RESEARCH ON GROWTH CHARACTERISTICS, BIOMASS AND CARBON OF NATURAL MANGROVE FORESTS IN CAN GIO, HO CHI MINH CITY

Abstract

The study was conducted in 4A, 6B, 14, 15A, 21 and 24 compartments of Can Gio Forest Management Board, from January to December 2024, by establishing 18 survey lines, each line is 3,600m long on average, the distance between lines is 1,000 - 1,500m, the total length is 61,500m passing through the main forest states of the study area; On the transects, 54 typical standard plots were arranged, with an area of ​​500 m²/plot, representing site type of clay, medium tidal flooding, low salinity (Mi), clay, medium tidal flooding, medium salinity (M) and clay, medium tidal flooding, high salinity (Mn) and the diference in the level of the Normalized Difference Vegetation Index (NDVI), level 0 (0,0 - 0,1), level 1 (0,1 - 0,2), level 2 (0,2 - 0,3), level 3 (0,3 - 0,4), level 4 (0,4 - 0,5) and level 5 (0,5 - 0,6) to collect the following indicators: diameter at breast height (D1.3), tree height (Hvn), tree height below the branch (Hdc), tree canopy diameter (Dt), tree species composition. The results determined that (1) the growth of D1.3, Hvn, Hdc, Dt of restored and poor mangrove forest stands depends on the site type and NDVI index; increasing in the direction of increasing NDVI level, highest at level 5 and lowest at NDVI level 1; increasing at site Mi and site M and low at site Mn; (2) forest reserves change according to NDVI level and site type; forest reserves increased with increasing NDVI level, highest at level 5 and lowest at level 0; high reserves in site Mi and site M and low in site Mn; (3) biomass and carbon accumulation capacity were high in site Mi and site M, low in site Mn; site Mi and site M with tree carbon reserve values ​​of 84.78 tons/ha and 77.42 tons/ha were statistically different from site Mn at 65.37 tons/ha; carbon reserves changed with increasing NDVI index.