172 P. D. DOGRA 



prefer mica-schists, screes, and flood plain deposits. At Gangotri they 

 grow on flood-plain deposits and moraines. In Kumaon, blue pine forests 

 mixed with little firs grow on gneissic sub-soils. In Nepal they grow on 

 alluvial plains at high altitudes. 



Tree Growth and Description 



At Kalpa in Kinnaur-Sutlej , these trees are tall, 60 to 140 feet in 

 height and 6 to 10 feet in girth. The trees, in general, have conical 

 crowns ending in leader shoots but trees with spreading or truncated 

 crowns are also found. Branches and foliage are dense. The foliage is 

 dark bluish green, relatively short and stiff, especially on slopes 

 exposed to bright sunshine. The rate of tree growth is good but slower 

 than that of the moist upper- level monsoon zone blue pine (Fig. 2) . An 

 average of 9.1 rings have been calculated per inch of radius from ring- 

 countings of 49 stumps in Kishanganga valley in Kashmir and the mean 

 annual girth increment is stated to be about 0.7 inches (Troup, 1921). 

 In the dry climate trees look younger and vigorous, though older in age, 

 because the growth is slow but good. These trees are, however, highly 

 susceptible to attacks of Arceuthobium nrlnutissimum Hook, which causes 

 considerable damage. 



Flowering, Pollination and Seed-Set 



Flowering is abundant and pollination occurs during the warm, dry 

 days of the second half of May, about 7 to 10 days later than in the high- 

 level monsoon zone pine. May is also the flowering time at Joshimath in 

 Kumaon (Strachey, 1906) . The female receptivity period is of short dura- 

 tion (4 days) . The trees produce cones profusely and the seed-set is 

 good. Some trees of this zone have large and heavy seeds. 



DRY OR ARID HIGH-LEVEL NON -MONSOON ZONE BLUE PINE 



The trees form very open forests scattered in patches at high alti- 

 tudes (10,000 to 12,500 feet or more) and on gentle slopes around arid 

 valleys situated near the northern limit of blue pine. These valleys 

 have an annual precipitation of 10 to 30 inches, mostly in form of winter 

 snow (Fig. 6) . The blue pine grows in pure patches or mixed with Cedrus 

 deodava, Pinus gevardiana, Abies spectabilis (D. Don) Spach, Betula 

 utilis Don, Rhododendron, Picea and Juniperus spp. 



Very little is known about the dry or arid high-level blue pine 

 because it grows in regions not easily accessible to man. 



Habitat and Soil 



The trees prefer gentle, protected slopes capable of holding enough 

 snow to meet the summer moisture needs. In highly arid regions the trees 

 may grow on stream beds near water. Blue pine also grows on very steep 

 slopes at high altitudes with more than 15 feet of snow. Snow slides and 

 avalanches are, therefore, commonly experienced by these trees. In fact, 

 the blue pine often occurs on narrow marginal strips along regular paths 

 of snow slides. 



In the interior valleys, the blue pine can be found in patches on 

 snow-holding slopes and shallow ravines protected from strong winds. Blue 

 pine trees were seen on the way to Gangotri glacier growing on moraines 



