Introducing the criteria of good acorn producer identification (Case study: Poldokhtar forests, Lorestan province)

Abstract

Sexual regeneration is one of the important topics in silviculture that is based on seed production. Seed production is very important in oak, because oak seeds (acorns) are main source of food for animals and human. Zagros forests located along the Zagros mountains in western and southern Iran are covered with different species of oak and Brant`s oak ( Quercus brantii Lindl.) is the dominant species of these forests. Since acorn production ability of different oak trees is different due to differences in genetic structure and other influential factors such as site and climate, identification of good acorn producers is very important. In this research, 30 Brant’s oak trees were selected in a part of Poldokhtar forests in Lorestan province, Iran, and their acorn production were studied during 4 years (2014-2017) using crown count method. For sample trees, trunk and crown health characteristics, maturity, single-stem, minimum diameter of 15 cm and no touching of adjacent crowns were considered and their quantitative variables were measured. Two criteria were used to identify good acorn producers: trees that produce acorn each year and their average acorn production were higher than the average acorn production of the stand. Based on the results, the mean number of acorns of sample trees in 4 years was 476.6 and the lowest and highest acorn produced was 0 and 5696, respectively. Also, only one tree had the characteristics of the good acorn producer. The results of this study showed that even with 3 years of acorn production monitoring in Brant`s oak trees can be identified with acceptable accuracy of native good acorn producers. In this research, good acorn producers of Brant`s oak were identified in a part of the forests of Lorestan province and the necessary recommendations for their conservation is discussed.