Estimating above-ground biomass in six mangrove tree species, north eastern Queensland

Mangrove trees of six species were sampled in order to derive allometric relationships for estimating leaf biomass, branch biomass, stem biomass and total above-ground biomass from measurements of the diameter of the stem at breast height (DBH). Rhizophora apiculata, Rhizophora stylosa, Bruguiera gymnorhiza, Bruguiera parviflora, Ceriops tagal var. australis and Xylocarpus granatum were sampled from the mangrove forests of Hinchinbrook Island, the Murray River and the Daintree River in north Queensland between 1985 and 1988.For each species, the diameters of stems of trees from a range of size-classes were measured. The trees were then felled and divided into leaves, branches, stem and above-ground roots. The fresh weight of each component was measured in the field and subsamples of each component were collected, weighed and taken to the laboratory for determination of dry weight. This research was undertaken to determine if allometric relationships existed between stem diameter at breast height (DBH) and above-ground biomass, which would enable reliable, non-destructive estimates of the biomass of mangrove trees. Reliable estimates of biomass combined with growth rates are required for estimates of primary productivity.

本研究选取6个物种的红树植物作为采样对象，旨在通过胸径（diameter at breast height, DBH）的测量值，推导用于估算叶生物量、枝生物量、茎生物量及地上总生物量的异速生长关系。研究于1985年至1988年间，在澳大利亚昆士兰州北部的欣钦布鲁克岛、墨累河及丹特里河的红树林群落中，采集了以下6个物种的样本：尖叶红树（Rhizophora apiculata）、柱果红树（Rhizophora stylosa）、木榄（Bruguiera gymnorhiza）、小花木榄（Bruguiera parviflora）、澳洲角果木（Ceriops tagal var. australis）及木果楝（Xylocarpus granatum）。针对每个物种，研究人员测量了不同径级个体的茎干直径。随后将采样树木伐倒，分为叶片、枝条、茎干及地上根系四部分。野外现场测定各组分的鲜重，并采集各组分的子样本称重后带回实验室，测定其干重。本研究旨在探究胸径与地上生物量之间是否存在异速生长关系，以此实现对红树植物生物量的可靠、非破坏性估算；可靠的生物量估算结果结合生长速率，可用于初级生产力的评估。