Chiboub Fellah, N.Bouguima, S.M.Moussaoui, A.2013-04-092013-04-092012-03https://dspace.univ-tlemcen.dz/handle/112/1717Water level may influence local community dynamics. We examine how seasonal variations in water level affect the outcome of prey-predator interactions in Parloup Lake in the south of France. We propose a new model to describe the annual cycle of persistence by using continuation theorem of coincidence degree.enArticle