生物学と医学

概要

Evaluation of the Riverine Vegetation of Wadi Tafna in the Tlemcen Region (Western Algeria)

Lamia Korso-Bouabdallah, Mohamed Bouazza and Hassiba Stambouli-Meziane

The vegetal landscape of riverine forest bordering streams of course, has a character linked to the high volatility of the intermittence of the latter. The watercourse temporary (wadis) are characterized by a vegetation and flora of Mediterranean type, (Tamarix, Nerium, Vitex, Phoenix...) in contrast to the permanent water courses at the level of the vegetation of leafy bed major European type, based mainly, poplar, ash or alder. In Western Algeria, the riverine forest vegetation is complex and fragile environments to several utilities. Latter by its diversity and these developed root systems will thus limit erosion of the banks and provide a stable structure to the formation. To identify and quantify the riverine forest on the Mediterranean coast in the South, especially in Western Algeria, we conducted surveys on land with an area of 100 m2 for each record, and then each species was conducted of two indices (abundance – dominance and sociability. The factorial analysis of correspondences has carried out us to classify these plant species according to the degree of salinity of the Wadi, the substrate and the slope. The riverine vegetation of wadi Tafna has been classified as follows: The so-called purely riverine forest vegetation is which are directly linked to the Wadi (in contact with the water and who are): Tamarix africana; Nerium oleander; Fragmites communis; Chenopodium album; Rumex bucephalophorus; etc. Vegetation low riverine forest is usually trained pre-forestieres species on siliceous substrate and are: Crateagus monogyna; Halimium halimifolium; Withania frutescens; Atriplex halimus; Acacia sp; Zygophyllum sp; Bryonia dioica; Calycotome intermedia; Suaeda sp. In conclusion, the inadequacy of our knowledge of the biology and ecology of vegetation riverine forest of our region requires multiscale study and multidisciplinary in order to better understand the structure and operation of all hydro-system. These phyto-sociological and phyto-dynamic data lead to classify these plants according to ecological factors of their site and understand its evolution and diversity through the study area.