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Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Decree-Law 4/2024 of 5 January, as amended by Rectification Declaration 15-A/2024/1 of 5 March (DL 4/2024), provides a regulatory framework for the voluntary carbon market in Portugal, the primary aim of which is to mitigate greenhouse gas (also called GHG) emissions in the national territory. DL 4/2024 outlines the market's fundamental principles, main features and functioning, and aims to ensure that carbon projects contribute to effectively mitigating GHG and promoting socioeconomic and environmental benefits. This article analyses the legal framework of the voluntary carbon market, while also presenting its main challenges. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction: The use of axillary marking prior to Neoadjuvant Systemic Therapy (NST) is a controversial matter regarding patients with positive Lymph Nodes (LN). Several methods were tested to make possible the decrease of false negative rate in comparison to sentinel lymph node adding more accuracy to the results. This study aims to evaluate the oncological outcomes in patients who had undergone selective axillary dissection with 4% carbon marking before TSN. Methods: A prospective study was performed with cT1-T4, cN1-N2 breast cancer patients classified as suspected LNs undergoing concomitant 4% carbon marking. After TSN, targeted LNs were identified and resected associated to the sentinel lymph node (SLN) biopsy. The oncological outcomes pointed out were overall survival (OS), causespecific survival (CSS), distant disease-free survival (DDFS), axillary recurrence (AR) and local recurrence (LR). Results: A total of 168 patients were evaluated for a median period of 49 months. The axillary emptying was reached in 89 (50.6%) cases. Five of 168 patients (2.9%) had axillary recurrence (AR). There was a significant link between axillary emptying and AR (0 vs. 6% p = 0.012). The DDFS was 140/168 (83.3%), OS 158/168 (94%) and CSS 158/163 (96.9%). Conclusion: The use of carbon marking in selective axillary dissection is a reliable low-cost method with simple execution. Among the oncological outcomes AR may not be considered for post downstaging axillary evaluation analysis since it is a rare event and not necessarily related to OS or DDFS.

Due to the urge to reduce greenhouse gas emissions in agricultural systems, studies are being conducted in the fields of the Pampa biome to understand the dynamics of carbon exchanges and propose mitigation measures. In this study, a model was calibrated to estimate the net ecosystem exchange (NEE) of CO2 in the native fields of the Pampa biome used for livestock, based on classical equations of ecosystem respiration and carbon assimilation through photosynthesis. For this purpose, NEE data obtained using the Eddy Covariance (EC) technique from a native field at the Santa Maria site in the years 2015 and 2016 were used to obtain the parameters utilized in the model. The parameters were obtained for each season, and the model was evaluated for the years 2019 and 2020 for both the Santa Maria site and the Aceguá site, located about 300 km from Santa Maria. The results showed that the model was able to estimate the NEE for the Santa Maria site with an average R² = 0.80 and RMSE 0.08 g C m-2 30 min-1, and for the Aceguá site with R² = 0.75 and RMSE 0.10 g C m-2 30 min-1. However, the model showed higher R² and higher RMSE during the summer and spring periods and lower values in winter and autumn at both sites. This model can be used to estimate the NEE of CO2 in the native fields of the Pampa biome as a basis for predicting CO2 absorption/emission across different seasons. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Relações Internacionais is the property of Relacoes Internacionais and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The relationship between food production and the preservation of the environment has become a topic of international debate, mainly related to greenhouse gas emissions. In this way, it became increasingly important to know potential sources and sinks of these gases, mainly evaluating the carbon balance in the area of agriculture and livestock. In Rio Grande do Sul, agricultural activity is extremely important culturally and economically, occupying a large part of the state, mainly within the Pampa biome, which has large areas of natural pastures capable of serving as fodder for animals. In this work, we quantified the exchange of CO2 through the Eddy Covariance methodology in two experimental sites of native pasture of the Pampa biome used for cattle raising, in the rotating system, which aims to maintain the diversity of the native pasture. With one-year data we showed that both sites were CO2 sinks, ranging from -82,4 g C m-2 a-1 to -282,3 g C m-2 a-1, due to differences in environmental conditions and vegetation composition. Thus, raising cattle on the natural pasture of the pampa biome can contribute to offsetting greenhouse gas emissions in other agricultural sectors. [ABSTRACT FROM AUTHOR]

Data collected by sensors are always subject to possible failures, whether due to power failure, external interference, among others. Moreover, much of the data is not considered during the filtering process because it is physically inconsistent. These failures result in the need to implement various methods of data processing, with a focus on filling in missing records. In the case of CO2 flux data, filling in the missing data is crucial to obtain annual data and the carbon balance. The REddyProc package is widely used and documented in terms of filling this type of data. However, modern methods have been increasingly explored to optimize this process. In this study, we compare data filling between the REddyProc package and the KNN Imputer method. Preliminary results show that the REddyProc package has better statistical indices when filling CO2 streams compared to the KNN method. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência e Natura is the property of Revista Ciencia e Natura and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Conjuntura Internacional is the property of Conjuntura Internacional and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The objective of this work was to evaluate cassava (Manihot esculenta) crop yield, as well as soil density and carbon content, under no tillage and conventional cultivation, in rotation with palisade grass (Urochloa brizantha) subjected to grazing. Treatments consisted of cassava cultivated as follows: in conventional tillage after 2 (CC-2P) and 4 (CC-4P) years of pasture; in no-tillage after 2 (NTC-2P) and 4 (NTC-4P) years of pasture; and with perennial pasture (PP) of palisade grass. The CC-2P treatment showed higher cassava yield in the 2016/2017 crop year (63.29 Mg ha-1) than NTC-2P (47.85 Mg ha-1). However, in the 2018/2019 crop year, no significant yield differences were observed between CC-4P (60.95 Mg ha-1) and NTC-4P (60.68 Mg ha-1). Between 2012 and 2019, soil carbon content (0-10 cm) decreased in the CC-2P treatment. In 2019, carbon stock was higher for NTC-4P compared with CC-4P and CC-2P, increasing from 16.41 to 21.46 Mg ha-1 between 2012 and 2019. Cassava yield varies depending on crop year, whereas soil carbon content decreases after CC-2P, but increases after NTC-4P.

ABSTRACT In the Serra da Mantiqueira region the pedogenetic studies contribute to both the understanding of past events and supporting the conservation of natural resources. This study aimed to characterize the soils from the Minas Gerais high-mountains region to evaluate the influence of paleoenvironmental conditions on pedogenesis. Five profiles were selected and characterized for morphological, physical and chemical properties. Isotopic analyses of 13C were performed in soil samples collected at depths of 10, 20, 30, 40, 50, 60, 80 and 100 cm; except in P2, which was collected up to 60 cm deep. Erratic distribution of the particle-size fractions and C contents highlight the sedimentary nature of the profiles, resulting from the erosive action favored by the relief. High organic C content in subsurface and its accumulation in the surface were observed in the profiles, which suggests the occurrence of the melanization process. In the profiles P2, P4 and P5 (Cambissolos/ Cambisols) the brownish color indicates the xanthization process, while in P1 (Argissolo/ Lixisol), is highlighted the process of eluviation and illuviation resulting in the increase of clay in subsurface and presence of clay films. In P3 (Latossolo/ Ferralsol), the low values of sum of bases, silica removal and SiO2/Al2O3 ratio (ki index) values below 1.0 point to the advanced weathering and the allitization process. The variation in the isotopic signature of δ13C indicates a drier past condition, with mixed vegetation, with gradual change of vegetation with predominant C3 photosynthetic pathway. In P1 and P4, the decrease in the contents of δ13C in surface results from anthropic action.

El estudio de la pólvora en la Castilla medieval ha contado hasta el momento con un exiguo conocimiento sobre su proceso de fabricación. Con el presente trabajo se pretende dar a conocer y analizar un manuscrito datado en época de los Reyes Católicos y conservado en el Archivo Histórico de la Nobleza, Casa del Infantado, dedicado a la escopeta. Así como aportar luz sobre los procesos técnicos relacionados, refinado del salitre y el azufre y composición del carbón.

Carbon sequestration by soils in different production systems contributes greatly to the reduction of greenhouse gases. The objective of this study was to quantify the carbon stored in four land uses at different soil depths. To this end, a 22 factorial experiment in complete randomized block design (CRBD) was carried out. The factor A: land uses (natural pastures, shelterbelts, fodder banks, and potato crop) and the factor B: two soil depths (30 and 60cm), with three replications. . As a result, statistical differences were found among soil uses (p>0.0573) and between depths of 30 and 60cm (p 0.0659). The fodder bank presented a higher organic carbon content (139.85tC.ha-1) at 60cm depth and the potato monoculture (63.32tC.ha-1) at 30cm depth while, at both depths, natural pasture reported lower values (54.45 and 60.02tC.ha-1). Hence, the importance of productive systems to accumulate more carbon at greater depths of soil (60cm) compared to lower depths (30cm), which may be linked to agricultural opperations made on the soi surface, generating carbon leakage.

ABSTRACT: This research evaluated the effect of liming (with and without) and biochar (with and without) on sorghum cv. BRS Ponta Negra growth and Arenosol chemical properties in the Semiarid environment. The experimental design was in randomized blocks, with treatments in a 2x2 factorial scheme, corresponding to the application or not of lime (0 and 2.5 t ha-1) and biochar (0 and 12.5 t ha-1). Biochar was produced from cashew branches. The experiment was conducted in 16 m² plots where the forage sorghum cultivar BRS Ponta Negra was cultivated. The soil chemical characteristics, the production attributes, and the structural characteristics of the sorghum cultivar studied were evaluated. There was no interaction between factors. The use of biochar increased the pH and Ca and P contents in the soil and contributed to increasing the panicle mass (2.51 t ha-1 of DM). Lime application affected the soil Ca content as the dose of 2.5 t ha-1 resulted in higher values of culm diameter (15.25 mm), panicle mass, and culm mass (2.63 and 7.50 t ha-1 of DM, respectively). Therefore, these results allowed to outline strategies for the use of limestone and biochar for forage production in semiarid environments in sandy soils. Because, these materials improve some chemical attributes of the soil and the production of forage sorghum. It is noteworthy that edophoclimatic conditions can change the response patterns observed in this research. Therefore, research in other regions is essential.

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Este trabajo de investigación presenta un análisis de la eficiencia técnica de las empresas del sector carbón y sus derivados en Colombia, durante el periodo 2011-2014. Como fundamentación teórica se utilizaron los conceptos de análisis envolvente de datos (DEA), específicamente el modelo CCR-O, enfocado en salidas y en la técnica multivariada de análisis discriminante. Para el desarrollo de la investigación se realizó un estudio empírico racional, con un enfoque evaluativo, que permitió establecer una estructura DEA para valorar las eficiencias. Para esta investigación se trabajó con 14 grandes empresas del sector minero en Colombia; como fuente de información primaria se tomó la reportada por la Superintendencia de Sociedades en los respectivos años. Con base en la estructura DEA, se valoraron las eficiencias de las empresas y se establecieron aquellas que se constituyeron en referentes de evaluación de las empresas ineficientes; seguidamente, se calcularon las proyecciones de las variables de salida que permiten que las empresas ineficientes alcancen las eficiencias de acuerdo con el modelo CCR-O enfocado en salidas. Por último, se utilizó la técnica análisis discriminante, que permitió validar la pertenencia de una empresa del sector a ser eficiente o no. La eficiencia promedio de las empresas bajo el modelo DEA en el periodo de estudio alcanzó un nivel alto, de 84,5 % y la técnica análisis discriminante indicó una validación del 80,3 %. Este trabajo aporta criterios a los responsables de la toma de decisiones para mejorar la eficiencia en el sector.

ABSTRACT This research aimed to estimate the seasonal economic value of ecosystem goods and services from research on the use of mangroves in the Cuiarana community in the Eastern Amazon. The methodology of Total Economic Value was used, through interviews with 15 residents who extract products from the mangrove. For the ecosystem services, atmospheric carbon (measured by a micrometeorological tower), and organic carbon (monitored by soil sampling during 2017) were used. In determining product values, the quantities extracted at market prices and the value of services were estimated using carbon credits. The results indicate that the ecosystem produces 9 community assets, that generate R$ 75,033.50 (US$ 23,622.93 ha/year) and R$ 17,627.15 (US$ 5,549.58 ha/year) for capture and storage respectively. The VET value corresponded to R$ 986,132.50 (US$ 310,465.79). Ecosystem services and the economic values of atmospheric (p = 0.0278) and soil carbon credit (p = 0.0354) indicated higher importance in the rainy season due to the precipitation that favored an increase in the amount of carbon. This behavior was verified by the Principal Components Analysis (50.1%), which showed that in the less rainy season goods are more important when compared to the ecosystem services.

The capture of CO2 has been a challenge through time; however, there are different methods which contribute to minimize the emission of carbon dioxide to the environment. There are different kinds of these methods: physical, chemical and biological. One of the biological methods is the “culture of micro-algaes”. The micro-algaes are microorganisms of rapid growth that can fix carbon dioxide easier than any others biological systems, but is necessary an optimal environment for the development of these microorganisms. The method is based in evaluate the behavior of micro-algaes in the capture of CO2 , with different conditions and concentrations of nutrients as phosphorus and nitrogen for each experiment. This process allows establishing the optimal concentration for the capture of CO2. By means of statistical software version 7, which gives us an approximation of the concentrations of these nutrients, together with statistical estimates, charts, tables, highlighting which of the nutrients will have a higher incidence in the microorganism, and the production of biomass. With the analysis of the results, it is possible to make a difference of this method with other methods of geological capture, which are focused in energy and water consumption. Finally, with the analysis of costbenefit, it will determine the viability of the project and stimulate the application in the industry as a measure of mitigation of the environmental impact.

Few studies have evaluated the effect of earthworms on plants and biological soil attributes, especially among legumes. The objective of this study was to evaluate the influence of earthworms (Amynthas spp.) on growth in the common bean (Phaseolus vulgaris L.) and on soil biological attributes. The experiment was conducted in a greenhouse using a completely randomized design with five treatments and eight repetitions. The treatments consisted of inoculation with five different quantities of earthworms of the genus Amynthas (0, 2, 4, 6, and 8 worms per pot). Each experimental unit consisted of a plastic pot containing 4 kg of soil and two common bean plants. The experiment was harvested 38 days after seedling emergence. Dry matter and plant height, soil respiration, microbial respiration, microbial biomass, and metabolic quotient were determined. Earthworm recovery in our study was high in number and mass, with all values above 91.6% and 89.1%, respectively. In addition, earthworm fresh biomass decreased only in the treatment that included eight earthworms per pot. The presence of earthworms increased the plant growth and improved soil biological properties, suggesting that agricultural practices that favor the presence of these organisms can be used to increase the production of common bean, and the increased soil CO2 emission caused by the earthworms can be partially offset by the addition of common bean crop residues to the soil.

Resumen. Con frecuencia se ha afirmado que las compañías ferroviarias de propiedad británica hasta 1947 tenían interés en la importación de carbón y que por esa razón fueron un obstáculo para el desarrollo de la producción nacional de petróleo. La creación en 1920 de la Compañía Ferrocarrilera de Petróleo y las inversiones hechas en la transformación de las locomotoras a vapor para quemar combustible líquido después de la Primera Guerra Mundial muestran hechos que son incompatibles con aquella información. La principal preocupación de las compañías ferroviarias fue siempre dar un servicio de transporte reduciendo al mínimo los costos de explotación, entre ellos los de combustible. Cuando el carbón importado, por su precio y por su escasez, se convirtió en un problema, las compañías no dudaron en buscar la sustitución por petróleo argentino. También invirtieron sumas importantes en convertirse ellas mismas en productoras de ese combustible en la Argentina.

La minería de carbón, junto con la construcción y el asfaltado de las carreteras, son aspectos a los que Nader Koochaki ha atendido desde que en 2012 colaborara en la exposición Castillete. Retablo Minero de Carme Nogueira en el MUSAC. La extracción y el consumo de los combustibles fósiles han transformado el espacio y el tiempo de nuestras vidas. Desde la configuración urbana de Teherán a las protestas mineras acaecidas en León y Asturias, Nader explora restos y rastros que han quedado inscritos en el territorio desde la particularidad de la materia. A partir de pensar la práctica expositiva como ejercicio editorial, el autor explora otras formas de edición y publicación. En este texto se repasan algunas de las operaciones vinculadas a una línea de trabajo que se caracteriza por estar formándose como secuencia de un ejercicio editorial continuado.

The objective of this work was to assess the quality of the charcoal of the species Cecropia glaziovii, produced in small rural properties, in the municipality of Biguaçu, in the state of Santa Catarina, and in the laboratory and to compare its properties with charcoal from other species. We analyzed charcoal samples from three sources: charcoal samples collected from Cecropia glaziovii kilns Biguaçu, SC (1), charcoal samples produced in these same kilns, but from several different species (2) and samples obtained from the laboratory carbonization of woods from three Cecropia glaziovii trees collected in the same rural properties (3). It was determined the gross calorific value, percentage of volatile, percentage of ash, and fixed carbon. Analyzing the samples of charcoal, the averages for the energy analysis showed that the charcoal from sample 2 presents better characteristics compared to the samples 1 and 3. Sample 2 had a gross calorific value (GCV - 7,281 Kcal/Kg to 7,336 Kcal/Kg), lowest volatiles content (TV - 26.26%), lower ash content (TC - 2.05 to 2.46%) and higher fixed carbon content (66.02%). The average of the properties of Sample 3 was also compared to other species of commercial importance to produce charcoal. The gross calorific value (6,573 Kcal/Kg) and percentage of fixed carbon (61.32%) were respectively lower when compared to other carbon species: Mimosa scabrella (7201.28 Kcal/Kg; 85.40%), Eucalyptus bentamii (8,777 Kcal/Kg; 81.85%), and Eucalyptus grandis (7632 Kcal/Kg; 75-80%). The percentage of volatile (35.00%) and ash (3.68%) were respectively higher than those from other species: Mimosa scabrella (12.70%; 1.90%), Eucalyptus bentamii (17.17%; 0.96%) and Eucalyptus grandis (20-25%; 1.70%). The results indicate that the quality of the Cecropia glaziovii charcoal is lower when comparing to other species. However, its production is recommended due to the abundance of the species in this region. [ABSTRACT FROM AUTHOR]

Copyright of Ambiência is the property of Revista Ambiencia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Global demand for renewable energy has continued to increase with a strong global tendency. In this away, the objective of this study was to evaluate the calorific value of different tree biomass components of E. grandis and E. urophylla with 60 months old, to analyze the economic feasibility of the total or partial use of its biomass for energy generation. Higher and lower calorific value, ash content and organic carbon of the tree components (wood, branches, bark and leaves) were evaluated. Regarding to the calorific values, leaves showed higher values when compared to the other tree components with 4,904 kcal kg-1, followed by branches with 4,290 kcal kg-1, wood with 4,126 kcal kg-1 and bark, with the lowest (3,641 kcal kg-1) calorific value. In relation to the nutrient use efficiency (NUE), wood showed the highest values, which is something highly desirable and of great interest to forestry. In the other hand, leaves showed the lowest values of the NUE, with the exception of Ca and Mg that were lower in the bark, indicating the importance of maintaining these components in the soil after harvest. Regarding to the cost to replace the nutrients (NPK) exported by one ton of wood biomass, E. grandis and E. urophylla showed values of R$ 14.05 and R$ 11.54 respectively, being the biomass of this component the cheapest in terms of nutrients reposition. On the other hand, tree leaves component showed the higher cost of NPK replacement, emphasizing the low economic viability to export this biomass. [ABSTRACT FROM AUTHOR]

Wood density (DM) is an important variable for estimates of tree or arboreal-shrub carbon stocks in terrestrial ecosystems. Calculated from sample disks using the sapwood shell and core of the disks using the dry weight as a function of the saturated volume of the part. This subject is little investigated in forests and even less in open areas of the Amazon biome as savannah and grassland areas of the Brazilian Amazon. The largest block of Brazilian Amazonian savannas is in Roraima. This study investigated the variation of the basic wood density of common shrubs in the Roraima tillage, near the city of Boa Vista - RR. The DM variations of 8 common species in the area around Boa Vista were verified in transects following the traditional routes of the Lavrado. The non - destructive method was used to obtain wood pieces from the shrub canopy with diameters between 5 and 10cm, following recommendations from previous works. The results indicated that DM among species differed significantly (ANOVA; F 7.148 = 6.9362; P <0.0001); we also observed some inter-specific differences using Tukey's test. The distinctions detected here should be related to environmental and individual variations and should be considered as an important tool to improve the estimates of carbon stocks and flow in arborealshrubby plants of savanna areas in the Amazon, helping to refine biomass data, accumulation and release of carbon. [ABSTRACT FROM AUTHOR]

Firewood as humankind's most used fuel, was replaced by coal from XIII century on due to a number of factors. Thus coal became Second Industrial Revolution driving energy after the invention of the thermal machine in XVIII century. This text addresses the various technological, social, economic and environmental aspects that influenced this process, which culminated in the adoption of fossil fuel as the most consumed energy in the last two hundred years. [ABSTRACT FROM AUTHOR]

El objeto de este estudio es indagar y explicar qué supone la práctica del carboneo y el carbón en el reino de Córdoba durante el periodo bajomedieval. Ante la carencia de estudios antracológicos, las fuentes documentales plasman la tipología de carbones existentes, cómo se obtenía esta materia prima, a qué usos se destinaba, cómo era transportado hasta la ciudad, y en último lugar, su comercialización. Gracias a esta información se puede comprender el significado que tenía el carboneo para nuestros antepasados, pues nos han dejado un legado carbonífero que seguimos utilizando en la actualidad.

ABSTRACT World wet tropical forests, and especially the ones in the Colombian Pacific area, are the target of a small tree (minor diameter) selective harvest process, used in short-cycle industries, such as bioenergy. This situation generates a reduction in stored carbon and biomass, and becomes an emission of greenhouse gases (GHG). Allometric models for aboveground biomass are few, despite being an important tool of carbon calculation. The goal of this study was to develop multi-species allometric models for small trees aboveground biomass in wet tropical forests. A total of 61 individuals (diameter at breast height -DBH- < 12 cm) was measured, cut and weighed to estimate their biomass. The model with the best adjustment was selected considering criteria of determination coefficient (R2) and adjusted R2, mean quadratic error of prediction, Akaike and Bayesian Information Criteria and the biological logic of the model. Best-fit allometric model (R2= 0,72) was with DBH and total height as independent variables, considering that it is a multi-species model coming from forests with a high diversity.

The use of solar energy is growing sharply in the past years. The most used material for solar cells is high-purity silicon produced by refining low-purity silicon. With the increasing demand for photovoltaic components, new refining processes have been investigated. Carbon is one of the impurities to be removed and one possible removing technique is based on the settling of silicon carbide particles. Settling tests were carried out at 1,500°C during one and six hours. Results show that differences in settling time do not affect carbon removal significantly and that the carbon contents after settling are still higher than that required by standards for solar grade silicon (43 ppm). Results from this work and from literature show that settling is not a feasible processing step for carbon removal to the level needed for photovoltaic applications.

Wood density (DM) is a widely used variable for estimating carbon stocks of trees and shrubs in terrestrial ecosystems. This subject is little investigated in open areas of the Amazon, such as savannas and meadows. The objective of this study was to investigate the DM response of trees and shrubs typical of savanna areas of the northern extreme of Amazonia in relation to edaphic factors and altimetry in six different collection sites. We collected about 8 sample disks in three different diameter classes (<5cm, 5- 10cm and> 10cm) of each of the 75 individuals observed along six sample sites in open savanna areas of Roraima. Around each individual, four soil samples were collected, distant 1m from the base of the plants, in the N, S, L and O directions at a depth of 20cm. The soil samples were homogenized and analyzed according to texture and fertility. The DM variation was verified as a function of: pH, exchangeable bases, texture and soil organic matter. The DM varied between species (p <0.0001) from 0.512g.cm-3 (H. articulatum) to 0.665g.cm-3 (R. montana), but was not associated with altimetry (R2 = 0.0264 , p = 0.1598) and to edaphic factors (R2 = 0.0079; p = 0.5454), except for H. aticulatum (R2 = 0.6084; p = 0.0381 in soil attributes) and tending to A. ovata (R2 = 0.4923, p = 0.539 in soil attributes and p = 0.573 in altimetry). These results demonstrate that edaphic and altimetric variations may influence the DM variation of some species of the open savanna of Roraima. [ABSTRACT FROM AUTHOR]

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ABSTRACT The objective of the study was to present mathematical models and strategies for fitting equations to estimate dry biomass for tree species in forest restoration areas. The presence of outliers was analyzed in each fitted equation using values of the matrix H, leverage points, means of standard and studentized residuals, and of influential points through DFFITS, DFBETAS and COOK distance values. Furthermore, the normality, homoscedasticity and independence of residuals were checked. The accuracy of the fitted equations was evaluated by means of the R2adj., Syx, analysis of residuals, and AIC and BIC criteria. The results showed that the model for estimating dry biomass as a function of the variables Dc2, DBH2, Hc2 and DBH provides the more accurate solution, with Syx = 40.91% and R2adj. = 0.92. We concluded that the performance of this equation improves when adjusted to data stratified by classes of height-diameter ratio, which reduces the value of the estimated error.

A diferencia de otros latecomers, la historia energética chilena ha estado profundamente vinculada al consumo de carbón mineral. Su importancia en la matriz energética disminuiría desde 1953, abandonando industrias y ferrocarriles para concentrarse en la generación de gas y electricidad. Esta transición daría inicio a un nuevo ciclo de vida del mineral, caracterizado por un estrecho vínculo con la generación termoeléctrica. Desde 1990, el incremento de la demanda eléctrica dinamizó el consumo de carbón a niveles nunca antes vistos. El objetivo de este artículo es analizar el consumo de carbón mineral en la economía chilena durante los últimos 40 años. La hipótesis defendida es que, después de un declive en el consumo de carbón a fines de la década de 1960, se abre una transición caracterizada por el uso del mismo para la generación termoeléctrica.

The objective this paper was to quantify the hourly variability of CO2 fluxes in the year of the El Niño, in 2015, in a tropical rain forest in the Western Amazon. Data of CO2 fluxes collected at 63.5 m height in a tower of the Large- Scale Biosphere-Atmosphere Experiment in Amazonia in the Jaru Biological Reserve, composed of the Open Ombrophilous forest, were analyzed. Data from the dry-wet period were used, which by convention, the negative and positive values indicate absorption and emission of CO2, respectively. The CO2 uptake in the forest had higher levels between 9:30 a.m. and 4:00 p.m., with mean values between -19 and -13 μmol m-2 s-1, however the peak absorption occurs at 1:00 p.m. with -30 μmol m-2 s-1, considering that at this time the sun's rays are most intense. In average, the Rebio Jaru absorbs more than the areas of the transition Amazonia-Cerrado, indicating that the physiological activities in Ombrophilous forest require a greater amount of carbon. The average daily behavior of CO2 fluxes showed higher concentrations of absorption during the day than emissions overnight, behaving as a carbon sink, corroborating the importance of the forest in assimilation of the atmospheric carbon. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate qualitatively the ecosystem services (ES) by type of agroforestry systems (AFS) based on seven pre-selected environmental indicators. The models of AFSs evaluated were multi-stratified, in alleles, taungya and hedgerows. The multi-stratified AFS shave a greater potential for ES provision because they have the composition that most resembles a natural forest. [ABSTRACT FROM AUTHOR]

We assessed the effect of different winter crops on indicators of soil quality related to C and N cycling and C fractions in a Rhodic Kandiudult under no-till system at implantation, during two growing seasons, in Londrina PR Brazil. The experimental design was randomized blocks with split-plot in time arrangement, with four replications. The parcels were the winter crops: multicropping of cover crops with black oat (Avena strigosa), hairy vetch (Vicia villosa) and fodder radish (Raphanus sativus); sunflower (Heliantus annuus) intercropped with Urochloa ruziziensis; corn (Zea mays) intercropped with Urochloa; and corn; fodder radish; or wheat (Triticum aestivum) as sole crops. The subplots were the years: 2008 and 2009. Determinations consisted of total organic C, labile and resistant C, total N, microbial biomass C and N, the C/N ratio of soil organic matter, and the microbial quotient (qMic), besides microbiological and biochemical attributes, assessed only in 2009. The attributes significantly changed with the winter crops, especially the multicropping of cover crops and fodder radish, as well as effect of years. Despite stimulating the microbiological/biochemical activity, fodder radish cropping decreased the soil C in the second year, likewise the wheat cropping. The multicropping of cover crops in winter is an option for management in the establishment of no-till system, which contributes to increase the concentrations of C and stimulate the soil microbiological/biochemical activity.

En Cuba no existen antecedentes sobre cómo abordar de forma integrada la producción de madera para aserrío y la retención de carbono. Se establecieron 30 parcelas temporales de 500 m 2 en plantaciones de Pinus caribaea Morelet var. caribaea Barret y Golfari en la región de Tope de Collantes, ubicada en el macizo montañoso de Guamuhaya, provincia Sancti Spiritus, Cuba; en ellas se midieron el diámetro normal (d 1,30 ), la altura total y el grosor de corteza por árbol (GCa), calculando el volumen total con corteza por árbol (VTcca), el rendimiento por hectárea (R) y la retención de carbono (C). Se analizaron las tendencias de variación de estas variables con el espaciamiento manteniendo fijos los efectos sitio y edad primero y confundiendo el efecto sitio dentro del efecto espaciamiento después. En todos los casos el d 1,30 y el VTcca presentaron tendencias ascendentes con el aumento del espaciamiento, en tanto que el GCa, el R y el C presentaron tendencias descendentes, sugiriendo que para combinar la producción de madera para aserrío con la retención de carbono, resulta conveniente identificar un espaciamiento de compromiso entre ambas variables, que para esta especie y en estas condiciones resultó ser de 990 árboles*ha -1 , equivalente a 3,2 m x 3,2 m. In Cuba there are no precedents about how to manage wood plantations for sawmill, together with carbon retention. There were used 30 temporal plots (500 m 2 each) in plantations of Pinus caribaea M. var. caribaea B. & G. in Tope de Collantes, region of Cuban south-centre mountains in Sancti Spiritus province. In each plot were measured normal diameter (d 1,30 ), total height and bark thickness by tree, and then it was calculated total volume with bark per tree, yield per hectare and carbon retention in order to analyse variation tendencies of those variables with spacing, using first as fixed effects site and age and then, confounding site effect within spacing. In all cases normal diameter and total volume with bark per tree had increasing tendencies with respect to spacing, while bark thickness by tree, yield per hectare and carbon retention presented decreasing ones. Those results suggest that for an adequate combination of wood production for sawmill together with carbon retention, it would be convenient to establish a compromise spacing between both variables, which for that species and site conditions was 990 trees per hectare, equivalent to 3,2 m x 3,2 m.

Studies on the quantification of forest biomass in Caatinga are important due to the scarcity of information related to the theme in the biome and in particular in the state of Bahia, Brazil. The objective of this study was to evaluate the biomass stock and their distribution in the components of the aerial part of forest species with higher population density and the potential to use the biomass expansion factor (FEB) to obtain estimates of aerial biomass in the area of Caatinga, located in Contendas do Sincorá National Forest, BA. The biomass was quantified by destructive method. Representative trees of the nine species with the highest population density were selected felled, and distributed in three diametric classes. The average amount of total biomass and carbon per tree, considering all the species sampled, were estimated at 50.7 kg tree-1 and 25.3 kg tree-1. Jatropha mollíssima is dissimilar in relation to the biomass allocation (branches > stem > leaves) in relation to the other species (stem > branches > leaves). The highest values of individual biomass were verified in the species Commiphora leptophloeos (171 kg tree-1), Coccoloba oblonga (76 kg tree-1) and Pseudobombax simplicifolium (40 kg tree-1). The mean FEB obtained for all species (1.74) provided estimated values close to the real ones. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the capacity of storage of carbon in species of grasses natural of high andean, between January of 2012 and March of 2013. They were defined two sampling areas in the districts of Huasicancha and Chicche of the county of Huancayo, Junín. The first of the areas was located in the place Pumahuasi (18L 466456E 8628580N) and the second in Vista Alegre (18L 464886E 8642964N), between 3 845 and 3 870 meters of altitude. 10 plants per species were collected at random, between April and May, considering the moment of maximum growth of the plants. The samples were washed and dried off to the atmosphere during 15 days, being completed the drying in a stove to 60 °C, during 48 hours. The determination of the percentage of dry matter of the samples was carried out by the difference between the initial and final weights. While that the determination of the percentage of carbon was carried out through the method of Walkley-Black. The results of the correlation of weight between air biomass and biomass radicular were highly significant r = 0.9856 ** and b = 3.4507. The percentage of the weight of the root regarding that of the air biomass oscillated between 27.93% and 30.20%, respectively. The content of carbon expressed as percentage varied according to the part of the plant and the origin place.

Natural forests are areas rich in biodiversity that contribute to the maintenance of environmental sustainability through the production of litter and nutrient cycling. Litter is a major route of nutrient return to the system plant – soil – plant and its determination to analyze the restructuring of anthropogenic forest environments. The knowledge of litterfall is critical to determine the potential for regeneration of an area through the intake and nutrient cycling. We quantified litter production in areas of white sand with vegetation in different stages of regeneration the National Park Sierra de Itabaiana, Sergipe State. In each of the areas of white sands open (ABA), white sands intermediary (ABI) and white sands closed (ABF) was installed 15 litter traps and litter fall was collected monthly from January to December 2011. The total contribution of litter on the White Sand Closed (2092 kg ha-1) was more than double the contribution in Areia Branca Open (881 kg ha-1) and White Sand Intermediate (687 kg ha-1). The leaf fraction contributed the largest mass in all areas and periods, and was the one with greater seasonal variation related to variation in precipitation. Precipitation was one of the factors that determined the seasonality of litter deposition in natural vegetation of the National Park of Sierra de Itabaiana, Sergipe State.