Rachid Sabbahi

Insect pollinator declines are increasingly documented worldwide, yet assessment of pollination resilience often focuses on species loss or current ecosystem function without explicitly considering changes in interaction structure and recovery history. In dryland agroecosystems, pollination function may remain apparently stable despite progressive erosion of specialist-mediated interactions and interaction-network diversity. We propose the Arid Zone Pollinator Paradox (AZPP) as a falsifiable hypothesis of structural-functional decoupling and history-dependent recovery. Under chronic environmental stress, selected pollination functions may remain temporarily buffered as functionally constrained interactions are lost and remaining broad-interaction taxa provide partial compensation, while interaction-network structure and the pool of compatible interaction alternatives progressively contract. A rigidity-trap trajectory is proposed as a possible downstream outcome under sufficiently persistent structural erosion and constrained rewiring, rather than as an assumed or inevitable stage. Four proximate mismatch pathways—temporal, spatial, morphological, and attraction/cue-related—are identified as alternative routes through which environmental filtering may generate asymmetric interaction loss and constrain compensatory interaction replacement. Multiple environmental stressors may further amplify these processes, but are treated as context-dependent modifiers rather than necessary components of the hypothesis. AZPP generates three principal predictions: structural-functional decoupling under chronic stress, history-dependent recovery following stress alleviation, and asymmetric interaction loss accompanied by contraction of functionally compatible alternatives. These predictions can be tested using longitudinal interaction-network monitoring, comparative analyses, stress-release or restoration experiments, and abundance- and co-occurrence-constrained null models. Grounded primarily in ecological observations from Moroccan drylands, AZPP is proposed for comparative testing across arid and semi-arid agroecosystems to determine its broader applicability and boundary conditions. The framework is primarily formulated for bee-dominated pollination systems, with extension to other pollinator guilds remaining an empirical question.

This study investigated the chemical composition, antioxidant activity, and genotoxic potential of essential oils (EOs) obtained by hydrodistillation from aerial parts of four wild-growing Lamiaceae species in eastern Morocco: Spanish ziziphora (Ziziphora hispanica L.), felty germander (Teucrium polium L.), French lavender (Lavandula dentata L.), and topped lavender (Lavandula stoechas L.). Gas chromatography–mass spectrometry (GC-MS) analysis revealed eucalyptol (40.08%), thujopsene (11.25%), β-myrcene (15.82%), and fenchone (30.69%) as the major constituents in Z. hispanica, T. polium, L. dentata, and L. stoechas, respectively. Antioxidant capacity was evaluated using three complementary assays: 2,2-diphenyl-1-picrylhydrazyl radical scavenging, ferric reducing antioxidant power, and β-carotene bleaching. L. stoechas and L. dentata exhibited the strongest antioxidant activities, with IC₅₀ values ranging from 0.284 to 1.71 mg/mL across assays. Genotoxicity was assessed in rat leukocytes using the alkaline Comet assay at EO concentrations of 2.5, 5, and 10 µg/mL. All tested EOs induced statistically significant DNA damage compared to the negative control, though the extent varied by species and concentration; notably, L. stoechas at 2.5 µg/mL showed the lowest genotoxic impact. These findings highlight the dual potential of these EOs as natural antioxidants while underscoring the need for dose-dependent safety evaluation prior to therapeutic or industrial application. Given that DNA damage was detectable even at 2.5 µg/mL, a conservative practical recommendation is to keep EO levels below 2.5 µg/mL-equivalent in preliminary applications, pending further in vivo toxicology to establish NOAEL-based exposure limits.

Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) hold significant potential across multiple industries, with applications extending from food technology to pharmaceuticals. Although numerous studies have explored their technological and biological functionalities such as thickening, stabilization, and health-promoting effects the existing literature remains fragmented regarding the biosynthesis mechanisms, genetic regulation, and structure function relationships of LAB-derived EPS. Moreover, current reviews often address these aspects separately, lacking an integrated perspective that connects molecular mechanisms to practical applications. This review fills these gaps by providing a comprehensive and unified analysis of LAB produced EPS, covering their classification, biosynthetic pathways (including the influence of genetic determinants), structural diversity, technological roles, and biological activities. It also evaluates recent advances in production optimization and analytical characterization techniques. By consolidating dispersed knowledge, this review offers a holistic framework that links molecular insights with functional outcomes, thus supporting the rational design of LAB strains for targeted EPS production. The focus on LAB EPS is particularly relevant due to their Generally Recognized as Safe (GRAS) status, which enhances their applicability in food and health-related sectors compared to microbial EPS from other sources. Ultimately, this review contributes a critical synthesis that guides future research and industrial innovation, aligning with the growing demand for naturally derived, multifunctional, and health-promoting biopolymers.