Height structure of spruce mountain forests of Babia hora -- Oravské Beskydy

The paper analyses the height structure of mountain spruce forests in the nature reserve Babia hora, Slovakia. The analysis consisted of the three partial tasks (1) analysis of the relationship between maximum tree height and elevation, (2) derivation and evaluation of height-diameter curves separately for species and elevation categories, (3) frequency analysis of tree heights. The results revealed a tight correlation of maximum tree height to elevation (correlation index equal to 0.91), and between tree height and diameter (correlation index varied from 0.93 to 0.99). For Norway spruce (Picea abies L./Karst), height-diameter relationship was described by a five-parameter exponential function, because simpler functions were not able to represent the small values below the usual truncation point satisfactorily. In case of rowan (Sorbus aucuparia L.), Gompertz function was used for the description of height-diameter relationship. Tree height frequencies were analysed by frequency analysis. The results indicated that the most differentiated vertical structure is in the stage of growth. The stage of breakdown is characterised by bimodal distribution. With increasing elevation the differences between the vertical structure of the stage of optimum and breakdown diminish, while the differences between the stage of growth and the stages of optimum and breakdown become more distinct.