A common allometric equation for predicting stem weight of mangroves growing in secondary forests

The allometric relationship for stem weight Ws is usually expressed as a function of stem diameter and height, similar to the variable d.b.h. H-2, which equals the squared diameter at breast height multiplied by tree height. However, this relationship often differs between tree species, and this segregation of the relationship by species forces the researcher to do a tremendous amount of field work to determine a series of allometric equations for all tree species in the forest. In this study, we examined the segregation in the d.b.h. H-2-Ws allometric relationship for five mangrove species. We examined the overall stem shape and the specific gravity of stem relating to the allometric relationships. The difference in the specific gravity was found to be the main cause of the segregation in the d.b.h. H-2-Ws relationship. By taking into consideration the specific gravity of stem, we established a common equation for the five mangrove species.