ImpactassessmentofannualprecipitationandgroundwatertableonSeidlitziarosmarinusgrowinganddevelopmentinSiah-kuhrangelands

In this research, the reactions of the Seidlitziarosmarinus species to the fluctuation of precipitation and ground water table were studied at Siah-kuh in Ardakan-Yazd. For this purpose, plant parameters of Seidlitziarosmarinus were monitored every yearalong four permanent lines transect in 60 plots (2 m2). Every year, Water table measured in three pisometric wells and Meteorological data were collected from nearby climatological station.Regarding the amount of collecting data after nine years, Groundwater depth varied from 12.5 to 19.71 m and the entire region experienced two drought years (2001 and 2005) throughout the study years.Vegetation response to groundwater and precipitation fluctuation analyzed by correlation and regression analysis. The regression results show that canopy cover and the density of the Seidlitziarosmarinus species in the region are highly influenced by the water table depth (R2=0.97 and R2=0.9 respectively). By using stepwise regression, an equation between the amount of yield and annual precipitation was obtained with a high correlation coefficient (R2=0.8). Thus, Increase in water table depth in the coming years will has more ecological consequences for Seidlitziarosmarinus plant communities. Finally, it led to bioenvironmental deterioration such as land desertification in Siah-kooh, Ardakan. To avoid land desertification in this area, optimization of groundwater usage in agricultur and industry in Yazd-Ardakan plain is very important.