Structure and Spatial Distribution of Dead Wood in Two Temperate Old-Growth Mixed European Beech Forests

Abstract

Old-growth forests are often looked at as reference for close to nature silviculture, which aims to manage forests in a natural way. An important component of these forests is the large amount of deadwood they possess; the role of dead wood in the forest ecosystem has been well recognised. A detailed investigation of dead wood characteristics (the amount per stand, species, dead wood type, decay class, size and spatial distribution) was performed in two Romanian old-growth European mixed beech forests: Runcu Grosi Reserve (sessile oak-beech) and Sinca (silver fir-beech). Dead wood pieces were classified as belonging to one of seven dead wood types and one of five decay classes. The total amount of the dead wood was greater in Runcu Grosi (240.8 m3 ha-1) than in Sinca Forest (135.5 m3 ha-1). The majority of the dead wood in Runcu Grosi was composed of sessile oak (91.7%), whereas in Sinca Forest, the main dead wood species was silver fir (67.0%); both species exhibited higher values of probability density than beech, the second most important species. The dead wood exhibited much variation in tree size and in dead wood type, and covered the entire spectrum of decomposition classes. The main spatial pattern of all standing dead trees was random in both forests (over 55%), with a reduced participation of regularity and aggregation. The results of this investigation could be used as key values derived from natural conditions to enhance the biodiversity related to dead wood in managed temperate beech mixed forests.