Rangelands cover about 82% of the arid area of Morocco. It is generally acknowledged that these areas are threatened by desertification. Monitoring desertification requires accurate knowledge about the current status of rangeland degradation. Remote sensing is widely used to assess changes in land cover, but its use in arid rangelands has limitations because of spectral confusion among various types of land cover. The objective of this study was to assess the severity and spatial extent of rangeland degradation in the high plateaus of eastern Morocco, using a knowledge-based approach combining remote sensing and ancillary data. This approach relies on analyzing datasets derived from Landsat TM satellite imagery, lithology, bioclimatic data and field measurements. The level of rangeland degradation was assessed using indicators such as vegetation parameters, grazing levels and cultivation intensity, which provided a high level of accuracy for mapping and monitoring the degradation of the arid rangelands. The results showed that the total area of degraded rangeland in the high plateaus of eastern Morocco is about 17,417 km 2 , accounting for 48% in the studied area.

Le système pastoral des hauts plateaux du Maroc oriental est caractérisé par l’étendue des parcours (3,2 millions d’hectares) et la dominance de l’élevage ovin (1,2 million de têtes). Ce travail, mené à Béni Mathar au nord et à Maâtarka au sud, traite la question des changements d’occupation des terres de parcours et de conduite des troupeaux, à partir de l’hypothèse d’une dégradation des parcours suivie d’une baisse de la pression de pâturage. Cette dynamique est perçue par l’étude de l’occupation des sols en 1970, 1988 et 2013. Les modes de conduite sont identifiés au travers d’enquêtes (85) et lors d’ateliers participatifs. L’analyse de l’occupation des sols montre la régression des bonnes formations végétales et leur substitution par des formations de moindre valeur, et une baisse des apports fourragers sur parcours. Parallèlement, on note une augmentation des effectifs d’animaux de moins en moins mobiles et de plus en plus supplémentés (20 à 40 p. 100 de satisfaction des besoins, essentiellement par l’orge et le son de blé), et un changement progressif dans la composition raciale des troupeaux en faveur de la race Ouled Djellal (à valeur commerciale compétitive) au détriment de la race locale Béni Guil. L’histoire de la société pastorale étudiée témoigne d’une capacité d’adaptation malgré les perturbations socio-économiques et climatiques relevées depuis l’indépendance. Les grands éleveurs (plus de 200 brebis) profitent davantage des pâturages et savent mieux spéculer lors de la commercialisation que les petits éleveurs (moins de 50 brebis) qui sont davantage menacés par l’abandon de l’élevage.

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Predicting infections by Puccinia striiformis f. sp. tritici, with sufficient lead times, helps determine whether fungicide sprays should be applied in order to prevent the risk of wheat stripe rust (WSR) epidemics that might otherwise lead to yield loss. Despite the increasing threat of WSR to wheat production in Morocco, a model for predicting WSR infection events has yet to be developed. In this study, data collected during two consecutive cropping seasons in 2018–2019 in bread and durum wheat fields at nine representative sites (98 and 99 fields in 2018 and 2019, respectively) were used to develop a weather-based model for predicting infections by P. striiformis. Varying levels of WSR incidence and severity were observed according to the site, year, and wheat species. A combined effect of relative humidity > 90%, rainfall ≤ 0.1 mm, and temperature ranging from 8 to 16 °C for a minimum of 4 continuous hours (with the week having these conditions for 5% to 10% of the time) during March–May were optimum to the development of WSR epidemics. Using the weather-based model, WSR infections were satisfactorily predicted, with probabilities of detection ≥ 0.92, critical success index ranging from 0.68 to 0.87, and false alarm ratio ranging from 0.10 to 0.32. Our findings could serve as a basis for developing a decision support tool for guiding on-farm WSR disease management, which could help ensure a sustainable and environmentally friendly wheat production in Morocco.