tree mortality and dieback in daland forest park, iran: an assessment of human and environmental factors

Forests are important ecosystems that contain a wide range of living organisms. recently, many forest trees, particularly in forest parks, have been  experiencing dieback due to various factors, causing  concerns among the public, researchers, and relevan authorities. due to the importance of this issue, this study investigated the effect of environmental and human factors on the dieback and death of trees in daland forest park, located in the golestan province, northeastern iran. we used an rtk-dgps to record the positions of dieback-affected trees and their percentages of dieback in circular plots of 1000 m2. in addition, all dead trees were visually identified using a uav orthomosaic from 2021, and their locations were recorded. the effects of recreational areas, forest types, distance from water wells, and forest roads on tree dieback were analyzed. in addition, the relative impact of variables on dead trees was calculated. based on tree dieback analysis using completely randomized factorial, tree dieback occurrence in the forest type is significantly affected, at a 99% confidence level. additionally, the distance from water wells, recreation zones, and forest roads had a mutual effect on the amount of tree dieback. the analysis  of  dead trees showed that their occurrence was relatively higher  in  recreation-centered zones,  certain forest types, and at distances of 0-100 meters from forest roads and  200-400 meters from water wells. based on the findings, it is recommended to halt  water extraction from the park’s wells and implement management treatments  around forest roads and recreation zones to reduce pressure factors. it is also necessary to investigate the causes of tree mortality and  dieback in other parts of the  hyrcanian forest.

tree mortality and dieback in daland forest park, iran: an assessment of human and environmental factors

forests are important ecosystems that contain a wide range of living organisms. recently, many forest trees, particularly in forest parks, have been  experiencing dieback due to various factors, causing  concerns among the public, researchers, and relevan authorities. due to the importance of this issue, this study investigated the effect of environmental and human factors on the dieback and death of trees in daland forest park, located in the golestan province, northeastern iran. we used an rtk-dgps to record the positions of dieback-affected trees and their percentages of dieback in circular plots of 1000 m2. in addition, all dead trees were visually identified using a uav orthomosaic from 2021, and their locations were recorded. the effects of recreational areas, forest types, distance from water wells, and forest roads on tree dieback were analyzed. in addition, the relative impact of variables on dead trees was calculated. based on tree dieback analysis using completely randomized factorial, tree dieback occurrence in the forest type is significantly affected, at a 99% confidence level. additionally, the distance from water wells, recreation zones, and forest roads had a mutual effect on the amount of tree dieback. the analysis  of  dead trees showed that their occurrence was relatively higher  in  recreation-centered zones,  certain forest types, and at distances of 0-100 meters from forest roads and  200-400 meters from water wells. based on the findings, it is recommended to halt  water extraction from the park’s wells and implement management treatments  around forest roads and recreation zones to reduce pressure factors. it is also necessary to investigate the causes of tree mortality and  dieback in other parts of the  hyrcanian forest.