RESEARCH ON NATURAL REGENERATION OF POOR AND RESTORING MANGROVES IN CAN GIO, HO CHI MINH CITY

Abstract

The study on natural regeneration of poor and restoring mangroves in Can Gio, Ho Chi Minh City was conducted from January to May 2024. The objectives of the study were to (i) determine the species composition of regenerating trees, (ii) determine the quantity, quality and potential trees, (iii) influence of site and, (iv) influence of NDVI. The study established 54 standard plots, with an area of ​​500 m² to determine species composition, density, diameter at breast height, height, and canopy diameter of tall trees. Each plot consisted of 5 plank plots, with an area of ​​4 m² (1 in the center of the plot and 4 plots in the east, west, south, and north directions, 5 m from the center of the plot) to determine the species composition of regenerated trees, and measure regenerated trees according to height levels (level 1: <0.5 m, level 2: 0.5 - 1.0 m, level 3: 1.0 - 1.5 m). The results identified 14 species, with five species having the highest regeneration rate (accounting for 89.3%) including Avicennia officinalis (44.4%), Rhizophora apiculata (21.7%), Avicennia alba (9.4%), Ceriops decandra (8.6%) and Ceriops tagal (5.2%); (2) The proportion of regenerated trees gradually decreased as the height of regenerated trees increased, the height class <0.5 m accounted for 93.4%, the height class 0.5 - 1.0 m was 5.6% and the height class 1.0 - 1.5 m accounted for only nearly 1.0%; (3) the site factor clearly affected the species composition and quantity and quality of regenerated trees; (4) the forest status (according to NDVI level) clearly affected the regeneration ability of the forest; the proportion of regenerated trees was most promising at NDVI 3 and NDVI 4.