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Book (series)A strategic reassessment of fish farming potential in Africa 1998
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No results found.The present study is an update of an earlier assessment of warm-water fish farming potential in Africa, by Kapetsky (1994). The objective of this study was to assess locations and areal expanses that have potential for warm-water and temperate-water fish farming in continental Africa. The study was based on previous estimates for Africa by the above author, and on estimates of potential for warm-water and temperate-water fish farming in Latin America by Kapetsky and Nath (1997). However, a nu mber of refinements have been made. The most important refinement was that new data allowed a sevenfold increase in resolution over that used in the previous Africa study, and a twofold increase over that of Latin America (i.e. to 3 arc minutes, equivalent to 5 km x 5 km grids at the equator), making the present results more usable in order to assess fish farming potential at the national level. A geographical information system (GIS) was used to evaluate each grid cell on the basis of severa l land-quality factors important for fish-farm development and operation regardless of the fish species used. Protected areas, large inland water bodies and major cities were identified as constraint areas, and were excluded from any fish farming development altogether. Small-scale fish farming potential was assessed on the basis of four factors: water requirement from ponds due to evaporation and seepage, soil and terrain suitability for pond construction based on a variety of soil attributes a nd slopes, availability of livestock wastes and agricultural by-products as feed inputs based on manure and crop potential, and farm-gate sales as a function of population density. For commercial farming, an urban market potential criterion was added based on population size of urban centres and travel time proximity. Both small-scale and commercial models were developed by weighting the above factors using a multi-criteria decision-making procedure. A bioenergetics model was incorporated int o the GIS to predict, for the first time, fish yields across Africa. A gridded water temperature data set was used as input to a bioenergetics model to predict number of crops per year for the following three species: Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus) and Common carp (Cyprinus carpio). Similar analytical approaches to those by Kapetsky and Nath (1997) were followed in the yield estimation. However, different specifications were used for small-scale and co mmercial farming scenarios in order to reflect the types of culture practices found in Africa. Moreover, the fish growth simulation model, documented in Kapetsky and Nath (1997), was refined to enable consideration of feed quality and high fish biomass in ponds. The small-scale and commercial models derived from the land-quality evaluation were combined with the yield potential of each grid cell for each of the three fish species to show the coincidence of each land-quality suitability class with a range of yield potentials. Finally, the land quality-fish yield potential combinations were put together to show where the fish farming potential coincided for the three fish species. The results are generally positive. Estimates of the quality of land show that about 23% of continental Africa scored very suitable for both small-scale and commercial fish farming. For the three fish species, 50-76% of Africa's land has the highest yield range potential, and the spatial distribution of th is yield is quite similar among the species and farming systems. However, the spatial distribution of carp culture potential was greater than for Nile tilapia and African catfish. Combining the two farming system models with the favourable yields of the three fish species suggest that over 15% of the continent has land areas with high suitability for pond aquaculture. -
Book (stand-alone)Guidelines for brackish water use for agricultural production in the Near East and North Africa region 2023
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No results found.Water scarcity is one of the major challenges in the 19 countries of the Near East and North Africa (NENA) region. The lack of water is affecting important irrigated areas, limiting the increase of food production needed to address the growing demand due to population growth. In most countries of the NENA region, the need to use non-conventional water resources, including brackish water, is well recognized. Brackish water is loosely defined as water that is more saline than freshwater, but less saline than seawater. It covers a large range of salinity levels, from 500 to 30 000 mg/l of total dissolved solids (TDS). Despite the presence of large amounts of brackish water and its potential for use in growing a number of crops, it is only used in limited amounts for irrigation. The successful use of brackish water for irrigation requires a basic understanding of scientific principles affecting the interactions among the climate, the applied water, the soil, the crop, and the environment. Equally important is the application of suitable technology and management practices that will facilitate the optional use of this poor-quality water. The successful use of brackish water requires a higher level of management and likely the adoption of new irrigation management practices. Because climate, water quality, soil type, and crop tolerance to salinity vary from location to location, guidelines, with some degree of site-specific flexibility, must be developed. -
ArticleThe impact of modern logging on the forest environment of felling site in the context of climate change
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Over the past decade, the importance of the global climate change impact and extreme weather events on forest ecosystems and the activities of the timber industry has become increasingly apparent. In this regard, forest ecosystems are vulnerable in environmental terms, with regard to the impact of logging machinery, post-harvest restoration of soils, ground cover and woody vegetation. The concept behind our scientific research is to ensure sustainable forest management, the need to preserve and protect forest soils, which is very important for the successful subsequent renewal and productivity of future forests. On the basis of our own field research, studying modern practices and reviewing the literature for practical use in logging enterprises, we offer ways and means to minimize damage to forest soils. These ways and means are based on the choice of a wood harvesting system, and organization of logging operations considering the terrain. The most important practices of sustainable forest management are planning the season of logging, cutting technologies, leaving felling residues on the soil surface, and training of specialists who work in the forest. In addition, technological solutions are important, including selection of a system of machines and mechanisms, the mass and size of equipment, the number of passes for vehicles, use of tires of different size, tyre pressure control, use of anti-skid tracks, and use of global positioning systems in conjunction with geographic information systems. Findings and recommendations of new scientific research will be an important contribution to the management decision-making process, will contribute to the development of technologies and its implementation in practice. One of the main areas of research is development of innovative guidelines for science-based climate-smart forest management, aimed at reducing the negative impact of logging technologies on the forest environment and biodiversity conservation. Keywords: Sustainable forest management, Adaptive and integrated management, Climate change, Biodiversity conservation ID: 3479028
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