La Diversité Floristique Des Pelouses Humides D’altitude: Cas De Quelques Sites Du Haut Atlas Marocain

Abstract

Résumé. Dans le Haut Atlas, les pelouses humides et pozzines constituent des pâturages assez convoités. Leur flore se caractérise par une grande richesse spécifique: 165 taxons inventoriés dans la zone d’étude (plateau de l’Oukaimeden, plateau de Tichka et l’amont de la haute vallée d’Ait Mizane) avec un taux d’endémisme estimé à 30,3% et un degré de rareté qui atteint 31%. Dans un contexte dominé par l’élément méditerranéen, la flore de ces pelouses est très enrichie de souches septentrionales 15,7%, repoussées vers nos latitudes méridionales lors des dernières glaciations. Ces zones humides vulnérables de par leur structure, fonctionnement écologique et état de conservation, se trouvent très touchées par les changements climatiques et les mutations environnementales récentes. Summary. In the High Atlas mountains, the wet grasslands and pozzines constitute a highly coveted pastoral resource. Its flora is characterized by a great specific richness: 165 taxa are recorded in the study area (Oukaimeden plateau, Tichka plateau and the upstream of the Ait Mizane high valley) and schow a rate of endemism estimated at 30.3% and a degree of rarity reaching 31%. In a Mediterranean context, the wet grasslands flora is supplemented with plants of northern origin 15.7%, pushed towards the extreme southern latitudes during the last glaciations. These wet pastures, highly sensitive by their structure, ecological functions and their conservation state, are very affected by the climatic changes and the global environmental changes.

Conservation assessments and Red Listing of the endemic Moroccan flora (monocotyledons)

“…). It can be found in a few localities: in Taroudant Province, near Tizi‐n‐Test on the road from Marrakech to Taroudant at 2100 m; in Azilal Province near the Bridge, about 30 km south on the road from Demnate to Toufrine at 1840 m; in Ouarzazate Province, 5 km south below Tizi‐n‐Tichka in the road from Marrakech to Ouarzazate at 2180 m; and in Kerdouz Mountain near Tiznit in the Macaronesian formations of Souss (Jahandiez & Maire, ; Emberger & Maire, ; Maire, ; Nègre, ; Peltier, , ; Fennane & Ibn Tattou, , ; Speta, ; Benabid, ; Förther & Podlech, ; Taleb & Fennane, ; Carbutt & Edwards, ; Manning et al ., ; Clayton et al ., ; Hammada, ; Jury et al ., ; Alaoui Haroni et al ., ; Dobignard & Chatelain, ; Rankou et al ., ; eMonocot, ).…”

“…). It can be found between 500 and 1600 m elevation in a few localities: in Taza, on the Akrech River banks in the Zaer Forest, in the Jorf Lihoudi and El Gara in Safi Province, in Ouled Taima, between Tiznit and Massa River, in Hadra south of Krindelt village and in the Assaka Valley (Jahandiez & Maire, ; Emberger & Maire, ; Maire, ; Nègre, ; Fennane & Ibn Tattou, , ; Speta, ; Benabid, ; Förther & Podlech, ; Taleb & Fennane, ; Manning et al ., ; Valdès, ; Clayton et al ., ; Hammada, ; Alaoui Haroni et al ., ; Dobignard & Chatelain, ; Rankou et al ., ; eMonocot, ).…”

“…). It can be found between 1500 and 2200 m elevation in a few localities: Haouz, Souss, the Ait Messane River Valley and between Tinitine and Anferkou villages (Jahandiez & Maire, ; Emberger & Maire, ; Maire, ; Nègre, ; Peltier, , ; Fennane & Ibn Tattou, , ; Speta, ; Benabid, ; Förther & Podlech, ; Taleb & Fennane, ; Carbutt & Edwards, ; Manning, Goldblatt & Fay, ; Clayton et al ., ; Hammada, ; Alaoui Haroni, Alifriqui & Ouhammou, ; Dobignard & Chatelain, ; Rankou et al ., ; eMonocot, ).…”

“…It is a bulbous geophyte, preferring humid to dry siliceous substrates, slightly salty low‐mountain and well‐drained sandy–loamy soils. This species grows in full sunlight to mid‐shaded habitats; it flowers from June to August and is found in sub‐humid to arid Mediterranean bioclimates (Jahandiez & Maire, ; Maire, ; Nègre, ; Peltier, , ; Speta, ; Benabid, ; Förther & Podlech, ; Taleb & Fennane, ; Carbutt & Edwards, ; Manning et al ., ; Hammada, ; Alaoui Haroni et al ., ; eMonocot, ).…”

“…It is a bulbous geophyte, preferring moist humid to dry siliceous substrates in slightly salty low‐mountain and well‐drained sandy–loamy soils, and the biotopes are often porphyritic, schistic and granitic. It flowers in September and is found in sub‐humid to arid Mediterranean bioclimates (Maire, ; Nègre, ; Speta, ; Benabid, ; Förther & Podlech, ; Taleb & Fennane, ; Manning et al ., ; Valdès, ; Hammada, ; Alaoui Haroni et al ., ; eMonocot, ).…”