Deforestation in the Brazilian Amazon has been partially attributed to the establishment of settlement projects. Acknowledging the difficulties in quantifying the rate and patterns of deforestation, the objective of this paper is to determine forest dynamics (deforestation and reforestation) in areas where settlement projects have been established, at multiple levels and using different methods. Using satellite images from 1985 to 2010, a study was conducted in five settlement projects in Pará State, aiming to determine forest dynamics at municipal and settlement levels. At property level, participatory maps were constructed to understand settlers' perception of forest/non-forest areas. The results show that reforestation is the current process in the municipality and in some settlements. Settlers, however, perceive areas with secondary regrowth as potentially fertile cropland and might deforest again in the future. More research is needed to elucidate whether the observed reforestation will lead to a forest transition or is merely a temporary trend.De l'espace et du terrain: les dynamiques déterminantes des forêts au sein des projets de colonies en Amazonie, la région Brésilienne F.H. DINIZ, K. KOK, M.C. HOTT, M.A. HOOGSTRA-KLEIN et B. ARTSLa déforestation de l'Amazonie Brésilienne est en partie attribuée à l'établissement de projets de colonisation. Connaissant les difficultés de quantifier les taux et les modes de déforestation, l'objectif de ce rapport est de déterminer les dynamiques de la forêt (déforestation et reboisement) dans les zones où des projets de campement ont été établis, à de multiples échelles en utilisant différentes méthodes. En analysant des images satellites de 1985 à 2010, une étude fut conduite sur cinq projets d'installation dans l'Etat du Pará, visant à déterminer les dynamiques de la forêt à l'échelle de la municipalité et à l'échelle du campement. A l'échelle individuelle, des cartes construites via la participation des colons furent utilisées afin de comprendre la perception des colons par rapport aux zones forestières et non-forestières. Les résultats montrent que le reboisement est un processus actuel au niveau de la municipalité et sur quelques campements. Cependant, les colons perçoivent les zones de régénération secondaire comme potentiellement fertiles pour la culture et risquent de déforester une nouvelle fois ces zones dans le futur. Ainsi, de plus amples recherches sont nécessaires afin de savoir si le reboisement observé conduira à une forêt de transition écologique ou si celui-ci n'est plutôt qu'une étape temporaire.Desde el espacio hasta el suelo: Identificando las dinámicas de los bosques donde existieron proyectos de desarrollo en la Amazonia Brasilera F.H. DINIZ, K. KOK, M.C. HOTT, M.A. HOOGSTRA-KLEIN y B. ARTSLos proyectos de desarrollo han sido catalogados como responsables, en algún grado, de la deforestación en la Amazonia Brasilera. Conociendo las dificultades ya identificadas por otros autores, en la determinación de las tasas y los patrones de deforestación, po...
The aim of this study was to determine the favorable constant temperature range for Mahanarva spectabilis (Distant) (Hemiptera: Cercopidae) development as well as to generate geographic distribution maps of this insect pest for future climate scenarios. M. spectabilis eggs were reared on two host plants (Brachiaria ruziziensis (Germain and Edvard) and Pennisetum purpureum (Schumach)), with individual plants kept at temperatures of 16, 20, 24, 28, and 32°C. Nymphal stage duration, nymphal survival, adult longevity, and egg production were recorded for each temperature*host plant combination. Using the favorable temperature ranges for M. spectabilis development, it was possible to generate geographic distribution. Nymphal survival was highest at 24.4°C, with estimates of 44 and 8% on Pennisetum and Brachiaria, respectively. Nymphal stage duration was greater on Brachiaria than on Pennisetum at 20 and 24°C but equal at 28°C. Egg production was higher on Pennisetum at 24 and 28°C than at 20°C, and adult longevity on Pennisetum was higher at 28°C than at 20°C, whereas adult longevity at 24°C did not differ from that at 20 and 28°C. With these results, it was possible to predict a reduction in M. spectabilis densities in most regions of Brazil in future climate scenarios.
There is currently a lot of interest in determining the state of Brazilian grasslands. Governmental actions and programs have recently been implemented for grassland recovery in Brazilian states, with the aim of improving production systems and socioeconomic indicators. The aim of this study is to evaluate the vegetative growth, temporal vigor, and long-term scenarios for the grasslands in Zona da Mata, Minas Gerais State, Brazil, by integrating phenological metrics. We used metrics derived from the normalized difference vegetation index (NDVI) time series from moderate resolution imaging spectroradiometer (MODIS) data, which were analyzed in a geographic information system (GIS), using multicriteria analysis, the analytical hierarchy process, and a simplified expert system (ESS). These temporal metrics, i.e., the growth index (GI) for 16-day periods during the growing season; the slope; and the maximum, minimum, and mean for the time series, were integrated to investigate the grassland vegetation conditions and degradation level. The temporal vegetative vigor was successfully described using the rescaled range (R/S statistic) and the Hurst exponent, which, together with the metrics estimated for the full time series, imagery, and field observations, indicated areas undergoing degradation or areas that were inadequately managed (approximately 61.5%). Time series analysis revealed that most grasslands showed low or moderate vegetative vigor over time with long-term persistence due to farming practices associated with burning and overgrazing. A small part of the grasslands showed high and sustainable plant densities (approximately 8.5%). A map legend for grassland management guidelines was developed using the proposed method with remote sensing data, which were applied using GIS software and a field campaign.
This paper applied pedological mapping in an experimental center of "APTA-Frutas" in Jundiaí, São Paulo, Brazil, using morphometric parameters and GIS tools. The aim of this work was to obtain a preliminary legend of a soil map and to compare the preliminary map with maps made by the traditional soil survey methods. The area has 59 hectares and is located at a mountainous relief in the Atlantic Plateau. The original soil map of this area was made at 1:10 000. A digital elevation model (DEM) was generated with 4 m spatial resolution based on a topographical map at 1:10 000 scale, where the level curves are equidistant at 5 m. Based on the DEM we generated altitude, curvature and slope maps. In order to map the hydromorphic soils it was generated a buffer around the hydrography. We also calculated frequency distribution graphics of altitude, curvature and slope maps. After the interpretation of the frequency distribution, we defined classes to predict the soils types. The curvature map was divided into two class intervals (< or = 0 and > 0), the altitude map was divided into four class intervals (690-703, 704-714, 715-730, and 731-757 m), and the slope map was divided into four class intervals (0-9, 10-19, 20-44, and 45-72%). The maps were reclassified and converted to shape files. The shape files were intersected with the others to generate the final preliminary soil map. The methodology was adequate for the preliminary mapping of some types of soils.
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1RESUMO -As imagens de sensoriamento remoto orbital juntamente com as ferramentas em Sistemas de Informações Geográficas têm possibilitado diversos estudos sobre as alterações na cobertura das terras. O objetivo deste trabalho foi detalhar os resultados do mapeamento de uso e cobertura das terras e alterações em uma região no Nordeste do Estado de São Paulo entre 1988 e 2003, especificamente em relação à vegetação natural. A avaliação da dinâmica das áreas de remanescentes de vegetação natural das terras revelou retração de 0,14% em relação à área total dos municípios (51.649,5 km2). Mas houve avanço da vegetação ripária de 0,22% em relação à área total. Dos 125 municípios da região em estudo e possuidores de remanescentes de vegetação natural, 60,8% mantiveram praticamente a mesma porcentagem de cobertura vegetal natural (florestas estacionais, secundárias, cerrado e vegetação ripária) em 2003 com relação a 1988. Considerando somente as áreas com floresta estacional, secundária e cerrado, o número de municípios cresce para 79,2% do total. Os municípios que mantiveram os maiores percentuais de cobertura vegetal natural de Floresta Estacional, Floresta Secundária e Cerrado no período foram: Águas da Prata, com 39,9% de sua área municipal total, Rifaina (31,7%), São Sebastião da Grama (24,9%) e Pedregulho (24,0%). A ocupação das terras de 1988 a 2003 caracterizou-se pela dinâmica de substituição entre atividades que competem por área no setor rural, comum nas regiões administrativas tecnicamente mais avançadas do Estado de São Paulo.Palavras-chave: Vegetação natural e Dinâmica. DYNAMICS OF THE NATIVE VEGETATION IN NORTHEASTERN SÃO PAULO STATE BETWEEN 1988 AND 2003 ABSTRACT -The images of orbital remote sensing, along with tools available in Geographic Information
Increasing agricultural productivity with economic and environmental sustainability is one of the main challenges in agriculture. The aerial survey platforms known as unmanned aerial vehicles (UAV), socalled drones, allow monitoring, evaluation, and decision support activities to improve the management of crops and herds in farms of any production scale. Vegetation indices are used to map the vegetation cover, mainly o n a large scale, using satellite images. However, sensors coupled to UAV platforms provide other indices that can be used to detect the stress load of vegetation at more precise spatial scales. The Visible Atmospherically Resistant Index -VARI and the Green Leaf Index -GLI showed similar performances in the initial vegetative stages of corn crop. Both indices were sensitive to class discrimination at intervals that indicate from bare soil and low vigor (shades of red, orange, and yellow) to the condition of high vegetation vigor (shades of green). The results of vegetation indices in the visible spectrum range prove the applicability of the method for data collection and information extraction related to development and growth of crops. Overall, the indice s VARI and GLI appear as a potential alternative for crop monitoring using low cost RGB sensors onboard UAV platforms.
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