Monitoring of the oak decline phenomenon and its impact on biomass and leaf area in the forest stand, Yasouj

Monitoring forest stands can provide valuable information to forest managers. This study shows the phenomenon of Persian oak decline in a 1-hectare plot. The study was performed over four years, and it was used to see the changes in leaf dieback, with all of the trees, a total of a hundred trees, were analyzed. Trees were classified into four dieback categories: healthy trees, trees with crown dieback, trees with less than 50% crown dieback, and trees and trees that had more than 50% crown dieback. Trees that had the dieback. Also, leaf area was monitored. In the first year of the study, 65% of trees experienced crown dieback. There was a change in dieback, and after a year, 10 to 25% more trees had crown dieback. Over time, it reached about 80%. According to the research, the leaf area decreases from the healthy category to the completely dead one. It turns out the average leaf area in high forest trees was higher than in coppice trees. The study of leaf area also showed a strong correlation between the crown dieback and leaf size. The study also found that the trees with a crown dieback of over 50%, had consistently smaller leaves than healthy trees.