZIL: A REVIEW

Plants can stablish symbiosis with arburcular mycorrhiza fungi (AMF), in which the fungus uses carbohydrates synthesized by plant photosynthesis in exchange for soil nutrients. AMF symbiosis may benefit plants by increasing the rates of nutrient uptake, tolerance to abiotic stresses, protection against pathogens and, by promoting resilience of forest species to adverse conditions. Knowledge about the diversity of mycorrhizas may help stablish relationships of species selection, AMF production and inoculation. Therefore, the objective of this review is to compile information to identify existing patterns in AMF diversity in Brazilian forest ecosystems. Compilation was based in 74 articles (in English, Portuguese and Spanish languages) searched in the Web of Knowledge and selected for having the keywords “forest”, “diversity”, “mycorrhizal” and “Brazil”, and that identified AMF species by spore morphology. Compilation resulted in a list of 164 AMF species and indicated that AMF species are not plant host specific but they are selected by environmental conditions where the host grows. Some AMF species were ubiquitous and some were rare in forest ecosystems. Rare AMF species may be an artefact of AMF identification because, in comparison to molecular tools, spore morphology may underestimate AMF diversity. Four AMF species, Acaulospora scrobiculata, Acaulospora foveata, Clareoideglomus etunicatum and Glomus macrocarpum, were ubiquitous to several biomes, existed in different stage of forest succession and seemed to be adapted to different forest managements. Therefore, A. scrobiculata, A. foveata, A. mellea, C. etunicatum and G. macrocarpum could have potential to be used as AMF inoculant in forest species.

Distribution and density of lobsters in the Brazilian oceanic ecosystem Rocas Atoll

Abstract Lobsters are recognizable faunal elements that play an important role as top predator in the trophic webs in benthic ecosystems and have an economic importance due to the intensive and valuable fishery. In Rocas Atoll (03°51′S 33°48′W) the presence of five species of lobsters in low tide pools was observed by visual census. These were: Enoplometopus antillensis Lütken, 1865; Palinurellus gundlachi Von Martens, 1878; Panulirus argus (Latreille, 1804); Panulirus echinatus Smith, 1869; and Parribacus antarcticus (Lund, 1793). This atoll appears to be dominated by P. echinatus followed by P. argus, P. antarcticus, P. gundlachi and E. antillensis, respectively. We also observed the presence of some potential predators that perhaps feed on lobster species and control these populations in the atoll. This work and future information could help to better understand the variability of lobster diversity and density in this unique atoll.

Seasonal and inter-annual variability in phytoplankton over a 22-year period in a tropical coastal region in the southwestern Atlantic Ocean

Plankton time-series studies are necessary to improve our understanding of changes in aquatic ecosystems worldwide. Nevertheless, coastal tropical and sub-tropical regions long-term data series are scarce, especially in the Southern Hemisphere. Thus, the present study aims at identifying the factors controlling plankton variability at different temporal scales in a tropical coastal ecosystem in Brazil between 1987 and 2009. Three sampling stations were visited monthly at Ilha Grande Bay, a meso-oligotrophic coastal ecosystem in Rio de Janeiro, Brazil, to define the seasonal and inter-annual variability in the chlorophyll a (Chla) and nanoplankton and microphytoplankton abundances, and the main controlling factors. Salinity, water temperature, Secchi disk depth and inorganic nutrient concentrations were also measured. The dataset from the three sampling stations did not show significant differences for most of the measured variables; the stations were considered replicates. The mean annual Chla values were <1.0 mg m−3, and the mean phytoplankton densities were <3.0 × 105 cells L−1. Both variables exhibited maximum values during the warmer and rainy season (November to March), with decrease in February, and minimum values during the colder and dry season (May to October). The microphytoplankton abundance, mainly diatoms, was high especially after the strong 1997/1998 El Niño event, whereas higher nanoplankton abundances were associated with La Niña events. In conclusion, over the short-term (seasonal), seasonal rainfall regime influences the phytoplankton, probably via the greater dissolved inorganic nutrients availability, especially nitrate and silicate. However, over the long-term (inter-annual), El Niño/La Niña events are responsible for the large-scale phytoplankton variability.

Seagrass can mitigate negative ocean acidification effects on calcifying algae

The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.

Soil organic carbon fractions and humic substances are affected by land uses of Caatinga forest in Brazil

Caatinga is a Brazilian dry ecosystem that occupies around 1 million km2 and is one of the largest tropical dry forests of the world. About 46% of the area that was originally covered has been deforested. Land use can cause pronounced reduction in soil carbon stocks that play a major role in the global carbon cycle. The objective of this study was to improve our understanding of the effect of land use on oxidizable carbon fractions, total carbon stocks and humic substances in different layers of soil in a Brazilian semi-arid region. We analyzed soils from tropical dry forest (TDF), forest succession with Anadenanthera falcata (ANA), with Tabebuia alba (TAB), secondary scrubby regeneration (SCR), and non-irrigated maize (MS). Forests showed larger fractions of more labile carbon, except for TDF. The most recalcitrant fraction of carbon stock, humin fraction stock, with the different land use decreased by 38–53% compared to TDF. Oxidizable carbon fractions, carbon stocks, and humic fraction stocks were able to differentiate the successional land uses and agricultural cover from TDF, mainly in the 0–5 cm layer. Our results show that changes in land use, especially with ANA forest succession, showed a larger labile carbon fraction, indicating easy decomposition and loss. Our results provide an alternative tool for the management of deforested areas in tropical dry caatinga ecosystems. This would contribute to the conservation of dry forest systems and could serve as guideline for sustainable management of agriculturally impacted caatinga areas.

A new species of Pyrrhosphodrus (Hemiptera: Heteroptera: Reduviidae) from the Caatinga ecosystem in Brazil, with notes on the genus.

A new species of Reduviidae (Hemiptera: Heteroptera) from Caatinga ecosystem, Pyrrhosphodrus caatingensis Lapischies Forero sp. nov., is described. The new species is distinguished from its congeners by its overall reddish coloration with black areas; by the black legs, with femora with a subapical yellowish broad ring, tibiae with apical and subapical yellowish annuli; and genital characters. Comments about the biology, feeding habits, habitus, genitalic images, and a distribution map of the new species are given. In addition, the following synonymy is proposed: Pyrrhosphodrus militaris Stål, 1866 = P. theresina (Berg, 1879), syn. nov. A key to separate the known species of Pyrrhosphodrus Stål, 1866 is provided.

Lizard assemblages on sandy coastal plains in southeastern Brazil: An analysis of occurrence and composition, and the role of habitat structure.

Data on the structure of lizard communities in the different biomes and ecosystems of Brazil are still limited. In this study, we related the species richness, abundance and the spatial occurrence of lizards to the structure of the vegetation found on the coast of the state of Espírito Santo, southeastern Brazil, to determine whether habitat influences the structure of lizard communities. We conducted fieldwork in 2012, 2013 and 2014, collecting data in standardized samples. We analyze whether variables of vegetation structure influenced species richness and abundance, using Generalized Linear Models (GLMs). We recorded 12 lizard species from eight families. In general, species richness and abundance were similar among sites. Locally, we recorded the highest species richness in shrubby vegetation, open Clusia vegetation, and the restinga forest zone. Bromeliads explained the occurrence of teiids, although there was no systematic relationship between species richness and vegetation structure. Our results provide important insights into the characteristics of the lizard communities found on sandy coastal plains and contribute to the conservation of these species in these ecosystems.

Genomic analysis of MCR-1 and CTX-M-8 co-producing Escherichia coli ST58 isolated from a polluted mangrove ecosystem in Brazil.

Genomic surveillance studies monitoring the dissemination of multidrug-resistant Enterobacteriaceae in polluted aquatic ecosystems are urgently required. The aim of this study was to report the draft genome sequence of an MCR-1 and CTX-M-8 co-producing Escherichia coli isolated from a polluted mangrove ecosystem in Northeast Brazil. Total genomic DNA was sequenced on an Illumina NextSeq platform and was assembled using CLC Genomics Workbench. The whole-genome sequence was evaluated through bioinformatics tools available from the Center of Genomic Epidemiology as well as additional in silico analysis. The genome size was calculated at 5089467bp, comprising a total of 5068 protein-coding sequences. The strain was assigned to sequence type 58 (ST58) and revealed the presence of mcr-1, blaCTX-M-8 and other clinically significant genes responsible for conferring resistance to colistin, β-lactams, trimethoprim and quinolones. In addition, genes conferring resistance to silver (silR) and quaternary ammonium compounds (sugE) were identified. These data provide valuable information for comparative genomic analysis regarding the dissemination of MCR-1-producing E. coli at the human-animal-environment interface.

Critical Success Factors of Brazilian Business Incubators

The main purpose of this study is to determine the Critical Success Factors (CSF) of Brazilian business incubator management and understand how they are structured. These factors are essential to improve the performance of these Brazilian businesses and to strengthening the Brazilian entrepreneurial ecosystem. The strategy used was survey, and the data obtained were analyzed using the statistical technique of Exploratory Factor Analysis. The validated CSF were grouped into seven constructs. Thus far, the literature does not present any article within the scope proposed here. Additionally, the statistical technique used here is applied for the first time in this theme.

Challenges of multi-level water governance at micro-watershed level – A case from Rio de Janeiro, Brazil

The micro-watershed level can be a promising unit for the integration and coordination of water management functions that affect sustainable water use and livelihoods of local communities such as farmer groups. Recent projects in the state of Rio de Janeiro in Brazil have advocated interventions at this level. However, micro-watersheds are still not adequately incorporated in the multi-level governance systems of water and related ecosystems in Brazil. Further, a complex landscape of non-local actors and higher-level policies interact and determine resource use patterns at the micro-watershed level. This paper maps stakeholders and shows their influence areas on key water issues using the example of micro-watersheds in Rio de Janeiro. It also highlights the key challenges arising from the governance practice and the institutional framework related to micro-watersheds.