Remote sensing tracks daily radial wood growth of evergreen needleleaf trees.

Autor: Eitel JUH; Department of Natural Resources and Society, College of Natural Resources, University of Idaho, Moscow, ID, USA.; McCall Outdoor Science School (MOSS), College of Natural Resources, University of Idaho, McCall, ID, USA., Griffin KL; Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA.; Department of Earth and Environmental Sciences, Columbia University, Palisades, NY, USA.; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA., Boelman NT; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA., Maguire AJ; Department of Natural Resources and Society, College of Natural Resources, University of Idaho, Moscow, ID, USA.; McCall Outdoor Science School (MOSS), College of Natural Resources, University of Idaho, McCall, ID, USA., Meddens AJH; School of the Environment, Washington State University, Pullman, WA, USA., Jensen J; Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA., Vierling LA; Department of Natural Resources and Society, College of Natural Resources, University of Idaho, Moscow, ID, USA.; McCall Outdoor Science School (MOSS), College of Natural Resources, University of Idaho, McCall, ID, USA., Schmiege SC; Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA., Jennewein JS; Department of Natural Resources and Society, College of Natural Resources, University of Idaho, Moscow, ID, USA.
Jazyk: angličtina
Zdroj: Global change biology [Glob Chang Biol] 2020 Jul; Vol. 26 (7), pp. 4068-4078. Date of Electronic Publication: 2020 May 05.
DOI: 10.1111/gcb.15112
Abstrakt: Relationships between gross primary productivity (GPP) and the remotely sensed photochemical reflectance index (PRI) suggest that time series of foliar PRI may provide insight into climate change effects on carbon cycling. However, because a large fraction of carbon assimilated via GPP is quickly returned to the atmosphere via respiration, we ask a critical question-can PRI time series provide information about longer term gains in aboveground carbon stocks? Here we study the suitability of PRI time series to understand intra-annual stem-growth dynamics at one of the world's largest terrestrial carbon pools-the boreal forest. We hypothesized that PRI time series can be used to determine the onset (hypothesis 1) and cessation (hypothesis 2) of radial growth and enable tracking of intra-annual tree growth dynamics (hypothesis 3). Tree-level measurements were collected in 2018 and 2019 to link highly temporally resolved PRI observations unambiguously with information on daily radial tree growth collected via point dendrometers. We show that the seasonal onset of photosynthetic activity as determined by PRI time series was significantly earlier (p < .05) than the onset of radial tree growth determined from the point dendrometer time series which does not support our first hypothesis. In contrast, seasonal decline of photosynthetic activity and cessation of radial tree growth was not significantly different (p > .05) when derived from PRI and dendrometer time series, respectively, supporting our second hypothesis. Mixed-effects modeling results supported our third hypothesis by showing that the PRI was a statistically significant (p < .0001) predictor of intra-annual radial tree growth dynamics, and tracked these daily radial tree-growth dynamics in remarkable detail with conditional and marginal coefficients of determination of 0.48 and 0.96 (for 2018) and 0.43 and 0.98 (for 2019), respectively. Our findings suggest that PRI could provide novel insights into nuances of carbon cycling dynamics by alleviating important uncertainties associated with intra-annual vegetation response to climate change.
(© 2020 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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