Oasis is a specific landscape that characterizes arid areas. The structure of oasis ecosystem depends mainly on desert-oasis-rivers components. Generally, oases are spread along non-perennial rivers (wadis) and shallow water table. However, the sustain-ability of oasis system is threatened by a combination of factors (water scarcity, Bayoud disease, climate change, rural exodus, etc.).The objective of this article is to highlight the crucial role of groundwater resources, although they remain invisible, play in the conservation and sustainability of oasis system. The aim is to understand and analyze the various interactions between groundwater table and the dynamics of palm groves, taking into consideration all existing factors (natural and human). A histori-cal analysis tracing both the oasis dynamics and the groundwater evolution has been established. A diachronic approach was adopted in order to reconstruct the history of the Tafilalet plain by performing a literature search that was supported by surveys conducted with different actors in this region. The results showed that groundwater is the basic resource for the survival of the oasis system in the Tafilalet plain. Besides being the main source for irrigation water supply, groundwater contributes directly in the water supply of the date palm, which represents the oases keystone.
Key words: Oasis dynamics, Sustainability, Groundwater table, Date palm, Tafilalet.