Applying survival analysis for assessment of forests sustainable development

Tree mortality has traditionally been evaluated in forest inventories through summaries of dead trees by location, species, and several causal agents. Although these methods were most commonly used, in order to assess forests sustainable development, they have had limited use in detecting mortality trends and development dynamics. This study proposes the application of survival analysis for the purpose of analyzing tree mortality. Individual tree growth increments were used to estimate survival and hazard functions for the Elatia forest (Drama, Northeast Greece). These estimates provided indications of regional mortality by diameter at breast height (DBH) and diameter growth (ΔDBH) between successive measurements. Comparisons of survival/hazard curves and tests of effects of species and crown class (CC) on individual survival curves were conducted. Survival analysis technique, by using the variables of DBH and ΔDBH, could help foresters to evaluate regional tree mortality trends, and, consequently, forests sustainable development.