Biodiversité des espaces verts publics de la commune urbaine de Marrakech (CUM) (Maroc). Biodiversity of the public green spaces in the Urban District of Marrakesh (UDM) (Morocco)

English. The Public Green Space (PGS) in urban zones is a major interest in the sustainable development, both regarding environment and the quality of life of their users. The present study constitutes a first research which is interested in the PGS of the Urban district of Marrakesh (UDM) to have a basis of scientific data on these spaces and to help taking decision and environmental planning of it. It aims at (i) the study of the diversity of the ornamental flora (ii) and the analysis of the structure and the distribution of these PGS. So, the prospecting concerned 50 PGS distributed on 5 districts of the UDM. The results showed a diversity of ornamental flora which contains 297 vascular species, distributed in 212 genera and 88 families. 77 % of species are exotic. This specific richness is dominated by 12 families which contain 142 species distributed in 85 genera. The frequency, the origin and the biological type of these species are much diversified. The study of the structure highlighted 4 types of PGS that differ by their size and their function. The analysis of the floral affinity of the PGS-UDM revealed 13 groups which distinguish by their floral compositions. Consequently, the PGS-UDM contributes deeply to the preservation and the increase of the floral diversity and improvement of the esthetic quality of the city of Marrakesh.Fraçais. En milieu urbain, l’espace vert public (EVP) constitue un enjeu majeur du développement durable, tant en matière d’environnement que de qualité de vie de leurs usagers. La présente étude présente une première recherche sur les EVP de la ville de Marrakech permettant de disposer d’une base de données scientifiques sur ces EVP qui va aider à la prise de décision et de planification environnementale de la ville. Elle vise (i) l’étude de la diversité de la flore ornementale (ii) et l’analyse de la structure et la répartition spatiale de ces EVP. La prospection a concerné 50 EVP urbains répartis sur les 5 arrondissements de la ville. Les résultats ont montré une diversité de la flore ornementale qui s’élève à 297 espèces vasculaires, réparties en 212 genres et 88 familles et dont 77 % des espèces sont exotiques. Cette richesse spécifique est dominée par 12 familles qui détiennent 142 espèces réparties en 85 genres. La fréquence, l’origine et le type biologique des espèces sont très diversifiés. L’étude de la structure a fait ressortir 4 types d’EVP qui diffèrent par leur taille et leur fonction. L’analyse de l’affinité floristique des EVP-CUM a fait apparaître 13 groupes qui se distinguent par leurs compositions floristiques. En conséquence, les EVP de la ville contribuent vivement à la conservation et l’accroissement de la diversité floristique et à l’amélioration de la qualité esthétique de la ville de Marrakech

Biodiversité des espaces verts publics de la commune urbaine de Marrakech (CUM) (Maroc).

The Public Green Space (PGS) in urban zones is a major interest in the sustainable development, both regarding environment and the quality of life of their users. The present study constitutes a first research which is interested in the PGS of the Urban district of Marrakesh (UDM) to have a basis of scientific data on these spaces and to help taking decision and environmental planning of it. It aims at (i) the study of the diversity of the ornamental flora (ii) and the analysis of the structure and the distribution of these PGS. So, the prospecting concerned 50 PGS distributed on 5 districts of the UDM. The results showed a diversity of ornamental flora which contains 297 vascular species, distributed in 212 genera and 88 families. 77 % of species are exotic. This specific richness is dominated by 12 families which contain 142 species distributed in 85 genera. The frequency, the origin and the biological type of these species are much diversified. The study of the structure highlighted 4 types of PGS that differ by their size and their function. The analysis of the floral affinity of the PGS-UDM revealed 13 groups which distinguish by their floral compositions. Consequently, the PGS-UDM contributes deeply to the preservation and the increase of the floral diversity and improvement of the esthetic quality of the city of Marrakesh.En milieu urbain, l’espace vert public (EVP) constitue un enjeu majeur du développement durable, tant en matière d’environnement que de qualité de vie de leurs usagers. La présente étude présente une première recherche sur les EVP de la ville de Marrakech permettant de disposer d’une base de données scientifiques sur ces EVP qui va aider à la prise de décision et de planification environnementale de la ville. Elle vise (i) l’étude de la diversité de la flore ornementale (ii) et l’analyse de la structure et la répartition spatiale de ces EVP. La prospection a concerné 50 EVP urbains répartis sur les 5 arrondissements de la ville. Les résultats ont montré une diversité de la flore ornementale qui s’élève à 297 espèces vasculaires, réparties en 212 genres et 88 familles et dont 77 % des espèces sont exotiques. Cette richesse spécifique est dominée par 12 familles qui détiennent 142 espèces réparties en 85 genres. La fréquence, l’origine et le type biologique des espèces sont très diversifiés. L’étude de la structure a fait ressortir 4 types d’EVP qui diffèrent par leur taille et leur fonction. L’analyse de l’affinité floristique des EVP-CUM a fait apparaître 13 groupes qui se distinguent par leurs compositions floristiques. En conséquence, les EVP de la ville contribuent vivement à la conservation et l’accroissement de la diversité floristique et à l’amélioration de la qualité esthétique de la ville de Marrakech

The first use of morphologically isolated arbuscular mycorrhizal fungi single-species from Moroccan ecosystems to improve growth, nutrients uptake and photosynthesis in Ceratonia siliqua seedlings under nursery conditions.

International audienceThe carob tree (Ceratonia siliqua L.) is an important component in semi-arid Mediterranean ecosystems, particularly in Morocco where it plays a considerable socioeconomic role. This species is widely used in the reforestation programmes and in the rehabilitation of degraded soils serving both environmental and socioeconomic objectives. In spite of these assets, this species is suffering the particular climatic conditions, rare and irregular rains, long hot and dry summers, generally, leading to desertification processes. To withstand these contrasting conditions, selected arbuscular mycorrhizal fungi (AMF) were tested for their contribution to the growth, nutrient uptake and photosynthesis improvement of the carob tree C. siliqua under nursery conditions. The objective of this study was, to evaluate the effects of some arbuscular mycorrhizal fungi complexes isolated in different Mediterranean ecosystems compared to single-species isolates selected using morphological tools on the growth, mineral nutrition, and chlorophyll content of C. siliqua seedlings. The results indicate that all the used AMF inocula stimulated significantly the height of C. siliqua seedlings after eight months under nursery conditions. An increase in plant height between 33% and 70% compared to a control without inoculation was recorded. Similarly, the aerial dry weight recorded an increase of 62% to 124% comparing inoculated and non-inoculated seedlings. The root dry weight has shown an increase rate of 24% to 86% compared to the control. The analysis of mineral contents in plant tissues, showed a highly significant increase in P. N. K. Ca and Mg levels of the aerial parts compared to the control. A significant increase in chlorophyll contents was noticed when inoculated seedlings were compared to non-inoculated ones. This study had confirmed the importance of AMF improving the growth of C. siliqua seedlings; the AMF complexes remain to have the important growth and mineral nutrition responses. However some single-species have shown similar magnitude to the complexes for all analysed parameters. A large biofertilizer potential of the single-species isolates in the inoculation of C. siliqua is demonstrated for the first time

Symbiotic interactions between a newly identified native mycorrhizal fungi complex and the endemic tree Argania spinosa mediate growth, photosynthesis, and enzymatic responses under drought stress conditions

International audienceWater deficit or drought is the most important abiotic stress limiting plant growth performance and plant community development; this is typical in the Mediterranean area where plants are often severely and permanently water limited. Such is the case of the argan tree (Argania spinosa (L.) Skeels), one of the tree species most affected by desertification and global warming. To advance knowledge on how this tree can withstand drought stress, inoculation with a native complex of arbuscular mycorrhizal fungi (AMF), composed mainly of the genus Glomus, was studied in connection with a set of growth and physiological parameters. Under controlled conditions, inoculated and non-inoculated argan seedlings were grown for 3 months under three water regimens: 25%, 50%, and 75% relative to the field capacity of used soil substrate. The results showed that the argan tree had different growth abilities to develop and withstand the various applied water limitations. The AMF complex stimulated the growth and mineral nutrition of argan seedlings under the different imposed levels of water deficiency. Relative water content (RWC) in leaves, water potential, and stomatal conductance in argan leaves showed a general improvement in inoculated seedlings compared to non-inoculated ones. Soluble sugar and proline contents significantly increased in non-inoculated seedlings compared with inoculated seedlings under water-limiting conditions (25%). Similarly, oxidative enzyme (catalase, peroxidase, superoxide dismutase) activity increased significantly in drought-stressed seedlings. Non-inoculated seedlings showed the highest accumulation of these enzymes. Moreover, mycorrhizal symbiosis establishment positively correlated with argan tree seedlings in terms of growth, mineral nutrition, soluble sugar and proline contents, and enzymes activities. The main results from the current study suggest that AMF improve the ability of A. spinosa to tolerate drought by enhancing mineral nutrition and the transport of high levels of water by enhancing the RWC and water potential in leaves. Finally, the alleviation of the destructive effects of reactive oxygen species was modulated by enzymatic scavenging activity. Hence, the use of AMF in the technical process of argan seedlings production is highly recommended in different ecofriendly restoration strategies, with the aim of producing high quality seedlings capable of tolerating drought stress

Mycorrhizal Fungi Inoculation Improves Capparis spinosa’s Yield, Nutrient Uptake and Photosynthetic Efficiency under Water Deficit

Agricultural yields are under constant jeopardy as climate change and abiotic pressures spread worldwide. Using rhizospheric microbes as biostimulants/biofertilizers is one of the best ways to improve agro-agriculture in the face of these things. The purpose of this experiment was to investigate whether a native arbuscular mycorrhizal fungi inoculum (AMF-complex) might improve caper (Capparis spinosa) seedlings’ nutritional status, their morphological/growth performance and photosynthetic efficiency under water-deficit stress (WDS). Thus, caper plantlets inoculated with or without an AMF complex (+AMF and −AMF, respectively) were grown under three gradually increasing WDS regimes, i.e., 75, 50 and 25% of field capacity (FC). Overall, measurements of morphological traits, biomass production and nutrient uptake (particularly P, K+, Mg2+, Fe2+ and Zn2+) showed that mycorrhizal fungi inoculation increased these variables significantly, notably in moderate and severe WDS conditions. The increased WDS levels reduced the photochemical efficiency indices (Fv/Fm and Fv/Fo) in −AMF plants, while AMF-complex application significantly augmented these parameters. Furthermore, the photosynthetic pigments content was substantially higher in +AMF seedlings than −AMF controls at all the WDS levels. Favorably, at 25% FC, AMF-colonized plants produce approximately twice as many carotenoids as non-colonized ones. In conclusion, AMF inoculation seems to be a powerful eco-engineering strategy for improving the caper seedling growth rate and drought tolerance in harsh environments

Application of Native or Exotic Arbuscular Mycorrhizal Fungi Complexes and Monospecific Isolates from Saline Semi-Arid Mediterranean Ecosystems Improved <i>Phoenix dactylifera</i>’s Growth and Mitigated Salt Stress Negative Effects

The date, the palm tree (Phoenix dactylifera L.) is an important component of arid and semi-arid Mediterranean ecosystems, particularly in Morocco where it plays a considerable socio-economic and ecological role. This species is largely affected by desertification, global warming, and anthropic pressure. Salinity is a very worrying problem that negatively affects the growth and the physiological and biochemical activities of the date palm. In these arid zones, the main challenge is to develop new environmentally friendly technologies that improve crop tolerance to abiotic restraints including salinity. In this sense, Arbuscular mycorrhizal fungi (AMF) have received much attention due to their capability in promoting plant growth and tolerance to abiotic and biotic stresses. It is thus fitting that the current research work was undertaken to evaluate and compare the effects of native AMF on the development of the growth and tolerance of date palm to salt stress along with testing their role as biofertilizers. To achieve this goal, two complexes and two monospecific isolates of native and non-native AMF were used to inoculate date palm seedlings under saline stress (0 g·L−1 Na Cl, 10 g·L−1, and 20 g·L−1 Na Cl). The obtained results showed that salinity drastically affected the physiological parameters and growth of date palm seedlings, whilst the application of selected AMF significantly improved growth parameters and promoted the activities of antioxidant enzymes as a protective strategy. Inoculation with non-native AMF complex and monospecific isolates showed higher responses for all analyzed parameters when compared with the native complex and isolate. It therefore becomes necessary to glamorize the fungal communities associated with date palm for their use in the inoculation of Phoenix dactylifera L. seedlings