Tree population structure of certain Himalayan forest associations and implications concerning their future composition

Abstract

This study deals with the regeneration status of certain tree components of forests in the northwestern catchment of the river Gola in Kumaun Himalaya and explores possible compositional changes in time. Pinus roxburghii, Quercus floribunda and Quercus lanuginosa in their respective forest types had a stable population structure with a large percentage of young individuals (seedlings) and relatively few old ones, indicating that these species are frequent reproducers. The girth class distribution of the individuals of Quercus leucotrichophora in the Quercus leucotrichophora forest suggests that this species is likely to disappear gradually. In this forest, although forest composition will remain unchanged for some time, a complete absence of seedlings of any species shows the possibility of its complete replacement by a scrub or a grassland vegetation. In the mixed forest, the dominant species, viz., Quercus leucotrichophora, Persea odoratissima and Bauhinia retusa did not have saplings/seedlings, indicating a possible change in forest composition in the near future when Sapium insigne, Cocculus laurifolius, Celtis eriocarpa and Acer oblongum are likely to gain dominance. Finally, suggestions are made to explain the poor regeneration of Quercus leucotrichophora.