Quantitative profile structure of certain forests in the Kumaun Himalaya

Abstract

The structure of forests occurring within the north-western catchment of the river Gola in Kumaun Himalaya is quantitatively described. All the forestt indicated a total of four strata ; two upper strata represented by trees, the third stratum represented mainly by shrubs, and the fourth of herbs. The tree heighs of the A₂ (top most) stratum decreased with an increase in altitude. On the other hand, the proportion of trees devoted to the canopy in the A₁ and A₂ strata increased with an increase in altitude. In all forests, the crowns of the A₁ and A₂ strata were more deep than wide. In general, the shrub layer in-three oak forests was comparatively dense and the crowns of the shrubs overlapped with each other. The canopy index, a relative measure of canopy coverage, of tree and shrub layers was maximum for Quercus floribunda forest and minimum for Pinus roxburghii forest. Further, tho cooler aspects developed a greater canopy index for these layers as compared to the warmer aspects. Oak forests exhibited a poor development of their herb layers. The trees in the Quercus lanuginosa forest we ere more stable, while in Pinus roxburghii forest they were specially susceptible to wind effect. In general the warmer aspects had more stable trees, while the cooler aspects showed a lower tree stability. The different forest types, presently studied, could be graded, as follows, in a decreasing order of potential for soil protection : Quercus flori-bunda > Quercus leucotrickophora>Quercus lanuginosa >mixed>Pinus roxburghii.