MORPHOLOGY OF SILVER FIR (ABIES-ALBA MILL ) .2. ROOT BRANCHING, ARCHITECTURAL MODEL AND CROWN ANALYSES

The work presented describes the branching pattern of both the crown a nd the roots of fir. To describe the branching pattern (crown and root system) a terminalogy is suggested, using which, the type, order, tim e of development (ontogenesis) and localisation of structural elements can be assessed. A simple whole tree model for fir is used as a basis to assess changes. A detailed crown analysis was carried out on old c rowns. the yearly height growth increment traced back morphologically and the branching of the S-1-axes were investigated. Further, the age of the needles on various branches of crowns differing in the degree o f damage were determined. Using longitudinal sections of the crown, in formation could be gained about the distribution and contribution of r egular and proventitious branches and needles within the crown. Firs a re able to develop secondary crowns, which must be divided into those with light-adapted or shade-adapted crowns. The character and the size of these crowns has important influence on the length growth of the b ranches and thickening of the lower trunk. The high regeneration capac ity of firs using proventitious shoots is especially considered. Possi ble causes for crown thinning are discussed.