Tree diversity, regeneration and carbon stock in the forests of chure region, madhesh province, Nepal

Abstract

Forest plays an important role in conserving tree diversity and contributes in carbon sequestration. The current study assesses tree diversity, regeneration and carbon stock in the forests of Chure region, Madhesh Province, Nepal. The data was collected following a two-phase systematic sampling with stratified systematic cluster sampling technique. A total of 67 tree species from 57 genera and 29 families were documented in 69 plots, with Fabaceae being the most species-rich family. The Shannon-Wiener’s diversity index (3.0) and Simpson diversity index (0.89) indicated high tree species diversity presence. The Margalef’s richness index (9.06) indicated high species richness. The most important tree species was Shorea robusta, with highest Importance Value Index (80.63%). Among eight Districts, species diversity and richness was highest in Saptari and lowest in Mahottari District. The regeneration pattern followed an inverse J-shaped curve which suggests the presence of healthy regeneration trend. Riverine forests experienced the highest disturbance and lowest regeneration while the government forests had experienced higher disturbance than the community forests and protected forests. The Canonical Correspondence Analysis revealed that, the species diversity was high in less disturbed forest areas and areas that were farther away from the motorable roads. Also, Shorea robusta was found abundantly in more disturbed cites. The one-way ANOVA showed that the government forest experienced highest disturbance while protected forest had experienced minimum disturbance. The KruskalWallis H test indicated the significant difference on carbon stock between three forest types and between three forest management regimes. The highest carbon stock was found in Sal forests and lowest in riverine forests as confirmed by Post-hoc Mann Whitney U tests with Bonferroni correction. The protected forest (PNP) stored highest and the government forest stored the lowest carbon stock among the forest management regimes. These findings highlight the importance of forests in terms of diversity as well as its contribution in carbon stock, in different management strategies. Key words: Diversity, Disturbed forest, Regeneration, Community forest, Forest management