Regeneration of White Oak ( Quercus leucotrichophora ) in Two Pine Invaded Forests in Indian Central Himalaya - Management of Natural Resources in a Changing Environment - page 200

Fig. 1 White oak regenerating forest site I in Indian central Himalaya. A - H represent girth classes
of individuals of the species in cm. A : seedlings, B : 10-30, C : 30.5-60, D : 60.5-90, E : 90.5-120,
F : 120-150, G : 150.5-180 and H : >180
According to Singh et al. ( 1984 ) pine has greater nutrient conserving ability
than oak and it creates N shortage in the soil that makes it diffi cult for oak to
reinvade pine encroached sites. Present study addressed the question what
conditions favour oak to reestablish in these sites. Present study observes that after
the fi re removes the pine, oak is able to reoccupy the sites in moist valley areas
only with some degree of shade. The mountain ridge areas with higher light
conditions remain under pine. It seems that nutrient required by oak would be
fl owing down to valley sites from the mountain slopes through surface and
subsurface runoff during rainy seasons. Once the oak gets established it further