Top/root biomass ratio of a secondary mangrove ( Ceriops tagal (Perr.) C.B. Rob.) forest

Abstract

In southeast Asia, secondary mangrove forests cover a vast area, and the precise estimation of their biomass is necessary for evaluating the carbon stocking pattern in the coastal areas of the tropics. In order to estimate the above-ground biomass of a Ceriops tagal forest, allometric relationships were examined using some variables relating to the stem diameter ( DBH, D B) and length ( H). The relationship for the stem weight of an individual tree was the most significant when the variable DBH 2 H was used. Whereas, for the branch and leaf weights the variable D B 2( H− H B) gave the best fit. For estimating the root biomass, the method using the horizontal distribution of the root density [Komiyama, A., Ogino, K., Aksornkoae, S., Sabhasri, S., 1987. J. Trop. Ecol. 3, 97–108] was further developed and used. The biomass estimation was carried out for 77 tree stems in a 7 m×10 m area, where C. tagal was dominant and associated with Rhizophora apiculata and Xylocarpus moluccensis. The estimated biomass were 53.35, 23.61, 13.29, 1.99, and 87.51 t ha −1, respectively, for the stem, the branch, the leaf, the prop root, and the below-ground root. In this forest, the root biomass was large enough to give the top/root biomass ratio as low as 1.05. The biomass-allocation pattern of the secondary C. tagal forest and its ecological significance are discussed.