Montane forests have been under long-term synergistic chronic effects of natural and anthropogenic stress impacts, and imposed from time to time to acute climatic and pollution stress events. Crown structure transformation (formation of secondary shoots of different orders in successive series on damaged and/or defoliated branches) is a very sensitive indicator of long-term tree damage processes (30-40 years back), and of the subsequent regenerative processes. Tree crowns on six permanent research plots in the Krkonošc Mts were visually investigated and classified into several stages of crown structure transformation. One or more trees from the most frequent stages were selected for investigation of the branch structure transformation. Set of indicators, enabling to estimate stress response history of trees at branch, tree, and stand levels, was proposed. Rate of secondary shoot formation, which compensates a defoliation of primary shoots, indicates overcharging of stress exceedance starting level. Significant harmful effect time can be detected by estimation of the time of termination of annual wood production of primary shoots. In addition, trends of probable subsequent development of trees investigated were estimated at branch, tree, and stand levels. The proposed approach outlined in this paper could be used for the investigation of structural and functional changes of various ecosystems under multiple stress impacts.