An estimation of ecosystem services provided by urban and peri-urban forests: a case study in Juiz de Fora, Brazil / Uma estimativa dos serviços ecossistêmicos fornecidos pelas florestas urbanas e peri-urbanas: um estudo de caso em Juiz de Fora, Brasil

Urban expansion has led to the replacement of natural landscapes and environmental degradation, making cities and their urban and peri-urban forests (UPFs) vulnerable to climate change, especially on the formation of heat islands. Using i-Tree Canopy program (v. 7.0), we estimate the ecosystem services provided by UPFs in Juiz de Fora (Minas Gerais State, Southeastern Brazil), through the analysis of the (1) annual removal of atmospheric pollutants, (2) annual removal of atmospheric carbon, (3) total carbon stock in vegetation, and (4) the monetary benefits of sequestered and stocked carbon, based on Future Carbon Credit (CFI2Z1) as a monetary proxy. The results showed an average total amount of removal of 4.45 thousand tons of air pollution annually. The average annual total carbon storage was 158 thousand tons and the equivalent CO2 was 580 thousand tons, with an estimated total value of R$ 173 million per year. Significant values of the gross carbon stock (3.98 million tons) and equivalent CO2 (14.59 million tons) were found, being valued at R$ 4.35 billion. We concluded that the Juiz de Fora UPFs have a great potential for socio-environmental and economic benefits.

A expansão urbana levou à substituição de paisagens naturais por paisagens urbanas e à degradação ambiental, tornando cidades e suas florestas urbanas e peri-urbanas (FUPs) vulneráveis às mudanças climáticas, especialmente à formação de ilhas de calor. Utilizando o software i-Tree Canopy (v.7.0), estimamos os serviços ecossistêmicos promovidos pelas UPFs em Juiz de Fora (Minas Gerais, Sudeste do Brasil), por meio da análise de (1) remoção anual de poluentes atmosféricos, (2) remoção anual de carbono atmosférico, (3) estoque de carbono na vegetação e (4) os benefícios monetários do carbono sequestrado anualmente e estocado, utilizando o Mercado de Crédito de Carbono Futuro (CFI2Z1) como um proxy monetário. Os resultados apresentam uma quantidade total média de remoção de 4,45 mil toneladas de poluentes do ar, anualmente. O armazenamento médio anual de carbono total foi de 158 mil toneladas e o de CO2 equivalente foi de 580 mil toneladas, com um valor total estimado anual de R$ 173 milhões. Foram encontrados expressivos valores do estoque bruto de carbono (3,98 milhões de toneladas) e CO2 equivalente (14,59 milhões de toneladas), sendo avaliado em R$ 4,35 bilhões. Concluímos que as FUPs de Juiz de Fora possuem um grande potencial para benefícios socioambientais e econômicos.

An estimation of ecosystem services provided by urban and peri-urban forests: a case study in Juiz de Fora, Brazil / Uma estimativa dos serviços ecossistêmicos fornecidos pelas florestas urbanas e peri-urbanas: um estudo de caso em Juiz de Fora, Brasil

ABSTRACT: Urban expansion has led to the replacement of natural landscapes and environmental degradation, making cities and their urban and peri-urban forests (UPFs) vulnerable to climate change, especially on the formation of heat islands. Using i-Tree Canopy program (v. 7.0), we estimate the ecosystem services provided by UPFs in Juiz de Fora (Minas Gerais State, Southeastern Brazil), through the analysis of the (1) annual removal of atmospheric pollutants, (2) annual removal of atmospheric carbon, (3) total carbon stock in vegetation, and (4) the monetary benefits of sequestered and stocked carbon, based on Future Carbon Credit (CFI2Z1) as a monetary proxy. The results showed an average total amount of removal of 4.45 thousand tons of air pollution annually. The average annual total carbon storage was 158 thousand tons and the equivalent CO2 was 580 thousand tons, with an estimated total value of R$ 173 million per year. Significant values of the gross carbon stock (3.98 million tons) and equivalent CO2 (14.59 million tons) were found, being valued at R$ 4.35 billion. We concluded that the Juiz de Fora UPFs have a great potential for socio-environmental and economic benefits.

RESUMO: A expansão urbana levou à substituição de paisagens naturais por paisagens urbanas e à degradação ambiental, tornando cidades e suas florestas urbanas e peri-urbanas (FUPs) vulneráveis às mudanças climáticas, especialmente à formação de ilhas de calor. Utilizando o software i-Tree Canopy (v.7.0), estimamos os serviços ecossistêmicos promovidos pelas UPFs em Juiz de Fora (Minas Gerais, Sudeste do Brasil), por meio da análise de (1) remoção anual de poluentes atmosféricos, (2) remoção anual de carbono atmosférico, (3) estoque de carbono na vegetação e (4) os benefícios monetários do carbono sequestrado anualmente e estocado, utilizando o Mercado de Crédito de Carbono Futuro (CFI2Z1) como um proxy monetário. Os resultados apresentam uma quantidade total média de remoção de 4,45 mil toneladas de poluentes do ar, anualmente. O armazenamento médio anual de carbono total foi de 158 mil toneladas e o de CO2 equivalente foi de 580 mil toneladas, com um valor total estimado anual de R$ 173 milhões. Foram encontrados expressivos valores do estoque bruto de carbono (3,98 milhões de toneladas) e CO2 equivalente (14,59 milhões de toneladas), sendo avaliado em R$ 4,35 bilhões. Concluímos que as FUPs de Juiz de Fora possuem um grande potencial para benefícios socioambientais e econômicos.

Ecosystem services supply by the soil of forest fragment in a highland humid enclave / Provisão de serviços ecossistêmicos pelo solo de um fragmento florestal do Brejo Paraibano

The encroachment of agricultural activities on the remnants of the Atlantic Forest in the high altitudes of the Brazilian Northeast led to the formation of forest fragments that need to be better understood. To this end, research was conducted in a forest fragment of Mata do Pau-Ferro in a highland humid enclave, locally known as "Brejo Paraibano", to characterize the soil through chemical, physical, mineralogical, and geochemical attributes, to evaluate the potential ofthe soil in the provisionof services environment. Ferralsols samples were collected and analyzed in a layer from 0 to 20 cm deep. The results showed that soil properties have a direct influence on the provision of ecosystemservices, especially support, regulation, provision, andcultural services. Among the properties, essential nutrient content, carbon stock, minerals that can provide nutrients in the long term, texture, density, and organic matter content stand out, favoring water storage and adequate development of plant species.(AU)

O avanço das atividades agropecuárias sobre os remanescentes de Mata Atlântica de Altitude do Nordeste acarretou na formação de fragmentos de floresta que precisam ser melhorentendidos. Para tanto, a pesquisa foi realizada em um fragmento florestal da Mata do Pau-Ferro no Brejo Paraibano com o objetivo de caracterizar o solo por meio de atributos químicos, físicos, mineralógicos e geoquímicos a fim de avaliar a potencialidade do solo na prestação de serviços ambientais. Foram coletadas amostras de um Latossolo Amarelo Distrófico húmico na camada de 0 a 20 cm de profundidade e carreadas as análises. Os resultados demonstraram que as propriedades do solo influenciam diretamente a oferta de serviços ecossistêmicosespecialmente os de suporte, regulação, provisão e culturais. Dentre as propriedades destacam-se os teores de nutrientes essenciais, estoque de carbono, minerais que podem fornecer nutrientes no longo prazo, textura, densidade e teores de matéria orgânica que favorecem armazenamento de água e adequado desenvolvimento de espécies vegetais.(AU)

Accumulation and decomposition of cultural residues of Theobroma grandiflorum, Paullinia cupana, Bixa orellana and forest in the southern region of Amazonas / Acúmulo e decomposição dos resíduos culturais de cupuaçu, guaraná, urucum e floresta na região sul do Amazonas

The litter deposited on the soil surface at various stages of decomposition is important for primary productivity that impacts the microbial communities and soil carbon storage. The objective of this study was to evaluate the accumulation and decomposition of cultural residues of Theobroma grandiflorum (Willd. ex. Spreng) Schum, Paullinia cupana (Mart.) Ducke, Bixa orellana L., and forest in the Amazon region. The study was carried out in the São Francisco settlement, Canutama in the south of Amazonas, in a randomized block experimental design, and the treatments consisted of four areas with different crops: 1 - P. cupana; 2 - T. grandiflorum; 3 - B. orellana; 4 - Native woodland area (forest), in time subdivided plots: 7, 15, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, and 330 days after the distribution of the bags in the field, all with four repetitions. To evaluate the contribution and fractions of litter, conical collectors were used in each area, and collections were performed monthly in the period from March 2020 to February 2021. The estimate of the decomposition rate of the litter was done by quantifying the loss of mass, using litter bags, which allow for a direct analysis of the rate of decay over time. The forest and P. cupana environments presented the highest litter production, and greater deposition when compared to environments cultivated with T. grandiflorum and B. orellana. The forest and B. orellana areas showed the highest speed of decomposition, while the opposite situation occurred under T. grandiflorum and P. cupana cultivation.

A serrapilheira depositada na superfície do solo, em vários estágios de decomposição tem importância na produtividade primária que impacta nas comunidades microbianas e estocagem de carbono no solo. Objetivouse neste trabalho avaliar o acúmulo e decomposição dos resíduos culturais de cupuaçu, guaraná, urucum e floresta na região do Amazonas. O estudo foi realizado no assentamento São Francisco, Canutama no Sul do Amazonas, em delineamento experimental de blocos casualisados, sendo que os tratamentos constaram de quatro áreas com diferentes culturas: 1- Guaraná; 2 ­ Cupuaçu; 3 ­ Urucum; 4 ­ Área de mata nativa (floresta), em parcelas subdivididas no tempo: 07, 15, 30, 60, 90, 120, 150, 180, 210, 240, 270 e 300, 330 dias após a distribuição das sacolas no campo, todas com 04 repetições. Para avaliar o aporte e frações dá serapilheira, foram utilizados coletores cônicos em cada área, sendo as coletas realizadas mensalmente no período de março de 2020 a fevereiro de 2021. A estimativa da taxa de decomposição da serrapilheira foi realizada pela quantificação da perda de massa, utilizando-se litter bags, os quais permitem analisar de forma direta a taxa de decaimento ao longo do tempo. Os ambientes de floresta e guaraná apresentaram as maiores produções de serapilheira, e maior deposição quando comparados aos ambientes cultivados com cupuaçu e urucum. As áreas de floresta e urucum apresentaram a maior velocidade de decomposição, já a situação inversa ocorreu sob o cultivo do cupuaçu e guaraná.

Preservation of cv. Jubileu peaches in a conventional cold storage system under a dynamic controlled atmosphere / Conservação de pêssegos cv. Jubileu em sistema refrigerado convencional, atmosfera controlada e dinâmica

The peach tree (Prunus persica) has a considerable global economic impact because its fruits are consumed worldwide. As climacteric fruits, peaches ripen after harvest and are also highly perishable postharvest. The aim of this study was to investigate alternatives for extending storage time and preventing a decline in quality in peaches using conventional cold storage (CS) compared with controlled atmosphere (CA) and ultralow oxygen (ULO) systems. A completely randomized design was used, with a 3 x 6 factorial scheme (3 storage systems x 6 storage times), thirteen parameters assessed by analysis of variances and significance by Tukey's test and regression. Total soluble solids (TSS) varied from 12.72 to 16.07ºBrix, titratable acidity (TA) declined during storage and pH varied significantly among the systems used from 40 days of storage onwards. The best TSS/TA ratio was obtained under ULO after 40 days, while firmness and weight loss declined in CA and ULO, contrasting with the brightly colored pulp. Reducing and non-reducing sugars decreased under CA and ULO at 30 and 40 days of storage, whereas phenolic compounds and antioxidant activity remained similar in these systems at 30, 40 and 50 days. Carotenoids remained stable for up to 40 days in ULO.CA and ULO maintained the best physical and chemical quality parameters, both systems being the most recommended. The phytochemical compounds analyzed in this study changed little during storage in the systems analyzed.(AU)

O pessegueiro (Prunus persica) apresenta grande impacto econômico global, por produzirem frutos apreciados em todo o mundo. Seus frutos climatérios amadurecem após a colheita, além disso, possuem alta perecibilidade pós-colheita. O objetivo deste trabalho foi buscar alternativas que ampliem ainda mais o tempo de armazenamento evitando-se o decaimento da qualidade dos pêssegos, utilizando o sistema refrigerado convencional (SAR) em contraponto com a atmosfera controlada (SAC) e dinâmica com ultrabaixo oxigênio (SAUO). O delineamento experimental foi inteiramente casualizado em um esquema fatorial 3 x 6 (3 sistemas x 6 períodos) de armazenamento, e treze parâmetros analisados pelo teste análise de variância, significância pelo teste Tukey e regressão. Os valores de sólidos solúveis variaram de 12,72ºBrix a 16,07ºBrix, a acidez titulável reduziu ao longo do armazenamento, já o pH apresentou variação significativa a partir de 40 dias entre os sistemas utilizados. A relação SS/AT alcançou os melhores índices no SAUO até 40 dias, já a firmeza de polpa e a perda de massa apresentaram redução nos SAC e SAUO, contrastando com elevada coloração da polpa. Açúcares redutores e não redutores apresentaram redução no SAC e SAUO aos 30 e 40 dias de armazenamento, já para os compostos fenólicos e atividade antioxidante, nestes sistemas, com 30, 40 e 50 dias os valores mantiveram-se semelhantes. Os carotenóides foram mantidos até 40 dias no SAUO. O SAC manteve os melhores parâmetros de qualidade físico-químicos analisados, juntamente com SAUO, sendo ambos os mais indicados. Os compostos fitoquímicos analisados neste estudo apresentaram poucas alterações durante os dias de armazenamento nos sistemas analisados.(AU)

Clinical, hematological, blood gasometric and electrolytic changes in dogs receiving whole blood transfusions

Blood transfusion is a tool capable of saving lives. Patients undergoing blood transfusion usually present several alterations in the acid-base and electrolyte balance, aggravating the condition of critically ill patients. Some studies have demonstrated haematological alterations in certain species that received whole blood transfusions, however, few studies have evaluated acid base and electrolyte changes in dogs undergoing whole blood haemotherapy. The aim of this study was to analyze clinical, hematological, blood gas and electrolyte changes in anemic dogs after whole blood transfusion. Twenty nine dogs transfused due to anemia were enrolled in the study. Donors blood was collected in a transfusion bag containing citrate phosphate adenine dextrose and stored up to 24 h. Blood collections and evaluations were made before and 24 h after the transfusion. Data distribution normality was tested by the Shapiro Wilk Test. The means of the variables were compared by paired t-test. It was observed an increase in diastolic blood pressure and a reduction in heart rate (P < 0.05). There was a not significant increase in systolic blood pressure, temperature, and a reduction in respiratory rate per minute. Erythrocyte, haemoglobin and haematocrit averages were significantly increased after blood transfusion (P < 0.05). It was observed a reduction in the mean values of pH (P < 0.05), potassium (P > 0.05) and ionized calcium (P > 0.05) and an increase in the mean partial pressure of carbon dioxide (pCO2 ) (P < 0.001), bicarbonate (P > 0.05) and sodium (P < 0.05). The probable cause of anemia was monocytic ehrlichiosis (14/29), visceral leishmaniasis (1/29), babesiosis (1/29), co-infection of Ehrlichia canis and Leishmania infantum (2/29), co-infection of E. canis and Babesia vogeli (1/29). It was not possible to determine the etiology of the anemia in ten dogs. Heart rate significantly reduced after transfusion, probably because of the increase in hematocrit, hemoglobin and erythrocyte values. It may be justified by the displacement of extravascular fluid to the intravascular space. Mean values of systolic blood pressure were slightly elevated before transfusion and remained elevated afterwards, while diastolic and mean arterial pressure increased significantly after transfusion. These changes may be due to the morbid condition and may be influenced by many other factors. Haematocrit, haemoglobin and erythrocyte values increased significantly after transfusion, according to what was observed in other studies. The significant reduction in pH and increase in pCO2 reflects the compensatory mechanism for metabolic acidosis to increase ventilation, leading to pCO2 reduction and changes in pH. The reduction in pH due to the contact of the collected blood with conservative solutions is one of the main changes thar occurs during blood storage. It was described significantly lower pH in dogs' whole blood samples stored for more than 24 h in vacutainer plastic containing CPDA-1. We may assume there was no intense pH reduction in the present study because the bags were stored for up to 24 h. Although not statistically significant, the increase of pO2 mean reflects the improvement of tissue oxygen perfusion. It was observed a significant increase in sodium ions. The mean sodium ion concentration before transfusion was very close to the maximum reference value. Hyperkalaemia was not observed, nor was there significant reduction of potassium ions after transfusion. Several studies report hyperkalaemia and transfusion-associated cardiac arrests in humans, associated with infusion of large volumes of blood. Whole blood transfusion increased erythrogram values and did not negatively affect the electrolyte or acid-base status, representing a safe and useful tool in the intensive care of small animals.(AU)

Effect of flaxseed root performance on the structural quality of a Haplumbrept under conservationist management system, in Santa Catarina, Brazil / Efeito do desenvolvimento radicular do linho na qualidade estrutural de um Cambissolo Húmico sob sistema conservacionista de manejo em Santa Catarina, Brasil

Our goal was to evaluate the root development of flaxseed and its relationship with soil aggregation and organic carbon storage in two sowing seasons under soil conservationist management, in Santa Catarina state, Brazil. We used three flaxseed genotypes: Aguará and Caburé from Argentina, and Gold from Brazil, sowings in April and May in a no-tillage system under Haplumbrept. In the flowering stage, the root system was evaluated by image analyze using a Safira software. Root distribution maps were used by geostatistical kriging. At the harvest stage, soil blocks were sampled for analyze the aggregates morphometry by image with Quantporo software and the soil organic carbon. Undisturbed soil were sampled to determine the physical attributes. The experimental design was in randomized blocks with three repetitions, anova was performed by Fisher and the means compared by Tukey test. No physical impediments were found for the roots performance in the Haplumbrept under conservationist management system, these favored the irregularity of the aggregates surface observed by the low values of aspect and roughness in the different tested diameter ranges. Both Caburé and Aguará genotypes showed good roots spatial distribution in the soil profile in both sowing seasons with an increase in carbon storage in the smallest diameter aggregates (here considered the aggregates of 4.76-1 mm)...

O objetivo do trabalho foi avaliar o desenvolvimento radicular da linhaça e sua relação com a agregação do solo e o estoque de carbono em duas épocas de semeadura sob manejo conservacionista do solo, em Santa Catarina, Brasil. Foram utilizados três genótipos de linho: Aguará e Caburé-Argentina e Dourada-Brasil, semeados em abril e maio em sistema de plantio direto sobre Cambissolo Húmico. No estágio de floração, o sistema radicular foi avaliado por análise de imagem utilizando o programa Safira. Os mapas de distribuição radicular foram obtidos por krigagem - geoestatística. Na fase de colheita, foram amostrados blocos de solo para análise da morfometria de agregados por imagem no programa Quantporo além do carbono orgânico. Amostras de solo preservadas foram amostradas para determinar os atributos físicos. O delineamento experimental foi em blocos casualizados com três repetições, a anova foi realizada pelo teste de Fisher e as médias comparadas pelo teste de Tukey. Não foram encontrados impedimentos físicos para o desempenho das raízes no Cambissolo sob sistema de manejo conservacionista, favorecendo a irregularidade da superfície dos agregados observada pelos baixos valores de aspecto e rugosidade nas diferentes faixas de diâmetro testadas. Os genótipos Caburé e Aguará apresentaram boa distribuição espacial das raízes ao longo do perfil do solo em ambas as épocas de semeadura, com um aumento no armazenamento de carbono nos agregados de menor diâmetro (considerados aqui os agregados de 4,76-1 mm). O genótipo Caburé se adaptou às condições edafoclimáticas avaliadas, pois apresentou melhor desempenho radicular abaixo de 0,15 m.

Effect of flaxseed root performance on the structural quality of a Haplumbrept under conservationist management system, in Santa Catarina, Brazil / Efeito do desenvolvimento radicular do linho na qualidade estrutural de um Cambissolo Húmico sob sistema conservacionista de manejo em Santa Catarina, Brasil

Our goal was to evaluate the root development of flaxseed and its relationship with soil aggregation and organic carbon storage in two sowing seasons under soil conservationist management, in Santa Catarina state, Brazil. We used three flaxseed genotypes: Aguará and Caburé from Argentina, and Gold from Brazil, sowings in April and May in a no-tillage system under Haplumbrept. In the flowering stage, the root system was evaluated by image analyze using a Safira software. Root distribution maps were used by geostatistical kriging. At the harvest stage, soil blocks were sampled for analyze the aggregates morphometry by image with Quantporo software and the soil organic carbon. Undisturbed soil were sampled to determine the physical attributes. The experimental design was in randomized blocks with three repetitions, anova was performed by Fisher and the means compared by Tukey test. No physical impediments were found for the roots performance in the Haplumbrept under conservationist management system, these favored the irregularity of the aggregates surface observed by the low values of aspect and roughness in the different tested diameter ranges. Both Caburé and Aguará genotypes showed good roots spatial distribution in the soil profile in both sowing seasons with an increase in carbon storage in the smallest diameter aggregates (here considered the aggregates of 4.76-1 mm)...(AU)

O objetivo do trabalho foi avaliar o desenvolvimento radicular da linhaça e sua relação com a agregação do solo e o estoque de carbono em duas épocas de semeadura sob manejo conservacionista do solo, em Santa Catarina, Brasil. Foram utilizados três genótipos de linho: Aguará e Caburé-Argentina e Dourada-Brasil, semeados em abril e maio em sistema de plantio direto sobre Cambissolo Húmico. No estágio de floração, o sistema radicular foi avaliado por análise de imagem utilizando o programa Safira. Os mapas de distribuição radicular foram obtidos por krigagem - geoestatística. Na fase de colheita, foram amostrados blocos de solo para análise da morfometria de agregados por imagem no programa Quantporo além do carbono orgânico. Amostras de solo preservadas foram amostradas para determinar os atributos físicos. O delineamento experimental foi em blocos casualizados com três repetições, a anova foi realizada pelo teste de Fisher e as médias comparadas pelo teste de Tukey. Não foram encontrados impedimentos físicos para o desempenho das raízes no Cambissolo sob sistema de manejo conservacionista, favorecendo a irregularidade da superfície dos agregados observada pelos baixos valores de aspecto e rugosidade nas diferentes faixas de diâmetro testadas. Os genótipos Caburé e Aguará apresentaram boa distribuição espacial das raízes ao longo do perfil do solo em ambas as épocas de semeadura, com um aumento no armazenamento de carbono nos agregados de menor diâmetro (considerados aqui os agregados de 4,76-1 mm). O genótipo Caburé se adaptou às condições edafoclimáticas avaliadas, pois apresentou melhor desempenho radicular abaixo de 0,15 m.(AU)

Processes that influence dissolved organic matter in the soil: a review

In tropical regions, climate conditions favor fast decomposition of soil organic matter (SOM), releasing into the soil organic composts in solid, liquid, and gaseous forms with variable compositions. Dissolved organic matter (DOM), a complex mixture of thousands of organic compounds, is only a small fraction of the decomposition products; however, it is highly mobile and reactive to the soil. Therefore, DOM play a key role in soil aggregation (formation of organometallic complexes), energy source for microorganisms, as well as C storage, cycling, and provision of plant-available nutrients. DOM multifunctionality to sustain soil functions and important ecosystem services have raised global scientific interest in studies on DOM fractions. However, previous studies were conducted predominantly under temperate soil conditions in natural ecosystems. Therefore, there is paucity of information on tropical soil conditions under agricultural systems, where DOM turnover is intensified by management practices. This review synthesized information in the literature to identify and discuss the main sources, transformations, and future of DOM in soils. We also discussed the importance of this fraction in C cycling and other soil properties and processes, emphasizing agricultural systems in tropical soils. Gaps and opportunities were identified to guide future studies on DOM in tropical soils.

Processes that influence dissolved organic matter in the soil: a review

In tropical regions, climate conditions favor fast decomposition of soil organic matter (SOM), releasing into the soil organic composts in solid, liquid, and gaseous forms with variable compositions. Dissolved organic matter (DOM), a complex mixture of thousands of organic compounds, is only a small fraction of the decomposition products; however, it is highly mobile and reactive to the soil. Therefore, DOM play a key role in soil aggregation (formation of organometallic complexes), energy source for microorganisms, as well as C storage, cycling, and provision of plant-available nutrients. DOM multifunctionality to sustain soil functions and important ecosystem services have raised global scientific interest in studies on DOM fractions. However, previous studies were conducted predominantly under temperate soil conditions in natural ecosystems. Therefore, there is paucity of information on tropical soil conditions under agricultural systems, where DOM turnover is intensified by management practices. This review synthesized information in the literature to identify and discuss the main sources, transformations, and future of DOM in soils. We also discussed the importance of this fraction in C cycling and other soil properties and processes, emphasizing agricultural systems in tropical soils. Gaps and opportunities were identified to guide future studies on DOM in tropical soils.(AU)

Storage stability of minimally processed pinhão by using edible coatings with antimicrobial characteristics / Conservação de pinhão minimamente processado pelo uso de revestimentos comestíveis com características antimicrobianas

The pinhão shows high nutritional value; however, its consumption is still low owing to the long cooking time required because it is hard to peel, and it is susceptible to sprouting, larval infestation, and fungal contamination. Thus, this study aimed to evaluate the storage stability of minimally processed pinhão by using edible coatings with antimicrobial characteristics. The pinhões were subjected to minimal processing with the following treatments: Treatment A - control; Treatment B - chitosan; Treatment C - xanthan gum and clove essential oil. After drying, they were packed in polyethylene terephthalate and stored at 4 °C for nine days. The pinhões were analyzed for mass loss, total acidity, reducing sugars, vitamin C, color, firmness, respiratory rate, sensory characteristics, and microbial growth. In general, no differences were observed in mass loss, reducing sugars, and oxygen concentrations of the pinhões after any treatment. In addition, we observed a reduction in acidity and carbon dioxide concentrations, maintenance of color parameters, and the absence of growth of thermotolerant coliforms and coagulase positive Staphylococcus. Although the minimal processing did not increase the respiratory rate of pinhões, it did not stop the process of seed maturation. Of the coatings evaluated, chitosan coating of the pinhões was associated with a higher content of vitamin C as well as a lower number of psychrotrophic microorganisms. The coatings did not influence the taste and aroma of the minimally processed pinhões.

O pinhão apresenta alto valor nutricional, entretanto seu consumo ainda é pouco expressivo devido ao longo tempo de cocção, por apresentar um difícil descasque, ser susceptível ao processo de brotamento, infestação por larvas e deterioração fúngica. Assim, o presente trabalho teve por objetivo avaliar a conservação de pinhões minimamente processados por meio de revestimentos comestíveis com características antimicrobianas. Os pinhões foram submetidos ao processamento mínimo e após aos diferentes tratamentos: Tratamento A - controle; Tratamento B - quitosana; Tratamento C - xantanae óleo essencial de cravo-da-índia. Após, foram secos sob ventilação forçada, acondicionados em embalagem de Polietileno Tereftalato (PET) e armazenados a 4 ºC, durante 9 dias. Foram realizadas avaliações de perda de massa, acidez total titulável, açúcares redutores, vitamina C, firmeza, cor, taxa respiratória, análise sensorial e microbiológica. De uma forma geral, independente do tratamento, pôde se observar comportamento semelhante nas características dos pinhões, em relação ao aumento da perda de massa, dos açúcares redutores, da concentração de oxigênio e da deterioração fisiológica. Além disso, foi observada a redução da acidez e da concentração de dióxido de carbono, bem como a manutenção dos parâmetros de cor e a ausência de crescimento de coliformes termotolerantes e Staphylococcus coagulase positiva. O processamento mínimo não elevou a taxa respiratória dos pinhões, porém não freou o processo de maturação das sementes. Dos revestimentos avaliados, a quitosana possibilitou a obtenção de pinhões com maior teor de vitamina C e contagem de microrganismos psicrotróficos. Os revestimentos não influenciaram no sabor e aroma dos pinhões minimamente processados.

Storage stability of minimally processed pinhão by using edible coatings with antimicrobial characteristics / Conservação de pinhão minimamente processado pelo uso de revestimentos comestíveis com características antimicrobianas

The pinhão shows high nutritional value; however, its consumption is still low owing to the long cooking time required because it is hard to peel, and it is susceptible to sprouting, larval infestation, and fungal contamination. Thus, this study aimed to evaluate the storage stability of minimally processed pinhão by using edible coatings with antimicrobial characteristics. The pinhões were subjected to minimal processing with the following treatments: Treatment A - control; Treatment B - chitosan; Treatment C - xanthan gum and clove essential oil. After drying, they were packed in polyethylene terephthalate and stored at 4 °C for nine days. The pinhões were analyzed for mass loss, total acidity, reducing sugars, vitamin C, color, firmness, respiratory rate, sensory characteristics, and microbial growth. In general, no differences were observed in mass loss, reducing sugars, and oxygen concentrations of the pinhões after any treatment. In addition, we observed a reduction in acidity and carbon dioxide concentrations, maintenance of color parameters, and the absence of growth of thermotolerant coliforms and coagulase positive Staphylococcus. Although the minimal processing did not increase the respiratory rate of pinhões, it did not stop the process of seed maturation. Of the coatings evaluated, chitosan coating of the pinhões was associated with a higher content of vitamin C as well as a lower number of psychrotrophic microorganisms. The coatings did not influence the taste and aroma of the minimally processed pinhões.(AU)

O pinhão apresenta alto valor nutricional, entretanto seu consumo ainda é pouco expressivo devido ao longo tempo de cocção, por apresentar um difícil descasque, ser susceptível ao processo de brotamento, infestação por larvas e deterioração fúngica. Assim, o presente trabalho teve por objetivo avaliar a conservação de pinhões minimamente processados por meio de revestimentos comestíveis com características antimicrobianas. Os pinhões foram submetidos ao processamento mínimo e após aos diferentes tratamentos: Tratamento A - controle; Tratamento B - quitosana; Tratamento C - xantanae óleo essencial de cravo-da-índia. Após, foram secos sob ventilação forçada, acondicionados em embalagem de Polietileno Tereftalato (PET) e armazenados a 4 ºC, durante 9 dias. Foram realizadas avaliações de perda de massa, acidez total titulável, açúcares redutores, vitamina C, firmeza, cor, taxa respiratória, análise sensorial e microbiológica. De uma forma geral, independente do tratamento, pôde se observar comportamento semelhante nas características dos pinhões, em relação ao aumento da perda de massa, dos açúcares redutores, da concentração de oxigênio e da deterioração fisiológica. Além disso, foi observada a redução da acidez e da concentração de dióxido de carbono, bem como a manutenção dos parâmetros de cor e a ausência de crescimento de coliformes termotolerantes e Staphylococcus coagulase positiva. O processamento mínimo não elevou a taxa respiratória dos pinhões, porém não freou o processo de maturação das sementes. Dos revestimentos avaliados, a quitosana possibilitou a obtenção de pinhões com maior teor de vitamina C e contagem de microrganismos psicrotróficos. Os revestimentos não influenciaram no sabor e aroma dos pinhões minimamente processados.(AU)

Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities

The structural strength of soils has been extensively described by physical and mechanical properties evaluated on the mesoscale for different soils and management conditions. However, changes in the organization of the soil matrix at the microstructural level, which can be obtained by rheometry, are still seldom used in soil mechanics. Our aim was to use the amplitude sweep test, a rheometry technique, to investigate the microstructural strength of four subtropical soils (two Oxisols, an Ultisol and a Vertisol) and to discuss difficulties with respect to the samples, water content, soil density and vertical force. The various rheological properties which reveal the soil microstructural strength were determined: deformation at the end of the linear viscoelastic range, LVE range (LVE), shear stress at the end of the LVE range (LVE), deformation at yield point, YP (YP), storage and loss moduli at YP (GGYP), maximum shear stress (max), and integral z. In general, soil elasticity (LVE and YP) and microstructural strength (LVE and max) were greater in the Oxisols and the Vertisol, which both possess high clay content, while the latter also contains expansive clay minerals. The lowest structural strength was observed in the Ultisol which had a high sand content. As rheological properties are related to soil properties such as particle size distribution and carbon content, they can be applied in the evaluation of the microstructural strength of clayey and sandy soils and allows for inferences regarding inter-particle shear strength. However, the test is not applicable to very dry soil samples and sample preparations can affect the results. We suggest a number of approaches to find solutions for these difficulties/problems.

Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities

The structural strength of soils has been extensively described by physical and mechanical properties evaluated on the mesoscale for different soils and management conditions. However, changes in the organization of the soil matrix at the microstructural level, which can be obtained by rheometry, are still seldom used in soil mechanics. Our aim was to use the amplitude sweep test, a rheometry technique, to investigate the microstructural strength of four subtropical soils (two Oxisols, an Ultisol and a Vertisol) and to discuss difficulties with respect to the samples, water content, soil density and vertical force. The various rheological properties which reveal the soil microstructural strength were determined: deformation at the end of the linear viscoelastic range, LVE range (LVE), shear stress at the end of the LVE range (LVE), deformation at yield point, YP (YP), storage and loss moduli at YP (GGYP), maximum shear stress (max), and integral z. In general, soil elasticity (LVE and YP) and microstructural strength (LVE and max) were greater in the Oxisols and the Vertisol, which both possess high clay content, while the latter also contains expansive clay minerals. The lowest structural strength was observed in the Ultisol which had a high sand content. As rheological properties are related to soil properties such as particle size distribution and carbon content, they can be applied in the evaluation of the microstructural strength of clayey and sandy soils and allows for inferences regarding inter-particle shear strength. However, the test is not applicable to very dry soil samples and sample preparations can affect the results. We suggest a number of approaches to find solutions for these difficulties/problems.(AU)

Microbial activities, carbon, and nitrogen in an irrigated Quartzarenic Neosol cultivated with cowpea in southwest Piauí / Atividade microbiana, Carbono e nitrogênio de Neossolo Flúvico cultivado com feijão-caupi irrigado no sudoeste piauiense

The aim of this study was to evaluate microbial biomass and total organic carbon and nitrogen of an irrigated Quartzarenic Neosol cultivated with two cowpea cultivars in Bom Jesus, Piauí, Brazil. The experiment was conducted in a randomized experimental block design in split plots. The plots consist of two cowpea cultivars (Aracê and Tumucumaque) and the subplots were composed of five different irrigation regimes (L1 = 108.2; L2 = 214.7; L3 = 287.9; L4 = 426.1, and L5 = 527.7 mm). Soil samples were collected at a depth of 0-0.20 m in order to evaluate basal soil respiration, microbial biomass carbon, metabolic quotient, microbial quotient, content, and storage of soil carbon and nitrogen. Basal soil respiration, microbial biomass carbon, microbial metabolic quotient, and microbial quotient are influenced by the interaction between cowpea cultivars and irrigation. The cultivar Aracê showed greater stimulus to the microbial community, while the irrigation regimes with 214.7 and 287.9 mm (60 and 90% of ETo, respectively) provided the best moisture conditions for microbial activities.(AU)

O objetivo deste estudo foi avaliar a biomassa microbiana e os estoques totais de carbono orgânico e nitrogênio de um Neossolo Flúvico irrigado, cultivado com duas cultivares de feijão-caupi, no município de Bom Jesus, Piauí. O experimento foi instalado em delineamento experimental em blocos ao acaso dispostos em parcelas subdivididas, sendo as subparcelas cinco lâminas de irrigação por aspersão (L1=108,2; L2 = 214,7; L3 = 287,9; L4 = 426,1 e L5 = 527,7 mm) e as parcelas duas cultivares de feijão-caupi (Aracê e Tumucumaque). Foram coletas amostras de solo na profundidade de 0-0,20 m para as avaliações da respiração basal do solo, carbono da biomassa microbiana, quociente metabólico, quociente microbiano, teor e estoque de carbono e nitrogênio do solo. A respiração basal do solo, carbono da biomassa microbiana, quociente metabólico e quociente microbiano são influenciados pela interação entre cutivares de feijão-caupi e lâminas de irrigação. A cultivar Aracê apresentou maior estímulo a comunidade microbiana, enquanto as lâminas de irrigação com 214,7 e 287,9 mm (60 e 90% da ETo, respectivamente) proporcionaram as melhores condições de umidade a atividade microbiana.(AU)

Maturação de graviolas após armazenamento em atmosfera controlada / Maturation graviolas after storage in controlled atmosphere

Por se tratar de um fruto climatérico a graviola apresenta vida útil relativamente curta principalmente pela perda de firmeza provocada pelo amadurecimento comprometendo assim sua expansão para mercados distantes. Diante disso, o presente trabalho tem por objetivo avaliar o efeito de diferentes condições de atmosfera controlada no prolongamento da vida útil deste fruto. As características avaliadas após quinze dias em atmosfera controlada mais oito dias em temperatura ambiente foram: coloração da casca e da polpa, produção de etileno, taxa respiratória, firmeza, acidez titulável, pH, sólidos solúveis, teor de amido, incidência de podridões e degenerescência da polpa. As pressões maiores de CO2 comprometeram a qualidade dos frutos por acelerar a síntese de etileno favorecendo a perda de firmeza, a degradação dos compostos clorofílicos da casca e da polpa além de reduzir a qualidade após quatro dias de armazenamento em condições ambiente. O baixo nível de O2 aliado a menores pressões de CO2 é o mais recomendado para o armazenamento e prolongamento da vida útil deste fruto.

For it is a climacteric fruit sour sop has relatively short shelf life mainly due to the loss of firmness caused by maturation thus compromising its expansion into distant markets. Thus, this study aims to evaluate the effect of different controlled atmosphere conditions in extending the life of the fruit. The experimental design was completely randomized in a 5x3 factorial arrangement with five variations of carbon dioxide (CO2) under controlled atmosphere storage and three times after leaving the chambers, with five replicates and the experimental plot was composed of two fruits. After fifteen days in a controlled atmosphere and eight days, at room temperature were evaluated: color of skin and pulp, ethylene production, respiration rate, firmness, titratable acidity, pH, soluble solids, starch content, incidence of decay and degeneracy pulp. The greatest pressures of CO2 committed, fruit quality by accelerating ethylene synthesis favoring the loss of firmness, degradation of chlorophyll compounds of the skin and pulp and reduces the quality after four days of storage at ambient conditions. The lower pressure CO2 were more efficient for storing and extending the life of the fruit.

Maturação de graviolas após armazenamento em atmosfera controlada / Maturation graviolas after storage in controlled atmosphere

Por se tratar de um fruto climatérico a graviola apresenta vida útil relativamente curta principalmente pela perda de firmeza provocada pelo amadurecimento comprometendo assim sua expansão para mercados distantes. Diante disso, o presente trabalho tem por objetivo avaliar o efeito de diferentes condições de atmosfera controlada no prolongamento da vida útil deste fruto. As características avaliadas após quinze dias em atmosfera controlada mais oito dias em temperatura ambiente foram: coloração da casca e da polpa, produção de etileno, taxa respiratória, firmeza, acidez titulável, pH, sólidos solúveis, teor de amido, incidência de podridões e degenerescência da polpa. As pressões maiores de CO2 comprometeram a qualidade dos frutos por acelerar a síntese de etileno favorecendo a perda de firmeza, a degradação dos compostos clorofílicos da casca e da polpa além de reduzir a qualidade após quatro dias de armazenamento em condições ambiente. O baixo nível de O2 aliado a menores pressões de CO2 é o mais recomendado para o armazenamento e prolongamento da vida útil deste fruto.(AU)

For it is a climacteric fruit sour sop has relatively short shelf life mainly due to the loss of firmness caused by maturation thus compromising its expansion into distant markets. Thus, this study aims to evaluate the effect of different controlled atmosphere conditions in extending the life of the fruit. The experimental design was completely randomized in a 5x3 factorial arrangement with five variations of carbon dioxide (CO2) under controlled atmosphere storage and three times after leaving the chambers, with five replicates and the experimental plot was composed of two fruits. After fifteen days in a controlled atmosphere and eight days, at room temperature were evaluated: color of skin and pulp, ethylene production, respiration rate, firmness, titratable acidity, pH, soluble solids, starch content, incidence of decay and degeneracy pulp. The greatest pressures of CO2 committed, fruit quality by accelerating ethylene synthesis favoring the loss of firmness, degradation of chlorophyll compounds of the skin and pulp and reduces the quality after four days of storage at ambient conditions. The lower pressure CO2 were more efficient for storing and extending the life of the fruit.(AU)

Carbon pool ratios as scientific support to field morphology in the differentiation of dark subsurface soil horizons

In soil surveys, it is usual to find profiles with an uncommon disposition of horizons. Dark horizons in depth might be either the consequence of erosion and redeposition of soil materials from upslope or an indication of the podzolization process, which forms a spodic horizon. Few laboratory analyses are known to characterize dark subsurface horizons which could allow for the differentiation of spodic from buried A horizons. Some researchers propose C-humic and C-fulvic acid fraction ratios and forms of carbon to analyze characteristics of these horizons. Therefore, this research aimed to characterize dark subsurface horizons found in soils under a Eucalyptus minimum tillage system in the state of Rio Grande do Sul, Brazil, and to relate soil organic carbon to landscape features in toposequences. The characterization was performed by using the following ratios: humic acid and fulvic acid fractions (Cha/Cfa); pyrophosphate extractable-C and organic carbon (Cp/OC); fulvic acid fraction and pyrophosphate extractable-C (Cfa/Cp), and fulvic acid fraction and organic carbon (Cfa/OC). Soil organic carbon was related to slope gradient and Geomorphons in a Geographic Information System (GIS). None of the horizons analyzed met the criteria required for spodic horizon classification, where Cha/Cfa 0.50, Cfa/OC 0.30, and the ratio Cp/OC 0.50 simultaneously with Cfa/Cp 0.50. A relationship was found between landscape features and soil organic carbon content. The methodology proved to be satisfactory for providing scientific support to field morphology classification of dark subsurface horizons, specifically in the case where they could be misinterpreted as spodic horizons.

Carbon pool ratios as scientific support to field morphology in the differentiation of dark subsurface soil horizons

In soil surveys, it is usual to find profiles with an uncommon disposition of horizons. Dark horizons in depth might be either the consequence of erosion and redeposition of soil materials from upslope or an indication of the podzolization process, which forms a spodic horizon. Few laboratory analyses are known to characterize dark subsurface horizons which could allow for the differentiation of spodic from buried A horizons. Some researchers propose C-humic and C-fulvic acid fraction ratios and forms of carbon to analyze characteristics of these horizons. Therefore, this research aimed to characterize dark subsurface horizons found in soils under a Eucalyptus minimum tillage system in the state of Rio Grande do Sul, Brazil, and to relate soil organic carbon to landscape features in toposequences. The characterization was performed by using the following ratios: humic acid and fulvic acid fractions (Cha/Cfa); pyrophosphate extractable-C and organic carbon (Cp/OC); fulvic acid fraction and pyrophosphate extractable-C (Cfa/Cp), and fulvic acid fraction and organic carbon (Cfa/OC). Soil organic carbon was related to slope gradient and Geomorphons in a Geographic Information System (GIS). None of the horizons analyzed met the criteria required for spodic horizon classification, where Cha/Cfa 0.50, Cfa/OC 0.30, and the ratio Cp/OC 0.50 simultaneously with Cfa/Cp 0.50. A relationship was found between landscape features and soil organic carbon content. The methodology proved to be satisfactory for providing scientific support to field morphology classification of dark subsurface horizons, specifically in the case where they could be misinterpreted as spodic horizons.(AU)

Mecanismos de aclimatação das plantas à elevada concentração de CO2 / Acclimation mechanisms to elevated CO2 in plants

O metabolismo vegetal sofre alterações com o aumento da concentração de CO2na atmosfera terrestre. Inicialmente, a taxa fotossintética aumenta pela maior disponibilidade de CO2, após determinado tempo de exposição, observa-se algumas adaptações a fim de retornar ao equilíbrio inicial, caracterizando a aclimatação. O objetivo desta revisão foi descrever os mecanismos responsáveis pela aclimatação das plantas à elevada concentração de CO2 na atmosfera. Num curto prazo, enzimas e outras substâncias importantes para a fotossíntese começam a ficar escassas pelo metabolismo acelerado. Além disso, o amido excedente da elevada taxa fotossintética acumula-se no interior de cloroplasto­s, podendo prejudicar a fotossíntese. Num período mais longo de exposição, observa-se um decréscimo da vantagem produtiva do ambiente com elevado CO2e uma distribuição da biomassa, que favorece as partes vegetativas. A aclimatação no longo prazo está relacionada com a capacidade de o vegetal aumentar seus compartimentos de armazenamento.

The plant metabolism is altered with increasing of CO2concentration in the atmosphere. Initially the photosynthetic rate increases by the greater CO2available, after some time there is some adaptations in order to return to the initial equilibrium, characterizing acclimation. The objective of this review was to describe the acclimation mechanisms in plants to elevated CO2concentration. In the short term, enzymes and other important substances for photosynthesis are scarce by accelerated metabolism. In addition, excess starch of high photosynthetic rate, accumulated within chloroplasts can impair photosynthesis. A longer period there is a decrease in productive advantage on high CO2environment and biomass distribution that favors vegetative parts. Acclimation in the long term is related to the plant ability to increase its storage compartments.