Qualitative and quantitative evaluation of habitat and dead trees in the developmental old-growth phase in the oriental beech forests

Habitat trees provide diverse microhabitat for various organisms in forest ecosystems. Old-growth phase is one of the determined developmental phases of beech stand dynamics in the north of Iran. This research was carried out in Shafaroud forest in the west of Guilan province to assess the habitat and dead trees in this developmental phase, qualitatively and quantitatively. For this purpose, three one-hectare areas were selected and in each area, quantitative characteristics of habitat and dead trees including abundance, tree diameter, and height were recorded. Results revealed that from the different types of habitat trees, crack trees were the most frequent in the study area (31.7%) while other frequent types were cavities, burr and fork-spilled tress (29.3, 24.4 and 14.7%, respectively). The most frequent tree-related microhabitats were observed on the beech trees. The mean of dead volume in this phase was 37.1 m3 and Shanon and Simpson diversity indices were calculated as 1.9 and 1.7, respectively. Meanwhile, the Margalef and Pielou evenness indices were 0.8 and 0.9, respectively. The findings demonstrate that very thick beech trees (with the diameter of 70 cm and more) show the highest number of microhabitats as well as the most diversity. The presence of tree-related habitat trees in different forms should be considered in the planning and implementation of silviculture.