54 research outputs found
Note sur la présence d'une forme stérile d'Oxalis pes-caprae L. au Maroc.
About a presence of sterile form of Oxalis pes-caprae L. in MoroccoNote sur la présence d'une forme stérile d'Oxalis pes-caprae L. au MarocNote sur la présence d'une forme stérile d'Oxalis pes-caprae L. au Maro
Flore ("Pteridophyta" et "Spermatophyta") des zones humides du Maroc Méditérranéen: Inventaire et écologie
Despite the interest that one wears increasingly to wetlands through the world, few studies have been devoted to Moroccan wetland flora. After having prospected 45 sites, we have evaluated the specific diversity of wetland flora from 70 floristic inventories. Among 389 recognised species in this study, 175 are wetland species. Rare species or newly quoted have been underlined. On the other hand, the observed plant groupings have been classified according to the physiognomy and the specific composition. A particular attention has been devoted to the discussion of the main ecological factors affecting wetland plant groupings namely : the submersion, the salinity, the domestic organic loading, the local climate and the anthropic perturbations. Thereby, we have ranked dominant species in some ecological groups.Malgré l'intéret qu' on porte de plus en plus aux zones humides å travers le monde, peu d' etudes ont été consacrées å la flore hygrophile marocaine. Aprés avoir prospecté 45 stations, on a évalué la diversité spécifique des hygrophytes du Maroc méditerranéen å partir de 70 relevés floristiques. Sur les 389 espéces reconnues dans cette etude, 175 especes sont caractéristiques des zones humides. Les espéces rares ou nouvellement citées ont été soulignées. D'autre part, les phytocenoses observées ant été classées en fonction de la physionomie et de la composition spécifique. Une attention particuliere a été consacrée å la discussion des principaux facteurs écologiques influant sur les groupements hygrophiles å savoir : la submersion, la salinité, la charge organique domestique, le mésoclimat et les travaux d'aménagement. Ainsi, on a pu regrouper les espéces dominantes en classes écologiques
Contribution a la connaissance des algues marines benthiques du detroit de Gibraltar et de la mediterranée occidentale marocaine :I. Chlorophyceae et phaeophyceae
Contribution ¿¥la connaissance des algues marines beinhiques du Détroit de Gibraltar et de la Méditerranée occidentale mnarocaine .1. Chlorophyceae et Phaeophyceae. L'étude floristique du Détroit de Gibraltar et de l'ouest de la cóte méditerranéenne marocaine entreprise entre 1995 et 1998 a permis d'identifier 71 Chlorophyceae et 80 Phaeophyceae. Parmi les 151 espéces identifiées, 48 sont nouvelles pour la flore du Détroit de Gibraltar et 17 pour la flore du Maroc
Biomasse et accumulation des NPK chez Scirpus litoralis et Scirpus maritimus aux marais smir-Negro (NW du Maroc)
TolĂ©rance et accumulation du cuivre et du chrome chez deux espĂšces de lentilles dâeau : Lemna minor L. et Lemna gibba L.
Certains procĂ©dĂ©s dâĂ©puration extensive des eaux usĂ©es utilisent les lentilles dâeau. Les rejets des eaux usĂ©es sont de plus en plus sujets Ă des pollutions de natures diverses, notamment les mĂ©taux lourds. Dans ce travail, on procĂšde Ă une Ă©valuation comparĂ©e de la tolĂ©rance et de lâaccumulation de deux mĂ©taux lourds, le cuivre et le chrome, par deux espĂšces de lentilles dâeau Lemna minor et Lemna gibba. Bien que sous climat de type mĂ©diterranĂ©en, L. gibba soit plus utilisĂ©e que L. minor, les donnĂ©es disponibles dans la littĂ©rature concernent plutĂŽt L. minor. LâĂ©valuation des paramĂštres toxicologiques montre chez L. gibba une tolĂ©rance nettement supĂ©rieure aux effets toxiques des deux mĂ©taux expĂ©rimentĂ©s. Le chrome est moins toxique que le cuivre et sâaccumule Ă des taux supĂ©rieurs Ă ceux du cuivre dans les tissus des plantes. Pour les deux mĂ©taux, lâaccumulation est plus importante chez L. minor. Cependant, on pense que L. gibba serait plus indiquĂ©e dans des applications en phytoremĂ©diation que L. minor, vu sa tolĂ©rance et sa productivitĂ© en biomasse. Les potentialitĂ©s de ces deux espĂšces pour des applications de ce type se justifient par des taux dâaccumulation fort Ă©levĂ©s, spĂ©cialement pour le chrome oĂč ils dĂ©passent largement les 1000 ”g gâ1 de poids sec. En effet, les concentrations des plantes en Cr obtenues dans ce travail atteignent 2140 ”g gâ1 chez L. minor et 1710 ”g gâ1 chez L. gibba. Ces performances montrent un potentiel fort intĂ©ressant en comparaison Ă dâautres macrophytes comme la jacinthe dâeau par exemple.Natural wastewater treatment technologies are common practice in many regions of the world. Although these technologies are normally meant for domestic wastewater treatment, they can have broader applications such as the treatment of water contaminated by heavy metals.Among various existing technologies, systems that use duckweed are exploited for wastewater treatment in various regions of the world. In Morocco, this type of system has been tested on an experimental scale and a pilot scale. The most common duckweeds species are Lemna minor L. and Lemna gibba L. L. gibba is used in Mediterranean climates more often than L. minor, but literature data on the tolerance and accumulation of heavy metals are mostly available for L. minor.In the current study, we compared the tolerance and accumulation of two heavy metals, copper (Cu) and chromium (Cr), for these two duckweed species. Thus, this study compares the potential of these two duckweed species to be used as a method of decontaminanting Cuâ and Crâcontaminated water. The experimental design used hydroponic crops of the two species. Forty fronds of each species were sown in plastic pots containing 100 mL of White nutritive solution with a pH adjusted to 6.8. As experimental treatments, we used exposures corresponding to the following concentrations: 0.5; 1; 2; 3; 4; 5 mg Cu/L and 3; 5; 10; 20; 30; 35 mg Cr/L. Each treatment was repeated five times. In order to compensate for water loss by evapotranspiration, we added 15 mL of the corresponding solution to each treatment daily.Generally, the results obtained confirm that Cu is more toxic than Cr and that the two species of duckweed have different tolerance levels; L. minor is more sensitive than L. gibba for both metals. For Cu, we observed a highly significant inhibition of growth in response to the gradient of Cu concentrations used, the growth of L. minor being more affected than that of L. gibba. For example, the time required for L. minor colonies to double was more than four days for 1 mg Cu/L, whereas for L. gibba this was observed only at 3 mg Cu/L. The toxicological parameters reflect this observation as L. minor had both a lower NOEC (No Observed Effect Concentration) and a lower IC50 (50% Inhibition Concentration) than those reported for L. gibba. Comparatively, these results show a higher tolerance of Cu contamination for L. gibba.For Cr, L. minor was more sensitive than L. gibba, but in much less marked way than for Cu. Indeed, the time required to double the colony size and the NOEC value were similar for the two species, whereas the IC50 of L. minor was lower than that of L. gibba. The comparison of the rate of inhibition confirms a slightly greater sensitivity of L. minor to Cr exposure.The Cu and Cr concentrations in the biomass increased with the concentration of metal; the highest contents were observed in the treatments with the highest concentrations used: 5 mg Cu/L and 10 mg Cr/L. However, the BCF (Bioconcentration Factor) decreased with the concentration of the treatment; the highest values were observed for the treatments with the lowest concentrations (1 mg Cu/l and 3 mg Cr/L). With respect to possible applications in phytoremediation, the potential use of these two species would be more efficient for low levels of contamination.The two species accumulate the two metals at different rates; the accumulation of Cr is greater than that of Cu and L. minor shows higher rates of accumulation. Copper concentrations of approximately 800 ”g/g were obtained in L. minor exposed to 5 mg Cu/L. For Cr, concentrations were approximately 2140 ”g/g obtained in L. minor exposed to 10 mg Cr/L. For L. gibba, the maximum concentrations obtained were 745 ”g/g and 1710 ”g/g respectively for the treatments of 5 mg Cu/L and 10 mg Cr/L. Similarly, the BCF estimated at L. minor was higher than that of L. gibba.Compared with other macrophyte species, the duckweeds show a very interesting potential for metal accumulation. Indeed, for Cu, accumulation was definitely higher than that for other species such as Eichhornia crassipes and Polygonum hydropiperoides. The BCF obtained was higher than those observed for species of Typha and Spartina. These results confirm that L. minor and L. gibba could be good Cu accumulating species compared to other macrophytes. For Cr, other species of macrophytes accumulate this metal to a greater or lesser extent: E. crassipes (slower rate than that of the duckweeds), Nymphea alba (similar rate to that of the duckweeds) or Azolla pinnata (higher rate than the duckweeds). The Cr contents accumulated by the two duckweed species would justify their classification as hyperaccumulator species.With respect to tolerance, accumulation potential and biomass productivity, L. gibba shows potential as a species that could be used in phytoremediation and in particular the rhizofiltration of wastewater contaminated by Cu and Cr
PremiĂšre CaractĂ©risation Pomologique Des VariĂ©tĂ©s Locales De Lâolivier (Olea Europaea L.) Des Oliveraies Traditionnelles Des AgroĂ©cosystĂšmes Des Montagnes Du Nord-Ouest DuMaroc
Les oliveraies traditionnelles du nord-ouest du Maroc se diffĂ©rencient par une diversitĂ© variĂ©tale relativement importante contrairement au paysage olĂ©icole marocain dominĂ© par une seule variĂ©tĂ©, la Picholine marocaine. En effet, les pratiques traditionnelles locales Ă travers le maintien des vergers poly-variĂ©taux ont permis la conservation de variĂ©tĂ©s locales rares et sousutilisĂ©es. Dans cette Ă©tude nous avons rĂ©alisĂ© lâĂ©chantillonnage selon un dispositif Ă©quilibrĂ© (10 arbres par variĂ©tĂ© et 30 olives par arbre) des 6 variĂ©tĂ©s locales dĂ©nommĂ©es et reconnues par les agriculteurs (Zeitoun, Bouchouk, Hamrani, Kortbi, Asemlal, Semlal), dâun Ă©cotype dâolĂ©astre forme spontanĂ©e de lâolivier et deux variĂ©tĂ©s sĂ©lectionnĂ©es utilisĂ©es par les agriculteurs (Haouzia et Menara). LâĂ©tude pomologique sâest appuyĂ©e sur lâutilisation de 15 caractĂšres quantitatifs dĂ©crivant la taille et la forme des olives et des noyaux ainsi quâune estimation indirecte de la teneur en huile. Les rĂ©sultats obtenus montrent que les variĂ©tĂ©s Ă©tudiĂ©es se diffĂ©rencient le long dâun gradient de taille et du potentiel productif, les caractĂšres relatifs Ă la forme jouent un rĂŽle secondaire dans cette diffĂ©rentiation. Ainsi, les variĂ©tĂ©s Ă petites olives (OlĂ©astre et Asemlal) se diffĂ©rencient nettement des variĂ©tĂ©s Ă grosses olives (Meslal) et des variĂ©tĂ©s Ă olives de tailles intermĂ©diaires (Zeitoun, Hamrani, Bouchouk, Kortbi, Haouzia et Menara). Les variĂ©tĂ©s de tailles intermĂ©diaires se diffĂ©rencient plutĂŽt par les caractĂšres relatifs Ă la forme. La variĂ©tĂ© Kortbi se diffĂ©rencie nettement en sâopposant aux variĂ©tĂ©s sĂ©lectionnĂ©es Haouzia et Menara. Les variĂ©tĂ©s Zeitoun, Bouchouk et Hamrani se chevauchent largement.
Unlike the Moroccan olive oil landscape characterized by the dominance of a single variety, the Moroccan Picholine, the traditional olive groves of north-west Morocco are distinguished by a relatively large variety diversity. Indeed, local traditional practices through the maintenance of polyvarietal orchards have allowed the conservation of rare and underused local varieties. In this study we carried out the sampling according to a balanced design (10 trees per variety and 30 olives per tree) of the 6 local varieties named and recognized by the farmers (Zeitoun, Bouchouk, Hamrani, Kortbi, Asemlal, Semlal), an oleaster spontaneous form of the olive tree and two selected varieties used by farmers (Haouzia and Menara). The pomological study was based on the use of 15 quantitative characters describing the size and shape of the olives and endocarp, as well as an indirect estimate of the oil content. The results obtained show that the varieties studied are differentiated along a size gradient and the productive potential, the characters relating to the form play a secondary role in this differentiation. The varieties with small olives (Oleaster and Asemlal) are clearly distinct from the varieties with large olives (Meslal) and the olive varieties of intermediate sizes (Zeitoun, Hamrani, Bouchouk, Kortbi, Haouzia and Menara). The varieties of intermediate sizes are rather differentiated by the characters relating to the form. The Kortbi variety is clearly differentiated by opposing the selected Haouzia and Menara varieties. The varieties Zeitoun, Bouchouk and Hamrani largely overlap
Une forme spontanĂ©e de figuier (Ficus carica L.), le nÄbĆ«t
Le figuier est un arbre fruitier emblĂ©matique de la MĂ©diterranĂ©e au mĂȘme titre que lâolivier, la vigne ou lâamandier. Sa culture est trĂšs rĂ©pandue dans les montagnes du Rif oĂč elle reprĂ©sente un Ă©lĂ©ment caractĂ©ristique des agroĂ©cosystĂšmes traditionnels. La diversitĂ© variĂ©tale est exceptionnelle, elle est estimĂ©e Ă plus de 100 variĂ©tĂ©s locales. D'un point de vue socio-Ă©conomique, le figuier est trĂšs apprĂ©ciĂ© par les populations locales. En effet, au-delĂ de son importance alimentaire et Ă©conomique, le figuier a une valeur patrimoniale importante. Lâapproche ethnobiologique a permis dâapporter des Ă©lĂ©ments dâexplication aux diffĂ©rentes questions liĂ©es aux processus sociaux conduisant Ă la sĂ©lection et Ă la conservation de cette diversitĂ© variĂ©tale.Dans le cadre de cette diversitĂ© on relĂšve la coexistence de formes cultivĂ©es (variĂ©tĂ©s nommĂ©es) et spontanĂ©es (nÄbĆ«t) dans les vergers traditionnels. Ce qui nous amĂšne Ă nous interroger sur l'origine et la conservation de la diversitĂ© chez le figuier en relation avec la prĂ©sence des formes spontanĂ©es qui se multiplient par voie sexuĂ©e par opposition au figuier cultivĂ© qui est multipliĂ© par les hommes par boutures. En effet, nÄbĆ«t, arbre type du figuier spontanĂ©, prĂ©sente un statut controversĂ© en fonction des zones, des usages et des pratiques. Ces aspects feront lâobjet de notre communication.The fig tree is an emblematic fruit tree of the Mediterranean region as much as olive, grapevine or almond. Its cultivation is widespread in the Rif Mountains where it has a characteristic feature of traditional agroecosystems. Varietal diversity is exceptionally high, estimated at over 100 local varieties. From a socio-economic perspective, the fig tree is highly appreciated by the local populations. Indeed, beyond its food and economic importance, the fig tree has an important heritage value. The ethnobiological approach has provided explanatory elements to the various issues related to the social processes leading to the selection and conservation of this varietal diversity.Within this diversity, the coexistence of cultivated (named varieties) and spontaneous (nÄbĆ«t) forms in traditional orchards is noted. This leads us to explore the origin and conservation of the diversity of the fig tree in relation to the presence of spontaneous forms. Indeed, nÄbĆ«t, typical variety of the spontaneous fig tree which propagates sexually though seedlings as opposed to cultivated varieties â which are propagated clonally by men through cuttings - is controversial depending on the zones, the uses and the practices. These aspects will be the subject of our communication
Traditional agroecosystems as conservatories and incubators of cultivated plant varietal diversity: the case of fig (Ficus carica L.) in Morocco
<p>Abstract</p> <p>Background</p> <p>Traditional agroecosystems are known to host both large crop species diversity and high within crop genetic diversity. In a context of global change, this diversity may be needed to feed the world. Are these agroecosystems museums (i.e. large core collections) or cradles of diversity? We investigated this question for a clonally propagated plant, fig (<it>Ficus carica</it>), within its native range, in Morocco, but as far away as possible from supposed centers of domestication.</p> <p>Results</p> <p>Fig varieties were locally numerous. They were found to be mainly highly local and corresponded to clones propagated vegetatively. Nevertheless these clones were often sufficiently old to have accumulated somatic mutations for selected traits (fig skin color) and at neutral loci (microsatellite markers). Further the pattern of spatial genetic structure was similar to the pattern expected in natural population for a mutation/drift/migration model at equilibrium, with homogeneous levels of local genetic diversity throughout Moroccan traditional agroecosystems.</p> <p>Conclusions</p> <p>We conclude that traditional agroecosystems constitue active incubators of varietal diversity even for clonally propagated crop species, and even when varieties correspond to clones that are often old. As only female fig is cultivated, wild fig and cultivated fig probably constitute a single evolutionary unit within these traditional agroecosystems. Core collections, however useful, are museums and hence cannot serve the same functions as traditional agroecosystems.</p
Structure et diversitĂ© de la strate arbustive des forĂȘts de la PĂ©ninsule Tingitane (Maroc).
RĂSUMĂ. Structure et diversitĂ© de la strate arbustive des forĂȘts de la PĂ©ninsule Tingitane (Maroc). Cette Ă©tude concerne les communautĂ©s vĂ©gĂ©tales arbustives des massifs forestiers sur substrat grĂ©seux couvrant la PĂ©ninsule Tingitane au nord ouest du Maroc. La structure et la diversitĂ© de ces communautĂ©s ont Ă©tĂ© Ă©tudiĂ©es sur la base de 98 relevĂ©s reprĂ©sentatifs. Les subĂ©raies (Quercus suber) sont les formations forestiĂšres naturelles les plus reprĂ©sentatives et les plus diversifiĂ©es de lÂŽaire dÂŽĂ©tude. LÂŽaltitude sâest rĂ©vĂ©lĂ©e ĂȘtre un facteur Ă©cologique trĂšs discriminant, en sĂ©parant clairement les communautĂ©s arbustives des forĂȘts des hautes montagnes. Au niveau des zones de basses altitudes, la fertilitĂ©, lÂŽaciditĂ© et la perturbation anthropique jouent un rĂŽle dĂ©terminant dans la distribution des communautĂ©s vĂ©gĂ©tales arbustives. Cette distribution semble exprimer la dynamique de la vĂ©gĂ©tation selon un gradient de conservation-perturbation. En conclusion, lÂŽĂ©tude souligne lÂŽintĂ©rĂȘt remarquable que prĂ©sentent les forĂȘts du nord du Maroc, du point de vue de leurs significations Ă©cologiques, biogĂ©ographiques et Ă©volutives.Mots clĂ©s. PĂ©ninsule tingitane, diversitĂ©, Ă©cologie, strate arbustive, substrat grĂ©seux.RESUMEN. Estructura y diversidad del estrato arbustivo de bosques de la PenĂnsula Tingitana (Marruecos). Se estudian las comunidades arbustivas de los bosques que se presentan sobre la formaciĂłn de arenisca de la PenĂnsula Tingitana en el noroeste de Marruecos. Se analiza la estructura y diversidad de estas comunidades en base a 98 muestras representativas. Los alcornocales (Quercussuber) son las formaciones forestales mĂĄs representativas y mĂĄs diversificadas en el ĂĄrea de estudio. La altitud es el principal factor ecolĂłgico, separando nĂtidamente las comunidades arbustivas de los bosques de zonas altas, segĂșn el anĂĄlisis de correspondencia canĂłnica (CCA). Por otro lado, en los bosques de zonas bajas, la distribuciĂłn de las comunidades arbustivas viene determinada por el grado de fertilidad y acidez del suelo, y por la perturbaciĂłn antrĂłpica. Esta distribuciĂłn parece reflejar la dinĂĄmica de la vegetaciĂłn segĂșn un gradiente de conservaciĂłn â perturbaciĂłn. Por Ășltimo, el estudio  Cellellama la atenciĂłn sobre el gran interĂ©s que presentan los bosques del norte de Marruecos, desde el punto de vista ecolĂłgico, biogeogrĂĄfico y evolutivo.Palabras clave. PenĂnsula Tingitana, diversidad, ecologĂa, estrato arbustivo, areniscas
Disentangling the effect of farming practice and aridity on crop stable isotope values: a present-day model from Morocco and its application to early farming sites in the eastern Mediterranean
Agriculture has played a pivotal role in shaping landscapes, soils and vegetation. Developing a better understanding of early farming practices can contribute to wider questions regarding the long-term impact of farming and its nature in comparison with present-day traditional agrosystems. In this study we determine stable carbon and nitrogen isotope values of barley grains from a series of present-day traditionally managed farming plots in Morocco, capturing a range of annual rainfall and farming practices. This allows a framework to be developed to refine current isotopic approaches used to infer manuring intensity and crop water status in (semi-)arid regions. This method has been applied to charred crop remains from two early farming sites in the eastern Mediterranean: Abu Hureyra and âAin Ghazal. In this way, our study enhances knowledge of agricultural practice in the past, adding to understanding of how people have shaped and adapted to their environment over thousands of years
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