mortality of trees in the stem exclusion phase over the beech stand development

knowledge of the stand condition and the gradual replacement of tree species in different development stages and phases provide appropriate information related to the close to nature treatments. stem exclusion phase is one of the important development phases in the forest stands development. the aim of study was to analyze the characteristics of dead trees in the stem exclusion phase in the less disturbed forests of kheyrood, northern iran. three sample plots were laid out in this stem exclusion phase and some properties such as diameter, height of all standing and dead trees, as well as the decay stage of dead trees were recorded. results showed the maximum amount of mortality was observed in the 10 cm diameter class (n = 125). the proportion of snags was 39% while 61% of dead trees were recorded as log. the average volumes of standing and fallen dead trees were 31 and 69 percent, respectively. oriental beech as dominant tree species made up 47.2 % of decaying trees following by hornbeam (36.1%) has a significant contribution in dead wood pool in this phase. results of comparing trees mortality showed form, size, and decay class of dead trees were significantly different and the most of the dead trees was observed in the early decay stage, in small diameter class, and in form of snag. determining of the mortality rate and the quality and quantity of dead trees in this phase of the forest stands development can be applied as guidance in forest tending interventions..