Aim of study: Critics of the shelterwood system claim that regeneration felling in mature stands reduces plant species richness and promotes a monospecific dominance of Sal (Shorea robusta Gaertn. f.). In this context, the study aims to evaluate the regeneration dynamics in Sal forests following regeneration felling. Area of study: The study was conducted in the Sal forests of Nepal’s lowland, where a series of regeneration felling were implemented under the shelterwood system. Material and methods: A total of 270 rectangular plots, each measuring 10m2, were established across 90 annual felling plots, with three sample plots allocated per felling plot. Within each sample plot, seedlings and saplings were measured and counted. Main results: Light demanding species dominated both seedling and sapling layers, comprising 83% and 92% of the overall density, respectively. The diversity index was higher in the seedling layer (0.80) compared to the sapling layer (0.24). Since the most degraded plots were treated first, no clear trend in regeneration diversity and species richness was observed across the age groups (1-3 years, 4-6 years, and 7-9 years after harvesting). Research highlights: Gap promoted the regeneration of light-demanding species initially, and plant species richness increased over time following regeneration felling. As seedlings grew into saplings and provided shade, shade-tolerant species gradually began to appear. Therefore, species richness was influenced by the time elapsed since regeneration felling.
Thakur et al. (Tue,) studied this question.