Allometric equations of Dicksonia antarctica for estimating aboveground biomass and its associated contribution to forest carbon stocks in Victoria

• Main Author: Minnis, Byron
• Format: Other/Unknown Material
• Language: unknown
• Published: 2013
• Subjects: Vegetation management; Carbon sequestration; Dicksonia antarctica; Allometric equations; New Zealand; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/11343/56871

The use of forests as carbon sinks is increasingly recognised as a way to mitigate greenhouse gas emissions. Driven by the need to estimate carbon stocks for national greenhouse gas balance Inventories, regional and species-specific biomass data sets and allometric equations need to be developed to enable accurate prediction of aboveground carbon. Within Australian temperate moist forests, tree ferns are known to form a large component of the under storey; Dicksonia Antarctica in particular has been known to form large single-species stands excluding all other vegetation. Beets et aL (2012) recently conducted a study to develop mixed-species allometric equations for estimating carbon stocks of 4 New Zealand tree fern species in natural forests. However, there are currently no allometric models for Australian tree fern species and uncertainty remains regarding their quantitative contribution to the total carbon pool within these forests, and the application of allometrics developed for New Zealand tree fern species. The new allometric equations developed from this study are specific to D. Antarctica and have made it possible to predict total biomass for both the caudex and frond component to calculate the total stored carbon from 2 parameters; height and base diameter. Diameter at base was consistently found to be the best predictor of other parameters including: height, number of fronds, frond radius, caudex biomass, frond biomass and total tree fern biomass. The addition of height to allometrics also resulted in further improvements of biomass estimations. Aboveground carbon predictions were on average 50% higher than New Zealand allometric estimates with approximately 1937 tonnes of carbon per hectare stored in D. Antarctica demonstrating the importance of allometric equations developed through direct methods (destructive harvesting) that are species-specific. This significant contribution of D. Antarctica in the wet and temperate rain forests of the Central Highlands of Victoria have a number of implications for management in relation to the major drivers of carbon stock change predicted to occur in these forests including; frequent planned and unplanned bush fires, harvesting operations within publicly managed land, as well as future climate Change predictions for South-eastern Australia which could adversely impact on tree ferns and their associated contribution to forest carbon pools. The establishment of allometric relationships between parameters of Ii Antarctica can be coupled with light detection and ranging (LiDAR) prediction models so that it can be applied at a larger scale and allow for rapid estimation of available biomass and thus aid in planning for sustainable management of D. Antarctica.