Relative influences of multiple sources of uncertainty on cumulative and incremental tree-ring-derived aboveground biomass estimates
AffiliationUniv Arizona, Lab Tree Ring Res
Univ Arizona, Sch Nat Resources & Environm
MetadataShow full item record
CitationAlexander, M.R., Rollinson, C.R., Babst, F. et al. Trees (2018) 32: 265. https://doi.org/10.1007/s00468-017-1629-0
JournalTREES-STRUCTURE AND FUNCTION
Rights© Springer-Verlag GmbH Germany 2017
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractHow forest growth responds to climate change will impact the global carbon cycle. The sensitivity of tree growth and thus forest productivity to climate can be inferred from tree-ring increments, but individual tree responses may differ from the overall forest response. Tree-ring data have also been used to estimate interannual variability in aboveground biomass, but a shortage of robust uncertainty estimates often limits comparisons with other measurements of the carbon cycle across variable ecological settings. Here we identify and quantify four important sources of uncertainty that affect tree-ring-based aboveground biomass estimates: subsampling, allometry, forest density (sampling), and mortality. In addition, we investigate whether transforming rings widths into biomass affects the underlying growth-climate relationships at two coniferous forests located in the Valles Caldera in northern New Mexico. Allometric and mortality sources of uncertainty contributed most (34-57 and 24-42%, respectively) and subsampling uncertainty least (7-8%) to the total uncertainty for cumulative biomass estimates. Subsampling uncertainty, however, was the largest source of uncertainty for year-to-year variations in biomass estimates, and its large contribution indicates that between-tree growth variability remains influential to changes in year-to-year biomass estimates for a stand. The effect of the large contribution of the subsampling uncertainty is reflected by the different climate responses of large and small trees. Yet, the average influence of climate on tree growth persisted through the biomass transformation, and the biomass growth-climate relationship is comparable to that found in traditional climate reconstruction-oriented tree-ring chronologies. Including the uncertainties in estimates of aboveground biomass will aid comparisons of biomass increment across disparate forests, as well as further the use of these data in vegetation modeling frameworks.
Note12 month embargo; published online: 08 November 2017
VersionFinal accepted manuscript
SponsorsDOE Regional and Global Climate Modeling program [DE-SC0016011]; University of Arizona Water, Environment, and Energy Solutions (WEES) program; University of Arizona Sustainability of Semi-Arid Hydrology and Riparian Areas (SAHRA) program; Swiss National Science Foundation [P300P2_154543]; EU H2020 Program