Evaluating Enrichment Planting for Tropical Forest Restoration: A Case Study of Erythrophleum fordii and Manglietia conifera in Central Vietnam

This study evaluates the long-term effectiveness of enrichment planting as a restoration strategy in Central Vietnam, focusing on the performance of Erythrophleum fordii and Manglietia conifera. A restoration site was established in 2006 using a line planting over a 1-ha area, with no fertilizer applied and minimal tending during the first three years. After 18 years, E. fordii demonstrated superior growth performance, with a larger diameter at breast height (21.1 cm) and standing volume (94.56 m-3 ha-1), while M. conifera showed a lower diameter at breast height (16.8 cm) and standing volume (55.15 m-3 ha-1). Survival rates differed significantly between species, with E. fordii achieving 88.0% compared to 73.3% for M. conifera. Notably, M. conifera had better stem quality (90.9%) compared to E. fordii (80.8%). Regression analyses revealed weak to moderate correlations between growth parameters for E. fordii, indicating complex growth dynamics, while M. conifera exhibited minimal correlations, suggesting other factors influence its development. These findings highlight the species-specific trade-offs and complementary roles in mixed-species planting. This research provides descriptive evidence of the potential for enrichment planting to establish valuable tree species in degraded forests, emphasizing the importance of species selection and management strategies for achieving restoration objectives in sustainable forest management.