Abstract Geoprocessing techniques are generally applied in natural disaster risk management due to their ability to integrate and visualize different sets of geographic data. The objective of this study was to evaluate the capacity of classification and regression tree (CART) to assess fire risk. MCD45A1 product of the burnt area, relative to a 16-year period (2000-2015) was used to obtain a fire occurrence map, from center points of the raster, using a kernel density approach. The resulting map was then used as a response variable for CART analysis with fire influence variables used as predictors. A total of 12 predictors were determined from several databases, including environmental, physical, and socioeconomic aspects. Rules generated by the regression process allowed to of define different risk levels, expressed in 35 management units, and used to produce a fire prediction map. Results of the regression process (r = 0.94 and r² = 0.88) demonstrate the capability of the CART algorithm in highlighting hierarchical relationships among predictors, while the model’s easy interpretability provides a solid basis for decision making. This methodology can be expanded in other environmental risk analysis studies and applied to any area of the globe on a regional scale.

ABSTRACT The indiscriminate use of fire, every year has been causing an imbalance in nature, which can be perceived globally. The remote sensing represents the main technological alternative in detecting, dimensioning and understanding the dynamics of fire. Thus, the objective of this study was to analyze the spatio-temporal distribution of the burned areas of the Caatinga Biome using the MODIS MCD64A1 product, from 2001 to 2018. For this, the monthly subsets of the Burned Area MCD64A1 product were used for the period of study. The Canadian Forest Service classification was also adopted, which defines the burned areas in five different classes: I (0-0.09 ha); II (0.1-4.0 ha); III (4.1-40.0 ha); IV (40.1-200.0 ha); V (>200.0 ha). The results achieved in this study reveal that the state of Piauí has a statistically higher average of fire occurrences and burned area in the times series. The months that had the largest burned areas in the biome were September, August and October and the greatest recurrences of burned areas from May to December. The burned area size classes that presented the highest occurrences were III, IV e V. The biome undergoes systematic growth of degradation, which enhances its fragility in the face of fire.

RESUMO O uso do fogo de forma indiscriminada, a cada ano vem causando um desequilíbrio na natureza, que pode ser percebido em âmbito global. O sensoriamento remoto, representa a principal alternativa tecnológica na detecção, dimensionamento e na compreensão da dinâmica do fogo. Assim, o objetivo desse estudo foi analisar a distribuição espaço-temporal das áreas queimadas do Bioma Caatinga por meio do produto MODIS MCD64A1, no período de 2001 a 2018. Para isso, foram utilizados os subconjuntos mensais do produto Burned Area MCD64A1. Adotou-se também a classificação do Canadian Forest Service, no qual define as áreas queimadas em cinco classes diferentes: I (0-0,09 ha); II (0,1-4,0 ha); III (4,1-40,0 ha); IV (40,1-200,0 ha); V(>200,0 ha). Os resultados alcançados nesse estudo revelam que o estado do Piauí apresenta estatisticamente maior média de ocorrências de incêndios e área queimada na série temporal. Os meses que tiveram as maiores áreas queimadas no bioma foram setembro, agosto e outubro e maior recorrência de maio a dezembro. As classes de tamanho de área queimada que apresentaram maiores ocorrências foram III, IV e V. O bioma sofre sistemático crescimento de degradação, o que potencializa sua fragilidade ante ao fogo.

Abstract Fire risk mapping is a basic planning and protection element. This study presents the application of fuzzy logic in a geographic information system (GIS) as an alternative multi-criteria analysis for determining the areas of highest risk of forest fire in natural forest remnants in the Brazil. In the decision-making process, a set of factors that are relevant to fire safety were identified in the study area. For each input variable chosen for the model, a pertinence function was defined that best described its influence on fire risk. Subsequently, the variables were combined for the presentation of the final fire risk map. Concluded in the study that an increased risk of fire occurs at the wildland - urban interface. A strong relationship was observed between the fire ignition points and proximity to roads and urban areas. The proposed model was efficient to integrate the variables and determine areas of greatest risk.

ABSTRACT The aim of the present study was to propose a prediction system to estimate the diameter distribution and wood production in unthinned eucalyptus clone plantations. Data was obtained from permanent sample units, with ages from 28 to 78 months. The Weibull distribution was used to estimate the frequency of the number of trees per diameter class. Models were used to relate the Weibull distribution coefficients with forest stand attributes. The forest stand variables most correlated with the Weibull distribution parameters were the minimum, medium, maximum and quadratic diameters and the dominant height. The projected frequency of tree numbers and the production by diameter class obtained by the system of equations did not differ statistically from the observed values evaluated by the t-test at 95% probability.

Foram avaliadas as condições para prevenção e combate dos incêndios nas Unidades de Conservação (UCs) Estaduais do Espírito Santo. Foram realizadas entrevistas com os gestores das 16 UCs e visitas às mesmas, para análise de documentos, relatórios e planos de manejo. Os incêndios foram caracterizados segundo os grupos de causas e ordenados pelas classes de tamanho: I (0-0,009 ha), II (0,1-4,0 ha), III (4,1-40,0 ha), IV (40,1-200,0 ha) e V (>200 ha). Os menores déficits de pessoal e equipamentos operacionais foram apresentados pelas Unidades de Uso Sustentável. No entanto, a efetividade de gestão das Unidades de Proteção Integral é maior, com uma infraestrutura e pessoal permanente atuando nas mesmas. A maior causa dos incêndios foi representada pela queima para limpeza (20%), sendo classificados como tamanhos II e III (25%). Apesar das limitações de pessoal e equipamentos operacionais, as UCs Estaduais possuem condições mínimas para ações de prevenção e combate dos incêndios.

In this study, we evaluated the conditions for preventing and fighting forest fires in the Conservation Units (CU) of Espirito Santo state, Brazil. We visited the 16 existing CUs in the state. During these visits, we analyzed documents, reports and management plans and conducted interviews with the managers. The fires were characterized by main groups of causes and arranged according to size class: I (0-0.009 ha), II (0.1-4.0 ha), III (4.1-40.0 ha), IV (40.1-200.0 ha), and V (>200 ha). The Sustainable Use Units showed the lowest deficits of personnel and operating equipment; however, the management effectiveness of the Integral Protection Units is greater, presenting good infrastructure and permanent action of personnel. The major cause of fire was debris burning (20%) and the most common size classes were II and III (25%). Despite the limitations in personnel and operational equipment, the CUs hold the minimum conditions required for actions of prevention and combat to forest fires.

O objetivo deste estudo foi avaliar o potencial da utilização de resíduos orgânicos como componentes do substrato para produção de mudas de Chamaecrista desvauxii, vulgarmente conhecida como rabo-de-pitu, empregada na recuperação de áreas degradadas. Estabeleceram-se os tratamentos utilizando quatro tipos de substrato: lodo de esgoto (LE), casca de arroz carbonizada (CAC), palha de café in natura (PC in natura) e substrato comercial (SC), em diferentes proporções de volume. Quando as mudas atingiram 150 dias de idade, elas foram mensuradas quanto às seguintes características: altura, diâmetro do coleto, relação entre altura e diâmetro do coleto, massa seca da parte aérea, massa seca do sistema radicular, massa seca total, relação entre massa seca da parte aérea e massa seca do sistema radicular e índice de qualidade de Dickson (IQD). Os substratos formulados com lodo de esgoto, casca de arroz carbonizada e palha de café in natura propiciaram os melhores resultados das características avaliadas, sendo o tratamento com 60% LE + 20% CAC + 20% PC in natura o que proporcionou as mais adequadas características morfológicas avaliadas na produção de Chamaecrista desvauxii.

The objective of this study was to evaluate the potential of sewage sludge and organic waste as component of substrate for Chamaecrista desvauxii seedlings production. It was established ten treatments using four types of substrate: sewage sludge, carbonized rice hull, coffee straw and commercial substrate in different proportions. When the seedlings were at three months of age, the following parameters were measured: stem diameter, plant height, ratio between plant height and stem diameter, shoot dry mass, dry mass of root system, total dry mass, dry mass ratio of shoot/root dry mass and Dickson quality index (IQD). The substrates made with sewage sludge, carbonized rice hull and coffee straw provided better results of growth of seedlings. Moreover, the treatment with 60% sewage sludge + 20% carbonized rice hull + 20% coffee straw provided the best development of the morphological characteristics evaluated, and it was recommended for the production of Chamaecrista desvauxii.

ABSTRACT The objective of this work was to analyze the structure of forest landscape, between two conservation areas, through indices of landscape ecology. Mapping was obtained by scanning aerial photographs using photo-interpretation techniques at the scale of 1:2500. Patch Analyst (ArcGis 9.3) was used for the indices calculation. The fragments were divided in the following classes: very small (<5 ha); small (>5 and <10 ha); medium (>10 and <100 ha); and large (>100 ha). Indices of area, density, size, shape, proximity and central area were calculated; being obtained for different simulations of edge effect (40, 80, 100, 140 m). 2,652 fragments were found, representing 42.6% of forest cover. The very small fragments were predominant (2,201), followed by medium (216), small (177), and large fragments (58). There were differences in relation to classes, which demonstrated that the greatest present metrics showed good conservation. The middle and high classes indicated that public policies which encourage the creation of ecological corridors between the two protected areas should be generated.

RESUMO O objetivo foi analisar a estrutura da paisagem florestal entre duas Unidades de Conservação por meio de índices de ecologia da paisagem. O mapeamento foi obtido por digitalização de aerofoto, utilizando-se técnicas de fotointerpretação na escala 1:2500. No cálculo dos índices, foi utilizada Patch Analyst (ArcGis 9.3). Os fragmentos foram divididos em classes (muito pequeno: <5 ha; pequenos: >5 e <10 ha; médios: >10 e <100 ha; grandes: >100 ha). Foram calculados os índices de área, densidade, tamanho, forma, proximidade, área central (obtidos para diferentes simulações de efeito de borda: 40, 80, 100, 140 m). Encontraram-se 2.652 fragmentos, representando 42,6% de cobertura florestal. Os fragmentos muito pequenos dominam (2.201), seguidos pelos médios (216), pequenos (177) e grandes (58). Houve diferenciações em relação às classes, demonstrando que os maiores apresentam métricas que indicam boa conservação. As classes média e grande indicam a necessidade de criação de políticas públicas que incentivem a formação de corredores ecológicos entre ambas as áreas protegidas.