Growth dynamics of Norway spruce (Picea abies [L.] KARSTEN) in natural spruce forest ecosystems of the National Park Hochharz -: 1.: Regeneration phase and initial phase

Natural spruce forests in the strictly protected area of the National Park Hochharz above 920 m are structured into mosaics of formation phases connected in asynchronous cycles (shifting mosaic patterns) of 325 +/- 25 years. The paper describes the growth dynamics of the first two development phases after the decay of old-growth stands. The natural regeneration phase of two spruce ecosystems investigated is characterized by a very slow height development of spruce seedlings and saplings, small increment rates of diameters (CHD) and basal areas. The regeneration phase, for example, covers a period of 28 years. Similar conditions are found in boreal virgin spruce forests. Regardless of low growth rates and slight density of young crops, a process of reliable, covering and stable stand regeneration is initiated. In the following initial phase, comparable to thicket and pole stands, the absolute and relative growth rates increase exponentially and indicate the forming of slightly uneven-aged stand structures.