186 r SAHO 



Soils within the range of P. himekomatsu are derived from quartzites, 

 granites, clay-stones, sand-stones, tuffes and horn- stones. This species 

 grows especially well on soils with granitic parent material. It is 

 slightly drought resistant and like F. pentaphylla grows on ridge-tops or 

 on steep slopes near the ridges. 



Naturally regenerated seedlings of this species require more shade 

 than seedlings of P. densiflora, thus regeneration cannot be expected. 

 Utilization of this species is almost the same as for P. pentaphylla. 



Natural stands of P. himekomatsu are fast disappearing. Nowadays 

 one usually finds only remnant mature trees, as scattered individuals 

 mixed in stands of other species, or as cultured ornamentals. Natural 

 stands of this southern taxon of P. parvi flora are threatened with 

 extinction . 



PIN US PUMILA RE GEL 



The natural distribution of this species is at the tops of mountains, 

 except in northern Hokkaido where, as might be expected, it grows at 

 lower elevations (less than 300 m) . P. pumila was once considered to be 

 a variety of P. oembra L. One good distinction between these two species 

 is that the resin duct of P. oembra needles is in the mesophyll, while 

 that of P. pumila is beneath the epidermis. 



In general, P. pumila grows on very cold sites. In exposed and 

 windy places, the snow-cover often is blown away and the trees are 

 directly exposed to the cold weather; nevertheless it still grows normally 

 for the species. It cannot survive in localities having hot summers. 



The species extends to 70°N. latitude in northeastern Siberia. At 

 the northern limit of its natural distribution in Japan (Rebun Island, 

 off the northwest tip of Hokkaido, 45°N. latitude, at 300 m elevation), 

 the average minimum temperature is about -11.2 to -12.5°C (13 to 11°F). 

 At Mt. Hokuchin (2240 m elevation, the highest elevation attained by the 

 species in Hokkaido), the average minimum temperature is about -25.6°C 

 (-13°F). At the place of highest distribution on Honshu, Mt . Kitadake 

 (3180 m elevation), the average minimum temperature is about -21.5°C 

 (-4.5°F.). The southern limit of its natural distribution (35-l/2°N. 

 latitude) occurs in Japan, where the average maximum temperature is 

 about 18°C (64°F) at 2500 m elevation and about 25°C (77°F) at 1450 m 

 elevation. Annual precipitation at places within the natural distribti- 

 tion of P. pumila is about 1000 to 1500 mm. 



P. pumila grows on mountain ridges and in windy places where it 

 creeps along the ground (Fig. 4); however, it grows fairly erect in the 

 valleys and flat places where it reaches 3 to 5 m in height. Soils 

 within the range of P. pumila are derived from andesites, serpentines 

 and peridotites. This species is not found on relatively recent (Mt . 

 Fuji) or active (Mt. Asama) volcanoes. P. pumila has no industrial use 

 and no trial plantations have been established, even in high and windy 

 places. However, its value in stabilizing water and snowsheds is often 

 overlooked. 



