Optimizing reforestation: growth and survival of selected tree seedlings in different light and land-use conditions

Abstract

Tropical forest degradation has resulted in biodiversity loss and diminished ecosystem services. Light strongly increases tree growth but its effect on survival depends on life stage, species and stressors. Urban and disturbed landscapes may enhance plant growth but are often associated with increased turnover rates. Effective management should align species selection with site-specific light conditions, mitigate environmental stressors, and implement targeted thinning or enrichment planting strategies to optimize restoration outcomes. This study examines the growth and survival rates of tree seedlings in Sapong Estate, Tenom, Sabah, through a comparative analysis of natural forest and plantation landscapes. Seedling growth rates were quantified based on height increments over time, while survival rates were determined by the number of seedlings remaining at the end of the experimental period. A randomized complete block design (RCBD) was employed, with four seedling species—Rubroshorea cutrisii (Dipterocarpaceae), Dryobalanops aromatica (Dipterocarpaceae), Durio zibethinus (Bombacaceae), and Artocarpus odoratissimus (Moraceae)—planted under different light exposure conditions. Growth and survival rates were measured over time, and statistical analysis was conducted using ANOVA. Seedlings in plantation areas exhibited significantly higher growth rates (0.36 cm/day) than those in natural forest conditions (0.22 cm/day), with statistical significance (p < 0.05). However, survival rates between the two landscape types did not differ significantly (p > 0.05). While light exposure had limited influence on growth performance, shaded microsites markedly improved seedling survival (99.5%) compared to open areas (77.08%) with significance of (p<0.05). The findings suggest that land-use type and environmental conditions influence seedling performance, providing insights for ecological restoration strategies. Notably, D. aromatica and R. curtisii emerged as the fastest-growing species, confirming their suitability as priority candidates for restoration initiatives. To enhance seedling establishment and long-term forest recovery, it is recommended that restoration efforts prioritize the replanting of these species in shaded areas, where survival rates are markedly higher. Integrating species-specific performance with microhabitat considerations will strengthen restoration success and support biodiversity conservation in disturbed tropical landscapes.