Determination of Effective Factors on Natural Regeneration of Persian Oak in Kohgiluyeh and Boyer-Ahmad, Sothern Zagros, Iran

Understanding the factors that allow the successful regeneration of species is a key step toward the conservation and management of forests. This study was conducted to model and compare the impacts of some important influential factors on the presence and absence of two sources of natural regeneration of Persian oak (Quercus brantii Lind) – seedling recruitment and stump sprouts – in a less degraded forest in Southern Zagros in West of Iran. These models potentially result to reduce both management and plantation costs as well as providing cost and time effective decisions to reach the goals of forest preservation. The data were taken from nested sample plots with circular shapes. In addition to the number of instances of natural regeneration, consisting of seedlings and stump sprouts of Persian oak, within each main sample plot, the general characteristics of the forest stand, percent of crown cover closure, number of oak trees, dbh, crown diameter, and number of shoots in each tree stump were measured, counted, and or estimated. In each of the inner subplots within the main sample plots, features including litter depth, number of gravels and sheep and goat dungs were recorded. Using factor analysis and two logit models, the relationships between the presence and absence of recruitment seedlings and stump sprouts against the recorded factors were compared. Results showed that the presence of stump sprouts depends on the density of woody cover of the forest stand while among the recorded variables, absence of gravel had more influence on sprouting. Presence of gravels could be a metric/proxy for soil erosion. Synthesis and applications. For promoting the conservation and rehabilitation of these forests to accomplish their determined preservation objectives, it is recommended that the forest authority should prohibit animal grazing in the areas experiencing severe soil erosion as well as plant seeds— and even saplings—to conserve soil and limit soil erosion in the area.