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ŠUMARSKI LIST 3-4/2013 str. 49     <-- 49 -->        PDF

felling with short regeneration periods (so called stand management) was proposed. This system is still most commonly prescribed in management plans, but it is seldom put into practice. Generally, there is a great difference between planning the management of beech high forests in Serbia and putting these plans into operation.
Implementation of different management systems of beech high forests in Serbia and their frequent changes have resulted in exceptionally heterogenous structural development of beech high stands, which has had a particularly unfavourable influence on the quality and natural regeneration of the stands.
The sample consisted of eleven beech high stands, whose site and structural characteristics are representative of beech high forests in Serbia. The stands were selected in six forest areas, or nine management units. It has been 7 to 10 years since the last harvesting operations were performed in the selected stands.
These eleven stands are pure uneven-aged beech high stands. Other broadleaved species occur in two stands and they account for 3–5 % of volume. One stand is classified as submontane (Fagetum moesiacae submontanum B. Jov. 1967), and the other ten as montane (Fagetum moesiacae montanum B. Jov. 1953) beech forests. The forests developed on different parent rocks (sandstone, limestone, gneiss, andezite, rafter, granite, granodiorite, schists) and different soil types (dystric ranker, dystric cambisol, calcomelanosol, calcocambisol, luvisol, pseudogley, brunipodzol), which are 20–120 cm deep. The climate is temperate continental. The average annual temperature air in submontane beech forests (up to 700 m above sea level) exceeds 8.5 °C, while in the vegetation period it reaches approximately 14 °C. The annual precipitation typically ranges between 650 and 1000 mm. The average annual temperature in montane beech forests (from 700 to 1400 m above sea level) ranges from 6.2 to 9.5 °C, with 12.2–14.8 °C in the vegetation period. The annual precipitation typically ranges between 650 and 1100 mm (Stojanović et al., 2005).
The stands are most commonly characterized by irregular declining distribution of trees per diameter classes, typical of heterogeneous uneven-aged stands. There are trees with diameter at breast height (dbh) above 60 cm in all stands, while trees in one of the stands reach 80 to 100 cm in diameter. Regarding the age, the stands are typically uneven-aged with specific age structure. There is a significant percentage of trees above 200 years of age, while some trees are as old as 300–400 years. Ellenberg (1996) states that old-growth broadleaved forests in Europe are usually not even-aged, which corresponds to the characteristics of the studied beech stands.
The age of trees was determined on sample areas established in the stands at the distance of 200 x 200 m. The trees were bored to the center with Pressler borer at breast height. In order to determine the total age, ten years were added to the number of years calculated on the obtained increment core.
The total area of the stands is 241.9 ha. The average values of the structural elements of all stands together per hectare at the time of measuring were as follows: number of trees 298, basal area 27.0 m2, volume 383.9 m3 and volume increment 8.3 m3. Stand quadratic mean diameter is 34.2 cm and Lorey’s mean height 28.5 m. The area of individual stands is 9.8–32.3 ha. Their site class is I/II–III/IV. The altitude ranges from 400 to 1380 m. The average slope is 11–27°, the aspect is mostly north-western and the canopy closure degree is 69–94 %. The stand quadratic mean diameter ranges from 30 to 42 cm, while Lorey`s mean height amounts to 22–34 m. The number of trees is 214–308 per ha, basal area 22–33 m2 ha–1, volume 290–522 m3 ha–1 and volume increment 5.0–10.5 m3 ha–1. The quality and assortment structure of the investigated beech stands is poor. According to Matić`s classification (Matić, 1977) the percentage of the trees of the third (the lowest) silvicultural class in the existing volume is 45.0 %, individually from 26.5 % do 72.1 %. The percentage of the trees of the third and fourth technical class (the lowest classes) in the existing volume is approximatelly 28.6 %, individually from 11.0 % to 58.8  %. Logs are represented by about 40 % (Koprivica et al., 2010b).
A systematic sample was applied for the purposes of collecting and processing stand data. Circular sample plots of 500 m2 were arranged in a grid of 100 x 100 m. A set of 242 sample plots was established in the following stand arrangement: 20 (27a), 29 (122a), 16 (8a), 10 (8b), 23 (44a) 33 (116a), 23 (33a), 18 (42a), 10 (42b), 32 (31a) and 28 (46a).
Measurements that were performed in all sample plots included all dead wood that was completely or partly on the sample area. If those were whole trees or longer tree parts in a lying position, they were measured in sections, with roots being excluded from the measurements. It is a well-known fact that dead wood can occur both in a standing and in a lying position. The trees with a dbh above 5 cm and the old stumps with a top diameter above 7 cm were used for the measurements of standing dead wood. Lying dead wood was measured in all tree parts that were at least 3 cm in top diameter and more than 0.3 m long. These criteria were determined by the parallel measurements of living trees (diameter threshold of 5 cm and volume of wood above 3 cm in diameter).
Standing dead wood included elements of different types: a) whole standing dead trees (snags), b) snapped dead trees (at a height of 2.6 m and more) and c) old stumps (older than one year).
For whole dead trees (a), their breast diameters and heights were measured. When measuring the snapped snags at a