Effect of rainfall periods on Phenology of Festuca ovina

Phenology studies are one of the appropriate tools to determine the utilization time of rangelands.This research was aimed to study the phenology of Festuca ovina in the Bademestan rangelands of Zanjan province, located at 45 km northeast of Zanjan for four years. The results showed that the study species had a very special reaction to the rainfall amount and time, especially during the growing season i.e., from the onset of spring to July. In other words, no reproductive growth and formation of flowers were recorded in 2007-2008, whose rainfall was much less than average during the growing season (57.2 mm in the spring quarter). A sharp decline in rainfall during the spring caused the species not to complete its phenology and produce seeds. The year 2009-2010 had much less rainfall as compared with the year 2007-2008; however, due to the good rainfall in spring 2010, Festuca ovina could complete all phenological stages and flowering stage occurred. Therefore, it seems that the spring rains are vital for this species to complete the plant life cycle.