Understorey vegetation and its relation with the recognition of ..........

Abstract

Understorey vegetation is as important as overstorey vegetation in forests as it facilities overall regeneration and has crucial role in nutrient cycling. Understorey vegetation largely affects the regeneration of dominant tree species in forests, but little is known about such impacts. In this context, this research work was carried to assess the impacts of understorey vegetation on regeneration of Quercus semecarpifolia, and the effects of environmental factors on understorey vegetation and regeneration in Langtang National Park and its buffer zone of Central Nepal. Altogether, 308 plots of 1m×1m for shrubs and 77 plots of 1m×1m plots for herbs were used for data collection from which 160 plots were established in the national park and 148 plots were established in the buffer zone for shrubs species. Similarly, 40 plots were established at the National Park area and 37 plots were established at buffer zone areas for the herb species. Importance Value Index (IVI) of herbs and shrubs species, p-value and correlation of understorey vegetation with seedlings and saplings of dominant tree species, and soil attributes was analyzed. A total of 17 species of shrubs belonging to 12 families were recorded inside the national park and 29 species of shrubs belonging to 14 families in the buffer zone area. Similarly, altogether 30 species of herbs belonging to 17 families were recorded inside the national park and 30 species of herbs belonging to 18 families in the buffer zone area. Simpson’s index of diversity and Shannon-Wiener index of diversity of shrubs species inside the national park were found to be 0.9069 and 2.523, while those values for buffer zone were found to be 0.887 and 2.517, respectively. Similarly, Simpson’s index of diversity and Shannon-Wiener index of diversity of herb species in the national park were found to be 0.9415 and 3.0849, respectively while those values for buffer zone were found to be 0.9201 and 2.9849. There was no significant correlation between understorey species richness and organic matter content, soil pH and soil nutrients (N, P, K) and also the relationship was not observed between understorey vegetation with the seedling and sapling of Quercus semecarpifolia.