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| Registros recuperados: 172 | |
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| Lasserre, Pierre. |
| Coordinated ECOTRON Program on the Arcachon Basin (Aquitaine, France) : Control of marine biological production in a man-modified lagoon ecosystem (fish ponds). Results, synthesis and prospects. The "fish reservoirs" of the Arcachon Basin consist of eutrophic lagoon ecosystems, empirically exploited for extensive amphihaline fish culture (grey mullets, sea bass, eels, sea breams). The 1000 hectares of exploited farms, well integrated in a traditional socio-economic context, are presently not adapted for various reasons.The coordinate researches, which have been developed at Arcachon since 1974, within the ECOTRON (CNEXO) Program, show that these highly productive man modified ecosystems are well adapted for the development of semi-intensive aquaculture.... |
| Tipo: Text |
Palavras-chave: Lagunes côtières exploitées; Réservoirs à poissons; Bassin d'Arcachon; Fonctionnement écosystème; Contrôle productivité; Modélisation; Développement potentiel; Exploited coastal lagoons; Fish ponds; Arcachon Bay; Ecosystem functioning; Productivity control; Modelling; Potential development. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41676/40885.pdf |
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| Peck, Myron A.; Arvanitidis, Christos; Butenschon, Momme; Canu, Donata Melaku; Chatzinikolaou, Eva; Cucco, Andrea; Domenici, Paolo; Fernandes, Jose A.; Gasche, Loic; Huebert, Klaus B.; Hufnagl, Marc; Jones, Miranda C.; Kempf, Alexander; Keyl, Friedemann; Maar, Marie; Mahevas, Stephanie; Marchal, Paul; Nicolas, Delphine; Pinnegar, John K.; Rivot, Etienne; Rochette, Sebastien; Sell, Anne F.; Sinerchia, Matteo; Solidoro, Cosimo; Somerfield, Paul J.; Teal, Lorna R.; Travers-trolet, Morgane; Van De Wolfshaar, Karen E.. |
| We review and compare four broad categories of spatially-explicit modelling approaches currently used to understand and project changes in the distribution and productivity of living marine resources including: 1) statistical species distribution models, 2) physiology-based, biophysical models of single life stages or the whole life cycle of species, 3) food web models, and 4) end-to-end models. Single pressures are rare and, in the future, models must be able to examine multiple factors affecting living marine resources such as interactions between: i) climate-driven changes in temperature regimes and acidification, ii) reductions in water quality due to eutrophication, iii) the introduction of alien invasive species, and/or iv) (over-)exploitation by... |
| Tipo: Text |
Palavras-chave: Distribution; Modelling; Habitat; Resources; Man-induced effects. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00337/44845/44436.pdf |
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| Bergmann, Holger; Thomson, Kenneth J.. |
| A modified version of a system dynamics model constructed for an EU-wide case-study project (TOP-MARD) using STELLA software was used to simulate the effects of a number of development scenarios for a remote rural area in Northern Scotland, i.e. Caithness & Sutherland, which is characterised by a high regional importance of agriculture for the local economy. In this paper, the context of the modelling work in policy and socio-economic terms is first described. This is followed by the specification of the model and of the several modelling scenarios, which relate to the reconfiguration of Pillar 2 spending within the area and an reversal of recent Structural Funds spending for 2007 onwards. The modelling results are discussed, in terms of regional... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Modelling; Input-output; Systems dynamics; Rural viability; Marketing. |
| Ano: 2008 |
URL: http://purl.umn.edu/52645 |
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| OLIVEIRA,LAIO Z.; KLITZKE,ALINE R.; FANTINI,ALFREDO C.; ULLER,HEITOR F.; CORREIA,JEAN; VIBRANS,ALEXANDER C.. |
| Abstract The majority of Atlantic Forest fragments in Southern Brazil are second-growth forests dominated by fast-growing species with considerable market-value timber. Nevertheless, volume prediction models are scarce, especially to estimate tree total volume (i.e., stem plus branches). This study approached the issue through the following aims: to fit and select stem and total volume models (generic and species-specific) using data from 288 harvested trees in a management operation, and to fit generic and species-specific bark factors. The power model embedding diameter at breast height (D) and tree stem or total height (H) presented the greatest prediction strength for both stem and total tree volume. Models including only D to predict total tree volume... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Forest inventory; Mata Atlântica; Modelling; Regression. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000703729 |
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| Graham, Phil; White, A.. |
| Difficult seasonal conditions during the last six years have placed many farms under significant financial pressure. Producers have been looking for enterprise changes which will quickly improve their profits. New breeds have increased the options available, but there is rarely any local production data for them. Information in the media has done little more than create confusion about the true differences between sheep enterprises. Modelling allows this complex question to be looked at in a logical fashion and combines production and financial factors in the comparison. GrassGro® was used at two locations in southern NSW, Yass and Cowra, for the period 1960 to 2007. The results indicated that no enterprise performed consistently better based on profit per... |
| Tipo: Article |
Palavras-chave: Sheep enterprises; Modelling; GrassGro®; Profitability; Farm Management. |
| Ano: 2010 |
URL: http://purl.umn.edu/120870 |
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| ANDRADE, A. S.; SANTOS, P. M.; PEZZOPANE, J. R. M.; ARAUJO, L. C. de; PEDREIRA, B. C. e; PEDREIRA, C. G. S.; MARIN, F. R.; LARA, M. A. S.. |
| Crop models can aid the synthesis and application of knowledge, planning of experiments and forecasting in agricultural systems. Few studies have reviewed the uses and applications of these models for tropical forages. The purpose of this study was to review the information available in this scientific area, highlighting the main models, their applications and limitations. Several empirical models have been developed to predict the growth and biomass accumulation of tropical forages, especially for the genera Cynodon, Paspalum, Panicum and Brachiaria. Their application, however, is often location or region specific. The adaptation of mechanistic models to accurately predict biomass accumulation in tropical grasses is still limited. Recent advances have... |
| Tipo: Artigo de periódico |
Palavras-chave: Agricultural production; Systems simulator; CROPGRO; Grass; Modelling; Pasture. |
| Ano: 2016 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1066364 |
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| ANDRADE, A. S.; SANTOS, P. M.; PEZZOPANE, J. R. M.; ARAUJO, L. C. de; PEDREIRA, B. C. e; PEDREIRA, C. G. S.; MARIN, F. R.; LARA, M. A. S.. |
| Crop models can aid the synthesis and application of knowledge, planning of experiments and forecasting in agricultural systems. Few studies have reviewed the uses and applications of these models for tropical forages. The purpose of this study was to review the information available in this scientific area, highlighting the main models, their applications and limitations. Several empirical models have been developed to predict the growth and biomass accumulation of tropical forages, especially for the genera Cynodon, Paspalum, Panicum and Brachiaria. Their application, however, is often location or region specific. The adaptation of mechanistic models to accurately predict biomass accumulation in tropical grasses is still limited. Recent advances have... |
| Tipo: Artigo de periódico |
Palavras-chave: Agricultural production; Systems simulator; CROPGRO; Grass; Modelling; Pasture. |
| Ano: 2015 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1029145 |
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| Pallas Sanz, Enric. |
| The "Pertuis Breton" is a macrotidal estuary with an important mollusc exploitation of the inter-tidal zones. The main cultivated specie is M.edulis. In 1991, 250 long lines have been immersed in the centre of the bay. It will be able to extend the concession on the basis of the studies results about the trophy capacity of the "Pertuis Breton". Two deterministic models have been developed for to determining the geographical origin of the matter organic sources for the long line mussels culture, and the destine of this matter in the culture park: a) a model of trajectories of the organic matter particles, b) a coupled model of the hydrodynamic conditions and a ecophysiological model of the mussel growth. The result's simulations of the trajectories model... |
| Tipo: Text |
Palavras-chave: M. edulis; Potentialité mytilicole; Déplétion; Trajectoires; Modélisation; M. edulis; Trophy capacity; Depletion; Trajectories; Modelling. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00449/56098/57634.pdf |
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| Souza,Silvio José Ferreira de; Alves,Aline Inácio; Vieira,Érica Nascif Rufino; Vieira,José Antônio Gomez; Ramos,Afonso Mota; Telis-Romero,Javier. |
| The equilibrium moisture content for adsorption and desorption isotherms of mango skin was determined using the static gravimetric method at temperatures of 20, 26, 33, 38 and 44 oC in the 0.056 to 0.873 water activity range. Both sorption curves show a decrease in equilibrium moisture content as the temperature increasing. The hysteresis effect was observed at constant water activity. The Guggenheim, Anderson, and de Boer (GAB) model presented the best fitting accuracy among a group of models and was used to determine the thermodynamic properties of water sorption. Integral enthalpy and integral entropy areas showed inverted values for the adsorption and desorption isotherms over the wide range of water activity studied. These values confirm, in energetic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agricultural waste; Gravimetric method; Integral properties; Modelling; Water content. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612015000100157 |
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| Figueiredo, Tomás de; Ferreira, Alfredo; Gonçalves, Dionísio; Poesen, Jean. |
| Soils with rock fragments have been studied under several aspects in the last years. Research shows that a single pattern in the erosional response of these soils to rainfalls is not always found. In order to contribute to the understanding of this topic, an experiment was carried out, simulating interrill areas covered by rock fragments. This paper specifically aims at presenting and discussing temporal changes on sediment exported from such areas, also introducing a simple descriptive model to represent soil loss temporal evolution. Small bottom perforated boxes, 612 cm2 area, were filled with a silt-loam fine earth, very poor in organic matter, covered with simulated rock fragments and leaned at 10% slope gradient. The experiment comprised the exposure... |
| Tipo: Article |
Palavras-chave: Soil erosion; Rock fragments; Wash; Splash; Modelling. |
| Ano: 2009 |
URL: http://hdl.handle.net/10198/5269 |
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| Priour, Daniel. |
| Measurements at sea during fishing trials on bottom trawl, have revealed that the geometry of the trawl is affected by the catch. A series of 27 hauls of around 3h have been carried out during the EFFICHALUT project. This project aimed to find out improvements on the fishing gear in order to reduce the energy consumption. For this project numerous sensors have been used, for bridles tension, doors spread, vertical opening, doors attitude. The measurements show quite clearly that the doors spread decreases and the bridles tension increases along most of the hauls. The doors spread decreases by 1.35m per hour, with a standard deviation of 1.98m/h when the top bridle tension increases of 47kg/h, with a standard deviation of 59kg/h. The mean catch per haul is... |
| Tipo: Text |
Palavras-chave: Trawl; Data; Modelling; Doors spread; Bridle tension; Catch weight. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00186/29761/28208.pdf |
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| Souty, Francois; Brunelle, Thierry; Dumas, Patrice; Dorin, Bruno; Ciais, Philippe; Crassous, Renaud. |
| Interactions between food demand, biomass energy and forest preservation are driving both food prices and land-use changes, regionally and globally. This study presents a new model called Nexus Land-Use which describes these interactions through a generic representation of agricultural intensification mechanisms. The Nexus Land-Use model equations combine biophysics and economics into a single coherent framework to calculate crop yields, food prices, and resulting pasture and cropland areas within 12 regions inter-connected with each other by international trade. The representation of cropland and livestock production systems in each region relies on three components: (i) a biomass production function derived from the crop yield response function to inputs... |
| Tipo: Working Paper |
Palavras-chave: Land-use Change; Modelling; Global Biomass Projections; Environmental Economics and Policy; Q11; Q15. |
| Ano: 2012 |
URL: http://purl.umn.edu/122859 |
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| Registros recuperados: 172 | |
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