SPATIAL STRUCTURE OF UNEVEN-AGED STANDS OF FIR AND BEECH ON THE BORJA MOUNTAIN (BOSNIA AND HERZEGOVINA)

In the territory of Bosnia and Herzegovina, uneven-aged stands of fir and beech are very important from the economic and ecological point of view. A major practical lack of information on the simple structure of stands is that they cannot be used to draw valid conclusions about the spatial distribution of woody species, the position and dimensions of trees and this is one of the bases for sustainable management of mixed and uneven-aged forests. In four mixed uneven-aged fir and beech stands and one pure fir stand on the Borja mountain, the basic elements of tree growth were measured and the data needed to determine the indicators of the spatial stand structure were determined. According to the index of aggregation of Clark and Evans, when all trees are observed, on average there is a tendency towards a uniform spatial distribution of trees in the stand. When only fir trees were selected as reference trees, it is evident that there is a tendency to group fir trees in the stand. The diameter differentiation index shows that the average tree diameter differentiation is on all sample plots. The determined values ​​of the Weber’s height competition index by stands are approximately the same, ie it can be stated that there is no significant difference between stands in terms of competition between trees when it comes to vertical structure of stands.