Structure and regeneration patterns of the Juniperus excelsa Bieb. stands in the central part of the Nestos valley in the northeast of Greece, in the context of anthropogenic disturbances and nurse plant facilitation

Abstract

AbstractIn order to analyse the structure and regeneration patterns of the Juniperus excelsa Bieb. stands on the slopes of the Nestos valley, 40 sample plots were established and more than 120 J. excelsa trees and seedlings were cut and collected. The main results of this research indicate that stand structure, species mixture, age structure and stand development patterns were strongly determined by the interaction of anthropogenic disturbances such as grazing and illegal cuttings, and the facilitation of adult J. excelsa trees in the establishment of the J. excelsa seedlings. Their effect was influenced by site quality and J. excelsa together with other species ecology. Under present conditions, almost all J. excelsa seedlings, except for a small number of plants, are found under the facilitation of nurse plants that belong to the same species. It seems that the layer of litter underneath the nurse plants combined with the protection of seedlings against grazing play an important role in the establishment and growth of J. excelsa seedlings.