STUDY ON THE STRUCTURAL CHARACTERISTICS OF MANGROVE FORESTS AS A BASIS FOR PROPOSING CONSERVATION SOLUTIONS AT PHU QUOC NATIONAL PARK, AN GIANG PROVINCE

Abstract

This study was conducted to provide a scientific basis for the conservation of mangrove ecosystems in general and the endangered species Lumnitzera littorea in particular at Phu Quoc National Park. Remote sensing integrated with field verification was applied to determine the distribution range of mangrove forests. In addition, 25 sample plots (1.000 m² each) were established from February to August 2025, combined with inherited data from a 10.000 m² permanent ecological monitoring plot to analyze forest structural characteristics using Excel software. The results identified three typical plant communities with a total area of 79.9 ha. Lumnitzera littorea was identified as a dominant or co-dominant species in two communities: Lumnitzera littorea + Heritiera littoralis + Rhizophora apiculata + Bruguiera gymnorhiza and Lumnitzera littorea + Bruguiera gymnorhiza + Heritiera littoralis - Melaleuca cajuputi. Notably, the study additionally recorded a mixed Melaleuca cajuputi - Bruguiera gymnorhiza community, in which mangrove species were interspersed within Melaleuca forests, a feature not previously reported in earlier studies. Diameter and height distributions were consistent with the Weibull distribution function. The N/D distribution was concentrated mainly in small diameter classes and gradually decreased toward larger classes, while the N/H distribution was concentrated in medium height classes. Natural regeneration occurred in all three communities with high density, predominantly from seeds. Based on these findings, management solutions were proposed to maintain multi-layered forest structure, strictly protect mother trees, promote natural regeneration through assisted restoration, and enrich planting in canopy gaps to support in situ conservation of Lumnitzera littorea.