Background The carob tree (Ceratonia siliqua L.) is one of the most iconic tree species of the Mediterranean region, with valuable economic, ecological and cultural value. Carob has been exploited around the Mediterranean region since antiquity and has been regarded as an important component of natural habitats and traditional agroecosystems. Several studies have focused on its morphological, biochemical, and genetic diversity. However, less is known about the intraspecific variation of seed traits. In this regard, and as an overall objective, we intend to evaluate the amplitude and the expression of intraspecific variations of carob seed traits at different ecological scales ranging from individual trees to different geographical landscapes. In addition, we investigated how the climate along the study area affects the extent of carob seed variability. Using image analysis techniques, we measured seven traits related to the size and the shape of 1740 seeds collected from 18 populations of spontaneous C. siliqua distributed along a latitudinal transect in Morocco under different bioclimatic conditions. Results The morphometric analysis of carob seed showed the effectiveness of adopted approach to highlight the amount and the amplitude of intraspecific variation according to geographic and climatic factors. Seed trait analysis revealed high intraspecific variability, explained by differences between and among carob populations and geographic zones. Seed area, perimeter, length, and width showed the largest variability between geographic zones. However, circularity, aspect ratio, and seed roundness showed higher variability at the tree level. Finally, our results show that seed traits vary depending on altitude and climate condition. Conclusions Revealing the amount and the structure of intraspecific traits variability of carob seed provides interesting insights to understand the mechanisms underlying trees adaptation to various environmental and ecological conditions. Therefore, intraspecific variation of seed traits should be integrated into trait-based functional ecology to assess plant species responses to environmental changes.

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.

Oases play a crucial role in human societies and the conservation of biodiversity, especially in harsh environments like arid zones. They serve as sanctuaries for agrodiversity, preserving diverse agricultural resources under challenging climatic conditions. However, these agroecosystems are becoming increasingly vulnerable to climate fluctuations, droughts, and other environmental changes. Understanding these unique agroecosystems is essential for developing effective strategies to protect them. Agrodiversity serves as a key indicator of the overall health of traditional agroecosystems. To assess the richness and diversity of agrodiversity, field surveys were conducted in six representative oases in southern Morocco. Within each oasis, we interviewed 20 farmers in five ksour. Our findings confirm the widespread practice of polyculture and reveal significant diversity among the oases. A total of 55 crops were identified, consisting of 183 varieties. Specifically, the oasis of Tata employed 42 crops, Alnif had 41 crops, Guelmim had 38 crops, Aoufouss had 32 crops, Rich had 29 crops, and Zagora had 28 crops. The profiles of varieties clearly distinguish between ksour and oases, highlighting the unique identities of each oasis. The modernization of farming practices is influenced by factors such as farm size, plot fragmentation, dispersal, and irrigation methods. However, its consequences are concerning. There is a risk of losing agrodiversity and compromising the food security of local populations. The shift from household consumption crops to cash crops has negative implications for the availability of diverse and nutritious food. Moreover, modernization often leads to increased water consumption, further straining the already limited water resources in these oases.

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