The first exploited and domesticated olive forms are still unknown. The exceptionally well-preserved stones from the submerged Hishuley Carmel site (Israel), dating from the middle of the 7th millennium BP, offer us the opportunity to study the oldest table olives discovered so far. We apply a geometrical morphometric analysis in reference to a collection of modern stones from supposed wild populations and traditional varieties of various origins, genetic lineages and uses. Analyses carried out on modern material allow the characterization of the extent of stone morphological variation in the olive tree and the differentiation of distinct morphotypes. They also allow to discuss the status of supposed wild populations and the divergence between groups of varieties and their wild progenitors, interpreted from evolutionary and biogeographical perspectives. The shape of archaeological stones compared to the differentiation model unveils morphological traits of olives most likely belonging to both wild olive trees and domesticated forms, with some of them showing a notable domestication syndrome. These forms at the early stages of domestication, some of which are surprisingly morphologically close to modern varieties, were probably used for dual use (production of olive oil and table olives), and possibly contributed to the dispersion of the olive tree throughout the Mediterranean Basin and to its subsequent diversification.

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.

In the current context of global change, the increasing frequency and the length of drought periods are testing the resistance capacities of plants of dry habitats. However, although the adaptation of plants to drought has been widely studied, the anatomical features of wood influencing the functional responses of plants to drought are still lacking at the intraspecific level, especially for species with a wide geographical distribution. As a result, we have studied the variation of wood anatomical traits related to sap conduction (i.e., vessel surface area, vessel density, and number of vessels joined by radial file) in two wild olive subspecies distributed in Morocco (i.e.,Olea europaeasubsp.europaea. var.sylvestrisandOlea europaeasubsp.maroccana), in relation to various drought conditions. This functional study, based on wood trait measurements of 351 samples from 130 trees and 13 populations, explores potential sap conduction in relation to environmental parameters and as a result, strategies to resist water stress. We found that (1) branch diameter (BD) captured 78% of total wood trait variation, (2) vessel size (SVS) expressed 32% of intraspecific variation according to cambium age, and (3) the positive relationship between SVS and BD could be explained by climate type, vegetation cover changes, and therefore available water resources. Taking into consideration the diameter of the branch as the main factor of anatomical variation, established reaction norms (linear models) at the intrapopulation scale of vessel lumen area according to aridity show for the first time how the functioning of the cambium modulates and controls sap conduction, according to aridity and thus available water resources. They pinpoint the risks incurred by the wild olive tree in the perspective of a dramatic increase in aridity, in particular, the inability of the cambium to produce large enough vessels to efficiently transport sap and irrigate the leaves. Finally, this study opens new and interesting avenues for studying at a Mediterranean scale, the resistance and the vulnerability of wild forms and cultivated varieties of olive to heterogeneous and changing environmental conditions.