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Les actes de la 1re Rencontre scientifique internationale sur les oasis, ISMO 2023, se sont concentrés sur le thème ''Quel apport de la recherche scientifique pour la sauvegarde et le développement des oasis?'' et ont eu lieu à Errachidia du 20 au 22 novembre 2023. The proceedings of the 1st International Scientific Meeting on Oases, ISMO 2023, focused on the theme ''What contribution does scientific research make to the preservation and development of oases?'' and took place in Errachidia from November 20 to 22, 2023.

Terraced agroecosystems (TAS)—apart from being an important cultural heritage element—are considered vital for sustainable water resource management and climate change adaptation measures. However, this traditional form of agriculture, with direct implications in food security at a local scale, has been suffering from abandonment or degradation worldwide. In light of this, the need to fully comprehend the complex linkage of their abandonment with different driving forces is essential. The identification of these dynamics makes possible an appropriate intervention with local initiatives and policies on a larger scale. Therefore, the main aim of this paper is to introduce a comprehensive multidisciplinary framework that maps the dynamics of the investigated TAS’s abandonment, by defining cause–effect relationships on a hydrogeological, ecological and social level, through tools from System Dynamics studies. This methodology is implemented in the case of Assaragh TAS, a traditional oasis agroecosystem in the Moroccan Anti-Atlas, characterized by data scarcity. Through field studies, interviews, questionnaires and freely accessible databases, the TAS’s abandonment, leading to a loss in agrobiodiversity, is linked to social rather than climatic drives. Additionally, measures that can counteract the phenomenon and strengthen the awareness of the risks associated with climate change and food security are proposed.

Climate change is expected to greatly alter and modify the ecological conditions of plant growth and distribution, particularly in the Mediterranean Basin, considered as one of the most vulnerable zone to global warming in the world. In this chapter, we look at the biogeography of the olive tree, an emblematic species of the Mediterranean Basin, represented in Morocco by two wild subspecies: Olea europaea subsp. europaea var. sylvestris, the ancestor of all the olive varieties and widely distributed in the country, and Olea e. subsp. maroccana, endemic in a restricted southwestern area. We hypothesis, within the context of future warming, an increase of O. e. subsp. e. var. sylvestris distribution area is expected, while for O. e. subsp. maroccana, an alteration of its distribution is predicted, increasing seriously the risk of extinction. In order to assess the current and future potential geographic distribution of the two wild olive species in Morocco, a species distribution based-modelling was performed to understand the relationships between species distributions and climatic factors, on the basis of field data and 19 climatic variables. Two representative concentration pathways, RCP4.5 and RCP8.5, were used to forecast the future distribution of the two wild olive subspecies in 2050 and 2070. To avoid multicollinearity, the highly correlated climatic variables (r > 0.9, Pearson correlation coefficient) were deleted from the independent variables list. The Jackknife test was carried out to evaluate the relevance of the climatic variables for predictive modeling. The maximum entropy model for the current distribution of both species provides a satisfactory result, with a high value of the Area Under Curve equal to 0.980 (±0.001) for Olea europaea subsp. europaea var. sylvestris and equal to 0.997 (±0.001) for Olea europaea subsp. maroccana. Jackknife test indicates that precipitation and temperature variables play a significance role in wild olive species biogeographical dynamics in Morocco. The study results confirm our hypothesis of an expansion of O. e. subsp. e. var. sylvestris suitable area and the threatened aspect of Olea e. subsp. maroccana under climate change scenarios. The approach used in this study is promising to predict the potential distribution of wild olive species, and can be an effective tool to support conservation and restoration programs

Abstract Climate change is expected to alter many natural ecosystems around the world, by affecting plants growth and distribution. This is particularly emphasized for several Mediterranean plant species and communities. In this study, we investigate the suitable habitat and geographical distribution of a remarkable Mediterranean tree, Ceratonia siliqua L. (Leguminosae), in Morocco. We hypothesized a reduction in the carob tree suitable habitats under climate change scenarios. To this end, we applied the maximum entropy algorithm (Maxent) to generate current and future models using 303 occurrence points coupled with 19 bioclimatic variables. Two representative concentration pathways (RCP4.5 and RCP8.5) by 2050 and 2070 were considered as future input scenarios. The maximum entropy model provides satisfactory results, with a high value of the Area Under Curve equal to 0.987 (±0.001). Jackknife tests indicate that precipitation followed by temperature play a significant role in the biogeographical dynamics of the Moroccan carob tree. Thus, the obtained results confirm our hypothesis of a reduction of the suitable area under the projected climate change scenarios by 2050 and 2070. The approaches developed in this study is promising to predict the potential distribution of native Mediterranean species and can be an effective tool to support conservation and restoration programs.

The Qinghai-Xizang Plateau serves as an extensive gene pool for plateau species and a crucial focal point for global biodiversity conservation. Being a climate-sensitive region, the impacts of climate change have led to habitat loss, population extinction, and ecological imbalances, posing formidable challenges to the sustained effectiveness of existing protected areas. Despite substantial advancements in understanding species distribution, assessing habitat changes, and evaluating the efficiency of protected areas in recent decades, comprehensive evaluations encompassing all protected species are lacking, impeding conservation strategies. In this study, we gathered 137,856 observations, encompassing 2,605 species, and utilized the MaxEnt model to simulate changes in the current distribution patterns of endangered species and suitable habitats under future scenarios. We further proposed a climate smart approach to optimize the boundaries of protected areas in response to climate change. Key findings indicate that (1) the Qinghai-Xizang Plateau harbors 2,605 endangered species, constituting 34.04 % of the total endangered species catalog in China; (2) current high-adaptation habitats of Qinghai-Xizang Plateau cover a mere 7 % of the plateau, showing minimal alteration in protected efficiency under climate change scenarios (0.50 % increase); (3) incorporating the effects of climate change in adjusting protected area boundaries enhances their efficiency by an average of 20.52 %. Our proposed methodology holds promise for safeguarding endangered species on the Qinghai-Xizang Plateau and offers significant implications for analogous regions worldwide.

Les études liées au climat se sont généralement concentrées sur des traits « mécanistes » physiologiquement bien définis plutôt que sur des traits « fonctionnels » liés indirectement à la capture des ressources. Néanmoins, les réponses de terrain au climat sont susceptibles d'inclure à la fois une spécialisation « mécaniste » aux extrêmes climatiques et des stratégies « fonctionnelles » qui optimisent l'acquisition de ressources pendant des périodes moins sévères sur le plan climatique. Ici, cette hypothèse a été testée. Dix-sept traits (six « fonctionnels », six « mécanistes » et cinq « intermédiaires ») ont été mesurés sur 19 populations d'oléastres (oliviers sauvages) le long d'un gradient climatique au Maroc. L'analyse en composantes principales de l'ensemble de données sur les traits a identifié la taille et le « spectre économique mondial des feuilles » en tant qu'axes 1 et 2 de l'ACP. Cependant, contrairement à notre prédiction, ces axes, et les traits « fonctionnels » couramment mesurés, étaient peu corrélés au climat. Au lieu de cela, le PCA 3, peut-être lié à l'utilisation de l'eau et à la succulence, à la densité stomatique, à la teneur spécifique en eau des feuilles et à la forme des feuilles, selon l'altitude, l'aridité, les précipitations et la température. Nous avons conclu que, au moins pour les espèces à croissance lente, telles que l'oléaster, les traits « mécanistes » sont essentiels pour identifier les mécanismes de restriction climatique. Une collaboration significative entre les disciplines « mécanistes » et « fonctionnelles » constitue le meilleur moyen d'améliorer notre compréhension des impacts mondiaux du changement climatique sur la répartition et la performance des espèces. Los estudios relacionados con el clima generalmente se han centrado en rasgos "mecanicistas" fisiológicamente bien definidos en lugar de los "funcionales" relacionados indirectamente con la captura de recursos. Sin embargo, es probable que las respuestas de campo al clima incluyan tanto la especialización "mecanicista" a los extremos climáticos como las estrategias "funcionales" que optimizan la adquisición de recursos durante períodos menos severos desde el punto de vista climático. Aquí, se probó esta hipótesis. Se midieron diecisiete rasgos (seis 'funcionales', seis 'mecanicistas' y cinco 'intermedios') de 19 poblaciones de oleaster (aceituna silvestre) a lo largo de un gradiente climático en Marruecos. El análisis de los componentes principales del conjunto de datos de rasgos identificó el tamaño y el "espectro económico de las hojas en todo el mundo" como los ejes 1 y 2 del PCA. Sin embargo, contrariamente a nuestra predicción, estos ejes, y los rasgos "funcionales" comúnmente medidos, estaban poco correlacionados con el clima. En cambio, el PCA 3, tal vez relacionado con el uso del agua y la suculencia, junto con la densidad estomática, el contenido específico de agua de la hoja y la forma de la hoja, modelados con la altitud, la aridez, la lluvia y la temperatura. Llegamos a la conclusión de que, al menos para las especies de crecimiento lento, como el oleaster, los rasgos "mecanicistas" son clave para identificar los mecanismos de restricción climática. La colaboración significativa entre las disciplinas "mecanicistas" y "funcionales" proporciona la mejor manera de mejorar nuestra comprensión de los impactos globales del cambio climático en la distribución y el rendimiento de las especies. Climate-related studies have generally focussed upon physiologically well-defined 'mechanistic' traits rather than 'functional' ones relating indirectly to resource capture. Nevertheless, field responses to climate are likely to typically include both 'mechanistic' specialization to climatic extremes and 'functional' strategies that optimize resource acquisition during less climatically-severe periods. Here, this hypothesis was tested. Seventeen traits (six 'functional', six 'mechanistic' and five 'intermediate') were measured from 19 populations of oleaster (wild olive) along a climatic gradient in Morocco. Principal components analysis of the trait dataset identified size and the 'worldwide leaf economics spectrum' as PCA axes 1 and 2. However, contrary to our prediction, these axes, and commonly-measured 'functional' traits, were little correlated with climate. Instead, PCA 3, perhaps relating to water-use and succulence, together stomatal density, specific leaf water content and leaf shape, patterned with altitude, aridity, rainfall and temperature. We concluded that, at least for slow-growing species, such as oleaster, 'mechanistic' traits are key to identifying mechanisms of climatic restriction. Meaningful collaboration between 'mechanistic' and 'functional' disciplines provides the best way of improving our understanding of the global impacts of climate change on species distribution and performance. ركزت الدراسات المتعلقة بالمناخ بشكل عام على السمات "الميكانيكية" المحددة جيدًا من الناحية الفسيولوجية بدلاً من السمات "الوظيفية" المتعلقة بشكل غير مباشر بالاستيلاء على الموارد. ومع ذلك، من المرجح أن تشمل الاستجابات الميدانية للمناخ كلاً من التخصص "الميكانيكي" في الظواهر المناخية المتطرفة والاستراتيجيات "الوظيفية" التي تعمل على تحسين الحصول على الموارد خلال الفترات الأقل شدة مناخية. هنا، تم اختبار هذه الفرضية. تم قياس سبع عشرة سمة (ست سمات "وظيفية" وست سمات "ميكانيكية" وخمس سمات "متوسطة ") من 19 مجموعة من الزيتون الزيتي (الزيتون البري) على طول تدرج مناخي في المغرب. حدد تحليل المكونات الرئيسية لمجموعة بيانات السمات الحجم و "طيف اقتصاديات الأوراق في جميع أنحاء العالم" كمحاور PCA 1 و 2. ومع ذلك، على عكس توقعاتنا، فإن هذه المحاور، والسمات "الوظيفية" التي يتم قياسها بشكل شائع، كانت مرتبطة قليلاً بالمناخ. بدلاً من ذلك، فإن الأنيسول الخماسي الكلور 3، ربما يتعلق باستخدام المياه والعصارة، معًا كثافة الفم، ومحتوى معين من الماء الورقي وشكل الورقة، منقوشًا بالارتفاع والجفاف وهطول الأمطار ودرجة الحرارة. وخلصنا إلى أنه، على الأقل بالنسبة للأنواع بطيئة النمو، مثل الزيت، فإن السمات "الميكانيكية" هي المفتاح لتحديد آليات التقييد المناخي. يوفر التعاون الهادف بين التخصصات "الميكانيكية" و "الوظيفية" أفضل طريقة لتحسين فهمنا للتأثيرات العالمية لتغير المناخ على توزيع الأنواع وأدائها.