| 1. |
- Karlson, Martin, 1980-, et al.
(författare)
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Mapping Tree Canopy Cover and Aboveground Biomass in Sudano-Sahelian Woodlands Using Landsat 8 and Random Forest
- 2015
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Ingår i: Remote Sensing. - : MDPI AG. - 2072-4292. ; 7:8, s. 10017-10041
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Tidskriftsartikel (refereegranskat)abstract
- Accurate and timely maps of tree cover attributes are important tools for environmental research and natural resource management. We evaluate the utility of Landsat 8 for mapping tree canopy cover (TCC) and aboveground biomass (AGB) in a woodland landscape in Burkina Faso. Field data and WorldView-2 imagery were used to assemble the reference dataset. Spectral, texture, and phenology predictor variables were extracted from Landsat 8 imagery and used as input to Random Forest (RF) models. RF models based on multi-temporal and single date imagery were compared to determine the influence of phenology predictor variables. The effect of reducing the number of predictor variables on the RF predictions was also investigated. The model error was assessed using 10-fold cross validation. The most accurate models were created using multi-temporal imagery and variable selection, for both TCC (five predictor variables) and AGB (four predictor variables). The coefficient of determination of predicted versus observed values was 0.77 for TCC (RMSE = 8.9%) and 0.57 for AGB (RMSE = 17.6 tons∙ha−1). This mapping approach is based on freely available Landsat 8 data and relatively simple analytical methods, and is therefore applicable in woodland areas where sufficient reference data are available.
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| 2. |
- Nyberg, Gert, et al.
(författare)
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Enclosures in West Pokot, Kenya: Transforming land, livestock and livelihoods in drylands
- 2015
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Ingår i: Pastoralism. - : Springer Science and Business Media LLC. - 2041-7136 .- 2041-7128. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Dryland livestock production systems are changing in many parts of the world, as a result of growing human populations and associated pressure on water and land. Based on a combination of social and natural science methods, we studied a 30-year transformation process from pastoralism to a livestock-based agro-pastoral system in northwestern Kenya, with the overall aim to increase the understanding of the ongoing transition towards intensified agro-pastoralist production systems in dryland East Africa.Key to this transformation was the use of enclosures for land rehabilitation, fodder production, and land and livestock management. Enclosures have more soil carbon and a higher vegetation cover than adjacent areas with open grazing. The level of adoption of enclosures as a management tool has been very high, and their use has enabled agricultural diversification, e.g. increased crop agriculture, poultry production and the inclusion of improved livestock. Following the use of enclosures, livelihoods have become less dependent on livestock migration, are increasingly directed towards agribusinesses and present new opportunities and constraints for women. These livelihood changes are closely associated with, and depend on, an ongoing privatization of land under different tenure regimes.The results indicate that the observed transformation provides opportunities for a pathway towards a sustainable livestock-based agro-pastoral system that could be valid in many dryland areas in East Africa. However, we also show that emergent risks of conflicts and inequalities in relation to land, triggered by the weakening of collective property rights, pose a threat to the sustainability of this pathway.
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| 3. |
- Steglich, Thomas, 1983, et al.
(författare)
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Bran particle size influence on pasta microstructure, water distribution and sensory properties
- 2015
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Ingår i: Cereal Chemistry. - 0009-0352 .- 1943-3638. ; 92:6, s. 617-623
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Tidskriftsartikel (refereegranskat)abstract
- Whole-wheat pasta offers improved nutritional value compared to regular pasta, but lacks appeal to many consumers due to its negative organoleptic properties, such as texture and taste. Various approaches have been studied to improve these properties in whole-wheat products. Optimizing bran particle size showed its potential in noodles, but studies of its effects in pasta are scarce. Therefore, we produced spaghetti enriched with bran fractions similar in chemical composition, but with varying median particle sizes of 90, 160, 370 and 440 µm. The effect of bran particles and their median size on dried and cooked pasta was studied by light microscopy and 3D 1H magnetic resonance imaging. In general, bran particle size did not influence the macrostructure in cooked spaghetti. However larger bran particles created a more heterogeneous microstructure in contrast to smaller particles and affected starch granule swelling. Sensory analysis indicated a preference for pasta containing smaller particles. Our results give new insight into the microstructural features responsible for the negative consumer appeal, and could be used to guide future efforts in designing improved pasta formulations.
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