Chronology of plant formations settled on banks of “oued” tafna (Oran-Algeria)

Diachronic mapping (2004 and 2013), conducted as part of a program of phytoecological studies on “Oued” Tafna stations, illustrated a heterogeneous physiognomy of Tamaricaceae vegetation. The presence of salts and the appearance of a degraded structure affected the physiognomy of vegetation which is often organized according to a gradient of the soil substrate. Sequential dispersion of these populations was observed spatially. The Tamarix, the Atriplex and bioclimate also contributed to changes in environmental variables, including salinity, which are partly responsible of the large installation of halophytes, such as Atriplex halimus, Salsola vermiculata or Tamarix africana, on banks of “Oued” Tafna. Other formations also changed between 2004 and 2013. Installation of food crops was sometimes excessive; their surfaces generally exceeded 45% of the plots mapped. Thus, this study highlighted the evolution, over nearly 10 years, of the vegetation aspect on “Oued” Tafna banks and more specifically Tamaricaceae’ formations.