Functional similarity of tree species growth responses to ecological gradients quantified using a multimetric curve distanceFicko, Andrej (Avtor) Trifković, Vasilije (Avtor) functional similaritydistance measuresspecies clusteringgrowth modelingecological nicheecological gradientsQuantifying similarity among species responses to ecological gradients is challenging, yet increasingly important for adaptive forest planning under changing environmental conditions. We introduced an analytical workflow for growth curve similarity to compare species growth responses along ecological gradients and identify functionally similar tree species. Growth curves were parameterized for 40 species and 9 ecological factors based on 365,885 trees in temperate mixed uneven-aged forests, and trajectory similarity was quantified using multiple distance measures that capture distinct aspects of curve similarity. These included similarity in overall response shape and order of change (Fréchet distance), differences at extreme points (Hausdorff distance), similarity under shifts along ecological gradients (dynamic time warping distance), and average pointwise differences across the full gradient. We developed a novel indicator of functional similarity, the multimetric curve distance (MCD), a fused distance metric that accounts for the relative importance of ecological factors in the response profile. The ordination analysis revealed two to three main clusters of functionally similar tree species. Non-native species formed a distinct group, clearly separated from native climax species and from pioneer, drought-tolerant, and thermophilous species. Species differences were driven primarily by variation in curve shape and trajectory rather than by extreme values alone. From a management perspective, and in terms of resource-use patterns, our results suggest that non-native species such as Pseudotsuga menziesii and Pinus strobus are not direct functional equivalents of the dominant genera such as Fagus, Abies, or Picea, and will likely require new yield tables and management guidelines. The proposed analytical workflow allows flexible weighting of ecological factors and different segments of the response curves to reflect management objectives, such as emphasizing age-related growth for economic assessments or climate sensitivity for adaptation planning.20262026-07-30 09:29:14Članek v reviji185262sl