Mapping Deforestation in Cerrado Based on Hybrid Deep Learning Architecture and Medium Spatial Resolution Satellite Time Series

Cerrado is the second largest biome in Brazil, covering about 2 million km2. This biome has experienced land use and land cover changes at high rates due to agricultural expansion so that more than 50% of its natural vegetation has already been removed. Therefore, it is crucial to provide technology capable of controlling and monitoring the Cerrado vegetation suppression in order to undertake the environmental conservation policies. Within this context, this work aims to develop a new methodology to detect deforestation in Cerrado through the combination of two Deep Learning (DL) architectures, Long Short-Term Memory (LSTM) and U-Net, and using Landsat and Sentinel image time series. In our proposed method, the LSTM evaluates the time series in relation to the time axis to create a deforestation probability map, which is spatially analyzed by the U-Net algorithm alongside the terrain slope to produce final deforestation maps. The method was applied in two different study areas, which better represent the main deforestation patterns present in Cerrado. The resultant deforestation maps based on cost-free Sentinel-2 images achieved high accuracy metrics, peaking at an overall accuracy of 99.81%±0.21 and F1-Score of 0.8795±0.1180. In addition, the proposed method showed strong potential to automate the PRODES project, which provides the official Cerrado yearly deforestation maps based on visual interpretation.

Ocupação da Terra e Conflitos de Uso com as Áreas de Preservação Permanente Nativa Remanescente de Cerrado na Sub-bacia do Córrego do Veado, Bacia do Alto Taquari, MS

A conservação das florestas é de grande interesse de toda a sociedade, pois garante os serviços ambientais básicos que sustentam a vida e a economia do país. Nesse estudo, realizou-se um diagnóstico do uso da terra e cobertura vegetal visando avaliar os conflitos entre as atividades antrópicas e as áreas de vegetação nativa remanescente de Cerrado na sub-bacia do Córrego do Veado e propor ações de adequação, do ponto de vista da conservação dos recursos naturais e da biodiversidade, com base na legislação pertinente e nas características físicas da bacia. O estudo se baseou em imagens orbitais e dados vetoriais, processados em Sistema de Informação Geográfica para a geração de produtos cartográficos. Na bacia, foram registradas 81 propriedades rurais, a maioria composta de imóveis com menos de quatro módulos fiscais, onde a principal forma de uso da terra foi a Pastagem sobre áreas consolidadas. A bacia contém em torno de 20% da área coberta por vegetação nativa de Cerrado, porém grande parte das propriedades não apresenta área de Reserva Legal e muitas nascentes de afluentes e do Córrego encontram-se degradadas. As ações propostas referem-se à recuperação das faixas de vegetação ciliar que descumprem o mínimo de largura estabelecido pela legislação, e das áreas de Reserva Legal; à readequação do uso em áreas voltadas à conservação da biodiversidade e à avaliação do potencial turístico da região, como forma de uso sustentável em áreas com alta declividade, solos altamente erodíveis e onde a vegetação de Cerrado encontra-se preservada. The conservation of forests is of great interest to all of society, as it guarantees the basic environmental services that support the life and economy of the country. In this study, a diagnosis of land use and vegetation cover was carried out in order to assess the conflicts between human activities and the areas of native Cerrado remnant in the sub-basin of the Córrego do Veado and propose adaptation actions, from the point of view of the conservation of natural resources and biodiversity, based on the legislation and the physical characteristics of the basin. The study was based on orbital images and vector data, processed in a Geographic Information System for the generation of cartographic products. In the basin, 81 rural properties were registered, the majority consisting of properties with less than four fiscal modules, where the main form of land use was Pasture over consolidated areas. The basin contains around 20% of the area covered by native Cerrado vegetation, however most of the properties do not have a Legal Reserve area and many tributary and stream springs are degraded. The proposed actions refer to the recovery of the strips of riparian vegetation that do not comply with the minimum width established by the legislation, and the areas of Legal Reserve; the readjustment of use in areas aimed at the conservation of biodiversity and the evaluation of the tourist potential of the region, as a form of sustainable use in areas with high declivity, highly erodible soils and where the Cerrado vegetation is preserved.Keywords:River Basin, Conservation, Ecosystem Service, Forest Code.

Physical Attributes of Ferralsol in Fertigated Sugarcane Production Environments for Bioethanol in the Midwest of Brazil

Brazil is the world leader in the production and export of sugarcane derivatives, and its center-south region is the main producer. Fertigation with byproducts from bioethanol production can be adopted as a strategy to mitigate the soil physical deterioration resulting from the intensification of mechanized farming practices. The objective of this study was to evaluate the behavior of soil physical attributes under sugarcane cultivation in different crop cycles in fertigated areas in the midwest region of Brazil. The samples were collected in different Ferralsol layers (0.0–0.1, 0.1–0.2, 0.2–0.3, and 0.4–0.5 m) and fertigated crop cycles (first, third, fifth, seventh, and twelfth sugarcane cycles), as well as from native Cerrado vegetation (reference area), and the weight and volume relationships of the soil constituents and total soil were evaluated. Soil physical attributes are affected by sugarcane cultivation cycles and fertigation with vinasse. In the short term (third cycle), the results indicate deterioration of the physical attributes of the soil. However, throughout the cycles of sugarcane culture via fertigation (twelve cycles), the addition of vinasse leads to improvements in physical attributes and soil aggregation, promoting an increase in the longevity of the sugarcane crop. Therefore, the evaluation of the physical attributes of the soil in areas with vinasse application in different sugarcane cultivation cycles should be analyzed in areas of different regions, as this management practice indicates a high potential to increase the longevity of cultivation sugarcane, reducing production costs in the bioenergy sector.

THE ROLE OF THE XAVANTE INDIGENOUS PEOPLE IN WILDLIFE CONSERVATION

There is an urgent demand to evaluate and document the environmental conditions of the territories of indigenous people. This is basic in the efforts to achieve sustainable development goals adopted by all United Nations Member States in 2015. The Xavante people are hunters/gatherers and depend on natural resources for their physical, spiritual, and cultural survival. Their lands are localized in the state of Mato Grosso, Brazil, in a transitional area between the Cerrado vegetation and the Amazon rainforest. They have been developing environmental projects ~in order to manage their territory correctly for decades, as part of their survival strategy. In recent fieldwork, we stated that some major game species may still be abundant in the territory and we suggest that certain wildlife management measures in the past may be responsible for this. We easily registered most game species handled by the Xavantes, except for some edentates that were rarely detected. We confirm the giant anteater as the most vulnerable species to hunting effects. In this article, we point out the main threats for the territory and present new recommendations that may be fundamental for the conservation of biodiversity in the region and the survival of the Xavante people.

Introduction of native tree species into degraded Cerrado vegetation

Experimental restoration using tree seedlings is a common strategy for accelerating succession on degraded post-agricultural land formerly occupied by Cerrado vegetation. Seedling growth in degraded tropical lands is constrained by various factors. The goal of this study was to evaluate the seedling growth and survival of seven native tree species used to accelerate forest recovery in a gully area with stressful environmental conditions. The experimental design involved fenced and unfenced blocks, presence and absence of fertilization and use of an adhesive to prevent ant herbivory (four treatments with four replicates). Seedlings were planted in December 2006 and collection of data on seedling basal diameter, height, mortality and herbivory started on January 24th 2007 and continued every three months, until final data collection on January 31st 2009 (9 measurement dates). Overall seedling survival was 38 % and protecting seedlings did not influence growth, but seedlings grew faster in response to the addition of fertilizer containing N, P and K. The use of the adhesive Tanglefoot to exclude leaf cutter ants had no influence on growth. Fencing reduced seedling mortality, but combining fencing with Tanglefoot did not. Nutrient availability limits seedling growth and survival in the gully. Direct planting of seedlings of native trees may accelerate succession in degraded Cerrado lands subject to interventions that overcome constraints on seedling growth and survival.

Changes in the Cerrado vegetation structure: insights from more than three decades of ecological succession

Changes in the vegetation of Brazilian Cerrado may occur over time. However, long-term dynamics are not fully understood yet, especially woody plant encroachment (WPE). The objective of this study was to examine changes in vegetation structure in a preserved area in Triângulo Mineiro region, within the southern Brazilian Cerrado domain, over 32 years (1987, 2005, and 2019). We based the study on field and literature surveys, as well as satellite imagery, and hypothesized that, due to the absence of periodic fires or grazing, Cerrado open formations (i.e., grassland or savanna) tend to become denser due to WPE. Shrubby grassland cover assessed in 1987 disappeared in the following periods (from 30.0 % to 0.0 % in 2019) while forest formations increased (from 7.0 % in 1987 to 11.0 % in 2019). Changes between 2005 and 2019 occurred within the stricto sensu cerrado subdivisions, with reduction of sparse cerrado (from 34.2 % to 7.7 %) and an increase in dense cerrado (from 6.9 % to 39.8 %). Normalized difference vegetation index (NDVI) applied for similar periods indicates a progressive increase of values over time (from 1986 (0.61±0.10) to 2004 (0.65±0.06) and 2018 (0.78±0.05)) and corroborates the WPE process. These patterns imply the loss of biodiversity in open plant formation. Another major consequence was the reduction of wetlands and possible impact on water supply. Such patterns are important to support plant management plans for the threatened Cerrado open plant formations.

Dissolved organic carbon and nitrate flows in two micro-watersheds with different land uses

he impacts of human activities on watersheds can change the quality and possible uses of water resources. In this context, we evaluated the flows of dissolved organic carbon (DOC) and nitrate (NO3) in the surface waters of two micro-watersheds with different anthropic impacts. Water samples were collected from two micro-watersheds with different land uses (regenerated savanna and an agricultural site) from January 2014 to April 2015. In the rainy season, the samples were collected every 15 days, while in the dry season, samples were collected every 30 days. An automatic sampler in the stream collected the composed samples. Water flow was monitored with a sensor that measured the hydraulic load on the sill of the triangular spillway installed in each micro-watershed. The DOC and NO3 contents were analyze via UV-Vis spectrophotometry. The flow was estimated based on the DOC and NO3 flows and concentrations. The DOC concentrations were higher in the Cerrado micro-watershed; however, there was no difference in NO3 concentrations. In both watersheds, there was a significant increase in the concentrations of DOC and NO3 on rainy days, with was more pronounced in the agricultural watershed. The DOC and NO3 flows were higher in the micro-watershed with Cerrado vegetation on days with rain; while on days without rain, there was no difference.