Comprehensive review of morphological adaptations and conservation strategies of cactiform succulents: A case study of Euphorbia species in arid ecosystems

Cactiform succulents, belonging to the Euphorbia genus, are distinctive species found in the arid and semi-arid ecosystems of Macaronesia and the Arabian Peninsula. Resembling cacti in appearance, they exhibit unique morphological characteristics, such as succulent, green-stemmed structures with ribs, accompanied by a pair of stipular spines. These plants have evolved to thrive in well-draining substrates, including both surface and rocky soils, potentially as an adaptive strategy to combat edaphic drought conditions. Although initially associated solely with arid and desert environments, it is important to note that these cactiform succulents are not exclusively specialized for prolonged dry periods. Rather, they demonstrate morphological adaptations that help them endure arid conditions. The primary objective of this review is to provide an up-to-date synthesis of knowledge concerning cactiform succulents within the Euphorbia genus. It aims to underscore their capacity to flourish in both arid and semi-arid zones, while underscoring the pressing conservation challenges that threaten these plants with degradation and potential extinction. The prevailing climatic conditions, marked by extended and recurrent droughts exacerbated by escalating temperatures, climate fluctuations, and escalating human impact, collectively pose a formidable obstacle to conserving these cactiform succulents and their respective ecosystems. All these threats jeopardize these invaluable natural resources, which hold multifaceted significance spanning environmental, socio-economic, and medicinal domains

Ecological insights and conservation imperatives for Laurus azorica in Morocco

The Azores laurel Laurus azorica (Seub.) Franco is a highly esteemed forest species in Morocco due to its medicinal and aromatic properties. However, the natural habitats of this species are increasingly scarce, resulting in its classification as a rare species. This study comprehensively investigates the autoecology, plant communities, and distribution patterns of L. azorica, aiming to discern the crucial ecological factors underpinning its survival and shed light on its conservation status. Field surveys, including floristic relevés and environmental characterization, were conducted to identify the primary plant communities hosting remnants of L. azorica. Fieldwork and ecological analysis reveal five distinct plant communities associated with L. azorica: low elevation thermophilic holm oak woodland, mesophilic mid-altitude holm oak woodland, Quercus faginea, deciduous broadleaf mountain and Cytisus balansae plant communities. The study emphasizes the importance of ecological requirements such as oceanic exposure, rainfall, temperature, and forest mull soils in creating suitable habitats for L. azorica populations. Currently, L. azorica populations in Morocco are represented by small trees, shrubs, or bushes, often exhibiting distorted and damaged structures due to unregulated pruning. Natural regeneration of the species is completely absent. The value chain associated with L. azorica is limited, involving informal harvesters, intermediary herbalist grocers, and final consumers, due to the lack of a legal framework for resource evaluation caused by its severe depletion. To secure the survival of L. azorica in Morocco, it is crucial to address gaps in legislation, intensify conservation efforts, and promote sustainable development practices. Protecting and restoring the natural habitats of the species, along with implementing responsible harvesting practices, are essential steps towards conserving this valuable forest species

Essai d'optimisation de la mycorhization contrôlée du Cèdre de l'Atlas (Cedrus atlantica Manetti)

351 ref. *INRA d'Orléans, Documentation, Ardon 45166 Olivet Diffusion du document : INRA d'Orléans, Documentation, Ardon 45166 Olivet Diplôme : Dr. Ing

Effets de la fertilisation phosphatée sur la mycorhisation, la croissance et la nutrition en phosphore et en azote de semis de Cèdre (Cedrus atlantica Manetti) inoculés en pépinière par Tricholoma tridentinum Sing. var. cedretorum Bon.

National audienc

Ectomycorhisation de Cedrus atlantica en conditions controlées: efficacité de deux formes d'inoculum mycélien

National audienc

A comparison of ammonium, nitrate and proton net fluxes along seedling roots of Douglas-fir and lodgepole pine grown and measured with different inorganic nitrogen sources Context Sensitive Links

Correspondance: [email protected] audienceSignificant spatial variability in NH4+, NO3- and H+ net fluxes was measured in roots of young seedlings of Douglas-fir (Pseudotsuga menziesii) and lodgepole pine (Pinus contorta) with ion-selective microelectrodes. Seedlings were grown with NH4+, NO3-, NH4NO3 or no nitrogen (N), and were measured in solutions containing one or both N ions, or no N in a full factorial design. Net NO3- and NH4+ uptake and H+ efflux were greater in Douglas-fir than lodgepole pine and in roots not exposed to N in pretreatment. In general, the rates of net NH4+ uptake were the same in the presence or absence of NO3-, and vice versa. The highest NO3- influx occurred 0-30 mm from the root apex in Douglas-fir and 0-10 mm from the apex in lodgepole pine. Net NH4+ flux was zero or negative (efflux) at Douglas-fir root tips, and the highest NH4+ influx occurred 5-20 mm from the root tip. Lodgepole pine had some NH4+ influx at the root tips, and the maximum net uptake 5 mm from the root tip. Net H+ efflux was greatest in the first 10 mm of roots of both species. This study demonstrates that nutrient uptake by conifer roots can vary significantly across different regions of the root, and indicates that ion flux profiles along the roots may be influenced by rates of root growth and maturatio

Root system architecture and receptivity to mycorrhizal infection in seedlings of Cedrus atlantica as affected by nitrogen source and concentration

International audienc