Institut National de Recherche Forestière

Moringa stenopetala is a rapidly growing, unappreciated tree regarded as the “miracle tree” for its food, feed, and medicinal benefits. It appears to be a versatile and promising species for use under changing conditions. However, the biological response of Moringa stenopetala, a valuable but underutilized species, to drought remains unclear during its early growth stages. Therefore, the main aim of this study was to investigate the morphological, physiological, and biochemical responses of M. stenopetala seedlings to different levels of drought stress induced by PEG-6000. Four concentrations of PEG-6000 (0, 4, 8, and 12 percent) were applied to evaluate the effect of water deficit on the morphological, physiological, and biochemical characteristics of M. stenopetala. The results indicated that the water potential exhibited a statistically significant impact on the germination rate (82.5%) and the mean germination time. The osmotic potential of the PEG solution was found to have a significant impact on germination speed (93%), the kinetics of germination (39%), the germination index (102%), and the germination vigour index (91.25). The study further revealed a positive correlation between water stress and increased stem growth and root length. Concurrently, proline content exhibited a substantial decrease, directly proportional to the stress level incurred. The accumulation of soluble sugars in the leaves exhibited variation according to stress levels. Drought indices revealed that the moderate treatment of PEG gave the highest GSI (1.325), STI (1.325), MPI (0.93), and HM (0.906), indicating drought tolerance and potential regular growth under drought stress. PCA visualized the most relationships among the studied traits of Moringa under drought stress, revealing distinct groupings and key indicators of drought tolerance, where the first two principal components (PC1 and PC2) explain most data variation (83%). These conclusions emphasize the adaptive ability of Moringa under drought stress conditions, besides proving its application as a drought-resilient crop.

Abstract This study aimed to investigate the species distribution of the Barbary ground squirrel within Tindouf Cultural Park, an arid region where no prior occurrence records for this species existed. Additionally, we assessed the species’ potential range by modelling its bioclimatic niche. Our field trips conducted on 2023 to various habitats in the Tindouf cultural park have confirmed the presence of the Barbary ground squirrel in nine sites, primarily in rocky, mountainous areas with water sources. Vegetation in these areas is diverse, with a dominance of Acacia and Argan trees. The squirrels showed a preference for argan fruits. Using GBIF data, 2,133 geo-referenced observations were collected, showing an increase in occurrences from the 2000s. Due to the nature of the data collected (presence only) we used Maxent for modelling Barbary ground squirrel bioclimatic niche and distribution. The model used proved to be excellent, with an AUC value of 0.977. The Jackknife test identified the minimum temperature of the coldest month, the precipitation of the coldest quarter, and the average diurnal range as the main influencing variables on the presence of the Barbary ground squirrel. The predictive distribution map shows that the squirrel could potentially inhabit a larger area in Algeria than what is currently observed.

Glycaspis brimblecombei Moore is an invasive insect pest that primarily targets Eucalyptus species, with a particular preference for Eucalyptus camaldulensis. The mechanism of host selection involves the recognition of host volatiles by odorant binding proteins (OBPs), which play crucial roles in various insect behaviors, including intersexual communication, oviposition, and interactions with host plants. The objective of this study was to identify the phytochemicals responsible for this host preference. The chemical composition of the essential oil extracted from the infested leaves of E. camaldulensis Dehnh. was analyzed using gas chromatography-mass spectrometry, revealing a total of 66 compounds that accounted for approximately 97.218% of the total oil. The major components identified were p-Cymene (29.78%), β-Phellandrene (15.55%), and Crypton (9.34%). Among the 66 volatiles detected, nine compounds, including Farnesol, Nirolidol, (Z,Z)-Farnesal, (Z,E)-Farnesal, Valerenol, β-Cubebene, cis-Linaloloxide, trans-Linalool oxide, and L-Linalool, exhibited the lowest Gibbs free energy (ΔG) values, ranging from -7.74 to -6.84kcal/mol and favorable interactions with the hydrophobic cavity of the OBP CcapOBP22. Molecular dynamics simulations indicated that the docked models with (Z,E)-Farnesal, cis-Linaloloxide, and β-Cubebene were flexible and stable. This study may inform future pest management strategies targeting G. brimblecombei.

Accurate detection of phenological events, such as growth onset, cessation, and seasonal transitions, is essential for understanding tree growth dynamics, particularly in Mediterranean forests where bimodal growth patterns are common. While microcore analysis remains the most precise method, its labor-intensive nature has led researchers to rely on dendrometer-based approaches. However, traditional methods using dendrometer data— such as parametric growth curve fitting with phenological events detected as relative thresholds—are often biased by hydration-related fluctuations and may fail to accurately capture complex growth patterns. In this study, we compared commonly used detection methods, including the Gompertz and Richards parametric functions, a generalized additive model (GAM), and the zero-growth (ZG) concept, with a novel approach: the two-stage threshold approach (2STA). Our results showed that the 2STA consistently outperformed existing methods in identifying spring onset, summer cessation, and autumn onset, exhibiting deviations within the expected measurement uncertainty (±7 days). The method’s reliance on direct growth rate transitions, rather than smoothed curves or arbitrary percentiles, reduced errors associated with hydration-related stem fluctuations. However, year cessation was best estimated using a 95% relative growth threshold derived from the Richards function. These findings highlight the potential of the 2STA as a robust and objective method for phenological event detection using manually collected band dendrometer data, particularly for species with complex intra-annual growth patterns. Future research should focus on refining climate-based thresholds for cambial activity and validating the method across a wider range of species and environmental conditions.

Summary Ziziphora hispanica L. (Lamiaceae) is a medicinal aromatic plant which is native to Algeria in semi-arid regions, Morocco and southern Spain. Despite the medicinal and economic interests as well as the uncertain future that this species may encounter in its natural habitats, various aspects of the biology of its seeds have not been recognized up to date. To fulfill these gaps, seed germination has been studied under the effect of different incubation temperatures, and under the influence of defer-ential concentrations of water stress and saline stress. The seeds were first incubated at different temperatures (15, 20 and 25°C). Then, at 20°C, germination studies were carried out at various sodium chlo-ride concentrations (0, 25, 50, 75 and 100 Mmol /l) and various solutions of polyethylene glycol (PEG 6000 ) (0, -0.2, -0.4, and-0.6 Mpa). The results showed that Z. hispanica seeds were not dormant, and the optimal temperature of germination was 20°C, at which the maximum final germination percentage occurred (94%). A high negative correlation was obtained between the germination percentage and the various concentrations of NaCl. In comparison to other plant species that share its habitats, the results of the water stress impact tests indicate that Z. hispanica is very sensitive to water stress, indicating difficulties in germinating in semi-arid and arid regions and that climate change may restrict its natural habitats. The results of this study can serve as guidelines for propagation protocols of this species to support its conservation and cultivation.

The COVID-19 pandemic has had a profound impact on global public health, leading to significant epidemiological variations across regions. This study offers a comprehensive analysis of epidemiological trends in Algeria's wilayas, utilizing a robust methodology and real pandemic data. By examining key indicators such as new confirmed cases, total cases, deaths, and incidence rates, our research provides insights into the virus's spread and implications in various wilayas. The results reveal disparities in the epidemiological landscape, guiding public health strategies. Understanding underlying factors, including population density, social distancing, healthcare access, and local variables, is essential in grasping the pandemic's dynamics within each wilaya. Our study is an invaluable resource for public health officials and researchers, offering a detailed understanding of Algeria-specific epidemiological trends. These insights aid in guiding pandemic responses and implementing targeted interventions. In conclusion, our research enhances the understanding of COVID-19's impact in Algeria. It sheds light on epidemiological variations and provides essential information for an effective pandemic response. The study's rigorous methodology, using real pandemic data, emphasizes evidence-based decision-making to address COVID-19 challenges. It contributes to pandemic knowledge and serves as a blueprint for future epidemiological analyses in global health crises. Public health officials can use these findings to tailor responses to unique wilaya conditions, recognizing the need for localized strategies. This research underscores the interconnectedness of factors contributing to epidemiological variations, providing knowledge for ongoing COVID-19 responses and preparedness for future pandemics. In summary, our study significantly advances the understanding of COVID-19's impact on Algeria's wilayas. It offers crucial insights for public health strategies, policy decisions, and mitigating the pandemic's effects in the region. This research equips stakeholders with essential information for an effective and localized response.

Artemisia judaica L. locally named as “Teherdjeli” is used for its Jaundice, dysmenorrhea and Stomach diseases. In vitro investigation for its potential antibacterial, antibiofilm and sun protection factors were assessed. Essential oil of Artemisia judaica L. (10 μg.mL−1) has a more inhibiting effect on gram-positive bacteria Staphylococcus aureus (ATCC 33862) and clinically isolated (16.5 and 14.2 mm), respectively than gram-negative bacteria (Escherichia coli, Proteus mirabilis) clinical isolated (10.1 and 9 mm), respectively. Besides, essential oil was more potent and showed an appreciable antibiofilm activity against Staphylococcus aureus (ATCC 33862). Other tests such as sun protection factor (SPF) were studied and the value was found to be 3.49. The relevant antibiofilm, antibacterial and SPF activities of A. judaica L. essential oil (AJEO) corroborated with their chemical compositions. However, chemical constituents from AJEO (yield ∼1.1%, w/v), were characterized using (GC/ MS, FTIR, 13C NMR, 1H NMR, LRI determination, database and literature searches). The prominent components in AJEO were piperitone, which accounts for 69.01% of the total osil composition. This finding suggests that A. judaica L. is a promising plant for industry and can be used in several sectors as a conservative to preserve food spoilage, and cosmetic or pharmaceutical preparations.

Abstract The Mediterranean Basin covers more than 2 million square kilometres and is surrounded by three continents: Africa, Asia, and Europe. It is home to more than 500 million people and is projected to reach 670 million by 2050. The basin is rich in species diversity, with a great wealth of endemism. The supply of ecosystem services is greatly challenged due to the trend of land use and land cover (LULC) change coupled with other global change drivers. The current study thoroughly reviewed the existing body of knowledge on the impacts of LULC change on forest ecosystem services. The LULC change is driven by synergetic factor combinations of urbanization, population increase, agricultural land abandonment and deforestation putting additional strain on forest ecosystem services. The review shows the potential impacts on biodiversity as well as ecosystem services such as wood and non-wood forest products, water resources, and carbon stock. Moreover, there is evidence showing the threats of LULC change to saproxylic beetle species, a key agent in the nutrient cycling process, posing a significant risk to a nutrient-deficient ecosystem. Therefore, there is a need to mitigate the challenges posed by LULC change and adapt forest management practices to impending changes to sustain the provision of ecosystem goods and services.