Neste estudo foi realizada a avaliação da arborização de quatro praças da Tijuca, Rio de Janeiro, RJ, considerando a riqueza de espécies, análises morfométricas dos indivíduos, além do seu diagnóstico fitossanitário. Foram encontradas 310 árvores, distribuídas em 36 espécies e 14 famílias, com destaque para Cassia siamea e Delonix regia que, juntas, corresponderam a 32,4% dos indivíduos. Cassia siamea representou 9,4% dos indivíduos da Praça Castilho França, 32,3% da Varnhagen, 24,0% da Saens Pena e 11,1% da Xavier de Brito. Já Delonix regia totalizou 3,2% das espécies da Praça Varnhagen, 10,7% da Saens Pena e 35,2% da Xavier de Brito. Nas quatro praças foi encontrada uma distribuição proporcional entre as espécies exóticas e nativas. Todavia, comparando o número de indivíduos, foi constatado predomínio das exóticas. Considerando todos os indivíduos amostrados, 83,6% concentraram-se entre 5 m e 15 m de altura. Observou-se que 49,5% das árvores apresentaram DAP maiores que 30 cm. Considerando-se os aspectos fitossanitários, 64,5% das árvores encontravam-se saudáveis e 25,4% mostravam sinais de ataques de pragas, além disso, 10,1% sofreram injúrias. Diante desses fatos, recomenda-se a substituição dos indivíduos debilitados que sejam uma ameaça aos usuários ou prejudiquem a estética, procurando sempre utilizar o maior número de espécies nativas possível, para evitar a uniformidade. Também se faz necessário intensificar o controle das pragas e as atividades de educação ambiental, com o intuito de reduzir os danos nos exemplares da flora das praças urbanas.

This study evaluated the space-time variability of fire foci via environmental satellites for the State of Rio de Janeiro (SRJ) based on statistical procedures. The fire foci in the period of 2000 to 2015 were obtained from the BDQueimadas fire database. Descriptive, exploratory, and multivariate statistical analyses were performed in the software environment R i386 version 3.2.5. The north region had 6760 foci (21.11%), the south-central region had 3020 foci (9.43%), the Middle Paraíba had 6,352 foci (19.84%), the Metropolitan areas had 6671 foci (20.83%), and the Green Coast region had 292 foci (0.91%). The cluster analysis identified three homogeneous groups of fire foci (G1, G2, and G3) but did not include the municipality of Campos dos Goytacazes (NA). The G1 group (6.21 ± 0.01 foci, 57.61%) included areas throughout the state and covered the coastal region and lowlands towards the north. The G2 group (6.21 ± 0.01 foci, 34.81%) included the northern, south-central, and coastal shallows regions. The G3 group (6.21 ± 0.01 foci, 9.78%) included the mountain ranges of the state. Environmental characteristics and socioeconomic are crucial in the dynamics of fire foci in Rio de Janeiro.

This study compares the carbon footprints of two municipal solid waste treatment technologies—anaerobic digestion and a gas recovery system—with the aim of evaluating their potential for biogas recovery and greenhouse gas (GHG) mitigation. The analysis applies the 2006 IPCC model to real operational data from the Paracambi Waste Treatment Complex (Rio de Janeiro, Brazil), integrating carbon footprint estimation and environmental compensation modeling through tree planting. From a different perspective, this work evaluates the replacement of biogas recovery with a biologically controlled system based on material segregation. Within the limits and parameters defined for the system, anaerobic digestion achieved net emissions of 0.0029 tCO₂eq per ton of organic waste, compared to 1.14 tCO₂eq per ton for the biogas recovery system. This represents a potential 393-fold reduction in GHG emissions. However, this result is specific to the modeled conditions and does not consider the full life cycle impacts of non-organic waste fractions. The results suggest that anaerobic digestion, when integrated into an efficient selective collection system, can significantly improve energy recovery and mitigate the carbon footprint of waste management systems.

Forest structure studies may be carried out through the diametric distribution of individuals within a population, which is defined by characterizing the number of trees per unit area and diameter class intervals. The De Liocourt's q quotient can be used to assess the relationship between recruitment and mortality in forest communities because when a constant ratio occurs between the classes, it represents that the recruitment rate is similar to the mortality rate and the distribution can be considered as regular or balanced. This study aims to analyze the diametric structure of the arboreal component of a seasonal deciduous forest fragment located in the Peixe River Valley, Midwest of Santa Catarina State, Brazil. The sampled individuals were distributed in diameter classes with an amplitude of 5 cm, in which the center of the first class presented a value of 6.5 cm. Subsequently, the observed and estimated diametric distribution curves were constructed for the overall sampling and for species with the highest importance value (IV) and with different ecological attributes. The study area presented a deficit of trees in the overall and per species diameter classes when compared to a balanced forest. The De Liocourt's q quotient can be used to assess the diametric structure of deciduous forest fragments.

The present study aimed to determine heavy metal concentrations in the tree bark of the species Poincianella pluviosa in Volta Redonda municipality, Rio de Janeiro. Four sets of barks of eight trees with three replicates each from sectors 1 (W), 2 (S), 3 (E), and 4 (N) of the Volta Redonda center corresponding to the cardinal points were collected. The samples were digested in a nitroperchloric mixture and the lead (Pb), cadmium (Cd), nickel (Ni), copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) contents were determined by atomic absorption spectrophotometry. The cluster analysis (CA) formed 12 groups; among them, group 3 (G3) showed the presence of all seven elements in sector 1 and group 8 (G8) showed the presence of Pb, Zn, Fe, Ni, and Mn in sector 2. Kruskal-Wallis and Bonferroni tests showed that all elements presented statistically different values among the four sectors when compared with each other (p > 0.05). Sectors 1, 2, and 3 had the highest concentrations of heavy metals, which are directly associated with vehicle and railroad flow and iron and steel activities that are concentrated in these sectors. Bark can be used as an effective method for the monitoring of air pollution in urban areas.