Spatial and spectral remote sensing features to detect deforestation in Brazilian Savannas

The Brazilian Savannas have been under increasing anthropic pressure for many years, and land-use/land-cover changes (LULCC) have been largely neglected. Remote sensing provides useful tools to detect changes, but previous studies have not attempted to separate the effects of phenology from deforestation, clearing or fires to improve the accuracy of change detection without a dense time series. The scientific questions addressed in this study were: how well can we differentiate seasonal changes from deforestation processes combining the spatial and spectral information of bi-temporal (normalized difference vegetation index) NDVI images? Which feature best contribute to increase the separability on classification assessment? We applied an object-based remote sensing method that is able to separate seasonal changes due to phenology effects from LULCC by combining spectral and the spatial context using traditional spectral features and semivariogram indices, exploring the full capability of NDVI image difference to train random forest (RF) algorithm. We found that the spatial variability of NDVI values is not affect by vegetation seasonality and, therefore, the combination of spectral features and semivariogram indices provided high global accuracy (97.73%) to separate seasonal changes and deforestation or fires. From the total of 13 features, 6 provided the best combination to increase the separability on classification assessment (4 spatial and 2 spectral features). How to accurately extract LULCC while disregarding the ones caused by phenological differences in Brazilian seasonal biomes undergoing rapid land-cover changes can be achieved by adding semivariogram indices in combination with spectral features as input data to train RF algorithm

MAPPING PRIORITY AREAS FOR FOREST RECOVERY USING MULTICRITERIA ANALYSIS IN THE BRAZILIAN ATLANTIC FOREST

The collapse of a mining dam with 62 million cubic meters of mud in the Rio Doce basin resulted in the destruction of whole communities and large areas of the Atlantic Forest. As forest restoration activities are among the most costly conservation strategies, prioritization of restoration efforts is crucial. In the present article, this study mapped priority areas for forest recovery in a portion of the Rio Doce Basin (DO1) using a GIS-based (geographic information system) multicriteria decision analysis (MCDA) employing the weighted linear combination (WLC) method. Five factors with different weights were taken into consideration according to their level of importance: distance from the drainage network, distance from the native vegetation patches, slope, soil class and precipitation. A map of priority areas was produced in which 1.73% of the area was classified as very high priority for forest recovery, while 5.18% of the area was classified as high priority, 57.88% as medium priority, 1.34% as low priority and 0.00% as very low priority. The highest weights were attributed to the distance from the drainage network and the distance from native vegetation, revealing that areas of permanent preservation and those closer to forest fragments are priority areas for forest recovery. MCDA is a flexible and easy-to-implement method which generates maps with suitable solutions for forest recovery. The chosen approach can be replicated in regions that require support for decision making in environmental planning, such as the Pantanal biome, which is under considerable process of deforestation for the expansion of pastures.The collapse of a mining dam with 62 million cubic meters of mud in the Rio Doce basin resulted in the destruction of whole communities and large areas of Atlantic Forest. As forest restoration activities are among the most costly conservation strategies, prioritization of restoration efforts is crucial. In the present article, we mapped priority areas for forest recovery in a portion of the Rio Doce Basin (DO1) using a GIS-based (geographic information system) multicriteria decision analysis (MCDA) employing the weighted linear combination (WLC) method. Five factors with different weights were taken into consideration according to their level of importance: distance from the drainage network, distance from the native vegetation patches, slope, soil class and precipitation. A map of priority areas was produced where 1.73% of the area was classified as very high priority for forest recovery, while 5.18% of the area was classified as high priority, 57.88% as medium priority, 1.34% as low priority and 0.00% as very low priority. The highest weights were both for the distance from the drainage network and the distance from native vegetation, revealing that areas of permanent preservation and those closer to forest fragments are priority areas for forest recovery. MCDA is a flexible and easy-to-implement method generating maps with suitable solutions for forest recovery. The approach taken can be replicated in regions that require support for decision making in environmental planning, such as the Pantanal biome, which is under considerable pressure from deforestation for the expansion of pastures

THE LANDSCAPE OF OURO PRETO (MG, BRAZIL) THROUGH ANALYSIS OF ANTHROPIC ACTIVITIES IN RELATION TO THE ENVIRONMENTAL CONSERVATION

Understanding the complex interaction among landscape elements can improve the management of environmental conservation and anthropic activities. The aim of the present study was to develop a methodology that assists in the planning and management, harmonizing the conservation of natural areas with anthropic activities in the city of Ouro Preto (state of Minas Gerais, Brazil). The methodology used the weighted overlay algorithm of the ArcMap™ software, which weights among land use characteristics. In the present study, the following classes were used: slope; relief; soil; landscape ownership by individuals; presence of protected areas; economy; and type of management applied to the preservation or conservation of forests and fields. The most relevant anthropic activities (contained in the classes) were simulated, to the detriment of the forest reduction, according to their spatial locations. Consequently, a map with five weights was obtained, which were verified in the field with their respective descriptions. The physical changes occurred as a reflection of the economy, promoting environmental effects, especially related to the mining, tourism, agricultural and livestock activities, besides conservation of natural areas. All of them require ideally a shared management. The interactions among simulated classes aid to increase information in future planning. Understanding the anthropic and natural processes, which have taken place by either consolidation or isolation along the territory, can assist decision-making on the current directions and in the definition of future proposals. It was noticed that the landscape needs a management which creates sustainable alternatives for anthropic activities.Understanding the complex interaction among landscape elements can improve the management of environmental conservation and anthropic activities. The aim of the present study was to develop a methodology that assists in the planning and management, harmonizing the conservation of natural areas with anthropic activities in the city of Ouro Preto (MG, Brazil). The methodology used the weighted overlay algorithm of the ArcMap™ software, which weights among land use characteristics. In the present study, the following classes were used: slope; relief; soil; landscape ownership by individuals; presence of protected areas; economy; and type of management applied to the preservation or conservation of forests and fields. The most relevant anthropic activities (contained in the classes) were simulated, to the detriment of the forest reduction, according to their spatial locations. Consequently, a map with five weights was obtained, which were verified in the field with their respective descriptions. The physical changes occurred as a reflection of the economy, promoting environmental effects, especially related to the mining, tourism, agricultural and livestock activities, besides conservation of natural areas. All of them require ideally a shared management. The interactions among simulated classes aid to increase information in future planning. Understanding the anthropic and natural processes, which have taken place by either consolidation or isolation along the territory, can assist decision-making on the current directions and in the definition of future proposals. It was noticed that the landscape needs a management which creates sustainable alternatives for anthropic activities

Estimating Aboveground Biomass Loss from Deforestation in the Savanna and Semi-arid Biomes of Brazil between 2007 and 2017

Brazilian Savannas and Semi-arid woodlands biomes exhibit high levels of aboveground biomass (AGB) associated with high rates of deforestation. The state of Minas Gerais (MG), southeast of Brazil, encompasses landscape variations ranging from Savanna and Atlantic Forest to Semiarid woodlands. The understanding of land-cover changes in these biomes is limited due to the fact that most of the efforts for estimating forest cover changes has been focused on the tropical rain forests. Hence, the question is: What is the total amount of AGB loss across Savanna and Semi-arid woodland biomes in MG state, during the period 2007–2017? We first used a total of 1914 field plots from a forest inventory to model the AGB using a combination of remote sensing and spatio-environmental predictor variables to produce a spatial-explicit AGB map. Second, from a global map of forest cover change (GFC), we obtained deforestation patches. As a result, from 2007 to 2017, the Savanna and the Semiarid woodland biomes lost together 508,042 ha of native vegetation in MG state, leading to 21,182,150 Mg of AGB loss (4.65% of total AGB). In Savannas and Semi-arid woodland biomes in MG state, conservation initiatives must be implemented to increase the forests protection and expand AGB

Simulação e avaliação econômica de regimes de desbastes e desrama para obter madeira de Pinus taeda livre de nós.

Este estudo teve como objetivo simular e avaliar economicamente regimes de desbastes e de desrama para Pinus taeda, para obtenção de madeira livre de nós (clearwood) e de madeira para múltiplos usos. A área em estudo está situada no município de Jaguariaíva - PR. Foram testados dois cenários com diferentes números, épocas e intensidade de desbaste, com base em diferentes densidades iniciais de plantio, em diferentes níveis de produtividade, almejando a produção de madeira desramada, livre de nós, e de madeira não-desramada para vários usos. Os regimes de manejo gerados foram submetidos à análise de investimento a três taxas de desconto e a seis diferentes opções de preço da madeira desramada em relação à madeira não desramada, o que totalizou 86.022 diferentes opções de manejo. As simulações de crescimento, produção e desbastes foram obtidas com base no software PISAPRO. As análises econômicas foram realizadas valendo-se da maximização do valor presente líquido para uma série de infinitas rotações, utilizando, para tal, o software INVEST. Os regimes de manejo que apresentaram maiores rentabilidades, para as classes de sítio I e II e para os custos de produção e preços estipulados, foram aqueles com plantio de 833 árvores/ha e com corte final aos 21 anos, após a realização de três desbastes: sendo o primeiro um pré-comercial seguido de desrama aos 4 anos, mantendo 500 árvores/ha, o segundo um comercial aos 12 anos, mantendo 400 árvores/ha e o terceiro um comercial aos 14 anos mantendo 100 árvores/ha. Para a classe de sítio III, a melhor opção foi a adoção de regimes de manejo com plantio de 1.111 árvores/ha e corte final aos 20 anos, após a realização de um desbaste pré-comercial seguido de desrama aos 4 anos, mantendo 500 árvores/ha e de um desbaste comercial aos 12 anos, mantendo 200 árvores/ha. A segunda desrama, para as três classes de sítio, foi realizada entre 7 e 8 anos de idade

Exatidão dos modelos polinomiais não-segmentados e das razões entre volumes para representar o perfil do tronco de Pinus taeda.

O presente estudo teve como objetivos avaliar a: 1) exatidão das razões entre volumes compatíveis com sua respectiva função de afilamento; 2) os modelos polinomiais de potência inteira e dos modelos polinomiais de potências fracionárias e inteiras; 3) estudar a influência das classes de diâmetro, da produtividade dos sítios e das diferentes regiões na exatidão dos ajustes para representação do perfil do fuste de Pinus taeda na região nordeste do Paraná. Foram cubadas 304 árvores, utilizando-se do pentaprisma de Wheeler sobre tripé de base regulável com suunto acoplado. Nas proximidades de cada árvore cubada foi lançada uma parcela e medida a altura das árvores dominantes. Pôde-se efetuar assim a classificação de sítio no local de cada cubagem. Os diâmetros das árvores cubadas rigorosamente foram agrupados em classes, em intervalos de 5 cm. Para avaliação da exatidão das estimativas do perfil do fuste, foram utilizadas as seguintes estatísticas: coeficiente de determinação; erro padrão residual; desvio dos diâmetros em cada i-ésima posição no fuste; desvio padrão das diferenças dos diâmetros; soma do quadrado do resíduo relativo e porcentagem dos resíduos dos diâmetros. Verificou-se que o ajuste das equações de afilamento devem ser preferidos por sítio e classe de diâmetro, além da utilização do modelo polinomial de potências fracionárias e inteiras para as estimativas do perfil do fuste

Conflitos de Uso da Terra em Áreas de Preservação Permanente no Alto Rio Jequitinhonha, Brasil

A exploração das riquezas minerais da região do Alto Rio Jequitinhonha, em Minas Gerais, condicionou a degradação ambiental produzida na paisagem desde o século XVIII. A partir disso, este estudo objetivou analisar o conflito do uso da terra em Áreas de Preservação Permanente (APP) de mata ciliar do rio Jequitinhonha, Minas Gerais, segundo o Código Florestal brasileiro. Realizou-se o mapeamento do uso e cobertura da terra utilizando imagens RapidEye e a delimitação das APP em ambiente SIG. As classes geradas foram: (I) Vegetação Natural, (II) Afloramento Rochoso, (III) Área Antropizada e (IV) Curso Hídrico. A definição das APPs foi estabelecida de acordo com as diretrizes da legislação florestal. A sobreposição do mapa de uso e cobertura da terra com a delimitação das APP originou o mapa de usos conflitantes. A área total ocupada pelas formas de cobertura no território destinado à APP, subtraindo-se a classe Curso Hídrico, foi 2,10 km². Constatou-se 30,9% de uso indevido nos limites da APP (classe Área Antropizada). Diante dos resultados deste trabalho, nota-se que o cumprimento da legislação florestal e a fiscalização ambiental das propriedades rurais na área de estudo ainda são insuficientes. Salienta-se a necessidade de recomposição das áreas de APP, de modo a assegurar os serviços ecossistêmicos e hidrológicos relacionados à conservação ambiental. Os procedimentos metodológicos aqui aplicados, podem ser replicados para outras ecorregiões do Brasil, sob respaldo do código florestal brasileiro e legislações vigentes.

Estoque do potencial produtivo do Cerrado utilizando geotecnologias

Monitoring natural resources of our planet is essential to gather information to support strategies for conservation and a sustainable use of these natural resources. This monitoring is even more important in endangered biomes, as is the case of brazilian savannas, one of the most threatened and richest, in terms of biodiversity, savannas in the world. Usually, forest monitoring is accomplish by measuring the trees on the field, the so-called forest inventories, which are expensive, costly and extremely difficult to be performed periodically in extensive forests, as is the case of the Brazilian savannas. Therefore, this study aimed to update the information about volume and carbon stocks in savanna fragments in order to reduce tree measurements in the field. We used data from 61 savanna remnants, where 25 of them had 2 measurements with 5 years interval (monitoring). Multiple linear models, based on field data and reflectance values of Landsat images, were fitted and validated. Subsequently, the best models were applied to remnants that had only one measured, and then volume and carbon estimates were obtained for all 61 remnants in the second year of measurement. Additionally, maps updating the productivity of these remnants were generated.O monitoramento dos recursos naturais do nosso planeta é essencial para a obtenção de informações que possam subsidiar estratégias de conservação e utilização sustentável desses recursos. Tais estratégias se tornam ainda mais importantes em biomas ameaçados, como é o caso do Cerrado brasileiro, uma das savanas mais ricas e ameaçadas do mundo. Comumente o monitoramento das florestas é realizado por meio de inventários florestais, atividade onerosa, cara e extremamente difícil de ser realizada periodicamente em florestas extensas, como o Cerrado. Nesse sentido, o presente estudo teve como objetivo atualizar o mapeamento do estoque de volume e carbono em fragmentos de Cerrado, diminuindo a quantidade de levantamentos de campo por meio da aplicação de geotecnologias. Utilizaram-se dados de levantamento de campo de 61 fragmentos de Cerrado, sendo que em 25 deles foram realizadas 2 medições em um intervalo de 5 anos. Através dos dados de campo e valores de reflectância de imagens Landsat, modelos lineares múltiplos foram ajustados e validados. Posteriormente, esses modelos foram aplicados aos fragmentos que foram mensurados apenas uma vez. Dessa forma, foram obtidos os valores de volume e carbono para todos os 61 fragmentos, no ano da segunda medição, gerando mapas de produtividade atualizados