Abstract:
The effect of tree canopy opening in the regeneration layer of Sal (Shorea robusta) were
investigated in four strata of forest viz. 0-25, 25-50, 50-75 and 75-100 percentage crown
cover vegetation in Shorea robusta forests in Nawalparasi. Regeneration survey was
carried in two blocks each of 10 hector, where one block was silviculturally operated with
irregular shelter-wood system and another was undisturbed. The seedling density of Sal
(shorea robusta,) is higher in the 0-25 and 25-50 percentage crown cover than others two
strata. Likewise, sapling density was also higher in the 0-25 and 25-50 percentage crown
cover than dense strata. The Simpson index, Shannon diversity index, and Shannon's
Evenness, of the seedlings were increasing with increase in crown cover percentage which
indicate less diversity in open crown cover due to dominance of sal regeneration. Crown
cover percentage was found negatively correlated with regeneration stock per hectare. The
study shows that, open strata maintain seedling density, favor regeneration of Sal forests and
regeneration of Sal dependent to the intensity of light and suitable condition for germination.
Opening of crown directly provide sunlight on land surface which helps in germination of Sal.
