Zalihe biomase mrtvog drva u šumskim ekosustavima bukve (Fagus sylvatica L.) na području zapadnog Balkana, Bugarska

Abstract

SUMMARYThe 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 m 3 .ha -1 as a result of studies conducted in beech stands (Table 5). The standing dead wood biomass was 6.7-17.5 m 3 .ha . 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.

Importance of Dead Wood in Virgin Forest Ecosystem Functioning in Southern Carpathians

“…Studies on the AGB and CS in relation to other variables, such as altitude, are crucial for understanding the importance of virgin forests in slowing global warming. Our research, along with other studies [27,62,70], highlights that the DW biomass decreases with altitude and, implicitly, with air temperature [69].…”

“…The relationship between DW and living tree volumes has been highlighted previously [27,62], and recent studies performed in virgin forests in the Semenic Mountains (Southern Carpathians) have shown that the volume of dead wood there varied between 50 m 3 •ha −1 and 223 m 3 •ha −1 [21].…”