Investigation drought impact on Tamarix aphylla, Salix babylonica and Eucalyptus in Sistan plain

Sistan has recently confronted to periodic drought and water scarcity that destroyed vital resources especially vegetation. Information about reaction of the vegetation species to drought is necessary for protecting and biological restoring this ecosystem, so density of Tamarix aphylla, Salix babylonica and Eucalyptus were investigated using quadrates 50m × 50 m during wet (1366-1376) and drought years (1377-1387) in Sistan plain. MANOVA showed that vegetation species and drought significantly affected on species density. Although drought declined density of three species, tree species destroyed more than Tamarix as a shrub species. Salix that it has favorite condition in normal years and its root depth is lower than Eucalyptus lost its density sooner in drought years