System Dynamics Applied to Terraced Agroecosystems: The Case Study of Assaragh (Anti-Atlas Mountains, Morocco)

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, cological 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, uestionnaires 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

Evolution Du Couvert Végétal Naturel Au Niveau Des Massifs Forestiers De Mallalyine Et Taghramt (Rif Occidental Du Maroc)

This work presents the results of a cartographic study of the spatiotemporal evolution of vegetation cover in the forest areas of Mallalyine and Taghramt in the western Rif. It is based on a field survey and the photointerpretation of aerial photographs taken in 1986 and Google Earth images from 2013 (a period of twenty-seven years). Our study reports on the current state of degradation of the vegetation cover in the forests of Mallalyine and Taghramt. We have produced two land use maps showing how high and low formations as well as scrub have regressed by 62, 70 and 49 percent, respectively, between 1986 and 2013, while non-forested land and reforestation increased respectively by 26.3 and 1.53 percent relative to the area covered in 1986. The main factors contributing to the decline of vegetation cover are: deforestation (35 offenses registered every year with a degraded area of about 15 ha / year), clearing (27 offenses per year with an European Scientific Journal August 2018 edition Vol.14, No.24 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 20 affected area of about 20 ha / year), overgrazing (10 offenses of illegal grazing per year with a degraded area of about 12 ha / year), forest fires (4 to 5 fires per year with a degraded area of about 50 ha / year). In addition to these factors, we find increasing water scarcity

Aridity gradients shape intraspecific variability of morphological traits in native Ceratonia siliqua L. of Morocco

The carob tree (Ceratonia siliqua L.) is a significant fruit tree in the Mediterranean region with cultural, biological, and ecological importance. Despite its importance, intraspecific trait variability (ITV) in carob trees has been largely overlooked in previous studies. Understanding ITV and its relationship with environmental conditions is crucial for conservation and breeding programs. In this study, we investigated the variability of carob pod and seed-related traits across different ecological scales in 25 studied populations in Morocco. Significant differences in morphological traits were observed between carob populations at various ecological levels, and pod-related traits exhibited greater variability than seed traits. Correlation analysis revealed strong associations between carob morphological traits and environmental conditions, with altitude and aridity index playing an influential role. The aridity gradient was strongly related to changes in pod size, seed number, and size, as well as seed yield. Our findings highlight an important ITV reaching 45% at the intra-population level, 36.5% at the inter-geographic level, and 30% at the inter-population level. Overall, this study contributes valuable insights into the ecology and adaptation of carob trees, emphasizing the importance of considering intraspecific variability when studying this remarkable species. This knowledge is critical for addressing the challenges posed by climate change and human activities on the long-term survival and ecological functioning of carob populations

Assessing the impact of deficit irrigation strategies on agronomic and productive parameters of Menara olive cultivar: implications for operational water management

The olive tree is an iconic tree in the Mediterranean region, traditionally cultivated under rainfed conditions; however, olive cultivars are also found outside the Mediterranean region and are widely used for oil and olive production. However, with the increasing aridity and global changes, olive agroecosystems are facing sustainability challenges. This study aims to evaluate the effect of two deficit irrigation strategies on the agronomic and productive parameters of the Menara, olive cultivar as a tool for operational irrigation water management. For this purpose, an experiment was conducted on an olive orchard for two consecutive years (2021 and 2022), comparing four regulated deficit irrigation (RDI) treatments and two sustained deficit irrigation (SDI) treatments, with fully irrigated trees. The results showed that moderate and controlled water stress under RDI did not significantly affect the yield of the Menara olive cultivar. In addition, by reducing plant water requirement by 20% during sensitive periods and by 40% during normal periods, under RDI, it is possible to save between 25% and 30% of irrigation water and to increase water productivity by 5%–20% with a slight decrease in fruit yield ranging between 10% and 15%. However, the trees subjected to the sustained deficit irrigation strategy exhibited a reduced capacity for shoot growth compared to those under RDI and fully irrigated conditions. Our findings showed that water deprivation during sensitive periods reduced phenological traits and slowed down shoot growth. Furthermore, the water status of the trees was reflected in fruit volume, as a decrease in water supply resulted in a corresponding reduction in fruit volume. Although the study provides important insights into water management strategies for olive cultivation, the short observation period does not allow for long-term plant adaptation evaluation and productivity beyond 2 years. Therefore, it is recommended that future studies extend the observation period to better understand plant adaptation to irrigation regimes

Réponse de traits fonctionnels foliaires et anatomiques chez l'olivier sauvage (Olea europaea L.) dans un environnement hétérogène et changeant : le modèle du Maroc soumis aux changements globaux

In the current context of global changes, is mainly important to study adaptive plant strategies in response to environmental changes. Olive (Olea europaea L.), emblematic Mediterranean species, seems vulnerable to the effect of anthropogenic and climatic changes under its distribution area. The Moroccan range of wild (spontaneous) populations of this species extends along a latitudinal gradient integrated into an aridity gradient. Sampling along this gradient made it possible to study 27 populations (19 populations of sylvestris variety of the europaea subspecies, and 8 population of the endemic subspecies Olea maroccana). This thesis explores, (i) Intraspecific variability of leaf and wood anatomical traits along aridity gradient at different organization levels (interpopulation, intrapopulation and intraindividual level) (ii) the functional strategies deployed by the two wild olive subspecies interpreted as adaptive responses (iii) the relationship of these strategies with the plant communities differentiation and ecology where the studied populations were sampled. The obtained results confirm the climatic aspect of the gradient underlying this work, because they show that the main ecological factors explaining the diversity of wild olive plant communities are of climatic nature. Our results show that functional leaf traits variation of oleaster (O. e. subsp. e. var sylvestris) expresses the ability of the species to use available resources to respond to changing climatic conditions, particularly aridity. Moreover, analysis of the leaf traits intraspecific variability of the two wild olive subspecies highlights the existence of a trade-off between resources acquisition and conservation according to climate and plant community type. For wood anatomical traits, our results show a pattern of variations in response to biogeographic, climatic and vegetation gradients allowing the wild olive to maintain its sap conduction performance and consequently adapt to changes in ecological stressful conditions, in particular to aridity and aridification. The differentiation of wild olive populations along the latitudinal gradient by functional leaf and wood traits corresponds also to a differentiation of plant communities, which these populations are part of. Finally, this study has greatly expands our understanding of adaptive strategies of olive tree (Olea europaea L.) in Morocco in response to a latitudinal gradient of aridity.Dans le contexte actuel des changements globaux, il est important d’étudier les stratégies adaptatives des plantes en réponse aux changements environnementaux. L’olivier (Olea europaea L.), espèce emblématique méditerranéenne, semble vulnérable face à l’effet des changements anthropiques et climatiques que connait son aire de distribution. L’aire de distribution marocaine des populations sauvages (spontanées) de cette espèce s’allonge le long d’un gradient latitudinal assimilé à un gradient d’aridité. L’échantillonnage le long de ce gradient a permis d’étudier 27 populations (19 populations de la variété sylvestris de la sous-espèce europaea et 8 populations de la sous-espèce endémique maroccana). Cette thèse explore, (i) la variabilité intraspécifique des traits foliaires et anatomiques du bois à différents niveaux d’organisation (interpopulations, intrapopulations et intraindividus) le long d’un gradient d’aridité (ii) les stratégies fonctionnelles déployées par les deux sous-espèces d’olivier sauvage interprétées comme des réponses adaptatives (iii) la relation de ces stratégies avec la différentiation et l’écologie des communautés végétales où les populations étudiées ont été échantillonnées. Les résultats obtenus confirment la nature climatique du gradient sous-jacent à ce travail, car ils montrent que les principaux facteurs écologiques expliquant la diversité des communautés végétales à olivier sauvage sont de nature climatique. Nos résultats montrent que la variation des traits fonctionnels foliaires de l’oléastre (O. e. subsp. e. var sylvestris) exprime la capacité de l’espèce à utiliser les ressources disponible pour répondre à la variation de conditions climatiques, particulièrement l’aridité. En outre, l’analyse de la variabilité intraspécifique des traits foliaires chez les deux sous-espèces d’olivier sauvage met en évidence l’existence d’un compromis entre acquisition et conservation des ressources en fonction du climat et du type de communauté végétale. Au niveau des traits anatomiques du bois, nos résultats montrent un patron de variations en réponse aux gradients biogéographiques, climatiques et de végétation permettant à l’olivier sauvage de maintenir sa performance de conduction de la sève brute et par conséquence de s’adapter aux changements des conditions écologiques stressantes, notamment l’aridification du milieu. La différenciation des populations d’olivier sauvage le long du gradient latitudinal par les traits fonctionnels foliaires et du bois correspond également à une différenciation des communautés végétales dont ces populations font partie. Finalement, cette étude a permis d’élargir notre compréhension sur les stratégies adaptatives d’olivier sauvage (Olea europaea L.) au Maroc en réponse à un gradient latitudinal d’aridité

Response of functional leaf and wood anatomical traits of the wild olive (Olea europaea L.) in a heterogeneous and changing environment : Morocco as model to global changes

Dans le contexte actuel des changements globaux, il est important d’étudier les stratégies adaptatives des plantes en réponse aux changements environnementaux. L’olivier (Olea europaea L.), espèce emblématique méditerranéenne, semble vulnérable face à l’effet des changements anthropiques et climatiques que connait son aire de distribution. L’aire de distribution marocaine des populations sauvages (spontanées) de cette espèce s’allonge le long d’un gradient latitudinal assimilé à un gradient d’aridité. L’échantillonnage le long de ce gradient a permis d’étudier 27 populations (19 populations de la variété sylvestris de la sous-espèce europaea et 8 populations de la sous-espèce endémique maroccana). Cette thèse explore, (i) la variabilité intraspécifique des traits foliaires et anatomiques du bois à différents niveaux d’organisation (interpopulations, intrapopulations et intraindividus) le long d’un gradient d’aridité (ii) les stratégies fonctionnelles déployées par les deux sous-espèces d’olivier sauvage interprétées comme des réponses adaptatives (iii) la relation de ces stratégies avec la différentiation et l’écologie des communautés végétales où les populations étudiées ont été échantillonnées. Les résultats obtenus confirment la nature climatique du gradient sous-jacent à ce travail, car ils montrent que les principaux facteurs écologiques expliquant la diversité des communautés végétales à olivier sauvage sont de nature climatique. Nos résultats montrent que la variation des traits fonctionnels foliaires de l’oléastre (O. e. subsp. e. var sylvestris) exprime la capacité de l’espèce à utiliser les ressources disponible pour répondre à la variation de conditions climatiques, particulièrement l’aridité. En outre, l’analyse de la variabilité intraspécifique des traits foliaires chez les deux sous-espèces d’olivier sauvage met en évidence l’existence d’un compromis entre acquisition et conservation des ressources en fonction du climat et du type de communauté végétale. Au niveau des traits anatomiques du bois, nos résultats montrent un patron de variations en réponse aux gradients biogéographiques, climatiques et de végétation permettant à l’olivier sauvage de maintenir sa performance de conduction de la sève brute et par conséquence de s’adapter aux changements des conditions écologiques stressantes, notamment l’aridification du milieu. La différenciation des populations d’olivier sauvage le long du gradient latitudinal par les traits fonctionnels foliaires et du bois correspond également à une différenciation des communautés végétales dont ces populations font partie. Finalement, cette étude a permis d’élargir notre compréhension sur les stratégies adaptatives d’olivier sauvage (Olea europaea L.) au Maroc en réponse à un gradient latitudinal d’aridité.In the current context of global changes, is mainly important to study adaptive plant strategies in response to environmental changes. Olive (Olea europaea L.), emblematic Mediterranean species, seems vulnerable to the effect of anthropogenic and climatic changes under its distribution area. The Moroccan range of wild (spontaneous) populations of this species extends along a latitudinal gradient integrated into an aridity gradient. Sampling along this gradient made it possible to study 27 populations (19 populations of sylvestris variety of the europaea subspecies, and 8 population of the endemic subspecies Olea maroccana). This thesis explores, (i) Intraspecific variability of leaf and wood anatomical traits along aridity gradient at different organization levels (interpopulation, intrapopulation and intraindividual level) (ii) the functional strategies deployed by the two wild olive subspecies interpreted as adaptive responses (iii) the relationship of these strategies with the plant communities differentiation and ecology where the studied populations were sampled. The obtained results confirm the climatic aspect of the gradient underlying this work, because they show that the main ecological factors explaining the diversity of wild olive plant communities are of climatic nature. Our results show that functional leaf traits variation of oleaster (O. e. subsp. e. var sylvestris) expresses the ability of the species to use available resources to respond to changing climatic conditions, particularly aridity. Moreover, analysis of the leaf traits intraspecific variability of the two wild olive subspecies highlights the existence of a trade-off between resources acquisition and conservation according to climate and plant community type. For wood anatomical traits, our results show a pattern of variations in response to biogeographic, climatic and vegetation gradients allowing the wild olive to maintain its sap conduction performance and consequently adapt to changes in ecological stressful conditions, in particular to aridity and aridification. The differentiation of wild olive populations along the latitudinal gradient by functional leaf and wood traits corresponds also to a differentiation of plant communities, which these populations are part of. Finally, this study has greatly expands our understanding of adaptive strategies of olive tree (Olea europaea L.) in Morocco in response to a latitudinal gradient of aridity

Trait-based plant ecology a flawed tool in climate studies? The leaf traits of wild olive that pattern with climate are not those routinely measured.

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

Plant diversity in traditional agroecosystems of North Morocco

Questions: While globalisation favours intensive yield-maximizing agriculture with cropping practices that entail agrobiodiversity loss, extensive production systems still exist in areas of marginal lands such as in mountainous regions or islands. It is overdue to study such systems, their sustainability and ecology as potential models for decentralized environmentally balanced land-use. For that purpose, we investigated the composition of the wild arable (segetal) flora in traditional thermo- to mesomediterranean cereal-growing agroecosystems of northwestern Morocco. Study area: The Tingitane (Tangier) Peninsula in the Northwest of Morocco. Methods: A sample of 94 relevés was collected in six areas in the foreland of the Rif Mountains. Results: We found 209 species in 150 genera and 41 families, a mean of 22 species per relevé and a Shannon index of 3.04±0.06. A TWINSPAN classification revealed a high level of similarity between the areas, with the plant communities corresponding to the order Brometalia rubenti-tectorum, but also differences in species composition as a result of climatic, soil and land-use effects. Therophytes dominated, but biennial and perennial herbs indicating shallow tillage and fields under fallow were also common. Almost half of the species found were agrestal species (confined to arable fields), and almost a third were apophytes (native species occurring in fields but also in natural habitats). Twenty-nine species (14%) of the segetal flora were regional endemics and six are considered nationally rare. Although there is evidence of recent structural and floristic diversity decline, traditional agroecosystems tend to favour native species including some of particular conservation interest. Conclusions: The traditional agroecosystems of the Rif Mountains fulfil criteria of High Nature Value agriculture but, in view of recent socio-economic change, require support by policy for their maintenance. Taxonomic reference: Euro+Med PlantBase (http://www.europlusmed.org) [accessed 26 Nov 2022]. Syntaxonomic reference: EuroVegChecklist (Mucina et al. 2016). Abbreviations: TWINSPAN = Two Way Indicator Species Analysis

Diversity and ecology of aquatic insects (Ephemeroptera, Plecoptera and Trichoptera) in the Martil basin (Northwestern Morocco)

The current study aimed to examine the responses of Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa to the major physicochemical (temperature, pH, electrical conductivity, dissolved oxygen, biological oxygen demand, chemical oxygen demand) and hydro-morphological (stream width, water depth and current speed) factors affecting their abundance, rich- ness and distribution. Immature insects of Ephemeroptera, Plecoptera and Trichoptera were sampled as well as water during eight seasonal surveys conducted at 19 stations in Martil basin from spring 2016 to spring 2018. In total, 10,370 individu- als belonging to 22 families, 36 genera and 48 species were collected during the study period. Baetidae, Perlodidae and Hydropsychidae were the most abundant and diversified families, respectively for each order. Significant biotypological differences of the EPT assemblages were observed among stream types relating to their spatial distribution, hydrological features and pollution levels. However, species richness and abundance were positively correlated with DO, pH and altitude and negatively correlated with temperature and the other parameters measured. The taxonomic list compiled following our recent investigations includes six new species for the Martil basin enabling them to expand their range in northern Morocco. Furthermore, the biogeographical analysis shows that EPT taxa from Martil basin are essentially composed of Mediterranean elements, with a high proportion of Ibero-Maghrebian endemic species. Moreover, this study provides a basis for further studies to analyze the distribution patterns of EPT taxa through multi-dimensional approaches