Prediction of Ecological Succession of the Beech-Hornbeam Stand (Case study: Kheyrood forest, Nooshahr Province)

Dynamics of Forest communities, before the climax stage, are very high, and small changes in the conditions of the stands would result in sudden responses such as dominant species changing or increasing the number of accessory species in the accessory stand. This study aims to predict the sequence of the beech- hornbeam stand toward beech stand in the semi-virgin forest Hyrcanian of northern Iran.

After field studies, three sample plots with an area of ​​one hectare (100 × 100 m) were selected, which included hornbeam-beech type (middle stage type of Hyrcanian forest sequence). At first, four species turbulence factors, the ratio of number of seedlings to mother rootstocks, the percentage of abundance of dry matter and the indices of diameter and height differentiation in the sample plots were measured.

Layering Charts of species indicate the conspicuous presence of beech in the understory of three stands with 61.3 percentage on average. In addition, the average number of proportion of seedlings to the number of mother trees in beech and hornbeam were are 30.1 and 2.3, respectively. The highest percentage of dead trees’ (67%) frequency in the plots is related to Hornbeam species. The results of the TDi and THi indexes charts, with averages of 0.13 and 0.1, respectively, demonstrate a dramatic competition between beech and hornbeam.

Through the measuring of the competition in natural stands and combining results with other factors such as stage and seedling frequency and layering in the stand indicate that beech would be likely to be replaced by hornbeem.