Publicações

Mapping tropical tree species at landscape scales to provide information for ecologists and forest managers is a new challenge for the remote sensing community. For this purpose, detection and delineation of individual tree crowns (ITCs) is a prerequisite. Here, we present a new method of automatic tree crown delineation based only on very high resolution images from WorldView-2 satellite and apply it to a region of the Atlantic rain forest with highly heterogeneous tropical canopy cover the Santa Genebra forest reserve in Brazil. The method works in successive steps that involve pre-processing, selection of forested pixels, enhancement of borders, detection of pixels in the crown borders, correction of shade in large trees and, finally, segmentation of the tree crowns. Principally, the method uses four techniques: rolling ball algorithm and mathematical morphological operations to enhance the crown borders and ease the extraction of tree crowns; bimodal distribution parameters estimations to identify the shaded pixels in the gaps, borders, and crowns; and focal statistics for the analysis of neighbouring pixels. Crown detection is validated by comparing the delineated ITCs with a sample of ITCs delineated manually by visual interpretation. In addition, to test if the spectra of individual species are conserved in the automatic delineated crowns, we compare the accuracy of species prediction with automatic and manual delineated crowns with known species. We find that our method permits detection of up to 80% of ITCs. The seven species with over 10 crowns identified in the field were mapped with reasonable accuracy (30.596%) given that only WorldView-2 bands and texture features were used. Similar classification accuracies were obtained using both automatic and manual delineation, thereby confirming that species spectral responses are preserved in the automatic method and thus permitting the recognition of species at the landscape scale. Our method might support tropical forest applications, such as mapping species and canopy characteristics at the landscape scale.

In striking contrast to heartening events in the adjacent Amazon, Brazil’s Cerrado biome has seen continued deforestation over the past decade. Though approved in 2012, no study evaluated the impacts of new Brazilian Forest Code (FC) revision on biodiversity and ecosystem services. Here, we report the first assessment of the likely loss and gain in biodiversity and ecosystem services expected if the FC is properly enforced across 200 million hectares of the Cerrado. We also discuss the challenges associated to compliance with the law and present opportunities for conservation. Establishing restoration programmes in private properties with currently less native vegetation than required by the FC could create habitat for 25% more threatened species than now found in these places and could also increase water security and carbon stock in 56.6 MtC. More important, trading environmental reserve quotas coupled with the strategic expansion of protected areas on private and public land could definitely rescue the Cerrado from the brink.

No presente estudo avaliou-se a dinâmica das mudanças de usos e cobertura da terra no núcleo de desertificação de Cabrobó-PE, a partir de abordagem que inclui a variação espaço-temporal de dados ambientais e de clima. Para a execução do trabalho, utilizaram-se o software ArcGis e a Plataforma do Google Earth Engine. Essa plataforma combina um catálogo de imagens de satélite e conjuntos de dados geoespaciais com recursos de análise em escala planetária e os disponibiliza a cientistas, pesquisadores e desenvolvedores, o que possibilita detectar mudanças, mapear tendências e quantificar diferenças de alterações na superfície terrestre. De acordo com os resultados obtidos, foi possível constatar que as áreas de floresta no núcleo de Cabrobó diminuíram 54%, sendo estas substituídas por áreas de solo exposto e áreas degradadas no período de 2000 a 2016. As áreas degradadas foram caracterizadas por apresentarem temperatura de superfície mais elevada (37,5oC), tendo aumentado em 1oC no período de 2009 a 2016. O aumento da temperatura da superfície pode estar associado ao estresse hídrico que tende a se agravar em áreas com alto grau de degradação do solo. A combinação das informações analisadas no presente estudo permite monitorar áreas heterogêneas, identificando pontos críticos (hotspots) que requerem ações imediatas de recuperação e implementação de manejo adequado

The performance of the coupled ocean-atmosphere component of the Brazilian Earth System Model version 2.5 (BESM-OA2.5) simulating the historical period 1850-2005 is evaluated. Following climate model validation procedure, in which the atmospheric and oceanic main variabilities are validated against observation and Reanalysis datasets, the evaluation particularly focuses the mean climate state and the most important large8 scale climate variability patterns simulated in the historical run, which is forced by observed greenhouse gas concentration. The most significant upgrades in the models components are also presented briefly. BESM-OA2.5 is able to reproduce the most important large-scale variabilities, particularly over the Atlantic (e.g. the North Atlantic Oscillation, the Atlantic Meridional Mode and the Atlantic Meridional Overturning Circulation) and the extratropical modes that occur in both hemispheres. The models ability in simulating large-scale variabilities indicates its usefulness for seasonal climate prediction and climate change studies.

Neste trabalho, buscou-se elaborar um panorama da sustentabilidade dos nove estados da Amazônia Legal, com base em cinco dimensões, 13 temas e 54 indicadores que compõem o Índice de Desenvolvimento Sustentável IDS. Os resultados indicam que há diferenças nos níveis de sustentabilidade dos estados. Apenas Roraima foi classificado com um desempenho aceitável do IDS, enquanto o Maranhão apresentou nível crítico e os outros estados se mantiveram na faixa de alerta. As particularidades e vulnerabilidades de cada estado refletem as condicionantes históricas, as características geográficas e os modelos de desenvolvimento adotados. Considera-se que o IDS é uma ferramenta eficaz de avaliação devido à sua capacidade de abordar os temas essenciais da sustentabilidade e por sua simplicidade metodológica. ABSTRACT: In this paper, we elaborate a panorama of the sustainability for the nine states of the Legal Amazon, based on five dimensions, 13 themes and 54 indicators that form the Sustainable Development Index-SDI. Differences in states levels of sustainability have been evidenced. Roraima was the only state with acceptable SDI performance, while Maranhão had the lowest score. The other states remained in the Alert range. The particularities and vulnerabilities of each state reflect the historical constraints, the geographical characteristics, and the development models adopted so far. SDI is considered to be a good optionforan evaluation tool because of its ability to address key sustainability issues and its methodological simplicity.

Information about changes in land use and land cover is useful to address issues related to drylands management, as well as to support decision-making related to the sustainable use of soils. Since drylands are frequently affected by accelerated soil erosion, land degradation and desertification associated with vegetation cover losses, constant monitoring of land use and land cover changes are required. However, land use and land cover maps are often not available, making it difficult to monitor degradation. Therefore, in this work, we developed an efficient mapping method to monitor bare soil areas, which are indicative of land degradation in the case of the Northeast of Brazil, using Normalized Difference Vegetation Index images. The proposed methodology was field calibrated and applied to the region using 17-year (20002016) NDVI maps, with a spatial resolution of 250 m. Based on bare soil mapping, we estimated the degree of degradation using an index calculated from the persistence and frequency of bare soil during the study period. The results indicated that the degraded areas increased in the period of the study, mainly in areas of pasture and Caatinga. This expansion has been accelerated due to the severe drought that affected the region since 2011.

The Intergovernmental Panel on Climate Change (IPCC) projections of global mean temperature rises are worrisome for coffee crop due to the intolerance of the Arabica species to high air temperature variations. The crop has a large participation in the Brazilian trade balance; therefore, in this study, the impacts of climate change on the potential yield of Arabica coffee (Coffea arabica L.) were assessed in the areas of Southeast Brazil in future climate change scenarios. Simulations of the Eta Regional Climate Model at 5-km resolution used in this study were generated from a second dynamic downscaling of the HadGEM2-ES model runs. The projections adopted two scenarios of greenhouse gas concentration, the RCP4.5 and RCP8.5, and considered the period 2011-2100. The projections indicated a large reduction of about 20 to 60% of the areas currently suitable for coffee cultivation in Southeast Brazil. In the RCP8.5 scenario, at the end of century, coffee cultivation is suitable only in elevated mountain areas, which would pose difficulties to farming management due to the operation of agricultural machinery in mountain areas. In addition, coffee cultivation in these regions could produce environmental impacts in the remnant Brazilian Atlantic Forest. Areas of high climatic risk increase due to temperature increase. The projections showed that the potential yield could be reduced by about 25% by the end of the twenty-first century. These results of potential coffee yield in the future climate indicate a need for adaptation studies of Arabica coffee cultivation.

The vertical coupling between the troposphere and the ionosphere presents some remarkable features. Under intense tropospheric convection, gravity waves may be generated, and once they reach the ionosphere, these waves may seed instabilities and spread F and equatorial plasma bubble events may take place. Additionally, there is a close association between severe tropospheric convection and lightning strikes. In this work an investigation covering an equinox period (September-October) during the deep solar minimum (2009) presents the relation between lightning strike activity and spread F (equatorial plasma bubble) detected over a low-latitude Brazilian region. The results show a considerable correlation between these two phenomena. The common element in the center of this conformity seems to be the gravity waves. Once gravity waves and lightning strikes share the same source (intense tropospheric convection) and the effects of such gravity waves in the ionosphere include the seeding of instabilities according to the gravity waves magnitude, the monitoring of the lightning strike activity seems to offer some information about the subsequent development of spread F over the equatorial region.

The role of improving the enforcement of Brazil’s Forest Code in reducing deforestation in the Amazon has been highlighted in many studies. However, in a context of strong political pressure for loosening environmental protections, the future impacts of a nationwide implementation of the Forest Code on both environment and agriculture remain poorly understood. Here, we present a spatially explicit assessment of Brazil’s 2012 Forest Code through the year 2050; specifically, we use a partial equilibrium economic model that provides a globally consistent national modeling framework with detailed representation of the agricultural sector and spatially explicit land-use change. We test for the combined or isolated impacts of the different measures of the Forest Code, including deforestation control and obligatory forest restoration with or without environmental reserve quotas. Our results show that, if rigorously enforced, the Forest Code could prevent a net loss of 53.4 million hectares (Mha) of forest and native vegetation by 2050, 43.1 Mha (81%) of which are in the Amazon alone. The control of illegal deforestation promotes the largest environmental benefits, but the obligatory restoration of illegally deforested areas creates 12.9Mha of new forested area. Environmental reserve quotas further protect 5.8Mha of undisturbed natural vegetation. Compared to a scenario without the Forest Code, by 2050, cropland area is only reduced by 4% and the cattle herd by 8%. Our results show that compliance with the Forest Code requires an increase in cattle productivity of 56% over four decades, with a combination of a higher use of supplements and an adoption of semi-intensive pasture management. We estimate that the enforcement of the Forest Code could contribute up to 1.03 PgCO(2)e to the ambitious GHG emissions reduction target set by Brazil for 2030.

This paper shows recent progress in our understanding of climate variability and trends in the Amazon region, and how these interact with land use change. The review includes an overview of up-to-date information on climate and hydrological variability, and on warming trends in Amazonia, which reached 0.6-0.7 degrees C over the last 40 years, with 2016 as the warmest year since at least 1950 (0.9 degrees C + 0.3 degrees C). We focus on local and remote drivers of climate variability and change. We review the impacts of these drivers on the length of dry season, the role of the forest in climate and carbon cycles, the resilience of the forest, the risk of fires and biomass burning, and the potential “die back” of the Amazon forests if surpassing a “tipping point”. The role of the Amazon in moisture recycling and transport is also investigated, and a review of model development for climate change projections in the region is included. In sum, future sustainability of the Amazonian forests and its many services requires management strategies that consider the likelihood of multi-year droughts superimposed on a continued warming trend. Science has assembled enough knowledge to underline the global and regional importance of an intact Amazon region that can support policymaking and to keep this sensitive ecosystem functioning. This major challenge requires substantial resources and strategic cross-national planning, and a unique blend of expertise and capacities established in Amazon countries and from international collaboration. This also highlights the role of deforestation control in support of policy for mitigation options as established in the Paris Agreement of 2015.17

Analysis of extreme precipitation events in different time scales over Santos is presented using the rain gauge network for the period 19802015. Located in the humid tropics, the area presents high annual total rainfall, particularly concentrated in spring and summer. However, the rainiest monthJanuarywas also the one with the most homogeneous distribution. More than 40% of the days presented precipitation, which ranged from 0.1 to 332.9 mm. The precipitation variability was quite high, a fact observed in all scales evaluated, which reveals that the mechanisms that generate precipitation in the area are distinct throughout the year. The high precipitation variability is particularly important in the case of daily distribution: for instance, 25% of the rainy days responded for 71% of the total rainfall. Such concentration is a key element in the outbreak of numerous hazards, such as floods and landslides, that cause extensive property damage and loss of life, being the worst situations registered when extreme precipitation episodes coincide with storm surges.