Argania spinosa is among the most important species of the Moroccan forest in terms of ecological, environmental, and socio-economic aspects. However, it faces a delicate balance between regeneration and degradation in its natural habitat. Hence, the efforts to preserve and regenerate argan forests are crucial for biodiversity, soil quality, and local livelihoods, yet they face challenges like overgrazing and climate change. Sustainable management practices, including reforestation and community engagement, are vital for mitigating degradation. Similarly, exploiting the argan tree’s rhizosphere can enhance soil quality by leveraging its rich microbial diversity. This approach not only improves crop growth but also maintains ecosystem balance, ultimately benefiting both agriculture and the environment. This enrichment can be achieved by different factors: mycorrhizae, plant extracts, algae extracts, and plant growth-promoting rhizobacteria (PGPR). The benefits provided by PGPR may include increased nutrient availability, phytohormone production, shoot, root development, protection against several plant pathogens, and disease reduction. In this study, the effect of rhizobacteria isolated from the Agran rhizosphere was evaluated on germination percentage and radicle length for Argania spinosa in vitro tests, growth, collar diameter, and branching number under greenhouse conditions. One hundred and twenty (120) bacteria were isolated from the argan rhizosphere and evaluated for their capacity for phosphate solubilization and indole acetic acid production. The results showed that 52 isolates could solubilize phosphorus, with the diameters of the solubilization halos varying from 0.56 ± 0.14 to 2.9 ± 0.08 cm. Among 52 isolates, 25 were found to be positive for indole acetic acid production. These 25 isolates were first tested on maize growth to select the most performant ones. The results showed that 14 isolates from 25 tested stimulated maize growth significantly, and 3 of them by 28% (CN005, CN006, and CN009) compared to the control. Eight isolates (CN005, CN006, CN004, CN007, CN008, CN009, CN010, and CN011) that showed plant growth of more than 19% were selected to evaluate their effect on argan germination rate and radicle length and were subjected to DNA extraction and conventional Sanger sequencing. The 8 selected isolates were identified as: Brevundimonas naejangsanensis sp2, Alcaligenes faecalis, Brevundimonas naejangsanensis sp3, Brevundimonas naejangsanensis sp4, Leucobacter aridicollis sp1, Leucobacter aridicollis sp2, Brevundimonas naejangsanensis sp1, and Staphylococcus saprophyticus. The results showed that Leucobacter aridicollis sp2 significantly increased the germination rate by 95.83%, and the radicle length with a value of 2.71 cm compared to the control (1.60 cm), followed by Brevundimonas naejangsanensis sp3 and Leucobacter aridicollis sp1 (2.42 cm and 2.11 cm, respectively). Under greenhouse conditions, the results showed that the height growth increased significantly for Leucobacter aridicollis sp1 (42.07%) and Leucobacter aridicollis sp2 (39.99%). The isolates Brevundimonas naejangsanensis sp3 and Leucobacter aridicollis sp1 increased the gain of collar diameter by 41.56 and 41.21%, respectively, followed by Leucobacter aridicollis sp2 and Staphyloccocus saprophyticus (38.68 and 22.79%). Leucobacter aridicollis sp1 increased the ramification number per plant to 12 compared to the control, which had 6 ramifications per plant. The use of these isolates represents a viable alternative in sustainable agriculture by improving the germination rate and root development of the argan tree, as well as its development, while increasing the availability of nutrients in the soil and consequently improving fertilization.

Climate change, through increased aridity, threatens ecosystems, including Morocco’s endemic Argania Spinosa L. Skeels. This study assesses the impact of aridity on argan trees by analyzing morphological, ecophysiological, and biochemical parameters across various regions and comparing them with historical data. Significant variations were observed in leaf area, leaf length, chlorophyll content, relative water content, polyphenols, flavonoids, soluble sugars, and antioxidant activity, while leaf width ratio and chlorophyll ratio remained stable. Tioughza exhibited the largest leaf area (136.07 mm²), the highest chlorophyll content (436.76 mg/m²), and superior water retention (52.27%). Conversely, Ezzaouite showed the smallest leaf area (85.76 mm²) and lowest water content (37.68%). Increased aridity has intensified these differences, revealing the argan tree’s vulnerability to climate change. The findings underscore the need for targeted conservation efforts, including reforestation, strengthened legislation, and enhanced genetic research, to sustain this vital species.

Assessing the impact of natural disturbances on plant biodiversity is crucial amid biodiversity loss and climate change. Research highlights dynamic shifts driven by environmental factors, climate change, and human activity, emphasizing the need to maintain ecosystem stability for biodiversity conservation and sustainable development, particularly in arid and semi-arid regions. This study, conducted between 2021 and 2023, focused on the dynamics of plant communities in argan tree reserve areas. Six argan orchards were selected as study sites for detailed investigation. A total of 82 species belonging to 25 families were identified, with 23 families documented in 2021 and 21 families in 2023, including six endemic species to Morocco (Frankenialaevis subsp. velutina, Ononisnatrix subsp. arganietorum, Rumex papilio, Andryala integrifolia subsp. cedretorum, Chiliadenushesperius, and Reseda difussa). The majority of the plants present in the study area were annual and biennial herbaceous types, exhibiting minimal seasonal stability within the plant communities. However, how communities respond to the effects of fluctuating disturbances remains unclear. This study explores the indirect effects of natural disturbances on community metrics in argan orchards, assessing plant diversity, biomass, and density across different orchard types. It highlights the influence of climate, soil properties, and biotic interactions on plant community dynamics. We utilized alpha diversity indices (Shannon, Simpson, Pielou’s, and Margalef’s) and beta diversity indices (Jaccard and Sorenson Similarity) to examine these patterns. Seasonal changes were predominantly influenced by temperature and precipitation, while diverse soil types shaped by relief, climate, and water balance contributed to different ecological functions. The key findings indicated the highest plant diversity in “Tioughza” and the most significant plant density in “Imoulass” and “Ezzaouite”. Soil nutrients (N, C, and P) showed a positive correlation with plant biomass, highlighting their vital role in biomass accumulation, whereas temperature, C/N ratio, and loam percentage were found to be crucial for plant richness. Mixed modeling revealed a significant relation between density and biomass, but no significant effect between alpha diversity (Shannon Index) and elevation. This study concludes that soil texture and climate significantly shape the relationships between diversity, biomass, and density, recommending further research into interactions among plant diversity, cover, biomass, and soil fertility to support the sustainable management of argan orchards.

Argania spinosa (L.) Skeels is an endemic species to Morocco that has multiple uses. It plays multiple important roles in terms of its botanical, ecological, and economic properties. However, the domestication of this species will open up considerable economic opportunities for Morocco. Here, for the first time, we assessed the effect of different doses of compost and NPK fertilizers on the vegetative growth parameters, biochemical and antioxidant potential of the Argania spinosa plant, and soil properties. Over a two-year period (2022–2023), eight different treatments were applied across two experimental sites. These treatments included the following: T0 (Control), T1 (F1-80.50.70 g NPK/plant), T2 (F1-125.75.100 g NPK/plant), T3 (F2-160.100.140 g NPK/plant), T4 (F2-250.150.200 g NPK/plant), T5 (F1-2.5 kg/plant compost), T6 (F1-5 kg/plant compost), T7 (F2-5 kg/plant compost), and T8 (F2-10 kg/plant compost), with F1 and F2 being the frequencies of application. We compared several doses of fertilizers with no fertilization as a control. The results showed a significant influence of the compost and NPK fertilizer on the vegetative growth parameters. For the Tamjlojt site, the first year is important because treatments T3 and T4 significantly increased height by 71.94 ± 21.15% and 74.31 ± 12.31%, respectively. For the circumference, the results showed a significant improvement by the treatments T4 and T3, and T1 demonstrated the highest gain. For the collar diameter, all treatments showed a significant difference. The most notable difference was observed with treatments T3 and T7 with 115.63 ± 33.88% and 101.09 ± 20.84%, respectively. For the Rasmouka site, the second year was the most important. The treatments with the most important height increase were T7 and T8, with a value of 43.14 ± 10.06% and 36.44 ± 9.95%; the same was observed for collar diameter as a significant increase was found in T8 and T7 with a value of 55.05 ± 15.7% and 54.08 ± 9.64%. For the circumference parameter, the treatments that increased significantly this parameter were T8 and T7 with a value of 53.36 ± 15.11% and 50.34 ± 11.29% in 2023. In addition, the highest content of carbohydrates was recorded for the treatment T3 with a value of 148.89 ± 8.11 (mg EG/g). For phenolic determination, the highest value was 2532 ± 457.13 (µg GAE/mL), shown for treatment T1. For flavonoids, the treatments that showed a significant effect were T1 and T6 with a value of 2261.98 ± 184.61 and 1237.70 ± 95.65 (µg QE/mL), respectively. For the impact on soil properties, the electrical conductivity, at the Tamjlojt site, treatment T1 showed a significant increase to 1139.00 ± 241.30 (ms/cm), while at the Rasmouka site, treatment T8 showed a significant increase to 303.33 ± 9.33 (ms/cm). Concerning organic carbon, all treatments resulted in increased percentages of this parameter in the soil. For the Tamjlojt site, the T7 treatment had a significant positive effect on this parameter with a value of 0.87 ± 0.12%. For the Rasmouka site, the T3 treatment increased the percentage of organic carbon with a value of 1.17 ± 0.07%. In addition, the organic matter content showed an improvement with a value of 2.02 ± 0.12%. As there are no previous studies in Argania spinosa fertilization, this study greatly contributes to our understanding of the benefits of using different fertilizers at different doses, in particular T8 and T7 as organic fertilizers and T3, T4 as chemical ones, on argan growth, the biochemical and antioxidant properties of leaves, and its soil properties.

This study aimed to elucidate the relationship between chemical profiles and in vitro biological activities of essential oils from Cladanthus eriolepis, Asteriscus graveolens, and Teucrium luteum subsp. flavovirens. The chemical composition of these essential oils has been previously reported in our recent publications, revealing distinct chemical profiles with pronounced interspecific variability and identification rates of 83.3%, 96.7%, and 98.1%, respectively. C. eriolepis exhibited a chemical profile rich in aliphatic esters with a mixed monoterpene–sesquiterpene composition dominated by α-pinene (13.0%), isobutyl angelate (10.7%), and 2-methylbutyl angelate (9.5%), whereas A. graveolens was characterized by a high abundance of 6-oxocyclonerolidol (72.5%). T. luteum subsp. flavovirens showed greater chemical complexity, including elemol (16.4%), α-pinene (12.0%), and eudesmol isomers (14.3%). All essential oils exhibited significant biological activities across various in vitro assays. C. eriolepis showed the strongest acaricidal effect (LC₅₀ = 0.539 µL/mL) and notable inhibitory activities against acetylcholinesterase (AChE), tyrosinase, and α-glucosidase (78.4%, 74.6%, and 69.2%, respectively). T. luteum subsp. flavovirens displayed the highest antioxidant capacity (DPPH IC₅₀ = 51.60 µg/mL; FRAP IC₅₀ = 35.53 µg/mL). Overall, variations in chemical profiles strongly influence biological activities, highlighting their potential as multifunctional bioactive sources.