102 KURT HOLZER 



PINUS SIBIRICA 



P. sibirica has its natural distribution in the north of Siberia and 

 extends to the (northern) timber line, too. These forests are called Black 

 Taiga and contain the species Abies sibirica Ledeb. and Larix gmelinii 

 Rupr. Litvin (sometimes Picea obovata Ledeb.) in mixture (Belov, 1963). 

 P. sibirica comprises 5.3% of these stands (Buchholz, 1959). We also 

 find altitudinal distribution in the mountain regions, and in latitude it 

 is very widespread. Mirov (1967) reports three varieties of this tree: 

 the common form in the northern Siberian plains, a variety called P. 

 coronans Litv. (a mountain form in the Altai), and "forma depressa" 

 Komarov in the Transbaikal (which also seems to be a mountain form) . The 

 area of the Siberian stone pine exceeds nearly 28.8 million ha, and so 

 it is much more important than the two native European white pines. 

 Production of nuts (the seed) for men and animals is very important, and 

 sables bred for fur and meat are fed with the nuts (Kugler, 1962). 



SILVICULTURAL REQUIREMENTS OF P. CEMBRA AND P. PEUCE 



For best growth both P. cembra and P. peuce prefer light and humus 

 soils; heavy grassy soils very often make growth impossible. P. cembra 

 grows best in the subalpine shrub vegetation (Forstl. Bundesversuchsan- 

 stalt, 1961, 1963, 1965, 1967; Holzer, 1961). P. peuce does not like 

 calcareous soils. Neither can withstand shade except in their youth 

 (very often seedlings are growing below Rhodendron and Vaccinium shrubs; 

 later in life the plants have a strong need of light. The roots lie 

 parallel with the ground surface. A humid climate with wet air in summer 

 is preferred, and these species can withstand much snow in winter. They 

 are not injured by low-temperature extremes (Holzer, 1959) , and it is thus 

 that we find the most extensive and best stands on the north- and northwest- 

 facing slopes (Forstl. Bundesversuchsanstalt , 1961, 1963, 1965, 1967; 

 Nevole*, 1914; MUller, 1928; Tranquillini , 1956, 1958). 



GROWTH POTENTIAL AND INTRINSIC QUALITIES, PINUS CEMBRA, 

 P. PEUCE AND P. SIBIRICA 



The growth characteristics of both P. cembra and P. peuce are similar 

 and so we can speak about them without distinction. Usually we find very 

 slow juvenile growth, late cumulation of growth, and then long-continued 

 growth so that there remain some very old trees in the stands. 



JUVENILt GROWTH 



Juvenile growth is very slow with these species, even in the better 

 stands at optimal elevations. Slow growth persists for 20 to 30 years; 

 more than 5 years pass before an erect terminal shoot is attained as 

 shown in Figure 2(Figala, 1927; Oswald, 1963; Holzer, 1963, 1969; MUller, 

 1928). Growth of only a few cm per year is general, and we get the same 

 results when seedlings grow in natural high mountain zone (Oswald, 1963) 

 or in a warmer climate (Holzer, 1969) . P. sibirica, however, grows some- 

 what faster and the youthful period of restricted growth is shorter. 

 Consequently, P. sibirica plants of nearly double the growth attained by 

 the alpine P. cembra are produced at an age of 10 years (Holzer, 1969) . 



