100 research outputs found
Implementação de um sistema web-based para classificação automática de mudanças de uso/cobertura de solo
In the last decades, many works, demonstrated the efficiency in the use of high resolution images for the
classification of land use and covering changes at regional level. However, it became clear that the use of some techniques on great areas demands prohibitive costs, in a financial point of view as also a computational one. Especially, if we consider limited available resources in less developed areas of Brazil and of the world. The project is inserted in the context of an international effort for the development of a web-based system and includes some areas from Brazil. The main objective is to create technologies validated by the system methodologies, in a way the users use it in a decision-making process. It has as another objective a better understanding concerning the impact done on these areas by the changes of the land covering and use. The proposal here is to make a product that joins automatic routines, based on satellite images available without costs, that can be used in different scales of administration of the territory. It doesn't demand highly specialized technicians to manipulate the web application
Monitoring land use changes around the indigenous lands of the Xingu basin in Mato Grosso, Brazil
International audienceIndigenous lands represent an efficient way to protect indigenous communities and environment in Brazil. However, these lands are also highly affected y the land use changes occuring in its surroundings. We quantified the land use changes in the Xingu basin based on MODIS EVI data between 2000 and 2006. We estimated the deforested area inside and outside the indigenous lands, the crop expansion and intensification around the protected areas. Our results indicate that, even if indigenous lands are efficient to limit deforestation (97.5% of deforestation is outside the indigenous lands), crop expansion and intensification (double crop systems) are increasing rapidly, what may imply pollution of headwaters of the Xingu river which crosses the protected area
A social-ecological approach to identify and quantify biodiversity tipping points in South America’s seasonal dry ecosystems
ropical dry forests and savannas harbour unique biodiversity and provide critical ES, yet they are under severe pressure globally. We need to improve our understanding of how and when this pressure provokes tipping points in biodiversity and the associated social-ecological systems. We propose an approach to investigate how drivers leading to natural vegetation decline trigger biodiversity tipping and illustrate it using the example of the Dry Diagonal in South America, an understudied deforestation frontier. The Dry Diagonal represents the largest continuous area of dry forests and savannas in South America, extending over three million km² across Argentina, Bolivia, Brazil, and Paraguay. Natural vegetation in the Dry Diagonal has been undergoing large-scale transformations for the past 30 years due to massive agricultural expansion and intensification. Many signs indicate that natural vegetation decline has reached critical levels. Major research gaps prevail, however, in our understanding of how these transformations affect the unique and rich biodiversity of the Dry Diagonal, and how this affects the ecological integrity and the provisioning of ES that are critical both for local livelihoods and commercial agriculture.Fil: Thonicke, Kirsten. Institute for Climate Impact Research ; AlemaniaFil: Langerwisch, Fanny. Institute for Climate Impact Research ; Alemania. Czech University of Life Sciences Prague; RepĂşblica ChecaFil: Baumann, Matthias. Humboldt Universität zu Berlin; Alemania. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: LeitĂŁo, Pedro J.. Humboldt Universität zu Berlin; Alemania. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: VáclavĂk, Tomáš. Helmholtz Centre for Environmental Research; Alemania. PalackĂ˝ University Olomouc; RepĂşblica ChecaFil: Alencar, Anne. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; BrasilFil: Simões, Margareth. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); BrasilFil: Scheiter, Simon. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Langan, Liam. Senckenberg Biodiversity and Climate Research Centre; AlemaniaFil: Bustamante, Mercedes. Universidade do BrasĂlia; BrasilFil: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de EcologĂa Regional; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucumán; ArgentinaFil: Hirota, Marina. Universidade Federal de Santa Catarina; Brasil. Universidade Estadual de Campinas; BrasilFil: Börner, Jan. Universitat Bonn; AlemaniaFil: Rajao, Raoni. Universidade Federal de Minas Gerais; BrasilFil: Soares Filho, Britaldo. Universidade Federal de Minas Gerais; BrasilFil: Yanosky, Alberto. Consejo Nacional de Ciencia y TecnologĂa; ParaguayFil: Ochoa Quinteiro, JosĂ© Manuel. Instituto de InvestigaciĂłn de Recursos BiolĂłgicos Alexander von Humboldt; ColombiaFil: Seghezzo, Lucas. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Salta. Instituto de Investigaciones en EnergĂa no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de FĂsica. Instituto de Investigaciones en EnergĂa no Convencional; ArgentinaFil: Conti, Georgina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂa Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto Multidisciplinario de BiologĂa Vegetal; ArgentinaFil: de la Vega Leiner, Anne Cristina. Universität Greifswald; Alemani
Electrical conductivity mapping in relation to clay of a Ferralsol under no tillage system
O objetivo deste trabalho foi mapear e avaliar a variabilidade espacial da condutividade elĂ©trica do solo (CE), obtida por meio de sensor de contato de campo, num Latossolo Vermelho distrofĂ©rrico, sob plantio direto de grĂŁos, e relacionar a CE com os teores de argila medidos pelo mĂ©todo do densĂmetro, em amostras georreferenciadas de solo. As amostras foram coletadas numa área de 13 ha, por meio de uma grade de 40x40 m e de grades de 20x20 m, 10x10 m e 5x5 m. A continuidade espacial da CE e do teor de argila foi modelada com o uso de semivariogramas. A CE variou de 1,9 a 13,7 mS m-1, com valor mĂ©dio de 5,2 mS m-1 e coeficiente de variação de 48%. O mapa interpolado mostrou tendĂŞncia de aumento da CE com o aumento dos teores de argila. Os coeficientes de determinação foram de 0,78 e 0,77 entre CE e teor de argila, camadas 0–5 e 5–10 cm, respectivamente. O mapa da CE reflete suficientemente a variação espacial dos teores de argila para uso na delimitação de zonas de manejo.The objective of this work was to map and evaluate the spatial variability of the soil electrical conductivity (EC), measured with a contact sensor in a Rhodic Ferralsol under no till grain crops. The values of soil EC were related to soil clay content, measured by the densimetric method in georreferenced samples collected at 0–5 and 5–10 cm, in a 13 ha field. Soil samples were collected using a 40x40 m grid and densed grids of 20, 10 and 5 m spacing. Spatial continuity of EC and of clay content was modeled using semivariograms. Soil EC ranged from 1.9 to 13.7 mS m-1 with an average of 5.2 mS m-1 and coefficient of variation of 48%. The kriged map of soil EC pointed out a tendency of increase where clay levels were higher. Determination coefficients between soil EC and clay content were 0.78 and 0.77, respectively for 0–5 and 5–10 cm depth. The EC map adequatly reflects the spatial variation in soil texture for establishing the limits of management zones
Panorama atual e potencial de aplicação da abordagem dos serviços ecossistêmicos do solo no Brasil
Human pressure on ecosystems has undesirable impacts on human well-being. After the Millennium Project, much interdisciplinary research has been developed worldwide aiming to understand these impacts on ecosystem flows and processes, and to learn about the costs and the benefits of ecosystem services for production. Soil provides many ecosystem services, since its multi-functionality is the basis for food production, water filtration, nutrient cycling, and other goods essential to life. This article presents the main concepts and classifications of soil ecosystem services and of its functions; the indicators and the methods for assessment, modeling, and valuation of ecosystem services; some recent applications to assess and evaluate impacts of agricultural management practices on soil ecosystem services; as well as challenges and opportunities for research and for development of public policies related to agro-environmental sustainability in Brazil. Although the role of soil in supplying ecosystem services is yet undervalued, scientists are gradually recognizing soil processes and functions as fundamental to assess ecosystem services and the effects of land use and management on them. Interdisciplinary approaches to integrate science and public policies are necessary to build governance based on ecosystem services.A pressĂŁo humana sobre os serviços ecossistĂŞmicos tem resultado em impactos indesejáveis sobre o bem-estar humano. Com o Projeto Millennium, várias pesquisas interdisciplinares tĂŞm sido desenvolvidas em todo o mundo com o objetivo de entender esses impactos sobre os fluxos e os processos dos ecossistemas e internalizar os custos e os benefĂcios dos serviços ecossistĂŞmicos para a produção. O solo fornece muitos serviços ecossistĂŞmicos, uma vez que sua multifuncionalidade Ă© a base para a produção de alimentos, filtração de água, ciclagem de nutrientes e outros bens essenciais Ă vida. Este artigo apresenta os principais conceitos e classificações dos serviços ecossistĂŞmicos do solo e de suas funções; os indicadores e os mĂ©todos de avaliação, modelagem e valoração dos serviços ecossistĂŞmicos; algumas aplicações recentes para avaliar impactos de práticas de manejo agrĂcola sobre os serviços ecossistĂŞmicos do solo; bem como os desafios e as oportunidades para a pesquisa e para o desenvolvimento de polĂticas pĂşblicas relacionadas Ă sustentabilidade agroambiental no Brasil. Apesar de o papel do solo para prestação de serviços ecossistĂŞmicos ainda ser subestimado, os cientistas tĂŞm gradualmente reconhecido os processos e as funções do solo como fundamentais para avaliar os serviços ecossistĂŞmicos e os efeitos do uso e manejo da terra sobre eles. Abordagens interdisciplinares que integrem ciĂŞncia e polĂticas pĂşblicas sĂŁo necessárias para construir uma governança com base em serviços ecossistĂŞmicos
Safety assessment and behavioral effects of Solanum guaraniticum leaf extract in rats
ABSTRACT Solanum guaraniticum is a medicinal plant traditionally used to treat gastric and liver diseases. However, there is no documented evidence corroborating its safety. The present study evaluated the potential toxicity of S. guaraniticum leaf extract after acute administration in rats. Single doses of the extract (1.250, 2.500, and 5.000 mg/kg) were administered by gavage, and the rats were then monitored for 48 h and/or 14 days. Mortality, acute signs of toxicity, and general activity in the open field test were assessed as well as hematological and biochemical parameters, enzymatic activity (δ-aminolevulinate dehydratase and acetylcholinesterase), and oxidative stress parameters (lipid peroxidation level, non-protein thiol content, tissue catalase activity, and serum ferrous reducing power). Phytochemical analysis was also performed by HPLC. The results showed that extract administration produced no deaths (LD50 > 5,000 mg/kg), and no significant adverse effects regarding food consumption, body weight gain, gross pathology, or other parameters. However, the open field tests showed a decrease in spontaneous activity (crossing and rearing) mainly at 48 h after treatment. The results suggest that S. guaraniticum extract is not acutely toxic, but causes alterations in central nervous system activity
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