ABUNDANCE AND RICHNESS OF PLANT DIVERSITY INFLUENCING CANOPY GAP AND HEIGHT IN NATURAL AND PLANTATION FORESTS

Canopy gap and heights contribute to the maintenance of tree species diversity in forest ecosystems. Gap dynamics are a typical characteristic of both temperate and tropical forests and have a wide variety of causes and effects on forest life. Current study assesses the influence of canopy gaps and heights on plant species richness and abundance in natural and plantation forests. For this study, the Lawachara National Park (LNP) was selected purposively in 2015 for having great diversity of natural and plantation forests. A total of 117 circular plots of 7m radius each were taken arbitrarily without preconceived biasness. Results showed that in the old-growth forests, the percentage of canopy openness (47.7 ± 15.0) of natural forest was lower than plantation forests (53.0 ± 16.0) and richness and abundance of the natural forest was higher than plantation forests. For example, richness of natural forest was (12.0 ± 2.6) and plantation was (9.9 ± 2.9); species abundance of natural forest was Abundance was (211.1 ± 124.0) and plantation was (147.3 ± 86.6), respectively. The study revealed that negative influence of canopy openness/gap on species richness and had positive influence on abundance in natural forests but not in plantation forests. The study revealed that there was no significant relationship between canopy height (m) with richness (F = 0.76; p = 0.39) and log (abundance) (F = 0.27; p = 0.61) in the natural and plantation forest of the study area. These information will help to conserve and maintain plant biodiversity of the study area.