Salinity Management in Arid Regions - Restorative Redevelopment of Devastated Ecocultural Landscapes - page 421

FIGURE 21.2 ( Continued ) Resembling snow, extensive surface deposits of salt at the
ancient Mesopotamian city of Mari, located near the Syria-Iraq border.
other hand, “overdrainage” is the removal of water in excess of that required to main-
tain ecologically suitable and productive soil or marsh hydrology and water quality.
To effectively manage an ecological system, it is necessary to have some sort of
target or criteria to aim for, and salinity is no different in this regard (Dickey and
Madison 2004). One way to do this is to set criteria in terms of primary productivity
in relation to the sensitivity of various species in the habitat to salinity. Graphs of
plant productivity versus salinity show a threshold at which the impact begins to be
felt followed by productivity decreases, with the more tolerant species having higher