EXPANSÃO SUCROALCOOLEIRA NO ESTADO DE GOIÁS: UMA ANÁLISE EXPLORATÓRIA A PARTIR DE DADOS SÓCIO-ECONÔMICOS E CARTOGRÁFICOS

No atual cenário de crise energética e ambiental, os biocombustíveis, principalmente aqueles derivados da cana-de-açúcar, tornam-se cada vez mais prioritários e relevantes. Neste estudo procedemos, com base em dados cartográficos e sócio-econômicos, a uma análise exploratória da ocupação da cana-de-açúcar no Estado de Goiás, o qual, em função das suas características fisiográficas, acentuado desenvolvimento econômico, infra-estrutura implantada e planejada, e potencial agrícola, constitui-se em uma das principais alternativas à expansão sucroalcooleira no país. No período de 2005 a 2007, a área plantada com cana-de-açúcar, distribuída em 77 municípios, passou de 217.898,14 a 347.912,20 hectares. Conforme os nossos resultados sugerem, há uma clara dependência desta área plantada em relação à infra-estrutura existente e às áreas de relevo plano e solos férteis. Da mesma forma, é também evidente o avanço da cana sobre áreas já destinadas à outros usos agrícolas. Esta expansão, contudo, tem trazido poucos impactos sobre a economia Goiana, principalmente no que diz respeito à geração de empregos. Igualmente preocupante, é a constatação de passivos ambientais em áreas de preservação permanente e naquelas consideradas prioritárias para a conservação da biodiversidade. A expectativa é de que estes resultados sirvam de base à geração de cenários futuros, os quais norteiem o planejamento e a gestão territorial em Goiás. Palavras-chave: Cana-de-açúcar. Gestão territorial. Indústria sucroalcooleira. Sugarcane expansion in Goiás State: an exploratory analysis based on socioeconomic and cartographic data In the current scenario of energy crisis and global change, the biofuels, mostly those derived from sugarcane, are becoming a higher priority each day. Within this context, in this study, based on cartographic and socioeconomic data, we perform an exploratory analysis regarding the sugarcane occupation in the State of Goias, which, due to its physiographic characteristics as well as its prominent economic growth, existent and planned infrastructure, and agricultural potential, is a major alternative to the expansion of the ethanol production in the country. Between 2005 and 2007, the area with sugarcane, distributed over 77 municipalities, increased from 217.898,14 to 347.912,20 hectares. As our results suggest, the location of the sugarcane plantations is highly dependent on the available infrastructure, flat topography and soil fertility. Likewise, the expansion of the sugarcane over other crops is also evident. Interestingly, this expansion, which is also occurring over protected and priority areas for biodiversity conservation, has not produced significant impacts on the local economy. The expectation is that these results may help in the modeling of future scenarios, which are instrumental for the implementation of more adequate territorial policies. Key words: Sugarcane. Territorial policies. Ethanol productio

Woody aboveground biomass mapping of the brazilian savanna with a multi-sensor and machine learning approach

The tropical savanna in Brazil known as the Cerrado covers circa 23% of the Brazilian territory, but only 3% of this area is protected. High rates of deforestation and degradation in the woodland and forest areas have made the Cerrado the second-largest source of carbon emissions in Brazil. However, data on these emissions are highly uncertain because of the spatial and temporal variability of the aboveground biomass (AGB) in this biome. Remote-sensing data combined with local vegetation inventories provide the means to quantify the AGB at large scales. Here, we quantify the spatial distribution of woody AGB in the Rio Vermelho watershed, located in the centre of the Cerrado, at a high spatial resolution of 30 metres, with a random forest (RF) machine-learning approach. We produced the first high-resolution map of the AGB for a region in the Brazilian Cerrado using a combination of vegetation inventory plots, airborne light detection and ranging (LiDAR) data, and multispectral and radar satellite images (Landsat 8 and ALOS-2/PALSAR-2). A combination of random forest (RF) models and jackknife analyses enabled us to select the best remote-sensing variables to quantify the AGB on a large scale. Overall, the relationship between the ground data from vegetation inventories and remote-sensing variables was strong (R2 = 0.89), with a root-mean-square error (RMSE) of 7.58 Mg ha−1 and a bias of 0.43 Mg ha−1

Monitoring the spatial and temporal dynamics of the Brazilian Cerrado physiognomies with spectral vegetation indices: An assessment within the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA)

The large extension and diversity of the Cerrado vegetative cover, the second largest biome in South America, has a strong impact on regional, and possibly global, energy, water, and carbon balances. Nevertheless, as a major farming frontier in Brazil, it is estimated that about 40% of the Cerrado land cover has already been converted into cultivated pastures, field crops, urban development, and degraded areas. Despite this aggressive pace of land conversion, there have been few investigations on the operational utilization of remote sensing data to effectively monitor and understand this biome. Within this context, and within the goals and framework of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA), we evaluated the usefulness of spectral vegetation indices (VIs), to effectively monitor the Cerrado, detect land conversions, and discriminate and assess the conditions of the major structural types of Cerrado vegetation. Using a full hydrologic year (1995) of AVHRR, local-area-coverage (LAC), data over the Cerrado, converted to normalized difference vegetation index (NDVI) and soil adjusted vegetation index (SAVI), we were able to spatially discriminate three major communities based on their phenologic patterns. These included savanna formations and pasture sites, forested areas, and agricultural crops. We also analyzed wet and dry season, aircraft-based radiometric data and a ground-based set of biophysical measurements, collected over the Brasilia National Park (BNP), the largest LBA core site in the Cerrado biome. Overall, we found the MODIS vegetation indices, which include a continuity NDVI and the new enhanced vegetation index (EVI), to provide better performance capabilities with improved dynamic ranges and contrasts in seasonal dynamics. Land cover discrimination was favored by the NDVI, while the EVI more strongly responded to the seasonal contrast of the vegetative cover. Thus, the synergistic use of the MODIS VI products will very likely result in an improved monitoring capability and understanding of the Cerrado biome

Análise descritiva dos aspectos biofísicos associados aos padrões de cobertura e uso da terra na bacia hidrográfica do rio Vermelho, bioma cerrado

This study, focused on the Rio Vermelho watershed, a representative unit of the Cerrado biome, and considering a variety of satellite data for the 2001 and 2011 period, pursued a detailed analysis of the biophysical responses, in face of the historical processes that determined and shaped the landscape transformations. Some soil characteristics, for example soil and relief, were determining factors in the spatial organization of the landscape. Climatic factors, such as seasonality, have a direct influence on biomass levels of key vegetation formations, particularly those with shallow root systems (e.g. cultivated pastures), for which reductions in vegetation index values, as high as 50 %, can be observed during the dry season, from observation and proven correlation between the values of P and EVI. In fact, natural vegetation areas, comparatively to areas dominated by cultivated pastures, show very distinct and significant biophysical behaviour (p < 0.05). Likewise, two major landscapes could be identified, i.e. “Region 1” and “Region 2”, where converted and remnant vegetation areas predominate, respectivelly.O presente trabalho, ao utilizar a bacia hidrográfica do rio Vermelho como unidade experimental do bioma Cerrado, teve como objetivo principal realizar uma análise ampla das respostas biofísicas, frente aos processos históricos que condicionaram as transformações na paisagem, considerando o período entre 2001 a 2011 e uma ampla base de dados satelitária. Fatores climáticos, à exemplo da sazonalidade, tem uma influência direta na biomassa das principais formações vegetais, principalmente àquelas que apresentam sistemas radiculares superficiais (ex. pastagens cultivadas), com reduções nos valores dos índices de vegetação de até 50% durante o período de seca. De forma significativa, as áreas de vegetação natural, comparadas às áreas de pastagens cultivadas, apresentaram comportamentos distintos do ponto de vista biofísico (p < 0,05). Em fato, dois macroambientes puderam ser definidos para a área de estudo, i.e. “Região 1” e “Região 2”, onde predominam a ocupação antrópica e a vegetação natural remanescente, respectivamente

Estimating the World’s Potentially Available Cropland Using a Bottom-up Approach

Previous estimates of the land area available for future cropland expansion relied on global-scale climate, soil and terrain data. They did not include a range of constraints and tradeoffs associated with land conversion. As a result, very large values of the global land reserve area have been estimated. Here, we define potentially available cropland (PAC) as the moderately to highly productive land that could be used in the coming years for rainfed farming, with low to moderate capital investments, and that is not forested, legally protected, or already intensively managed. This productive land is underutilized rather than unused as it has ecological or social functions. We also define potentially available cropland that accounts for trade-offs between gains in agricultural production and losses in ecosystem and social services from intensified agriculture (PACt), to include only the PAC that would entail low ecological and social costs with conversion to cropland. The objective of this study is to reconceptualize and then estimate the size and geographic distribution of PAC and PACt. In contrast to previous studies, we adopt a “bottom-up” approach by analyzing detailed, fine scale observations and expert knowledge for six countries or regions that are often assumed to include a large reserve of PAC. We conclude first that there is substantially less potential additional cropland than is generally assumed once constraints and trade offs are taken into account, and secondly that converting land is always associated with significant social and ecological costs. There are few remaining places with “free and easy” lands.JRC.H.5-Land Resources Managemen

Monitoring of Carbon Stocks in Pastures in the Savannas of Brazil through Ecosystem Modeling on a Regional Scale

In 2020, Brazil was the seventh largest emitter of GHG (greenhouse gases), releasing ~2.16 GtCO2e (gigatons of carbon dioxide equivalent) into the atmosphere. Activities related to land use contributed approximately 73% of national emissions in that year. Considering that pastures represent the primary land use in the country, occupying approximately 20% of the territory, the mapping and monitoring of C stocks in these areas is essential to determine their contribution to national emissions. In this study, based on the integrated use of the CENTURY model, georeferenced databases, and the R environment, we mapped and analyzed, for the first time, the C stocks dynamics associated with the pasture areas of the Cerrado biome between 2000 and 2019. The average C stocks in the soil (0–20 cm) and in the aboveground biomass estimated by modeling were ~31 MgC·ha−1 and ~4 MgC·ha−1, respectively, values close to those observed in the literature for the region. Furthermore, the model results corresponded to the edaphic patterns of the region, with the highest average estimated C stocks in Cambisols (~34 MgC·ha−1) and the lowest in Neosols (~29 MgC·ha−1). The temporal dynamics of soil C stocks in these areas are directly related to the age of the pastures. In fact, stocks tend to be reduced in recently converted areas and stabilized in areas that have been under this land use for a longer time (≥30 years). As a result, a loss of ~103 MtC (millions of tons of carbon) was estimated in the Cerrado pasture soils in twenty years. The mapping and monitoring of C stocks in this land use type through approaches such as the one presented in this study is essential to support the Brazilian government’s efforts to mitigate C emissions

Técnicas avançadas de sensoriamento remoto aplicadas ao estudo de mudanças climáticas e ao funcionamento dos ecossistemas amazônicos Advanced remote sensing techniques for global changes and Amazon ecosystem functioning studies

Este artigo se propõe a apresentar exemplos de questões científicas que puderam ser respondidas no contexto do Projeto LBA (Large Sale Biosphere-Atmosphere Experiment in Amazonia) graças à contribuição de informações derivadas de sensoriamento remoto. Os métodos de sensoriamento remoto permitem integrar informações sobre os vários processos físicos e biológicos em diferentes escalas de tempo e espaço. Nesse artigo, são enfatizados aqueles avanços de conhecimento que jamais seriam alcançados sem a concorrência da informação derivada de sensoriamento.<br>This paper aims to assess the contribution of remote sensing technology in addressing key questions raised by the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). The answers to these questions foster the knowledge on the climatic, biogechemical and hydrologic functioning of the Amazon, as well as on the impact of human activities at regional and global scales. Remote sensing methods allow integrating information on several processes at different temporal and spatial scales. By doing so, it is possible to perceive hidden relations among processes and structures, enhancing their teleconnections. Key advances in the remote sensing science are summarized in this article, which is particularly focused on information that would not be possible to be retrieved without the concurrence of this technology