Assessing the Effects of Micro-Catchment Runoff Harvesting System and Forest Preservation on Curtail Oak Dieback Phenomenon and Understory Ground Cover in the Zagros Forest, Kermanshah, Iran

Oak forests in the Zagros, west Iran, are suffering from severe unusual dieback phenomenon which has been developed throughout forest area. However, combating this event needs short terms measurements for return soil moisture in soil profile during dry seasons. The objective of this research was to evaluate the effect of runoff harvesting through micro-catchment. The research work was conducted in the Kalehzard site, Kermanshah, Iran. The treatments include a Crescent Shaped Bund Preservation (CSB), Preservation treatment (PT), Crescent Shaped Bund without Preservation CSB-P and Control treatment (CT), resulting in a total of 12 plots. Each plot measured 50 ×30 meters performed in September 2012. The ground cover was estimated using a 1 m2 quadrate and all dried trees was recorded within plots every year. Soil moisture was measured in three layers (10, 30 and 50 cm) using time domain reflectometry (TDR). Finally, all data statistically were analyzed using SAS6.12 software. The result explored that dieback ratio was 30%, while there was increased during second year in CT. The data from TDR showed that CSB significantly enhanced soil moisture and consequently attributes in re-vegetation of dried tree (19 tree/ha) as well as reduction in dieback (37 tree/ha) compared to control treatment. Although the preserved treatment affects severity of dieback, there only curtail tree mortality rate (38 tree/ha), while CSB-P had minimum effect on forest mortality (6 tree/ha) due to absence of protection measures. In addition, significant increasing of plant cover and plant litter was found via CSB and PT. It is concluded that CSB can be considered as the possible adapted measure combating Zagros forest mortality through drought tension and climate change.