Estimating above-ground biomass in multi-stemmed mangrove trees along the arid coast of the Pilbara region, Western Australia

Single and multi-stemmed trees of the mangroves Rhizophora stylosa and Avicennia marina were sampled from Port Hedland, Dampier and Exmouth Gulf in the Pilbara region of Western Australia, to determine allometric relationships for estimating above-ground biomass from stem diameter.The stems of eleven Rhizophora stylosa and thirteen Avicennia marina trees were measured. The trees were then felled, divided into component parts and weighed. Weighed subsamples of each component part were also collected to determine dry weight. This research was undertaken to:1. derive allometric relationships between stem diameter at breast height (DBH) and above-ground biomass for Rhizophora stylosa and Avicennia marina, which commonly exhibit a multi-stemmed growth habit along the arid coastline of the Pilbara region.2. provide data to compare with the same species growing in eastern Australia, which exhibit a single stemmed growth habit. This research was a component of the project: "The ecology of arid zone mangroves in northwestern Australia". The project was developed around the working hypothesis that regional mangrove forest structure and growth, mangrove-based food chains and soil biogeochemistry are strongly regulated by aridity.