Quantitative Determination of the Selected Nests Pressure of Wood Species in the Middle Forest of Northern Iran (Case study: Gorazbon section of Kheyroud forest)

Understanding the ecological niche of the different species is essential in many ecological issues.  Ecological niches of species are one of the important factors in the tree species distribution pattern and for all species, it can be detected by examining distribution of species distribution. Ecological nest models often help to understand more ecosystems. These models are applicable in predicting ecosystem stability and sustainability ratios and ecosystems.

In order to determine the selective pressure of different species, the indicators of the equilibrium level of selected nests, the dominant level of selected nests and the crisis level of selected nests were used and 41.5 hectares of Khirud research and educational forest were fully surveyed (100%). Then, characteristics such as diameter equal to the chest of the trees were measured and using selective nesting indices, the selected pressure and nesting levels of beech, oak, hornbeam and alder species were measured.

The values of the selective pressure were measured for the species on the Fagus orientalis 66.419, Quercus persica 3. 313, Carpinus orientalis 261. 28, Alnus 36. 962 and tilia begonifolia 9. 39 respectively. The final results showed that Carpinus orientalis wasat a Dominates niche level, the Fagus orientalis and Alnus was in the balance niche level and the Quercus persica was in intermediate between balance and critical level and also tilia begonifolia was in the critical niche levels.

The Carpinus species were at the dominant level of selective pressure, the Tilla species were at the equilibrium level and the Quercus species were at the equilibrium level of the crisis nest. The results of this study showed that selective strain quantification is an important factor in determining the current status of endangered species.