Landscape‐variability of the carbon balance across managed boreal forests

Abstract

Boreal forests cover 10%-15% of the terrestrial land area and store about one third of the global forest carbon (C) pool (Astrup et al., 2018;Pan et al., 2011). Due to their large capacity for sequestering carbon dioxide (CO 2 ) from the atmosphere into biomass and soil (Myneni et al., 2001), these ecosystems are considered as key element in national and international policy frameworks

Four ways to define the growing season

“…In this case, the productive season can be defined by the first and last passing across a minimum rate of biomass production or net carbon gain. Measures include repeated biomass harvests (ΔB), and net ecosystem exchange (NEE) or net ecosystem productivity (NEP) derived from eddy covariance (Box 1; for a recent example see Peichl et al 2023).…”

“…In this case, the productive season can be defined by the first and last passing across a minimum rate of biomass production or net carbon gain. Measures include repeated biomass harvests (ΔB), and net ecosystem exchange (NEE) or net ecosystem productivity (NEP) derived from eddy covariance (Box 1; for a recent example see Peichl et al 2023). NDVI‐derived production indices have also become widespread and used as proxies for gross primary production (GPP), although NDVI is rather a surrogate for phenology (leaf greening) than productivity.…”

On the uncertainty in estimates of the carbon balance recovery time after forest clear‐cutting

“…To argue for his concern, Lindroth (2023) complemented our dataset with one additional data point representing emissions of 610 g C m −2 year −1 during the second post‐harvest year in another boreal clear‐cut site (Tong et al, 2022). He then re‐fitted the NEP trajectory through the extended dataset and finds that SST, CCP, and OCS shifted from the 8, 18, and 138 years reported in Peichl et al (2023) to 16, 39, and 155 years, respectively.…”

“…In response, we would first like to clarify that we acknowledged the weak point of lacking data from the first 4 years and its implications (i.e., underestimation of initial emissions) in the “Discussion” section of our article (Peichl et al, 2023; section 4.1). Given that, we appreciate the additional effort by Lindroth (2023) in reconciling the NEP recovery after clear‐cutting.…”

“…Lindroth (2023) has raised concerns regarding our recent contribution to Global Change Biology (Peichl et al, 2023). In this work, we investigated the variation of the annual net ecosystem production (NEP) across a managed boreal forest landscape using data collected over 3 years from 50 main and 7 additional forest stands ranging in age from 5 to 211 years old.…”