A Reassessment of Carbon Content in Tropical Trees

Accurate knowledge of carbon (C) content in live wood is essential for quantifying tropical forest C stocks, yet generic assumptions (such as biomass consisting of 50% carbon on a weight/weight basis) remain widely used despite being supported by little chemical analysis. Empirical data from stem cores of 59 Panamanian rainforest tree species demonstrate that wood C content is highly variable among co-occurring species, with an average (47.4±2.51% S.D.) significantly lower than widely assumed values. Prior published values have neglected to account for volatile C content of tropical woods. By comparing freeze- and oven-dried wood samples, we show that volatile C is non-negligible, and excluding the volatile fraction underestimates wood C content by 2.48±1.28% (S.D.) on average. Wood C content varied substantially among species (from 41.9–51.6%), but was neither strongly phylogenetically conserved, nor correlated to ecological (i.e. wood density, maximum tree height) or demographic traits (i.e. relative growth rate, mortality rate). Overall, assuming generic C fractions in tropical wood overestimates forest C stocks by ∼3.3–5.3%, a non-trivial margin of error leading to overestimates of 4.1–6.8 Mg C ha−1 in a 50-ha forest dynamics plot on Barro Colorado Island, Panama. In addition to addressing other sources of error in tropical forest C accounting, such as uncertainties in allometric models and belowground biomass, compilation and use of species-specific C fractions for tropical tree species would substantially improve both local and global estimates of terrestrial C stocks and fluxes.

[1]  Joel C Rubim,et al.  A spectrocolorimetric study on the effect of ultraviolet irradiation of four tropical hardwoods. , 2004, Bioresource technology.

[2]  C. Körner,et al.  Non-structural carbohydrate pools in a tropical forest , 2005, Oecologia.

[3]  Sean C. Thomas,et al.  Increasing carbon storage in intact African tropical forests , 2009, Nature.

[4]  O. Coomes,et al.  The fate of the tropical forest: Carbon or cattle? , 2008 .

[5]  Great Britain. Foreign,et al.  United Nations Framework Convention on Climate Change , 2019, The ‘Earth Summit’ Agreements: A Guide and Assessment.

[6]  D. A. King,et al.  The contribution of interspecific variation in maximum tree height to tropical and temperate diversity , 2005, Journal of Tropical Ecology.

[7]  S. Hubbell,et al.  GAP‐DEPENDENT RECRUITMENT, REALIZED VITAL RATES, AND SIZE DISTRIBUTIONS OF TROPICAL TREES , 2003 .

[8]  Richard Condit,et al.  The Importance of Demographic Niches to Tree Diversity , 2006, Science.

[9]  S. C. Thomas,et al.  Wood carbon content of tree species in Eastern China: interspecific variability and the importance of the volatile fraction. , 2007, Journal of environmental management.

[10]  Jérôme Chave,et al.  The relationship between wood density and mortality in a global tropical forest data set. , 2010, The New phytologist.

[11]  T. Garland,et al.  TESTING FOR PHYLOGENETIC SIGNAL IN COMPARATIVE DATA: BEHAVIORAL TRAITS ARE MORE LABILE , 2003, Evolution; international journal of organic evolution.

[12]  Campbell O. Webb,et al.  Are functional traits good predictors of demographic rates? Evidence from five neotropical forests. , 2008, Ecology.

[13]  S. Lamlom,et al.  Carbon content variation in boles of mature sugar maple and giant sequoia. , 2006, Tree physiology.

[14]  David D. Ackerly,et al.  Functional trait and phylogenetic tests of community assembly across spatial scales in an Amazonian forest , 2010 .

[15]  J. Boone Kauffman,et al.  ECOSYSTEM‐SCALE IMPACTS OF DEFORESTATION AND LAND USE IN A HUMID TROPICAL REGION OF MEXICO , 2000 .

[16]  T. Moore,et al.  Carbon storage of harvest-age teak (Tectona grandis) plantations, Panama , 2003 .

[17]  Campbell O. Webb,et al.  Phylomatic: tree assembly for applied phylogenetics , 2005 .

[18]  Roger M. Rowell,et al.  The Chemistry of solid wood , 1984 .

[19]  S. Lamlom,et al.  A reassessment of carbon content in wood: variation within and between 41 North American species , 2003 .

[20]  A. Di Fiore,et al.  Variation in wood density determines spatial patterns inAmazonian forest biomass , 2004 .

[21]  G. Powell,et al.  High-resolution forest carbon stocks and emissions in the Amazon , 2010, Proceedings of the National Academy of Sciences.

[22]  J. Lundberg,et al.  An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants : APG II THE ANGIOSPERM PHYLOGENY GROUP * , 2003 .

[23]  Sandra A. Brown,et al.  Monitoring and estimating tropical forest carbon stocks: making REDD a reality , 2007 .

[24]  R. B. Jackson,et al.  THE VERTICAL DISTRIBUTION OF SOIL ORGANIC CARBON AND ITS RELATION TO CLIMATE AND VEGETATION , 2000 .

[25]  Apgii.  An update of the angiosperm phylogeny group classification for the orders and families of flowering plants : APGII , 2003 .

[26]  Joseph S. Wright,et al.  Seasonal patterns of carbohydrate storage in four tropical tree species , 2002, Oecologia.

[27]  L. Poorter,et al.  Carbohydrate storage and light requirements of tropical moist and dry forest tree species. , 2007, Ecology.

[28]  A. Di Fiore,et al.  Increasing biomass in Amazonian forest plots. , 2004, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[29]  Eileen H. Helmer,et al.  Root biomass allocation in the world's upland forests , 1997, Oecologia.

[30]  Andrea Polle,et al.  FTIR spectroscopy, chemical and histochemical characterisation of wood and lignin of five tropical timber wood species of the family of Dipterocarpaceae , 2010, Wood Science and Technology.

[31]  Nathan J B Kraft,et al.  Functional traits and the growth-mortality trade-off in tropical trees. , 2010, Ecology.

[32]  B. Nelson,et al.  Estimates of forest biomass in the Brazilian Amazon: New allometric equations and adjustments to biomass from wood-volume inventories , 2008 .

[33]  Jérôme Chave,et al.  Estimation of biomass in a neotropical forest of French Guiana: spatial and temporal variability , 2001, Journal of Tropical Ecology.

[34]  Phillips,et al.  Changes in the carbon balance of tropical forests: evidence from long-term plots , 1998, Science.

[35]  R. B. Jackson,et al.  CO 2 emissions from forest loss , 2009 .

[36]  William F. Laurance,et al.  Dynamics of carbon, biomass, and structure in two Amazonian forests , 2008 .

[37]  Jeffrey Q. Chambers,et al.  MEASURING NET PRIMARY PRODUCTION IN FORESTS: CONCEPTS AND FIELD METHODS , 2001 .

[38]  W. Boerjan,et al.  Lignin biosynthesis. , 2003, Annual review of plant biology.

[39]  F. Bazzaz,et al.  ASYMPTOTIC HEIGHT AS A PREDICTOR OF PHOTOSYNTHETIC CHARACTERISTICS IN MALAYSIAN RAIN FOREST TREES , 1999 .

[40]  J. Chave,et al.  Towards a Worldwide Wood Economics Spectrum 2 . L E a D I N G D I M E N S I O N S I N W O O D F U N C T I O N , 2022 .

[41]  E. Martins.  The Comparative Method in Evolutionary Biology, Paul H. Harvey, Mark D. Pagel. Oxford University Press, Oxford (1991), vii, + 239 Price $24.95 paperback , 1992 .

[42]  E. Leigh,et al.  Tropical forest diversity and dynamism : findings from a large-scale plot network , 2004 .

[43]  J. Chambers,et al.  Tree allometry and improved estimation of carbon stocks and balance in tropical forests , 2005, Oecologia.

[44]  Thomas B. Croat.  Flora of Barro Colorado Island , 1978 .

[45]  S. Alam,et al.  Framework Convention on Climate Change , 1993 .

[46]  Campbell O. Webb,et al.  Picante: R tools for integrating phylogenies and ecology , 2010, Bioinform..

[47]  B. Dawson,et al.  UNITED NATIONS FRAMEWORK CONVENTION ON CLIMATE CHANGE (UNFCCC) , 2008 .

[48]  S. Hubbell,et al.  Spatial and temporal variation of biomass in a tropical forest: results from a large census plot in Panama , 2003 .

[49]  Erick,et al.  CARBON AND NUTRIENT ACCUMULATION IN SECONDARY FORESTS REGENERATING ON PASTURES IN CENTRAL AMAZONIA , 2004 .

[50]  Catherine Potvin,et al.  Variation in carbon storage among tree species: Implications for the management of a small-scale carbon sink project , 2007 .

[51]  Richard Condit,et al.  Assessing Evidence for a Pervasive Alteration in Tropical Tree Communities , 2008, PLoS biology.

[52]  Catherine Potvin,et al.  Assessing inter- and intra-specific variation in trunk carbon concentration for 32 neotropical tree species , 2003 .

[53]  R. Pettersen,et al.  The chemical composition of wood , 1984 .