Comparison of Planted Pine versus Natural Mix Forests in Nepal

Abstract

This study aimed to compare the socio-environmental benefits of one of the most widely planted forest species, i.e., Pinus roxburghii (Sarg., hereafter ‘Pine’ or ‘Pinus’) with naturally regenerated mixed forests in two community forests of Nepal. By analyzing tree rings, we estimate biomass production, carbon accumulation, and growth enhancement in both forest types using regression models, offering insights into sustainable forest management. Pinus forests exhibit instant social benefits through direct economic conversion and a higher rate of carbon sequestration. However, the lack of perpetuated production, due to unimodal stand structures, necessitates anthropogenic interventions for long-term sustainability. Challenges such as the absence of natural regeneration, frequent fires, limited undergrowth, limited species diversity, and likely soil erosion hinder long-term sustainability in Pinus forests. In contrast, natural regenerated mixed forests offer slow carbon sequestration with less opportunity for immediate economic conversion, yet they maintain a proportional age-class distribution and experience minimal fire incidence, abundant regeneration, higher biodiversity, and lower regeneration costs. Although no abrupt environmental disasters were observed through the dendrochronological assessment, a significant positive correlation (p < 0.05) was found between age and girth at breast height, biomass, and volume of the forests. This study underscores the crucial role of human intervention beyond conventional management focusing on the protection motive to production-oriented forests in optimizing the socio-economic and environmental benefits of both forest types in the changing socio-environmental challenges through informed management planning.