Stocks of dead biomass of beech (Fagus Sylvatica L.) Forest ecosystems in West Balkan range, Bulgaria

The dead trees play an important role in the functioning and productivity of the forests' ecosystems through influence over biological diversity, the accumulation of carbon dioxide, nutrient turnover and energy flux, hydrological processes, protection of the soils and the regeneration of tree species. The dead wood assures important habitats also. In historical aspect, for many years the dead wood was removed from the stands as a measure for protection against insects and fungi, which are perceived as a threat for the healthy forest status. This leads to reduction of the quantity of the dead wood in the forest ecosystems to critical low levels, which are not enough for maintaining the vital populations of many forest species. During the past years, the new settings in the national legislation, especially these related to the Natura 2000 development and management, require the quantity information about this component for the forest habitats assessment. In this regard, the objective of this study was to obtain quantitative data on stocks of dead forest biomass in beech communities in West Balkan Range. The amount of standing dead wood was calculated with height rates tables; method of line intersect sampling was used for determination of the lying dead wood stocks. Thomas scale was used to assess the degree of decomposition of standing dead biomass (Table 2) and a 4-point harmonized scale for lying biomass and stumps (Table 3). It was found total dead wood biomass stocks variation in the range of 14.48 - 41.8 m3.ha-1 as a result of studies conducted in beech stands (Table 5). The standing dead wood biomass was 6.7-17.5 m3.ha-1, lying dead wood biomass was 3.4-26.5 m3.ha-1, stumps were 0.28-6.4 m3.ha-1. The observed standing dead trees were mainly from the fourth level of decomposition. The prevailing rate of decomposition for lying biomass was B and for stumps were C and D (Table 6). It can be generalized from the results of current study that the percentage of the total amount of dead wood to the total forest yield was insufficient from a conservation perspective. © 2018 Hrvatsko Sumarsko Drustvo. All rights reserved.