WHITE PINES OF JAPAN 185 



Average density of 26~0 trees/ha, volume 115 m 3 /ha, and annual growth 

 6.46 nr/ha. This level of growth is a little poorer than Abies 



3 Mast., the most commonly planted tree species in Hokkaido. 

 In Honshu growth of P. pe ".r:r: : '.\- 1 '. a is also poorer than that of P. densiflora. 

 Therefore, foresters show little interest on making plantations of p. 

 pentaphylla. There is another reason why P. pentaphylla is not planted 

 widely. This is the heavy damage I ferana Wocke. Damage 



this insect is so severe that few uninfested cones can be collected. 

 Annual precipitation at Hakodate (40 km from Kobui) is 1178 mm, annual 

 average maximum temperature 12.2°C (54°F. ) and average minimum temperature 

 4.5°C (40° F). 



P. pentaphylla is rather resistant to wood-rotting fungi, and its 

 commonest use is for construction and home building. It is not used for 

 pulp, because of the phenolic substances in the heart wood. 



There are natural hybrids and varieties of P. pentaphylla as follows: 



(a) Finns hakkodeKsis Makino (1952) which is supposedly the hybrid 

 between P. pentaphylla and P. pumila. Morphologically, it is intermediate 

 between the two pines. The natural distribution of this dwarf pine hybrid 

 is only in the northern part of Honshu. 



(b) Pinus pentaphylla Mayr var. laevis Hara (Uehara, 1959), for 

 which variety the differentiating characteristic is smooth-surfaced bark 

 of both branches and trunk even when it becomes a big tree. The natural 

 distribution is restricted to Mt . Hidaka, Hokkaido, and Mt . Iide, 

 Yamagata Prefecture and Mt. Asama, Nagano Prefecture, Honshu. Rare trees 

 of this variety are mixed with P. pentaphylla in those places. 



PINUS HIMEKOMATSU MIYABE $ KUDO (SOUTHERN JAPANESE TAXON OF P. PARVIFLORA 

 SIEB. & ZUCC. AND SYNONYMOUS WITH P. PENTAPHYLLA MAYR. VAR. HIMEKOMATSU 

 MAKINO) 



The natural distribution of P. himekomatsu lies generally to the 

 south of that of P. pentaphylla, mainly from 31-1/2° to 37-1/2° N. 

 latitude. Where P. pentaphylla and P. himekomatsu grow on the same 

 mountain slopes in the central part of Honshu the species separate alti- 

 tudinally, with P. pentaphylla above and P. himekomatsu below. ?. 

 : :i~i<:™z7s^ occurs along the eastern or Pacific Ocean coast in north- 

 central Honshu, but does not occur on the Sea of Japan coast except to 

 the south of central Honshu (see Fig. 1 and Mirov, 1967, Fig. 3-4a) . 



At the northern limit of the natural distribution, Fukushima 

 Fiefecture, Honshu, the average minimum temperature is about -6.9 to -~.~ : 

 (19 to 18°F). At the highest place of its distribution, Mt . Ishizuchi 

 (1950 m above sea level), the average minimum temperature is about -10°C 

 (14°F) . .And at the southern limit cf the natural distribution, Kagoshima 

 Prefecture, Kyushu (700 to 900 m elevation) , the average maximum tempera- 

 ture is about 28 to 30°C (82 to 86°F) . 



.Annual precipitation is about 1000 to 3000 mm (39 to 118 inches), 

 but at Mt. Odaigahara, the precipitation reaches about 4000 mm (almost 

 160 inches) . This species is found in the area of heavy summer and 

 light winter rains. 



