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Antibiotic resistance, driven by the proliferation of antibiotic resistance genes (ARGs) and antibiotic resistance bacteria (ARBs), has emerged as a pressing global health concern. Antimicrobial resistance is exacerbated by the widespread use of antibiotics in agriculture, aquaculture, and human medicine, leading to their accumulation in various environmental compartments such as soil, water, and sediments. The presence of ARGs in the environment, particularly in municipal water, animal husbandry, and hospital environments, poses significant risks to human health, as they can be transferred to potential human pathogens. Current remediation strategies, including the use of pyroligneous acid, coagulants, advanced oxidation, and bioelectrochemical systems, have shown promising results in reducing ARGs and ARBs from soil and water. However, these methods come with their own set of challenges, such as the need for elevated base levels in UV-activated persulfate and the long residence period required for photocatalysts. The future of combating antibiotic resistance lies in the development of standardized monitoring techniques, global collaboration, and the exploration of innovative remediation methods. Emphasis on combination therapies, advanced oxidation processes, and monitoring horizontal gene transfer can pave the way for a comprehensive approach to mitigate the spread of antibiotic resistance in the environment.

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The aim of this study was to formulate novel biomixtures with the ability to dissipate globally used pesticides. For this, an effective stabilization of two wastes, poultry litter and activated sewage sludge, was achieved through a combination of composting and vermicomposting, with the aid of the earthworm Eisenia fetida. Hence, two different mixtures were prepared combining the wastes with and without the addition of sewage sludge, and their physicochemical and microbiological characterization was examined during both processes. Earthworms reproduction was promoted by more than fourteen times the initial number of individuals introduced. This step made it possible to obtain substrates rich in organic matter, stable and non-pathogenic. The resulting vermicomposted substrates (V-C1 and V-C2) were used to produce two different biomixtures with wheat stubble (WS) and soil (S): SWSV-C1 and SWSV-C2, and they were tested for the remediation of a solution of five pesticides (2,4-D, cypermethrin, imidacloprid, acetochlor and dimethoate) in a 119-days assay. Comparisons were made with a WS-only biomixture (SWS) and a soil control. All biomixtures were more successful in dissipating the pesticides than soil; 2,4-D, dimethoate, and acetochlor degradation reached more than 99% in the three biomixtures after 28-56 days of assay. Biomixtures containing either vermicomposts acted faster than SWS, particularly for 2,4-D, dimethoate and cypermethrin. The total microbial activity was found to be higher in the two biomixtures containing vermicompost, which can be linked to their enhanced performance in the degradation of pesticides. Although the germination of Lactuca sativa proved that neither of the three spent biomixtures were phytotoxic at the end (germination index >60%), only SWSV-C1 and SWSV-C2 proved to be safe for the survival of E. fetida. This work confirms that vermicompost improves the success of biomixtures, not only in terms of pesticide removal, but also providing non-toxic spent biomixtures.

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Biochar amendment has emerged as a potential solution for preventing, remediating, and mitigating agricultural compound pollution. This groundbreaking technique not only improves crucial soil properties like porosity, water retention capacity, cation exchange capacity, and pH, but also intricately impacts the interaction and retention mechanisms of polluting molecules. In this study, we investigate the dynamic of the herbicide Imazapic when subjected to applying pyrolyzed biochars, specifically at temperatures of 300 and 500 °C, within the context of a low-fertility soil characterized as dystrophic Yellow Ultisol (YUd) in a sugarcane cultivation area in Igarassu-PE, Brazil. The biochars were produced from sugarcane bagasse by pyrolysis process in a muffle furnace. In laboratory conditions, with saturated soil columns under steady-state, analyses of the mechanisms involved in interaction and transport and determining hydrodispersive parameters for Imazapic were performed by the two-site nonequilibrium transport model using the CXTFIT 2.0 program. Samples of YUd soil amended with biochar pyrolyzed at 300 °C presented a negligible interaction with Imazapic. However, adding biochar pyrolyzed at 500 °C (BC500) to the soil samples enhanced the adsorption coefficient and improved the interaction with Imazapic. This research points out that biochar produced from agricultural waste biomass, such as sugarcane bagasse specifically pyrolyzed at 500 °C, offers a potential means to adsorb herbicides, reducing their leaching to deeper layers of the amended soils and the risk of groundwater contamination and potential environmental negative impacts.

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Tropical stream ecosystems are under increasing human pressure, making the development of effective restoration approaches and expanding knowledge in this field urgent. This study evaluated the impact of riparian vegetation restoration and environmental context on stream ecosystem functioning by measuring key ecosystem functions - gross primary production (GPP), ecosystem respiration (ER), and nutrient uptake of ammonium and soluble reactive phosphorus - across ten tropical streams in southeastern Brazil. The streams represented a gradient from clearcut areas (impacted reaches) to relatively pristine conditions (reference reaches), including intermediate stages of vegetation recovery (restored reaches). In the short-term (~15-20 years after restoration), restoration led to reduced GPP akin to reference reaches. Yet, ER did not show the anticipated increase, suggesting a longer timeframe is necessary for restored streams to emulate the functional characteristics of reference reaches. Additionally, the restored reaches did not achieve the nutrient uptake efficiencies observed in both impacted and reference reaches, pointing to a partial recovery of ecosystem function. This study suggests that while riparian vegetation restoration contributes positively to certain aspects of stream function, environmental variables less related to this type of restoration, such as discharge and hydromorphology, significantly influence stream ecosystem functioning, highlighting the importance of considering environmental context in restoration efforts. A more holistic approach, possibly encompassing broader hydromorphological and habitat enhancements, is needed to fully restore ecological processes in these vital ecosystems. These insights are critical for informing future tropical stream restoration projects, advocating the use of ecosystem function metrics as comprehensive indicators of ecological recovery and restoration success.

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Microbial communities from freshwater sediments are involved in biogeochemical cycles and they can be modified by physical and chemical changes in the environment. Linking the microbial community structure (MCS) with physicochemistry of freshwater courses allows a better understanding of its ecology and can be useful to assess the ecological impact generated by human activity. The MCS of tributary channels from La Plata River affected by oil refinery (C, D, and E) and one also by urban discharges (C) was studied. For this purpose, 16S rRNA metabarcoding analysis, in silico metagenome functional prediction, and the hydrocarbon degradation potential (in silico predictions of hydrocarbon-degrading genes and their quantification by qPCR) of the MCS were studied. Principal coordinate analysis revealed that the MCS was different between sites, and it was not structured by the hydrocarbon content. Site C showed physicochemical characteristics, bacterial taxa, and an in silico functional prediction related to fermentative/heterotrophic metabolism. Site D, despite having higher concentration of hydrocarbon, presented autotrophic, syntrophic, and methanogenic pathways commonly involved in natural processes in anoxic sediments. Site E showed and intermediate autotrophic/heterotrophic behavior. The hydrocarbon degradation potential showed no positive correlation between the hydrocarbon-degrading genes quantified and predicted. The results suggest that the hydrocarbon concentration in the sites was not enough selection pressure to structure the bacterial community composition. Understanding which is the variable that structures the bacterial community composition is essential for monitoring and designing of sustainable management strategies for contaminated freshwater ecosystems.

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Mining activities put the Brazilian savannas, a global biodiversity hotspot, in danger of species and soil carbon losses. Experiments employing biosolids have been applied to rejuvenate this degraded ecosystem, but a lingering question yet to be answered is whether the microbiota that inhabits these impoverished soils can be recovered towards its initial steady state after vegetation recovery. Here, we selected an 18-year-old restoration chronosequence of biosolids-treated, untreated mining and native soils to investigate the soil microbiota recovery based on composition, phylogeny, and diversity, as well as the potential factors responsible for ecosystem recovery. Our results revealed that the soil microbiota holds a considerable recovery potential in the degraded Cerrado biome. Biosolids application not only improved soil health, but also led to 41.7 % recovery of the whole microbial community, featuring significantly higher microbiota diversity and enriched groups (e.g., Firmicutes) that benefit carbon storage compared to untreated mining and native soils. The recovered community showed significant compositional distinctions from the untreated mining or native soils, rather than phylogenetic differences, with physiochemical properties explaining 55 % of the overall community changes. This study advances our understanding of soil microbiota dynamics in response to disturbance and restoration by shedding light on its recovery associated with biosolid application in a degraded biodiverse ecosystem.

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Nanoscale zero valent iron (nZVI) is globally the main nanomaterial used in contaminated site remediation. This study aims to evaluate the sustainability of using nZVI in the nanoremediation of contaminated sites and to determine the factors that affect the sustainability of the use of nZVI in remediation. Five case studies of nZVI use on a pilot scale were selected. Life cycle analysis tools were used to evaluate environmental, economic, social impacts, and sustainability. The functional unit of the life cycle analyses was 1.00 m3 of remediated soil and groundwater. Case study of Brazil was the least sustainable, while case study of United States was the most sustainable. Only the modification of the functional unit results in variations in the sustainability index. Different factors influence the sustainability of nZVI in remediation, the main factor being the amount of nZVI used in the processes. Finally, this work contributes significantly to the state-of-the-art sustainable use of nZVI in remediation. This is a pioneering study in the detailed and comprehensive assessment of the sustainability of the use of nZVI in remediation. Through the analysis of case studies, it is possible to determine the main factors that influence the sustainability of the nZVI remediation life cycle.

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An environmental disaster caused by the rupture of a mining tailings dam has impacted a large area of the Rio Doce watershed in the Brazilian Atlantic Forest, resulting in unprecedented damage at spatial and temporal scales. The Atlantic Forest is one of the world's most important biodiversity hotspots. A long history of land use conversion has resulted in a highly fragmented landscape. Despite numerous restoration initiatives, these efforts have often biased criteria and use limited species assemblages. We conducted a comprehensive synthesis of the plant community in riparian forests along the Rio Doce watershed. Our work detailed vegetation composition (tree and sapling strata) and examined its relationship with edaphic and landscape factors, aiming to inform restoration projects with scientifically robust knowledge. A total of 4906 individuals from the tree strata and 4565 individuals from the sapling strata were recorded, representing a total of 1192 species from 75 families. Only 0.8% of the tree species and 0.5% of the sapling species occurred in all sampled sectors, with over 84% of the species occurring in a single watershed sector for both strata. We observed a high species heterogeneity modulated by turnover (92.3% in the tree, and 92.7% in the sapling strata) among sites. Overall, our research revealed a gradient of soil fertility influencing species composition across different strata. Additionally, we discovered that preserved landscapes had a positive impact on species diversity within both strata. The species exclusivity in the sampled sites and the high turnover rate imply the need to consider multiple reference ecosystems when restoring the watershed to reduce the risk of biotic homogenization. Finally, the reference ecosystems defined here serve as a basis for the selection of locally particular species in the implementation of restoration projects that aim to improve biodiversity, ecosystem services, and water security.

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Urban rivers are affected at different levels by the intensification of human activities, representing a serious threat to the maintenance of terrestrial life and sustainable urban development. Consequently, great efforts have been dedicated to the ecological restoration of urban rivers around the world, as a solution to recovering the environmental functionality of these environments. In this sense, the present work aimed to investigate the effectiveness of interventions carried out aimed at the recovery of urban rivers, through a systematic review of the literature between 2010 and 2022, using the search term "rivers recovery." The results showed that there have been notable advances in the implementation of river recovery programs in urban areas around the world between the years analyzed. The ecosystems studied were affected, for the most part, by the increase in the supply of nutrients from domestic and industrial effluents, in addition to having highly urbanized surroundings and with several changes in land use patterns. The preparation of this literature review made it possible to demonstrate that the effectiveness of river recovery is extremely complex, since river recovery projects are developed for different reasons, as well as being carried out in different ways according to the intended objective.

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Introduction: The lack of knowledge on seed germination and seedling establishment is a main constraint for the restoration of degraded areas, including the tropical dry forest known as Caatinga. Objective: To assess reserve and secondary metabolite mobilization during seed germination and seedling establishment in Erythina velutina. Methods: We scarified, disinfected, imbibed, sown between towel paper, and incubated seeds under controlled conditions. We hydroponically cultivated seedlings in a greenhouse. We harvested cotyledons at seed imbibition, radicle protrusion, hypocotyl emergence, apical hook formation and expansion of cordiform leaves, first trifoliate leaf, and second trifoliate leaf. Results: Seeds contained approximately 20 % starch, 14.5 % storage proteins, 11.6 % neutral lipids, and 5.7 % non-reducing sugars on a dry weight basis. Soluble sugars were mainly consumed from hypocotyl emergence to apical hook formation, while major reserves were mobilized from apical hook formation to expansion of first trifoliate leaf. Enzymatic activity increased from mid to late seedling establishment, causing the mobilization of starch, oils, and proteins. Terpenoid-derivatives, flavonoids, phenolic acids, and alkaloids were detected. Flavonoids and phenolic acids were present at almost all stages and terpenoid-derivatives disappeared at expansion of cordiform leaves. Conclusion: Soluble sugars support early seedling growth, while starch, oils and proteins are simultaneously mobilized from mid to late establishment by amylases, lipases, and acid proteases. The cotyledons contain secondary metabolites, which may act in seedling defense. High content of reserves and presence of secondary metabolites in the cotyledons could enable E. velutina seedlings endure stress, validating their use in the restoration of degraded areas.

Introducción: La falta de conocimiento sobre la germinación de semillas y el establecimiento de plántulas es una de las principales limitaciones para la restauración de áreas degradadas, incluido el bosque seco tropical conocido como Caatinga. Objetivo: Evaluar la movilización de reservas y metabolitos secundarios durante estas etapas de desarrollo en Erythina velutina. Métodos: Las semillas fueron escarificadas, desinfectadas, embebidas, sembradas entre toallas de papel e incubadas bajo condiciones controladas. Cultivamos las plántulas hidropónicamente en un invernadero. Recolectamos los cotiledones en la imbibición de la semilla, la protrusión de la radícula, la emergencia del hipocótilo, la formación del gancho apical y la expansión de las hojas cordiformes, la primera y segunda hoja trifoliada. Resultados: Las semillas contenían 20 % de almidón, 14.5 % de proteínas de almacenamiento, 11.6 % de lípidos neutros y 5.7 % de azúcares no reductores en peso seco. Los azúcares solubles se consumieron desde la emergencia del hipocótilo hasta la formación del gancho apical. Las principales reservas se movilizaron desde la formación del gancho apical hasta la expansión de la primera hoja trifoliada. La actividad enzimática aumentó desde la mitad hasta el final del establecimiento de las plántulas, movilizando almidón, aceites y proteínas. Se detectaron derivados de terpenoides, flavonoides, ácidos fenólicos y alcaloides. Los flavonoides y los ácidos fenólicos estuvieron en casi todas las etapas y los derivados terpenoides desaparecieron en la expansión de las hojas cordiformes. Conclusión: Los azúcares solubles apoyan el crecimiento temprano de las plántulas; el almidón, los aceites y las proteínas se movilizan simultáneamente desde el establecimiento medio hasta el final por amilasas, lipasas y proteasas ácidas. Los cotiledones contienen metabolitos secundarios, que pueden actuar en la defensa de las plántulas. El alto contenido de reservas y los metabolitos secundarios en los cotiledones podría permitir que las plántulas de E. velutina toleren estrés, validando su uso en la restauración de áreas degradadas.

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Sapindus saponaria L. (Sapindaceae) is a pioneer species used in programs to recover degraded areas. The trees also assist in the pest control of some insects due to the composition of saponins on their leaves. In addition, these chemical components are important to pharmaceutical product production. The objective was to evaluate the impact of spatial distribution, indices and ecological relationship of arthropods on S. saponaria leaves to preserve the balance of biodiversity. Aggregated distribution of arthropods was observed; the numbers of phytophagous arthropods were higher on the adaxial leaf face than on the abaxial part. Only Aleyrodidae (Hemiptera) had a higher presence on the abaxial leaf face of S. saponaria saplings. Abundance, diversity, and species richness of natural enemies correlated positively with phytophagous and pollinators insects. On the other hand, the number of Lyriomyza sp. mines correlated negatively with Pseudomyrmex termitarius (Smith) (Hymenoptera: Formicidae). All this information can assist and guide integrated pest management programs.

Sapindus saponaria L. (Sapindaceae) é uma espécie pioneira utilizada em programas de recuperação de áreas degradadas. As árvores também auxiliam no controle de alguns insetos pragas devido à composição de saponinas em suas folhas. Além disso, esses componentes químicos são importantes para a produção de produtos farmacêuticos. O objetivo foi avaliar o impacto da distribuição espacial, índices e relações ecológicas de artrópodes nas folhas de S. saponaria, a fim de preservar o equilíbrio da biodiversidade. Observou-se distribuição agregada; os números de artrópodes fitófagos foram maiores na face adaxial da folha do que na parte abaxial. Apenas indivíduos de Aleyrodidae (Hemiptera), tiveram maior presença na face abaxial das folhas, em mudas de S. saponaria. Abundância, diversidade e riqueza de espécies de inimigos naturais correlacionaram-se positivamente com insetos fitófagos e polinizadores. Por outro lado, o número de minas de Lyriomyza sp. correlacionou-se negativamente com o de Pseudomyrmex termitarius (Smith) (Hymenoptera: Formicidae). Todas essas informações podem ser usadas para auxiliar e orientar programas de manejo integrado de pragas.

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Nanomaterials have attracted much attention over the last decades due to their very different properties compared to those of bulk equivalents, such as a large surface-to-volume ratio, the size-dependent optical, physical, and magnetic properties. A number of solution fabrication methods have been developed for the synthesis of metal and metal oxides nanoparticles, but few solid-state methods have been reported. The application of nanostructured materials to electronic solid-state devices or to high-temperature technology requires, however, adequate solid-state methods for obtaining nanostructured materials. In this review, we discuss some of the main current methods of obtaining nanomaterials in solid state, and also we summarize the obtaining of nanomaterials using a new general method in solid state. This new solid-state method to prepare metals and metallic oxides nanostructures start with the preparation of the macromolecular complexes chitosan·Xn and PS-co-4-PVP·MXn as precursors (X = anion accompanying the cationic metal, n = is the subscript, which indicates the number of anions in the formula of the metal salt and PS-co-4-PVP = poly(styrene-co-4-vinylpyridine)). Then, the solid-state pyrolysis under air and at 800 °C affords nanoparticles of M°, MxOy depending on the nature of the metal. Metallic nanoparticles are obtained for noble metals such as Au, while the respective metal oxide is obtained for transition, representative, and lanthanide metals. Size and morphology depend on the nature of the polymer as well as on the spacing of the metals within the polymeric chain. Noticeably in the case of TiO2, anatase or rutile phases can be tuned by the nature of the Ti salts coordinated in the macromolecular polymer. A mechanism for the formation of nanoparticles is outlined on the basis of TG/DSC data. Some applications such as photocatalytic degradation of methylene by different metal oxides obtained by the presented solid-state method are also described. A brief review of the main solid-state methods to prepare nanoparticles is also outlined in the introduction. Some challenges to further development of these materials and methods are finally discussed.

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Conservation of the Amazon rainforest is a global concern and is supported by the Brazilian government's ratification of the Bonn Challenge and Paris Agreement and the introduction of national regulations on vegetation protection and restoration. Amazonas is the largest and least deforested of the states occupied by the Brazilian Amazon (< 3%). We carried out a survey on the current state and growth potential of seed and seedling production in Amazonas state, pointing out constraints where future investment can promote the achievement of large-scale restoration commitments. We visited the 35 officially registered seed producers or nurseries working with native seeds and interviewed their owners or managers using open and closed questions. Enterprises were mainly privately-owned family businesses with small production (10,001 - 100,000 seedlings per year) and concentrated in the metropolitan area of the state capital Manaus. We uncovered a further 54 non-officially registered nurseries. Annual production (2018) was almost four tons of seeds and nearly ten million seedlings. According to the owners, production could be increased five to seven times with existing infrastructure. Production is focused foremost on species for food production (48% seeds, 74% seedlings), while ecological restoration only makes up 35% of seed and 8% of seedling use. Major bottlenecks cited by the producers were low demand for native tree species, high transportation costs and excessive bureaucracy. To achieve large-scale restoration, we recommend enforcement of national policies for vegetation protection and restoration, and a restructuring of the seed and seedling sector with a bottom-up approach.(AU)

A conservação da Amazônia é uma preocupação global, apoiada pela ratificação do Bonn Challenge e do Acordo de Paris pelo governo brasileiro e pelas regulamentações nacionais de proteção e restauração da vegetação. O Amazonas é o maior e menos desmatado estado da Amazônia brasileira (<3%). Realizamos um levantamento do estado atual e potencial da produção de sementes e mudas no Amazonas, indicando os principais obstáculos e gargalos onde investimentos futuros podem ajudar a alcançar o compromisso da restauração ecológica em larga escala. Visitamos os 35 produtores de sementes ou mudas de espécies nativas oficialmente registrados, e entrevistamos seus proprietários ou responsáveis técnicos, utilizando um questionário com perguntas abertas e fechadas. Os empreendimentos eram predominantemente privados, familiares, com pequena produção (10.001 - 100.000 mudas por ano) e concentrados na região metropolitana de Manaus. Detectamos outros 54 viveiros não oficialmente registrados. A produção anual (2018) foi de quase quatro toneladas de sementes e quase dez milhões de mudas. Segundo os proprietários, esta produção poderia aumentar de cinco a sete vezes com a infraestrutura existente. A produção foi focada principalmente em espécies para produção alimentar (48% sementes, 74% mudas), enquanto apenas 35% de sementes e 8% de mudas foram destinadas para restauração ecológica. Os principais gargalos citados pelos produtores foram baixa demanda por espécies nativas, alto custo de transporte e excessiva burocracia. Para alcançar restauração em larga escala, recomendamos o cumprimento de políticas de proteção e restauração da vegetação e uma reestruturação do setor de sementes e mudas em uma abordagem ascendente (bottom-up).(AU)

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O monitoramento das práticas de restauração é um processo caro, mas essencial para verificar o seu sucesso. Uma forma de reduzir os custos amostrais é por meio da utilização de indicadores de biodiversidade, termo utilizado para um grupo funcional ou taxonômico que é concordante com outro grupo. O objetivo deste trabalho foi avaliar a concordância entre a riqueza e a composição de plantas regenerantes, formigas e outros artrópodes sob o dossel de quatro espécies arbóreas em uma área de restauração na Mata Atlântica, Brasil, bem como determinar a relação das comunidades biológicas com parâmetros ambientais e espaciais. Foi encontrado que as variáveis ambientais, muitas vezes ligadas a identidade da árvore, são preponderantes para determinar a relação entre formigas, outros artrópodes e plantas regenerantes. Além disso, as formigas demonstraram ser indicadores fracos da diversidade e composição de plantas regenerantes e outros artrópodes e essa relação não foi guiada pelas variáveis ambientais e espaciais. Assim, os resultados aqui encontrados recomendam cautela ao utilizar formigas como indicadores de biodiversidade de plantas e outros artrópodes em programas de monitoramento na Mata Atlântica.

Monitoring restoration practices is an expensive process, but essential to verifying their success. One way to reduce sampling costs is using biodiversity indicators, a term used for a functional or taxonomic group that is in agreement with another group. The objective of this work was to evaluate the agreement between the richness and composition of regenerating plants, ants and other arthropods under the canopy of four tree species in a restoration area in the Atlantic Forest, Brazil, as well as to determine the relationship of biological communities with parameters environmental and spatial. It was found that environmental variables, often linked to the tree's identity, are preponderant in determining the relationship between ants, other arthropods and regenerating plants. In addition, ants proved to be weak indicators of regenerating plants and other arthropods diversity and composition and this relationship was not guided by environmental and spatial variables. Thus, the results found here recommend caution when using ants as indicators of plant biodiversity and other arthropods in monitoring programs in the Atlantic Forest.

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Globally, forest-savanna mosaic landscapes are of significant conservation importance but have been widely impacted by human land-use. We studied how restoration, through cessation of long-term cattle grazing impacts (i) forest regeneration; (ii) forest understory structure and composition; and (iii) populations and diversity of large mammals and nocturnal birds, within naturally patchy gallery forests in the Beni Savannas of Bolivia. Comparing grazed and restored sites, we assessed the abundance and composition of tree functional types at different life stages (seedlings, saplings and adults), with focus on the region's key palm species Attalea princeps (motacú). Additionally, we surveyed habitat structure and composition in the shrub and ground-layer, and monitored occurrence and encounter rates of large mammals and nocturnal birds along dusk and evening transects. We found evidence of lower recruitment of motacú palms on the grazed site and lower potential for natural motacú regeneration. Principal Components Analysis revealed forests on grazed sites had simpler, more open shrub-layers and altered ground-layer structure and composition including increased bare ground. Mammal species richness was greater on the restored site, and there were more declining, globally threatened and site-unique species. Species richness was similar for nocturnal birds within forests on both the grazed and restored site, but nearly all species tended to be encountered more frequently on the restored site. Our results suggest cattle negatively impact forest regeneration and alter the structure and composition of the shrub and ground layer with potential consequences for the diversity and abundance of wildlife. Our study represents one of only a handful completed in the Beni region of Bolivia to date. The Beni is currently under pressure from widespread, largely unregulated cattle ranching. Our results thus provide vital evidence to support development of restoration and conservation policy, and its integration with rangeland management in this threatened and critically understudied region.

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The petrochemical industry is responsible for many accidental releases of pollutants in soil such as hydrocarbons and toxic metals. This co-contamination is responsible for a delay in the degradation of the organic pollution. Many successful technologies to remove these metals apply extracellular polymeric substances (EPS). In this study, we tested the application of an EPS from a Paenibacillus sp. to aid the bioremediation of soils contaminated with crude oil and nickel. We conducted a microcosm experiment to soils containing combinations of oil, nickel, and EPS. The final concentration of oil was evaluated with an infrared spectrometer. Also, we sequenced the metagenomes of the samples in an ion torrent sequencer. The application of EPS did not aid the removal of hydrocarbons with or without the presence of nickel. However, it led to a smaller decrease in the diversity indexes. EPS decreased the abundance of Actinobacteria and increased that of Proteobacteria. The EPS also decreased the connectivity among Actinobacteria in the network analysis. The results indicated that the addition of EPS had a higher effect on the community structure than nickel. Altogether, our results indicate that this approach did not aid the bioremediation of hydrocarbons likely due to its effect in the community structure that affected hydrocarbonoclastic microorganisms.

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In this study, two amendments, poultry waste and ammonium nitrate, were evaluated to condition and stabilize a mine tailing and thus help the vegetation cover settle. Individually, ammonium nitrate was tested as a nitrogen source and chicken bone ash as a phosphate source. For this, laboratory tests were made on soil columns from the area to be remediated. The mobility and availability of metals and nutrients were determined by analyzing their leachates chemically. The results showed that the use of chicken bone ash decreases soluble metal concentrations, particularly in Fe and soluble Mn. On the other hand, experimental conditions proved that the acidification produced by ammonium nitrate nitrification does not significantly increase the lechate metal content. Therefore, its use for fertilization does not involve phytotoxicity risks. Regarding the availability of macronutrients as well as trace elements, the results showed that the concentrations lie within the ranges suitable for plant nutrition. So, the treatments are effective both for fertilization and phytoremediation.

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The dispersion of mine tailings affects ecosystems due to their high content of potentially toxic elements. Environmental risk increases when the soil impacted by tailings is used for agriculture; this use may result in health impacts. This study analyzes the feasibility of remediating a calcareous soil (used for maize cultivation) polluted with lead in the semiarid zone of Zimapán, México, by using EDTA as an extractant. Total geoavailable and bioaccessible concentrations in the gastric and intestinal phases were determined to evaluate lead availability and health risk. The soil was then washed with EDTA, and the geochemical fractionation (interchangeable, carbonates, Fe/Mn oxy-hydroxides, organic matter-sulfides, and residual) and impact on the mesophile bacteria and fungi/yeast populations were analyzed. The results showed total Pb concentrations up to 647 ± 3.50 mg/kg, a 46% bioaccessible fraction (297 ± 9.90 mg/kg) in the gastric phase and a 12.2% (80 ± 5 mg/kg) bioaccessible fraction in the intestinal phase, indicating a health and environmental risk. Meanwhile, the geochemical fractionation before washing showed a Pb fraction mainly consisting of Fe/Mn oxy-hydroxides (69.6%); this reducible fraction may progressively increase its bioaccessibility. Geochemical fractionation performed in the washed soil showed differences from that determined before the treatment; however, the iron and manganese fraction, at 42.4%, accounted for most of the Pb. The soil microbiology was also modified by EDTA, with an increase in aerobic bacteria and a decrease in fungi/yeast populations. Although 44% total lead removal was achieved, corresponding to a final concentration of 363.50 ± 43.50 mg/kg (below national and USEPA standards), washing with EDTA increased the soluble and interchangeable lead concentrations. Statistical analysis indicated a significant effect (p < 0.05) of EDTA on the soil's geochemical fractionation of lead.

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This study analyzed natural regeneration floristic patterns in spring habitats submitted to different ecological restoration actions in the seasonal forest in Atlantic Forest biome, Rio Grande do Sul. We assessed floristic composition in six springs before restoration actions and 12 months later. We identified and counted all regenerating individuals with height greater than or equal to 30 cm and diameter at breast height less than or equal to 5 cm in eight plots in each spring. The richness and abundance of each spring and assessment were compared by the Kruskal-Wallis test (P<0.05). Detrended Correspondence Analysis (DCA) was performed to verify floristic patterns and association between species. Results showed an increase in richness and abundance after ecological restoration implementation. The DCA showed a distinct floristic composition between springs. The springs remaining natural vegetation and the successional stage of these vegetation influenced the natural regeneration floristic composition pattern. Passive restoration, which was effective by enclosure, favored natural regeneration recruitment.(AU)

O objetivo deste estudo foi analisar os padrões florísticos da regeneração natural em habitats de nascentes submetidos a diferentes ações de restauração ecológica na floresta estacional do bioma Mata Atlântica, Rio Grande do Sul. A composição florística foi avaliada em seis nascentes antes das ações de restauração e 12 meses depois. Todos os indivíduos regenerantes com altura maior ou igual a 30 cm e diâmetro à altura do peito menor ou igual a 5 cm foram contados e identificados em oito parcelas em cada nascente. A riqueza e abundância de cada nascente em cada avaliação foram comparadas pelo teste de Kruskal-Wallis (P <0,05). A Análise de Correspondência Retificada (DCA) foi realizada para verificar os padrões florísticos e a associação entre as espécies. Os resultados mostraram um aumento na riqueza e abundância após a implementação da restauração ecológica. A DCA apresentou uma composição florística distinta entre as nascentes. A vegetação natural remanescente nas áreas de nascente e o estágio sucessional da vegetação influenciaram o padrão de composição florística. A restauração passiva, efetivada pelo cercamento, favoreceu o desenvolvimento da regeneração natural.(AU)

Asunto(s)

RESUMEN

This study analyzed natural regeneration floristic patterns in spring habitats submitted to different ecological restoration actions in the seasonal forest in Atlantic Forest biome, Rio Grande do Sul. We assessed floristic composition in six springs before restoration actions and 12 months later. We identified and counted all regenerating individuals with height greater than or equal to 30 cm and diameter at breast height less than or equal to 5 cm in eight plots in each spring. The richness and abundance of each spring and assessment were compared by the Kruskal-Wallis test (P<0.05). Detrended Correspondence Analysis (DCA) was performed to verify floristic patterns and association between species. Results showed an increase in richness and abundance after ecological restoration implementation. The DCA showed a distinct floristic composition between springs. The springs remaining natural vegetation and the successional stage of these vegetation influenced the natural regeneration floristic composition pattern. Passive restoration, which was effective by enclosure, favored natural regeneration recruitment.

O objetivo deste estudo foi analisar os padrões florísticos da regeneração natural em habitats de nascentes submetidos a diferentes ações de restauração ecológica na floresta estacional do bioma Mata Atlântica, Rio Grande do Sul. A composição florística foi avaliada em seis nascentes antes das ações de restauração e 12 meses depois. Todos os indivíduos regenerantes com altura maior ou igual a 30 cm e diâmetro à altura do peito menor ou igual a 5 cm foram contados e identificados em oito parcelas em cada nascente. A riqueza e abundância de cada nascente em cada avaliação foram comparadas pelo teste de Kruskal-Wallis (P <0,05). A Análise de Correspondência Retificada (DCA) foi realizada para verificar os padrões florísticos e a associação entre as espécies. Os resultados mostraram um aumento na riqueza e abundância após a implementação da restauração ecológica. A DCA apresentou uma composição florística distinta entre as nascentes. A vegetação natural remanescente nas áreas de nascente e o estágio sucessional da vegetação influenciaram o padrão de composição florística. A restauração passiva, efetivada pelo cercamento, favoreceu o desenvolvimento da regeneração natural.

Asunto(s)