The influence of competition and dimensionalspatial characteristics of trees on their radial growth in Old-Growth Slãtioara forest, Romania

The paper tries to identify how the radial growths of trees from old-growth forests are influenced by some forest structural elements, but also how the radial growths depend on the biometric characteristics of trees. The analysis was made for mixed natural stands of coniferous and beech from Slătioara Natural Reserve. All selected natural stands have an uneven-aged structure. The main results have showed that tree diameter influences the radial growth especially in the case of shadow intolerant species (Norway spruce); when the preferences for light are decreasing, the correlation level between the two mentioned characteristics is also decreasing (beech, silver fir). The influence of neighbouring competitors on the radial growths of trees from the three main species was determined. The first ten competitor trees were identified and their competition on the reference trees was calculated according to the Hegyi pattern. It was found that, in natural uneven-aged stands, radial growths are mostly influenced by the competition exerted by the first nine competitor neighbours for Norway spruce, the first two competitor neighbours for silver fir and the first seven in case of beech. The competing neighbours that mostly influence the radial growth were analysed with respect to their azimuth against the reference trees. It was observed that the radial growths of Norway spruce are mostly influenced by the competitors located in S and SE. For silver fir and beech the highest influence over the radial growths comes from the competitors located in NE and E.