Testing the generality of above-ground biomass allometry across plant functional types at the continent scale.

Abstract

Accurate ground-based estimation of the carbon stored in terrestrial ecosystems is critical to quantifying the global carbon budget. Allometric models provide cost-effective methods for biomass prediction. But do such models vary with ecoregion or plant functional type? We compiled 15 054 measurements of individual tree or shrub biomass from across Australia to examine the generality of allometric models for above-ground biomass prediction. This provided a robust case study because Australia includes ecoregions ranging from arid shrublands to tropical rainforests, and has a rich history of biomass research, particularly in planted forests. Regardless of ecoregion, for five broad categories of plant functional type (shrubs; multistemmed trees; trees of the genus Eucalyptus and closely related genera; other trees of high wood density; and other trees of low wood density), relationships between biomass and stem diameter were generic. Simple power-law models explained 84-95% of the variation in biomass, with little improvement in model performance when other plant variables (height, bole wood density), or site characteristics (climate, age, management) were included. Predictions of stand-based biomass from allometric models of varying levels of generalization (species-specific, plant functional type) were validated using whole-plot harvest data from 17 contrasting stands (range: 9-356 Mg ha(-1) ). Losses in efficiency of prediction were <1% if generalized models were used in place of species-specific models. Furthermore, application of generalized multispecies models did not introduce significant bias in biomass prediction in 92% of the 53 species tested. Further, overall efficiency of stand-level biomass prediction was 99%, with a mean absolute prediction error of only 13%. Hence, for cost-effective prediction of biomass across a wide range of stands, we recommend use of generic allometric models based on plant functional types. Development of new species-specific models is only warranted when gains in accuracy of stand-based predictions are relatively high (e.g. high-value monocultures).

DOI: 10.1111/gcb.13201

Cite this paper

@article{Paul2016TestingTG, title={Testing the generality of above-ground biomass allometry across plant functional types at the continent scale.}, author={Keryn I Paul and Stephen H. Roxburgh and J{\'e}r{\^o}me Chave and Jacqueline R. England and Ayalsew Zerihun and Alison Specht and Tom Lewis and Lauren T. Bennett and Thomas G. Baker and Mark A. Adams and D. H. R. Huxtable and Kelvin D. Montagu and Daniel S Falster and Mike Feller and Stan Sochacki and Peter I. Ritson and G. N. Bastin and John R. Bartle and Dan T. Wildy and Trevor Hobbs and John S Larmour and Rob Waterworth and Hugh T L Stewart and Justin Jonson and David Ian Forrester and Grahame B. Applegate and Daniel S. Mendham and Matt Bradford and A. P. O'Grady and Daryl Green and R. J. Sudmeyer and Stan J Rance and John F. C. Turner and Craig V. M. Barton and Elizabeth Hedi Wenk and Tim L. Grove and Peter M. Attiwill and Elizabeth Pinkard and Don Butler and Kim Brooksbank and Beren Spencer and Peter Snowdon and N. O'Brien and Michael Battaglia and D MacKinnon - Cameron and Steve Hamilton and Geoff McAuthur and Jenny Sinclair}, journal={Global change biology}, year={2016}, volume={22 6}, pages={2106-24} }