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Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet. Some environments with high economic relevance, such as the ferruginous campo rupestre (rupestrian grassland known as Canga in Brazil), are even more susceptible to severe impacts due to their extreme habitat conditions and low resilience. The determination of reference ecosystems based on the intrinsic characteristics of the ecosystem is essential for conservation as well as to the implementation of ecological restoration. We proposed the reference ecosystem of the three main types of habitats of the ferruginous campo rupestre based on their floristic composition. We described the floristic composition of each habitat and evaluated the physicochemical properties of the soils and the relationship between plants and soils. All three habitats showed high diversity of plant species and many endemic species, such as Chamaecrista choriophylla, Cuphea pseudovaccinium, Lychnophora pinaster, and Vellozia subalata. The distribution of vegetation was strongly related with the edaphic characteristics, with a set of species more adapted to high concentration of base saturation, fine sand, organic carbon, and iron, while another set of species succeeded in more acidic soils with higher S and silt concentration. We provide support for the contention that the ferruginous campo rupestre is a mosaic of different habitats shaped by intrinsic local conditions. Failure to recognize the floristic composition of each particular habitat can lead to inappropriate restoration, increased habitat homogenization and increased loss of biodiversity and ecosystem services. This study also advances the knowledge base for building the reference ecosystem for the different types of ferruginous campo rupestre habitats, as well as a key database for highlighting those species contribute most to community assembly in this diverse and threatened tropical mountain ecosystem. [ABSTRACT FROM AUTHOR]

A functional approach to understand natural plant communities helps elucidate the dynamics of environmental filters and community assembly. Species classification into functional groups allows the translation of ecological complexity into simplified and applicable knowledge. Here, we developed a plant functional type (PFT) system to investigate whether functional structure (PFT composition and abundance) of plant communities varies between substrate types and plant physiognomies in an old climatically buffered infertile landscape (OCBIL), namely Brazilian campo rupestre. We sampled the herbaceous and shrubby vegetation and collected soil variables in four different plant physiognomies growing in quartzitic and ferruginous substrates. We classified the sampled species according to life‐history traits related to species persistence, reproduction, and biological interactions. Functional dissimilarity among plant physiognomies and the two substrate types and the role of soil factors affecting the dissimilarities were assessed. Pollination and seed dispersal syndromes, mycorrhizal association, and reproductive phenology were the main traits defining the PFTs. We found distinct functional structure between plant communities of different substrates and physiognomies, with a marked influence of chemical and physical soil factors. Also, we defined main PFTs profiles for each physiognomy, identifying core PFTs with basic combinations of traits, common to all or almost all physiognomies. The functional perspective proposed by this study provides applicable knowledge to the restoration and conservation of campo rupestre ecosystem, reinforcing the importance of habitat heterogeneity for maintaining its functioning. [ABSTRACT FROM AUTHOR]

Environments originating from banded iron formations, such as the canga, are important reference ecosystems for the recovery of degraded areas by mining. The objective of this work was to evaluate if the relationship between morphofunctional and photosynthetic attributes of native canga species from different functional group results in distinct responses when grown in iron mining tailings substrate. The experiment was carried out with species belonging to different functional groups: a widespread semi-deciduous tree-shrub, Myrcia splendens; an endemic deciduous shrub, Jacaranda caroba; and a nitrogen-fixing herbaceous species, Periandra mediterranea. The species were grown in two conditions, reference soil and iron ore tailing. Despite belonging to different functional groups when grown in tailings, the morphofunctional attributes presented similar responses between species.M. splendens was the species most affected by the conditions imposed by the iron ore mining tailings, with decreased light-use efficiency and electron transport. P. mediterranea had satisfactory growth and maintenance of photosynthetic attributes. J. caroba growing in the tailings increased the effective quantum yield of PSII. The photochemical and growth assessments were able to better explain the adaptive strategies developed by the species, guaranteeing a greater chance of success during the rehabilitation of mining substrates. [ABSTRACT FROM AUTHOR]

Old, climatically buffered, infertile landscapes (OCBILs) have a disjunct yet wide distribution worldwide. Old lineages, rare and geographically restricted species, generally characterise these landscapes. Although the last decade provided evidence supporting the OCBIL theory, many studies are biased towards local scales, woody plants and specific OCBILs. Therefore, broad‐scale investigations across different types of OCBILs are needed.We used 5186 flowering plant species (woody and herbaceous) distributed across 129 rocky outcrop sites in Brazil to investigate (1) the relative influence of climate on the phylogenetic diversity and structure of OCBILs; (2) their phylogenetic signature; (3) whether vegetation type influences phylogenetic diversity and structure of OCBILs after controlling for climate; and (4) the OCBILs' evolutionary median community age.We found that rocky outcrops exhibit lower than expected phylogenetic diversity and are home to plant communities composed of closely related species (i.e. phylogenetic clustering) relative to the reference species pool, primarily due to temperature seasonality. Each rocky outcrop shows a distinct phylogenetic signature, indicated by plant families with more descendant species than expected by chance. Even after controlling for climate, phylogenetic diversity and structure remain low and clustered in most rocky outcrops. The median community age estimated at the species level is lower in campos de altitude than in other rocky outcrops.Synthesis. We show that the influence of climate seasonality is pervasive in the phylogenetic diversity and structure of Brazilian rocky outcrops at different taxonomic levels. We also show that the phylogenetic signature of rocky outcrops comprises a mix of relatively old and young overrepresented plant families whose descendants contribute to their low phylogenetic diversity and phylogenetic clustering. Overall, the combination of low phylogenetic diversity, phylogenetic clustering and comparably low median community age across Brazilian rocky outcrops indicates that, on average, these OCBILs are subjected to strong environmental constraints and serve as arenas of recent diversification rather than a steady accumulation of taxa. Therefore, these findings indicate different OCBILs as hotspots for various plant lineages and species. [ABSTRACT FROM AUTHOR]

Amazon ironstone outcrops vegetation, or canga, is a remarkable environment in which the plants are adapted to peculiar circumstances. Knowledge regarding different aspects of this ecosystem remains modest, including necessary insights for its conservation and recovery, such as the reproductive phenology of priority species that form the plant community. This study aimed to monitor the reproductive phenology of critical native species that are categorized as rare, endemic, and/or threatened in the canga of the Amazon Rainforest, in Pará, Brazil. During February 2016 and May 2017, eleven species were evaluated regarding the presence or absence of flowering and fruiting phenophases, and these were associated with environmental variables. Phenological data were evaluated through circular statistical analysis. All studied species flowered and produced fruit during the monitoring period. The evaluated species have an annual reproductive cycle marked by seasonality and flowering peaks between March and April, during the wet season, and fruiting peaks during May, at the beginning of the dry season. The best period for collecting ripe seeds, a primary tool for the restoration of degraded areas, is June. Water availability may be essential for the establishment of annual plants and to induce flowering in both annual and perennial species. The reproductive phenophases of the studied species are concentrated within a short period and are synchronized, which may increase the possibility of cross‐pollination and minimize flower and seed predation. We discuss the challenges in including annual plants and the importance of having them and perennial species in conservation and restoration of degraded areas projects. [ABSTRACT FROM AUTHOR]

Lateritic duricrusts cover iron ore deposits and form spatially restricted, unique canga ecosystems endangered by mining. Iron cycling, i.e., the dissolution and subsequent precipitation of iron, is able to restitute canga duricrusts, generating new habitats for endangered biota in post-mining landscapes. As iron-reducing bacteria can accelerate this iron cycling, we aim to retrieve microbial enrichment cultures suitable to mediate the large-scale restoration of cangas. For that, we collected water and sediment samples from the Carajás National Forest and cultivated the iron-reducing microorganisms therein using a specific medium. We measured the potential to reduce iron using ferrozine assays, growth rate and metabolic activity. Six out of seven enrichment cultures effectively reduced iron, showing that different environments harbor iron-reducing bacteria. The most promising enrichment cultures were obtained from environments with repeated flooding and drying cycles, i.e., periodically inundated grasslands and a plateau of an iron mining waste pile characterized by frequent soaking. Selected enrichment cultures contained iron-reducing and fermenting bacteria, such as Serratia and Enterobacter. We found higher iron-reducing potential in enrichment cultures with a higher cell density and microorganism diversity. The obtained enrichment cultures should be tested for canga restoration to generate benefits for biodiversity and contribute to more sustainable iron mining in the region. [ABSTRACT FROM AUTHOR]

Abstract Background Canga is the Brazilian term for the savanna-like vegetation harboring several endemic species on iron-rich rocky outcrops, usually considered for mining activities. Parkia platycephala Benth. and Stryphnodendron pulcherrimum (Willd.) Hochr. naturally occur in the cangas of Serra dos Carajás (eastern Amazonia, Brazil) and the surrounding forest, indicating high phenotypic plasticity. The morphological and physiological mechanisms of the plants’ establishment in the canga environment are well studied, but the molecular adaptative responses are still unknown. To understand these adaptative responses, we aimed to identify molecular mechanisms that allow the establishment of these plants in the canga environment. Results Plants were grown in canga and forest substrates collected in the Carajás Mineral Province. RNA was extracted from pooled leaf tissue, and RNA-seq paired-end reads were assembled into representative transcriptomes for P. platycephala and S. pulcherrimum containing 31,728 and 31,311 primary transcripts, respectively. We identified both species-specific and core molecular responses in plants grown in the canga substrate using differential expression analyses. In the species-specific analysis, we identified 1,112 and 838 differentially expressed genes for P. platycephala and S. pulcherrimum, respectively. Enrichment analyses showed that unique biological processes and metabolic pathways were affected for each species. Comparative differential expression analysis was based on shared single-copy orthologs. The overall pattern of ortholog expression was species-specific. Even so, we identified almost 300 altered genes between plants in canga and forest substrates with conserved responses in the two species. The genes were functionally associated with the response to light stimulus and the circadian rhythm pathway. Conclusions Plants possess species-specific adaptative responses to cope with the substrates. Our results also suggest that plants adapted to both canga and forest environments can adjust the circadian rhythm in a substrate-dependent manner. The circadian clock gene modulation might be a central mechanism regulating the plants’ development in the canga substrate in the studied legume species. The mechanism may be shared as a common mechanism to abiotic stress compensation in other native species.

The increase in rates of habitat loss requires an understanding of how biodiversity is distributed. Campo rupestre is an old, climatically buffered, and infertile landscape located in Brazil. Considered a biodiversity hotspot, the campo rupestre is mainly threatened by mining activity that requires a large operating area. Campo rupestre is known for its restricted distribution area and high abiotic heterogeneity, which modulates species coexistence and richness. To recognise the association between habitat type and plant communities, we propose to describe the floristic composition of herbaceous and shrub components in four habitats of the campo rupestre comprising quartzite and ferruginous substrate. We classified habitat types by the main surface soil features. In each habitat, we sampled ten 100-m2 plots to access information on the shrub and ten 1-m2 plots for the herbaceous component. Altogether we sampled 153 species, belonging to 38 families. The cluster analysis ordered by Sorensen metric indicates a clear distinction of species composition in the shrub component in the four habitats. However, the floristic composition of the herbaceous component was similar between the four habitats but showed a distinction when contrasting with the substrate type. Our results highlight the local taxonomic distinction between habitat types and substrates, indicating that the ecological distinction among substrate types of the campo rupestre cannot be overlooked in conservation and restoration actions.

Advancing functional ecology depends fundamentally on the availability of data on reproductive traits, including those from tropical plants, which have been historically underrepresented in global trait databases. Although some valuable databases have been created recently, they are mainly restricted to temperate areas and vegetative traits such as leaf and wood traits. Here, we present Rock n' Seeds, a database of seed functional traits and germination experiments from Brazilian rock outcrop vegetation, recognized as outstanding centers of diversity and endemism. Data were compiled through a systematic literature search, resulting in 103 publications from which seed functional traits were extracted. The database includes information on 16 functional traits for 383 taxa from 148 genera, 50 families, and 25 orders. These 16 traits include two dispersal, six production, four morphological, two biophysical, and two germination traits—the major axes of the seed ecological spectrum. The database also provides raw data for 48 germination experiments, for a total of 10,187 records for 281 taxa. Germination experiments in the database assessed the effect of a wide range of abiotic and biotic factors on germination and different dormancy‐breaking treatments. Notably, 8255 of these records include daily germination counts. This input will facilitate synthesizing germination data and using this database for a myriad of ecological questions. Given the variety of seed traits and the extensive germination information made available by this database, we expect it to be a valuable resource advancing comparative functional ecology and guiding seed‐based restoration and biodiversity conservation in tropical megadiverse ecosystems. There are no copyright restrictions on the data; please cite this paper when using the current data in publications; also the authors would appreciate notification of how the data are used in publications. [ABSTRACT FROM AUTHOR]

Background: Canga is the Brazilian term for the savanna-like vegetation harboring several endemic species on iron-rich rocky outcrops, usually considered for mining activities. Parkia platycephala Benth. and Stryphnodendron pulcherrimum (Willd.) Hochr. naturally occur in the cangas of Serra dos Carajás (eastern Amazonia, Brazil) and the surrounding forest, indicating high phenotypic plasticity. The morphological and physiological mechanisms of the plants' establishment in the canga environment are well studied, but the molecular adaptative responses are still unknown. To understand these adaptative responses, we aimed to identify molecular mechanisms that allow the establishment of these plants in the canga environment. Results: Plants were grown in canga and forest substrates collected in the Carajás Mineral Province. RNA was extracted from pooled leaf tissue, and RNA-seq paired-end reads were assembled into representative transcriptomes for P. platycephala and S. pulcherrimum containing 31,728 and 31,311 primary transcripts, respectively. We identified both species-specific and core molecular responses in plants grown in the canga substrate using differential expression analyses. In the species-specific analysis, we identified 1,112 and 838 differentially expressed genes for P. platycephala and S. pulcherrimum, respectively. Enrichment analyses showed that unique biological processes and metabolic pathways were affected for each species. Comparative differential expression analysis was based on shared single-copy orthologs. The overall pattern of ortholog expression was species-specific. Even so, we identified almost 300 altered genes between plants in canga and forest substrates with conserved responses in the two species. The genes were functionally associated with the response to light stimulus and the circadian rhythm pathway. Conclusions: Plants possess species-specific adaptative responses to cope with the substrates. Our results also suggest that plants adapted to both canga and forest environments can adjust the circadian rhythm in a substrate-dependent manner. The circadian clock gene modulation might be a central mechanism regulating the plants' development in the canga substrate in the studied legume species. The mechanism may be shared as a common mechanism to abiotic stress compensation in other native species. [ABSTRACT FROM AUTHOR]

A recent state provision allows quarzitic campo rupestre (QCR) set-asides as in-kind compensation for ironstone campo rupestre (ICR) suppression in the Atlantic Forest, which induces out-of-kind compensation. However, the recently published state provision defines no clear parameters to demonstrate “ecological equivalence” as an in-kind compensation. We evaluated whether there is ecological equivalence between and ICR and QCR in the Brazilian Atlantic Forest. We show marked geological, pedological, floristic, structural, and functional differences between ICR and QCR. There is evidence that the new compensation rules only partially offset loss of biodiversity and ecosystem services hosted by ICR, determining limited effectiveness of the legislation for ICR conservation in the Atlantic Forest. We conclude that the development of clear compensation parameters based on scientific evidence and quantitative indicators is a priority gap for the conservation of ICR under increasing mining pressure.

Lateritic duricrusts cover iron ore deposits and form spatially restricted, unique canga ecosystems endangered by mining. Iron cycling, i.e., the dissolution and subsequent precipitation of iron, is able to restitute canga duricrusts, generating new habitats for endangered biota in post-mining landscapes. As iron-reducing bacteria can accelerate this iron cycling, we aim to retrieve microbial enrichment cultures suitable to mediate the large-scale restoration of cangas. For that, we collected water and sediment samples from the Carajás National Forest and cultivated the iron-reducing microorganisms therein using a specific medium. We measured the potential to reduce iron using ferrozine assays, growth rate and metabolic activity. Six out of seven enrichment cultures effectively reduced iron, showing that different environments harbor iron-reducing bacteria. The most promising enrichment cultures were obtained from environments with repeated flooding and drying cycles, i.e., periodically inundated grasslands and a plateau of an iron mining waste pile characterized by frequent soaking. Selected enrichment cultures contained iron-reducing and fermenting bacteria, such as Serratia and Enterobacter. We found higher iron-reducing potential in enrichment cultures with a higher cell density and microorganism diversity. The obtained enrichment cultures should be tested for canga restoration to generate benefits for biodiversity and contribute to more sustainable iron mining in the region.

Background and Aims: Rock outcrop vegetation is distributed worldwide and hosts a diverse and unique flora that evolved under harsh environmental conditions. Unfortunately, seed ecology in such ecosystems has received little attention, especially regarding seed traits, germination responses to abiotic factors and the potential role of phylogenetic relatedness on such features Here, we provide the first quantitative and phylogenetically-informed synthesis of the seed functional ecology of Brazilian rock outcrop vegetation, with a particular focus on quartzitic and ironstone campo rupestre., Methods: Using a database of functional trait data, we calculated the phylogenetic signal of seven seed traits for 371 taxa and tested whether they varied among growth forms, geographic distribution, and microhabitats. We also conducted meta-analyses that included 4,252 germination records for 102 taxa to assess the effects of light, temperature, and fire-related cues on the germination of campo rupestre species and explored how the aforementioned ecological groups and seed traits modulate germination responses., Key Results: All traits and germination responses showed a moderate-to-strong phylogenetic signal. Campo rupestre species responded positively to light and had maximum germination between 20-25 ºC. The effect of temperatures beyond this range was moderated by growth form, species geographic distribution, and microhabitat. Seeds exposed to heat shocks above 80 °C lost viability, but smoke accelerated germination. We found a moderating effect of seed mass for in responses to light and heat shocks, with larger, dormant seeds tolerating heat better but less sensitive to light. Species from xeric habitats evolved phenological strategies to synchronise germination during periods of increased soil water availability., Conclusions: Phylogenetic relatedness plays a major role in shaping seed ecology of Brazilian rock outcrop vegetation. Nevertheless, seed traits and germination responses varied significantly between growth forms, species geographic distribution and microhabitats, providing support to the regeneration niche hypothesis and the role of functional traits in shaping germination in these ecosystems., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

ABSTRACT Close association of iron mining and ferruginous rupestrian grassland places this ecosystem in a special condition of vulnerability, with a large number of degraded areas requiring restoration. Seedling transplantation and topsoil translocation can be used to recover native vegetation in degraded areas. This study aimed to experimentally test the application of two different topsoil depths (0.20 and 0.40 m) in a degraded area. We assessed the vegetation’s natural recovery and the survival of transplanted native species from rescue operations in four 200 m2 plots established in each topsoil depth. There was no influence of topsoil depth on the plant species survival, while the vegetation cover was greater on the thicker topsoil. However, exotic species with invasive potential contributed substantially to this vegetation cover, requiring management planning. Some planted native species stood out for their survival ability in the topsoil 49 months after planting. Application of 0.20 m topsoil layer showed to be able to provide native species’ natural recovery and survivorship.

ABSTRACT Sinningia rupicola (Gesneriaceae), espécie ameaçada de extinção e classificada como endêmica de canga do Quadrilátero Ferrífero é aqui apresentada sob uma abordagem ecológica, baseada na análise de dados referentes a registros realizados em duas Reservas Particulares do Patrimônio Natural (RPPN) da empresa Vale, situadas no Quadrilátero Ferrífero, Estado de Minas Gerais, Brasil: Capanema e Poço Fundo. O estudo visou caracterizar a população da espécie quanto ao número de indivíduos, área de ocupação (AOO), extensão de ocorrência (EOO) e aspectos ambientais dos locais de registros relacionados à topografia, cobertura vegetal e litologia, além de avaliação do substrato, micro-habitat e fenologia. Foram registrados 1.397 indivíduos, sendo 1.254 na RPPN Capanema e 143 na RPPN Poço Fundo. As populações foram registradas colonizando rochas Quartzíticas, em altitudes que variaram entre 1.400 e 1.600 m. As populações foram caracterizadas como predominantemente saxícolas, encontradas em floração entre janeiro e março e com frutos entre fevereiro e março. Os resultados obtidos neste estudo demonstram a ocorrência de Sinningia rupicola em litologias variadas, o que sugere que a distribuição da espécie em ambientes naturais é mais ampla do que a até então presumida.

Climate change has impacted biodiversity, affecting species and altering their geographical distribution. Besides understanding the impact in the species, it has been advocated that answering if different traits will be differently impacted could allow refined predictions of how climate change will jeopardize biodiversity. Our aim was to evaluate if climate change will potentially impact plant species differently, considering their traits. We evaluated 608 plant species that occur in the naturally open areas of ferruginous outcrops (namely, cangas) in the National Forest of Carajás (Eastern Amazon). Firstly, we estimated the effects of climate change on each species using species distribution modeling, and analyzed this impact in the set containing all species. Secondly, we classified plant species considering the following traits: (i) pollination syndromes (melittophily, phalaenophily, psychophily, cantharophily, entomophily, ornithophily, chiropterophily, anemophily); (ii) habit (tree, shrub, herb, liana, parasite); and (iii) the main habitat of occurrence (open areas and forests). Thirdly, we investigated if the effects of climate change could be significantly more intense considering all the different traits quoted. Our results showed that most plant species will potentially face reduction of suitable habitats under future climate and the scenarios showed that 42% of them may not find suitable areas in the cangas of Carajás. We found no significant difference within each analyzed trait, considering the potential impact of climate change. The most climatically suitable areas (i.e., areas with high probability of species occurrence in the future) are those in the southwest of the study area. These areas can be considered as priority areas for species protection against climate change.

Two short-tailed opossum species, Monodelphis glirina and M. touan , occur in sympatry in an area of eastern Amazonia. Habitat structure and resource availability may influence habitat use and, consequently, species distribution, detectability, occupancy, and abundance. We evaluated occupancy and detectability of the species M. glirina and M. touan in the Carajás National Forest to answer the following questions: (1) Do both species occur in canga and forest habitats? (2) Do detectability and occupancy of M. touan and M. glirina differ in areas of canga and forest? (3) Does the presence of one species affect the detection of the other? We undertook surveys at 50 sampling sites (26 in canga and 24 in forest habitat). In addition, we developed co-occurrence models to test the relationships between occupancy and detection of M. touan in the presence or absence of M. glirina. We captured 693 individuals of M. glirina (587 in canga and 106 in forest) and 112 of M. touan (only one individual captured in canga). Occupancy by M. glirina was positively influenced by superficial rock cover and litter depth, while detectability was negatively influenced by canopy cover. Occupancy by M. touan was influenced positively by canopy cover, number of fallen trunks on the ground, and litter depth (Ψ = 0.315). Data from forest sites where M. touan and M. glirina occurred more often corroborated our third hypothesis, that detectability of M. touan is low when M. glirina is present. Our results highlight the existence of habitat preference by the two species of Monodelphis. [ABSTRACT FROM AUTHOR]

Climate change has impacted biodiversity, affecting species and altering their geographical distribution. Besides understanding the impact in the species, it has been advocated that answering if different traits will be differently impacted could allow refined predictions of how climate change will jeopardize biodiversity. Our aim was to evaluate if climate change will potentially impact plant species differently, considering their traits. We evaluated 608 plant species that occur in the naturally open areas of ferruginous outcrops (namely, cangas) in the National Forest of Carajás (Eastern Amazon). Firstly, we estimated the effects of climate change on each species using species distribution modeling, and analyzed this impact in the set containing all species. Secondly, we classified plant species considering the following traits: (i) pollination syndromes (melittophily, phalaenophily, psychophily, cantharophily, entomophily, ornithophily, chiropterophily, anemophily); (ii) habit (tree, shrub, herb, liana, parasite); and (iii) the main habitat of occurrence (open areas and forests). Thirdly, we investigated if the effects of climate change could be significantly more intense considering all the different traits quoted. Our results showed that most plant species will potentially face reduction of suitable habitats under future climate and the scenarios showed that 42% of them may not find suitable areas in the cangas of Carajás. We found no significant difference within each analyzed trait, considering the potential impact of climate change. The most climatically suitable areas (i.e., areas with high probability of species occurrence in the future) are those in the southwest of the study area. These areas can be considered as priority areas for species protection against climate change. [ABSTRACT FROM AUTHOR]

• Phenological data in the endangered ironstone rupestrian grasslands are scarce. • Phenological behavior differed between growth forms and habitat types. • Seasonal water availability plays an important role in phenology of studied species. The vegetation of ironstone rupestrian grasslands (canga) is of significant conservation concern due to the rapid encroachment of mining activity and urbanization on the remnants of this ecosystem. Ecological studies that address the phenological patterns of this vegetation are still scarce, although they are essential for its conservation, management, and restoration. The present study investigated the vegetative and reproductive phenology of 11 species (five herbaceous and six woody) in two distinct habitats of rupestrian grasslands (campo rupestre), canga couraçada and capão forest, both located in the Iron Quadrangle in Catas Altas, Minas Gerais, Southeast Brazil. Monthly phenological monitoring of populations of the selected species was performed over two consecutive years. Circular statistical analysis was used to evaluate the degree of synchrony and the significance of seasonality on deciduousness, leaf flushing, flowering, and fruiting of each species. Additionally, phenophases were compared between growth forms and between habitats of occurrence. Most herbaceous species were classified as evergreen and showed seasonal flowering in the rainy season, while woody species exhibited greater variability in leaf change pattern. There were significant differences in the phenological behavior between different growth forms for the four phenophases evaluated, while the comparison between habitats indicated differences in phenology only for deciduousness and flowering. Phenological differences between growth forms can be attributed to physiological strategies and seasonal water availability, the latter of which limits the phenology of most herbaceous species to the rainy season. [ABSTRACT FROM AUTHOR]

Few ecologists and evolutionary biologists are familiar with the ecology and evolution of the campo rupestre , an ancient azonal peinobiome characterized by a fire-prone, nutrient-impoverished, montane vegetation mosaic, home to thousands of endemics and climate refugia. With the goal of providing a synthetic view of the campo rupestre , we provide a brief historical account of the biological research, revisit its geographical distribution and identify knowledge gaps. The azonal campo rupestre is distributed as isolated and naturally fragmented sky islands, mostly in Central and Eastern Brazil and in the Guyana Shield, with significant areas across the Amazon, Cerrado, Atlantic Forest, Caatinga and Pantanal. Our proposal to elevate campo rupestre to the level of biome is expected to improve communication among scientists and consolidate the use of the term campo rupestre in the ecological and evolutionary literature, as is the case for analogous ecosystems, such as kwongan , fynbos , páramos and tepuis. Based on the identification of knowledge gaps, we propose a research programme comprising ten key topics that can foster our understanding of the ecology and evolution of campo rupestre and, potentially, support conservation strategies. [ABSTRACT FROM AUTHOR]

Questions: Environmental filters limit the set of potentially coexisting species in plant communities. Paradoxically, some of the world's most biodiverse communities are subjected to strong abiotic filters. We explored how environmental heterogeneity provides conditions for niche segregation in a harsh megadiverse ecosystem, focusing on fine-scale factors that drive seedling recruitment. Due to the environmental stress (mainly nutrient and water scarcity), we expected the prevalence of positive plant interactions over negative ones to contribute to species coexistence. Location: Ironstone outcrop (canga) at Serra da Calçada, southeast Brazil. Methods: We characterised microhabitats with one or neither of two dominant shrubs Mimosa calodendron (Fabaceae) and Lychnophora pinaster (Asteraceae), and assessed which micro-environmental attributes affect seedling survival, growth, and abundance, as well as adult richness in the ecosystem. Results: Spatial heterogeneity in the community was mostly driven by differences in substrate properties, and plots with Mimosa calodendron and Lychnophora pinaster exhibited different biotic and abiotic conditions from those lacking these species. Microhabitats under both shrubs had greater adult richness, and those occupied by Mimosa calodendron had greater seedling abundance, suggesting positive effects of environmental conditions associated with these plants. Nevertheless, we identified two potential negative plant–plant interactions: larger crown area of the two dominant shrubs was associated with lower species richness, and greater understorey plant cover with lower seedling abundance. Over one year, 63% of the recorded seedlings survived, but measured attributes failed to predict survival. Seedling relative growth rates were species-specific and lower in microsites where the rocky substrate is fragmented. The most abundant seedling taxa occurred in association with specific microhabitats. Conclusions: Our study suggested that fine-scale spatial heterogeneity determines the outcome of plant–plant interactions in a stressful ecosystem.Micro-environmental heterogeneity allows for the spatial segregation of species recruitment, thereby broadening the range of viable strategies within a harsh megadiverse ecosystem. [ABSTRACT FROM AUTHOR]

A new species of Passiflora series Quadrangulares is described and illustrated from National Forest of Carajás in the Brazilian state of Pará, viz Passiflora carajasensis. This new species is recognized by linear‐lanceolate stipules, long‐ovate to oblong leaf blades, bracts 3–3.5 × 1.5–2.5 cm, erect sepals and petals, and corona with 6 series. It resembles P. longifilamentosa and P. trialata in having 3‐angular winged stems, and 3‐angular petioles and peduncles and a comparison of morphological characteristics between these species is provided, as well as a key for all species of Passiflora series Quadrangulares. [ABSTRACT FROM AUTHOR]

Brazilian ironstone outcrops (cangas) are nutrient‐poor stressful habitat dominated by slow‐growing woody species with high biodiversity and unique evolutionary history. Mining has produced great impacts on this ecosystem. Spontaneous regeneration of abandoned canga mined areas has not been observed. One of the active methods most widely used for ecological restoration in environments where soil has been lost or severely degraded is topsoil transposition due to the physical, chemical, and microbiological improvement of the substrate, in addition to the seed bank. Thus, plant succession was monitored for 40 months after topsoil transposition in a canga area degraded by aluminum mining, without any other type of management. A completely randomized design with 70 permanent plots (1 × 1 m) was used. Annual phytosociological surveys were carried out and floristic and vegetational spectra were constructed with the life‐forms proposed by Raunkiaer. Floristic composition was compared with a reference site. Overall, 105 species were identified. Both flora and vegetation changed over time, increasing resemblance to the reference areas. The floristic and vegetational spectra after 4 years of topsoil deposition are similar to pristine ones. The vegetation spectrum showed an increase in the dominance of phanerophytes and hemicryptophytes, while therophytes reduced their proportion. The early successional stage is dominated by weeds, like in other canga restoration studies, but did not impede the native species regeneration. Cangas's species recruited well from transposed topsoil. Unlike other studies with fertilized topsoil, our findings show the efficiency of topsoil transposition to provide initial conditions for the ecological restoration of this ecosystem. [ABSTRACT FROM AUTHOR]

We evaluated symbiotic (rhizobia) and non‐symbiotic efficiency and the diversity of native communities of plant growth‐promoting rhizobacteria (PGPR) in soil samples from an area in recovery after iron mining (RA) and from adjacent phytophysiognomies (Ironstone Outcrops, Neotropical Savanna, Atlantic Forest) in the Quadrilátero Ferrífero region, MG, Brazil, in two climate seasons. Greenhouse experiments were conducted with siratro (Macroptilium atropurpureum) as a trap plant. The SPAD index in siratro was more effective in detecting the difference between the symbiotic efficiencies of the communities of PGPR than shoot dry matter, with readings of the SPAD index greater in RA. Genetic diversity, of 327 strains evaluated by partial sequencing of the 16S rRNA gene, showed 29 genera in the dry season and 19 in the rainy season, among these genera some recognized as nodulating and endophytes, and others potentially endophytes. Genera belonging to the phyla Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were found. The nodule‐forming genera Bradyrhizobium and Rhizobium and the endophytic Paenibacillus were those of highest occurrence in both seasons and in all phytophysiognomies. The greater symbiotic efficiency and the high genetic diversity of the rhizobacterial community found in RA indicate that soil rehabilitation is effectively in process. As most of native legume species form symbiosis with Rhizobium and mainly Bradyrhizobium, these bacterial communities are an important source of potential inoculant strains, as well as, a relevant feature for the successful establishment of diverse legumes for revegetation purposes. [ABSTRACT FROM AUTHOR]

The Iron Quadrangle (IQ) is one of the main iron ore producing regions of the world. The exploitation of its reserves jeopardizes the high biological endemism associated with this region. This work aimed to understand the diversity and bacterial potential associated with IQ caves. Floor and ceiling samples of seven ferruginous caves and one quartzite cave were collected, and their microbial relative abundance and diversity were established by 16S rRNA gene amplicon sequencing data. The results showed that ferruginous caves present higher microbial abundance and greater microbial diversity compared to the quartzite cave. Many species belonging to genera found in these caves, such as Pseudonocardia and Streptacidiphilus, are known to produce biomolecules of biotechnological interest as macrolides and polyketides. Moreover, comparative analysis of microbial diversity and metabolic potential in a biofilm in pendant microfeature revealed that the microbiota associated with this structure is more similar to the floor rather than ceiling samples, with the presence of genera that may participate in the genesis of these cavities, for instance, Ferrovum, Geobacter, and Sideroxydans. These results provide the first glimpse of the microbial life in these environments and emphasize the need of conservation programs for these areas, which are under intense anthropogenic exploration.

In tropical iron ore regions, biologically mediated reduction of crystalline iron oxides drives ongoing iron cycling that contributes to the stability of surface duricrusts. This represents a biotechnological opportunity with respect to post-mining rehabilitation attempts, requiring re-formation of these duricrusts. However, cultivated dissimilatory iron reducing bacteria typically reduce crystalline iron oxides quite poorly. A glucose-fermenting microbial consortium capable of reducing at least 27 mmol/L goethite was enriched from an iron duricrust region. Metagenome analysis led to the recovery of a metagenome assembled genome (MAG) of an iron reducer belonging to the alphaproteobacterial genus Telmatospirillum. This is the first report of iron reduction within the Telmatospirillum and the first reported genome of an iron-reducing, neutrophilic member of the Alphaproteobacteria. The Telmatospirillum MAG encodes putative metal transfer reductases (MtrA, MtrB) and a novel, multi-heme outer membrane cytochrome for extracellular electron transfer. In the presence of goethite, short chain fatty acid production shifted significantly in favor of acetate rather than propionate, indicating goethite is a hydrogen sink in the culture. Therefore, the presence of fermentative bacteria likely promotes iron reduction via hydrogen production. Stimulating microbial fermentation has potential to drive reduction of crystalline iron oxides, the rate limiting step for iron duricrust re-formation.

We examined the reproductive strategy of two Amazonian quillworts (Isoëtes cangae and Isoëtes serracarajensis), endemic and threatened species of canga ecosystems. Sexual propagation was examined by in vitro fertilization assays, while asexual propagation was examined by tiller emission. Isoëtes cangae is an outcrossing species that reproduces exclusively by spore germination and is able to propagate by self- and cross-fertilization. Isoëtes serracarajensis reproduces asexually by emitting tillers from the plant corm, despite producing male and female sporangia. These distinct reproductive strategies in the different species may be linked to their contrasting habitats. Isoëtes cangae inhabit a permanent oligotrophic lake with mild environmental changes, while I. serracarajensis are found in temporary ponds facing severe seasonal drought, where asexual propagation may represent an adaptive advantage to the short growth period during access to water. We also observed different relationships between plant growth and reproductive traits between the species, despite their common production of sporophytes with high survival rates. Together, these results are of paramount importance for establishing conservation plans for both species considering the advantages of sexual propagation to maintain the genetic diversity of I. cangae and the diligent management required to do the same with asexually propagated I. serracarajensis.

Mineralogical and whole rock geochemical analyses for 60 elements on 31 samples of hard ferruginous crust (canga) provide insights into the evolution of the lateritic profile developed on itabirite. Canga can form in two environments: in situ canga that typically caps itabirite and transported canga that covers country rock. Both have similar mineralogical and chemical compositions. Detrital haematite and rare quartz inherited from the itabirite and iron ore comprise the matrix of canga, cemented by goethite, minor gibbsite, and rare manganese oxides and secondary phosphates. Fe2O3 represents more than 91% of its chemical composition and the concentrations of trace elements are low, generally less than 50 ppm. A comparison of the chemical weathering of dolomitic itabirite against the quartz itabirite shows that, although weathering processes are less effective in the former, the geochemical trends of major and trace elements are similar. Negative Ce anomalies (Ce/Ce* = 0.8) and U/Th ratios lower than 1.5 suggest that saprolite formation occurred under slightly anoxic and mildly acidic conditions, allowing rare earth elements (REEs) to remain in the saprolite and also the formation of secondary Al phosphates, instead of Fe phosphates. These conditions became more aggressive during the canga formation process, resulting in further removal of trace elements from the system. The canga formation (pedogenesis) and the chemical weathering of the itabirite (saprolite formation) are independent, but interrelated processes that have been occurring since the Palaeocene. [ABSTRACT FROM AUTHOR]

Summary: Ironstone outcrop habitats harbour rare and endemic rupicolous plants. In southeast Brazil, they concentrate on mountaintops in the Iron Quadrangle (IQ), an intensively exploited iron ore reserve. To evaluate the current habitat availability of 32 plants endemic to canga (ironstone outcrops) and to support priority conservation areas and actions, we compared their functional connectivity in the IQ before (1960s) and after (2014) massive habitat loss to opencast mining. The Integral Index of Connectivity and associated metrics of habitat availability were used to evaluate present and past connectivity at a threshold distance of 500 m. The overall canga habitat loss up to 2014 was 50%. The historical configuration of 334 patches totalling 18 654 ha was already disconnected and the proportion of patches acting as relevant stepping stones was thus very low. Furthermore, in both the historical and current settings, the largest contribution to habitat availability came from 'intrapatch connectivity' (i.e., patch area), especially in the east sector. All the IQ canga endemics fall into the International Union for Conservation of Nature (IUCN) Critically Endangered category and require protection. The recommended strategy for their conservation is to protect large, preferably well-preserved ironstone patches. This measure will require finding the middle ground between economic development and conservation of natural heritage. [ABSTRACT FROM AUTHOR]

• Canga is a unique iron duricrust that caps and protects supergene enriched iron ores. • Geochemical evidence suggests surface processes contribute to ongoing canga evolution. • Iron cycling by plants and microbes is likely a significant process in canga. • Iron mine restoration will benefit from understanding these biogeochemical processes. Supergene enriched iron ore deposits in Brazil are typically blanketed by goethite-cemented breccias that form a protective duricrust known as canga. Moderately hard, well consolidated, permeable and resistant to erosion and chemical weathering, the canga blanket protects the relatively friable iron ore below. The protective canga horizons in the Carajás and Quadrilátero Ferrífero mineral provinces represent some of the longest-lived, continuously exposed land surfaces on Earth, and their formation is essential to supergene iron ore enrichment and preservation. Remarkably, the iron-rich duricrusts that have developed in Brazilian tropical rainforest environments, i.e, Carajás, yield geochronological results that indicate that these ancient erosion-resistant surfaces continue to evolve today. Active biogeochemical iron cycling is essential for the 'self-healing' cementation/re-cementation occurring in canga, suggesting that recurrent iron reduction and subsequent oxidation are responsible for canga evolution. Macroscopic biological features in canga including ferruginised plant roots and termite tracks have been linked to the biogeochemical cycling of iron. The 'organic' textures in canga can be traced to the microscopic scale, preserving fossilised bacterial cell envelopes and permineralised biofilms. At the canga surface, naturally rare and endemic rupestrian plant species carve out an existence, commonly in the absence of soil. Growth of grasses also promotes metal cycling highlighting that the rhizosphere contributes to canga evolution. The fossilisation of microbial biofilms and rhizosphere horizons consolidates canga, affecting its permeability, limiting water transport and enhancing biogeochemical cycling. The development of canga has been essential for the formation, preservation, and discovery of iron ore deposits, and its restoration will ultimately be required for mined land remediation of these unique ecosystems. [ABSTRACT FROM AUTHOR]

Struthanthus flexicaulis is a hemiparasite abundant in ironstone outcrops in southeast Brazil. We evaluated its host preference among species of the plant community, taking into account the abundance and foliage cover of the hosts. The importance of each species in the community and the mortality caused by the parasite were assessed based on a quantitative survey in 10 strips measuring 1m x 50m. The 10,290 individuals belonged to 42 species. Only 15 had a relative abundance in the plant community greater than 1%, of which 12 showed vestiges of parasitism. More than 80% of deaths in the community were associated with parasitism. Non-infected individuals had significantly less mortality rates (7%) than those infected (83%) (²= 1102.4, df = 1, p < 0.001). The observed infestation was different from the expected both regarding relative host abundance (²= 714.2, df = 11, p

Extensive mineral extractivism in the Brazilian Iron Quadrangle (IQ) region has destroyed large areas of land, decimating plant species, and their associated microbiota. Very little is known about the microbiota of the region; hence, cultivable bacteria associated with plants of its soils were investigated for their biotechnological potential. Samples were collected from nine plant species and six soils, and 65 cultivable bacterial isolates were obtained. These represent predominantly gram-positive bacilli (70%) capable of producing amylases (55%), proteases (63%), cellulases (47%), indole acetic acid (IAA) (46%), siderophores (26%), and to solubilize phosphate (9%). In addition, 65% of these were resistant to ampicillin, 100% were sensitive to tetracycline, and 97% were tolerant to high arsenic concentrations. Three isolates were studied further: the isolate FOB3 (Rosenbergiella sp.) produced high concentrations of IAA in vitro in the absence of tryptophan – shown by the significant improvement in plant germination and growth rate where the isolate was present. For isolates C25 (Acinetobacter sp.) and FG3 (Serratia sp.), plasmids were purified and inserted into Escherichia coli cells where they modified the physiological profile of the transformed strains. The E. coli::pFG3B strain showed the highest capacity for biofilm production, as well as an increase in the replication rate, arsenic tolerance and catalase activity. Moreover, this strain increased DNA integrity in the presence of arsenic, compared to the wild-type strain. These results help to explain the importance of bacteria in maintaining plant survival in ferruginous, rocky soils, acting as plant growth promoters, and to highlight the biotechnological potential of these bacteria.IMPORTANCE The Iron Quadrangle region is responsible for ∼60% of all Brazilian iron production and, at the same time, is responsible for housing a wide diversity of landscapes, and consequently, a series of endemic plant species and dozens of rare species – all of which have been poorly studied. Studies exploring the microbiota associated with these plant species are limited and in the face of the continuous pressure of extractive action, some species along with their microbiota are being decimated. To understand the potential of this microbiota, we discovered that cultivable bacterial isolates obtained from plants in the ferruginous rocky soil of the Iron Quadrangle region have diverse biotechnological potential, revealing a genetic ancestry still unknown.

Plants living above and around caves represent an important, albeit poorly studied, resource within cave ecosystems. The presence of plant material (root-like structures or rhizothemes, saplings, seeds, and seedlings) correlates positively with the biodiversity of the cave dwelling animals as shown for iron-ore caves in Carajás, Pará, Brazil. Plant material collected in caves has proven to be difficult to identify by traditional botanical methods, thus this research aims to provide a qualitative insight into the taxonomy and morphology of rhizothemes and other plant fragments found in the caves. The identification process used a combination of different molecular markers (ITS2, rbcL, and trnH-psbA) followed by a comparison of the sequences obtained against publicly available databases. The rhizothemes were submitted to micromorphological analysis to ascertain their putative root or stem origin and to compare their anatomy with known patterns found in the plant families or genera recovered through molecular matches. All studied samples were Angiosperms, mostly belonging to subclass Rosideae, within four orders: Malpighiales (Euphorbiaceae, Hypericaceae), Sapindales (Anacardiaceae and Sapindaceae), Myrtales (Myrtaceae), Fabales (Fabaceae), and only two belonging to subclass Asteridae, order Gentianales (Apocynaceae). Some of the samples were matched to generic level, with ITS2 being the best marker to identify the fragments because it shows high degree of sequence variation even at specific level and result reliability. All rhizothemes turned out to be roots, and correspondence was found between the existing literature and the individual anatomical patterns for the families and genera retrieved. DNA barcode has proved to be a useful tool to identify plant fragments found in this challenging environment. However, the existence of well curated, authoritatively named collections with ample biological information has proven to be essential to achieve a reliable identification.

Our objective was to evaluate the floristic and structural relationships between Canga tree communities and other vegetation types inserted in the physiognomic units set, in order to test the hypothesis that these communities have unique characteristics due to their specific environmental conditions. For this, we compared the structural and floristic attributes of Canga vegetation with adjacent semideciduous seasonal forest, Savanna and ecotone areas, evaluating the similarity in its behavior. Our results demonstrate the existence of distinct relationships among vegetation types in relation to different perspectives, related to macro-scale environmental attributes and to the phytogeographic context. In general, Canga tree vegetation has its structure associated with open vegetation types, such as the Cerrado (Savanna) and its composition associated with forest vegetation types, constituted by a community with specific ecological characteristics. Our results suggest the presence of ferruginous soils as a factor that contributes to environmental and ecological heterogeneity in vegetation matrices.

Vegetation and soil properties of an iron-rich canga (laterite) island on the largest outcrop of banded-iron formation in Serra de Carajás (eastern Amazonia, Brazil) were studied along a topographic gradient (738-762 m asl), and analyzed to test the hypothesis that soil chemical and physical attributes play a key role in the structure and floristic composition of these plant communities. Soil and vegetation were sampled in eight replicate plots within each of the four vegetation types. Surface (0-10 cm) soil samples from each plot were analyzed for basic cations, N, P and plant species density for all species was recorded. CCA ordination analysis showed a strong separation between forest and non-forest sites on the first axis, and between herbaceous and shrubby campo rupestre on the second axis. The four vegetation types shared few plant species, which was attributed to their distinctive soil environments and filtering of their constituent species by chemical, physical and hydrological constraints. Thus, we can infer that Edaphic (pedological) factors are crucial in explaining the types and distributions of campo rupestre vegetation associated with ferruginous ironstone uplands (Canga) in Carajás, eastern Amazonia, therefore the soil properties are the main drivers of vegetation composition and structure on these ironstone islands.

Highlights • Endangered Isoetes cangae produces large quantities of viable spores per sporangia. • Large number of sporelings emerge from male and female spores in vitro culture. • The megaspore nutrient reserve ensures longstanding sporeling growth. • Sporelings are able to grow in a range of substrates and temperature regimes. • Successful growth and low mortality suggest that I. cangae is a resilient species. Abstract Isoëtes L. is a nearly cosmopolitan rhizomorphic lycopsid genus fundamental to disentangling plant evolution because of its singular position in the Plantae kingdom. A threatened Amazonian species recently described is I. cangae, inhabiting an oligotrophic upland lake over an iron-rich region facing substantial environmental alterations. In this study, we aim to optimize a reproduction protocol that can assist in the conservation efforts of Isoëtes species in tropical areas. We observed an average of 126 megaspores or 318,000 microspores per sporangia in field-collected plants. We obtained an elevated percentage of sporelings (63%) from an in vitro mixed culture of mega- and microspores. In addition, we recovered a large number of sporelings around adult plants after cultivating them over quartzite sand and distilled water. The megaspore nutrient reserve ensured longstanding sporeling growth and development in these environmental conditions. However, the sporeling growth rate increased when they were planted over their original lake sediments or over an organic substrate, with nonsignificant differences between the substrates. An increase in temperature also increased the sporeling growth rate. Together with the very low sporeling mortality, these results suggest that I. cangae is a resilient species able to grow and colonize environments with low trophic characteristics with a range of substrates and temperature regimes. The protocols established in this study could be useful for the ex situ propagation and growth of a large number of sporelings, representing critical steps towards the population rescue and conservation of tropical Isoëtes species. [ABSTRACT FROM AUTHOR]

Highlights • Soil microbiome was assessed in revegetated Fe-mining site and pristine ecosystems. • First soil biota composition for canga , an ecosystem associated with Fe-rich rocks. • Soil microbiome of Fe-mining site and ecosystems was dissimilar at genus and family levels. • Plant community but not season affected soil microbiome. Abstract The Cerrado domain is composed of different phytophysiognomies and considered a hot spot of global diversity. However, few studies have assessed the soil microbiome of this domain using metabarcoding approach. This study aimed to determine the soil microbiome in a mining site under revegetation and compare with communities of pristine ecosystems. Soil samples were collected in the dry and rainy seasons in an iron-mining site under revegetation (RA), semi-decidual forest (FL), canga (NG) and Cerrado stricto sensu (CE). Soil community was accessed by the amplification of the 16S and 18S ribosomal gene fragments using high-throughput sequencing. The prokaryotic operational taxonomic units (OTUs) were assigned to 18 phyla, 48 classes, 73 orders, 123 families and 168 genera. Acidobacteria and Proteobacteria were the most abundant phylum for FL, CE and RA while Actinobacteria and Acidobacteria were dominant in NG. Relative abundance of families within each phylum varied mainly among sites, but not seasons. For Eukarya, OTUs were assigned to 15 phyla, 35 classes, 94 orders, 168 families and 247 genera. Opisthokonta, SAR (Stramenopiles, Alveolates, and Rhizaria), and Archaeplastida were the most abundant groups for all phytophysiognomies and Fungi accounted for 51–71% of total sequences. Principal coordinate analysis indicates that soil community composition was not influenced by season within each site. We concluded that soil microbiome was dissimilar among sites at the family and genus level but sites shared the same dominant phyla, and that differentiation of soil microbiome was driven mainly by plant community composition. [ABSTRACT FROM AUTHOR]

Mining activities modify the landscape and may have severe environmental impacts. The degree of recovery or disturbance of these environments must be determined, and microbiological indicators are most sensitive for this evaluation. The aim of this study was to evaluate the soil microbiological attributes of an area rehabilitated after iron mining activities and evaluate the adjacent phytophysiognomies. Soil samples were collected in a rehabilitated area revegetated with grass (RA) and in the phytophysiognomies of ironstone outcrops (IO), of neotropical savanna (NS), and of Atlantic Forest (AF) in two climate seasons (dry and rainy). Microbial biomass carbon, soil respiration, and enzyme activities (β-glucosidase, acid and alkaline phosphatase, arylsulfatase, urease, fluorescein diacetate hydrolysis) were determined, and the metabolic quotient ( q CO 2 ), the microbial quotient ( q Mic), and specific enzyme activities were calculated. Analyses of variance, means testing, and principal component analysis between the soil microbiological and physicochemical attributes were carried out. The microbiological indicators differed according to the type of phytophysiognomy and the season. Enzyme activities, microbial biomass, q CO 2 , soil respiration, and q Mic were sensitive in indicating differences among the phytophysiognomies, as well as organic carbon, total N, Fe, Cu, and Al 3+ contents, pH, potential acidity, cation exchange capacity, and clay and sand contents. The IO and NS phytophysiognomies exhibited the highest organic carbon and total N contents, whereas AF, NS, and IO exhibited the highest values of microbial biomass carbon. In both climate seasons, the AF exhibited higher values of soil respiration and enzyme activities. The Ironstone Outcrops exhibited high microbial biomass that was active in the processes of nutrient cycling, shown by its enzyme activities, whereas lower values of microbial biomass carbon and enzymes and higher values of q CO 2 were observed in RA. Nevertheless, RA exhibited higher specific enzyme activities and higher q Mic, indicating that the process of revegetation with grass favors activity of the microbial community, and promotes recovery of this area. [ABSTRACT FROM AUTHOR]

Extensive mineral extractivism in the Brazilian Iron Quadrangle (IQ) region has destroyed large areas of land, decimating plant species, and their associated microbiota. Very little is known about the microbiota of the region; hence, cultivable bacteria associated with plants of its soils were investigated for their biotechnological potential. Samples were collected from nine plant species and six soils, and 65 cultivable bacterial isolates were obtained. These represent predominantly gram-positive bacilli (70%) capable of producing amylases (55%), proteases (63%), cellulases (47%), indole acetic acid (IAA) (46%), siderophores (26%), and to solubilize phosphate (9%). In addition, 65% of these were resistant to ampicillin, 100% were sensitive to tetracycline, and 97% were tolerant to high arsenic concentrations. Three isolates were studied further: the isolate FOB3 (Rosenbergiella sp.) produced high concentrations of IAA in vitro in the absence of tryptophan – shown by the significant improvement in plant germination and growth rate where the isolate was present. For isolates C25 (Acinetobacter sp.) and FG3 (Serratia sp.), plasmids were purified and inserted into Escherichia coli cells where they modified the physiological profile of the transformed strains. The E. coli::pFG3B strain showed the highest capacity for biofilm production, as well as an increase in the replication rate, arsenic tolerance and catalase activity. Moreover, this strain increased DNA integrity in the presence of arsenic, compared to the wild-type strain. These results help to explain the importance of bacteria in maintaining plant survival in ferruginous, rocky soils, acting as plant growth promoters, and to highlight the biotechnological potential of these bacteria. IMPORTANCE The Iron Quadrangle region is responsible for ∼60% of all Brazilian iron production and, at the same time, is responsible for housing a wide diversity of landscapes, and consequently, a series of endemic plant species and dozens of rare species – all of which have been poorly studied. Studies exploring the microbiota associated with these plant species are limited and in the face of the continuous pressure of extractive action, some species along with their microbiota are being decimated. To understand the potential of this microbiota, we discovered that cultivable bacterial isolates obtained from plants in the ferruginous rocky soil of the Iron Quadrangle region have diverse biotechnological potential, revealing a genetic ancestry still unknown. [ABSTRACT FROM AUTHOR]

Plants living above and around caves represent an important, albeit poorly studied, resource within cave ecosystems. The presence of plant material (root-like structures or rhizothemes, saplings, seeds, and seedlings) correlates positively with the biodiversity of the cave dwelling animals as shown for iron-ore caves in Carajás, Pará, Brazil. Plant material collected in caves has proven to be difficult to identify by traditional botanical methods, thus this research aims to provide a qualitative insight into the taxonomy and morphology of rhizothemes and other plant fragments found in the caves. The identification process used a combination of different molecular markers (ITS2, rbcL, and trnH-psbA) followed by a comparison of the sequences obtained against publicly available databases. The rhizothemes were submitted to micromorphological analysis to ascertain their putative root or stem origin and to compare their anatomy with known patterns found in the plant families or genera recovered through molecular matches. All studied samples were Angiosperms, mostly belonging to subclass Rosideae, within four orders: Malpighiales (Euphorbiaceae, Hypericaceae), Sapindales (Anacardiaceae and Sapindaceae), Myrtales (Myrtaceae), Fabales (Fabaceae), and only two belonging to subclass Asteridae, order Gentianales (Apocynaceae). Some of the samples were matched to generic level, with ITS2 being the best marker to identify the fragments because it shows high degree of sequence variation even at specific level and result reliability. All rhizothemes turned out to be roots, and correspondence was found between the existing literature and the individual anatomical patterns for the families and genera retrieved. DNA barcode has proved to be a useful tool to identify plant fragments found in this challenging environment. However, the existence of well curated, authoritatively named collections with ample biological information has proven to be essential to achieve a reliable identification. [ABSTRACT FROM AUTHOR]

In the state of Pará (Brazil), until the beginning of last decade little was known about the composition of the fern and lycophyte flora. The ferruginous mountains of Carajás are located in Southeastern Pará, mostly inserted in the Floresta Nacional de Carajás. The objective of this work is to present a complete and updated list of fern and lycophyte species occurring in all vegetation types from Carajás ferruginous mountains as a contribution to the knowledge of these plant groups from the Brazilian Amazon. The species list was based on specimens collected between 2007 and 2013. About 1068 specimens deposited in the BHCB Herbarium were studied. A total of 186 species of pteridophytes were recorded, 175 species of ferns distributed in 22 families and 68 genera, and 11 species of lycophytes distributed in three families and four genera. The fern and lycophyte flora of Serra dos Carajás region corresponds to 64% of the Pará state flora of these groups and 34% of the Brazilian Amazon fern and lycophyte flora. Seven taxa are presented as new records for Pará state: Asplenium abscissum, A. otites, A. praemorsum, Blechnum lanceola, Elaphoglossum minutum, Doryopteris collina, and Hemionitis tomentosa. Three species are endemic to Serra dos Carajás, Isoetes cangae, I. serracarajensis, and Selaginella stomatoloma. [ABSTRACT FROM AUTHOR]

This work presents a floristic survey of Erythroxylaceae from the canga vegetation of Serra dos Carajás in the state of Pará, Brazil. Within the study area, the family is represented by nine species of Erythroxylum: Erythroxylum carajasense, E. citrifolium, E. leptoneurum, E. macrophyllum, E. mucronatum, E. nelson-rosae, E. rufum, E. squamatum and E. subracemosum. Erythroxylum carajasense and E. nelson-rosae, both endemic to the ferruginous formations of the Serra dos Carajás, are here evaluated as Endangered (EN) according to the International Union for Conservation of Nature (IUCN). Morphological descriptions, comments on geographic distribution and preferred habitat are provided, as well as illustrations of the main features for species identification. Additionally, E. ligustrinum var. carajasense Plowman was raised to the specific rank. [ABSTRACT FROM AUTHOR]

Background Ironstone ranges are considered hotspots for higher plants α and β diversity. The lack of studies and the intense degradation of the ironstone ranges, due to mining, motivated us to compile, for the first time, a list of vascular plants collected on iron-rich derived substrates from ancient landscape of south-eastern Brazil. All existing records in the Brazilian Virtual Herbarium of Flora and Fungi for each of the 43 municipalities containing ironstone ranges were downloaded, resulting in 17,954 vouchers identified to the species level. We found 2,933 species belonging to 160 families and 818 genera. New information For the first time, we identified 148 species mentioned in endangered flora official lists and 48 narrow endemic species. Collecting efforts must still be supported to properly sample the vegetation since, for 143 sites, less than 10 records/site were found. This dataset will assist with the indication of dozens of plant species whose threat criteria must be urgently assessed to subsidise public policies on the use and conservation of the Brazilian flora. [ABSTRACT FROM AUTHOR]

Abstract: (U‐Th)/He geochronology and cosmogenic 3He in iron oxides reveal mineral precipitation ages as old as 55 Ma and exposure ages greater than 5 Ma for canga‐cemented plateaus in the Quadrilátero Ferrífero, Brazil, showing that lateritic profiles overlying banded iron‐formation (BIF) landscapes in tropical regions have a long history of surface exposure. The long‐term erosion history obtained from cosmogenic 3He on BIF plateaus confirms that relic surfaces persist in the landscape for millions of years. Combined 3He and (U‐Th)/He dating shows that cangas are preferentially goethite cemented by biogeochemical reactions in the subsurface. Importantly, pebbles of hematite‐magnetite in colluvia or shallow creeks draining the canga‐cemented plateaus record a much longer exposure history than in situ canga blocks, showing that even older duricrusts, now eroded, once blanketed these plateaus. Physically stable but biogeochemically dynamic, cangas armor the landscape by pervasive and recurrent iron cycling and cementation, slowing down the delivery of weathered BIF or friable hematite–magnetite ore to erosion. [ABSTRACT FROM AUTHOR]