TY - THES ID - 145896127 TI - Contribution au développement durable des zones de parcours au Maroc : Modèles de contrôle optimal de la mise en culture des parcours et du surpâturage PY - 2000 PB - [S. l.] : [chez l'auteur], DB - UniCat KW - Sheep KW - Sheep KW - Goats KW - Goats KW - Grazing systems KW - Grazing systems KW - Rangelands KW - Rangelands KW - Environmental impact KW - Environmental impact KW - Stocking density KW - Stocking density KW - pasture improvement KW - pasture improvement KW - Models KW - Models KW - Morocco KW - Morocco UR - https://www.unicat.be/uniCat?func=search&query=sysid:145896127 AB - In Morocco, pressure on rangelands has been increasing for the last two decades, threatening the balance of the pastoral system. This regressive trend stems from the extension of crops into rangelands and from the drop in forage production because of overgrazing. In order to find a compromise between the agricultural production and rangeland preservation, control and long- term planning are central. Farming practices will need to be changed drastically. The complexity of the problem is best met with a modelling approach, which takes into account the various interactions between the land user's decisions and the many technical, economic and environmental constraints. For optimal control, two dynamic models were constructed, based on the maximum principle method, and tested at national and regional levels. The optimal rangeland cropping control model, applied to the national and the Tadla region levels, reproduces the current technical and economic conditions involved in land allocation between the rival activities i. e. cropping and pastoralism. Optimal rangeland levels were determinated and variations were simulated according to changes in the economic policy. The stocking rate optimal control model was tested in two pastoral regions i. e Oriental and Middle Atlas, and was led to the definition of optimal forage resource management, mainly the optimal stocking rate and the equilibrium level for the forage stock. Moreover, the bio-economic approach has power to be of great interest in the evaluation of the economic and climatic parameters affecting the management process. Results of both models have led to some proposals forwards an economic environment favourable to the preservation of rangeland areas and the promotion of a rational forage resource management. ER -