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Achard F.,European Commission - Joint Research Center Ispra | Stibig H.-J.,European Commission - Joint Research Center Ispra | Eva H.D.,European Commission - Joint Research Center Ispra | Lindquist E.J.,Forest Assessment | And 3 more authors.
Carbon Management | Year: 2010

This article covers the very recent developments undertaken for estimating tropical deforestation from Earth observation data. For the United Nations Framework Convention on Climate Change process it is important to tackle the technical issues surrounding the ability to produce accurate and consistent estimates of GHG emissions from deforestation in developing countries. Remotely-sensed data are crucial to such efforts. Recent developments in regional to global monitoring of tropical forests from Earth observation can contribute to reducing the uncertainties in estimates of carbon emissions from deforestation. Data sources at approximately 30 m × 30 m spatial resolution already exist to determine reference historical rates of change from the early 1990s. Key requirements for implementing future monitoring programs, both at regional and pan-tropical regional scales, include international commitment of resources to ensure regular (at least yearly) pan-tropical coverage by satellite remote sensing imagery at a sufficient level of detail; access to such data at low-cost; and consensus protocols for satellite imagery analysis. © 2010 Future Science Ltd. Source

Eberenz J.,Wageningen University | Herold M.,Wageningen University | Verbesselt J.,Wageningen University | Wijaya A.,Center for International Forestry Research | And 5 more authors.
2015 8th International Workshop on the Analysis of Multitemporal Remote Sensing Images, Multi-Temp 2015 | Year: 2015

This study predicts global forest cover change for the 1980s and 1990s from AVHRR time series metrics in order to show how the series of consistent land cover maps for climate modeling produced by the ESA climate change initiative land cover project can be extended back in time. A Random Forest model was trained on global Landsat derived samples. While the deforestation was underestimated by the model, major global patterns were effectively reproduced. Compared to reference data for the Amazon satisfying accuracies (>0.8) were achieved, but results are less promising for Indonesia. © 2015 IEEE. Source

Sanou H.,Sotuba BP 258 | Sanou H.,Copenhagen University | Angulo-Escalante M.A.,Investigacion en Alimentacion y Desarrollo A.C. | Martinez-Herrera J.,Jatro Bio Energy and Oilseeds SPR de RL | And 7 more authors.
Crop Science | Year: 2015

Jatropha curcas L. has been promoted as a “miracle” tree in many parts of the world, but recent studies have indicated very low levels of genetic diversity in various landraces. In this study, the genetic diversity of landrace collections of J. curcas was compared with the genetic diversity of the species from its native range, and the mating system was analyzed on the basis of microsatellite markers. The genetic diversity parameters were estimated, and analysis of molecular variance, principal coordinate analysis, and unrooted neighbor-joining tree were used to describe the relationship among populations. Results confirmed very low genetic diversity in African and Asian landraces. Mexican populations from the regions of Veracruz, Puebla, and Morelos were also found to have low levels of diversity (mostly monomorphic), while populations from Chiapas were polymorphic with an expected heterozygosity between 0.34 and 0.54. Bayesian analysis showed differentiation according to geographic locations, which was confirmed by principal coordinate analysis and neighbor-joining tree. Estimations of outcrossing rate of individual families from Chiapas showed that some mother trees were mainly outcrossing. Mating system could not be estimated in the landraces from Mali and populations from Veracruz, Puebla, and Morelos (Mexico), as these were highly monomorphic. The observed low level of genetic diversity in some of the populations and landraces suggests that breeding programs should test for genetic variation and heritability in relevant quantitative traits and estimate if sufficient gain can be expected from traditional testing and selection. Diversification of the local gene pools may be considered for breeding and selection. © Crop Science Society of America. Source

Kaeslin E.,Forest Assessment
Unasylva | Year: 2010

The article presents an overview of conservation issues affecting the successful coexistence of forests, people, and wildlife. Forest wildlife likewise offers both products and ecosystem services. Forests and wildlife together offer a basis for commercial and/or recreational activities like hunting, photography, hiking and birdwatching. There are two main drivers behind these threats. The increasing consumption of wealthier populations, which stimulates agricultural and industrial production, resource extraction, and tourism, leads to degradation of forests. As a result of faunal depletion, the remaining primary tropical and subtropical forests, which still provide good habitat for wild animals, are widely becoming empty of large vertebrate. The Convention on Biological Diversity (CBD) Liaison Group on Bushmeat defines bushmeat hunting as the harvesting of wild animals in tropical and subtropical forests for food and non-food purposes. Source

Potapov P.,South Dakota State University | Hansen M.C.,South Dakota State University | Gerrand A.M.,Forest Assessment | Lindquist E.J.,Forest Assessment | And 3 more authors.
International Journal of Digital Earth | Year: 2011

To collect and provide periodically updated information on global forest resources, their management and use, the United Nations Food and Agriculture Organization (FAO) has been coordinating global forest resources assessments (FRA) every 5-10 years since 1946. To complement the FRA national-based statistics and to provide an independent assessment of forest cover and change, a global remote sensing survey (RSS) has been organized as part of FAO FRA 2010. In support of the FAO RSS, an image data set appropriate for global analysis of forest extent and change has been produced. Landsat data from the Global Land Survey 1990-2005 were systematically sampled at each longitude and latitude intersection for all points on land. To provide a consistent data source, an operational algorithm for Landsat data pre-processing, normalization, and cloud detection was created and implemented. In this paper, we present an overview of the data processing, characteristics, and validation of the FRA RSS Landsat dataset. The FRA RSS Landsat dataset was evaluated to assess overall quality and quantify potential limitations. © 2011 Taylor & Francis. Source

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