Estimated Carbon Fluxes in Shrinking and Aging Plantations of Japanese Cedar

###############################################################################README for DatasetJuly 22, 2025. Prepared by J. Toriyama############################################################################### Title of DatasetEstimated Carbon Fluxes in Shrinking and Aging Plantations of Japanese Cedar AuthorsJumpei Toriyama1*, Shoji Hashimoto1, 2, Katsuhiro Nakao3, Taku M. Saitoh41Department of Forest Soil, Forestry and Forest Products Research Institute, Japan2Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan3Kansai Research Center, Forestry and Forest Products Research Institute, Japan4Center for Environmental and Societal Sustainability, Gifu University, Japan*E-mail: [e-mail] Abbreviations UsedNPP: Net Primary ProductionNEP: Net Ecosystem ProductionGCM: Global Climate ModelSSP1–2.6: Shared Socioeconomic Pathway 1–2.6 (low greenhouse gas emission scenario)SSP5–8.5: Shared Socioeconomic Pathway 5–8.5 (very high greenhouse gas emission scenario) DescriptionThis dataset comprises three CSV files: ssp126.csv, ssp585.csv and latlong.csv. The ssp126.csv and ssp585.csv correspond to the climate scenarios SSP1–2.6 and SSP5–8.5, respectively. These files contain model outputs of annual NPP, NEP, and vegetation carbon stocks for Japanese cedar plantations and secondary broadleaf forests across 49,440 meshes (i.e., grid cells) in Japan. The latlong.csv contains the latitude and longitude of 49,440 meshes. Simulations were conducted using the process-based model Biome-BGC, coupled with the MT-CLIM preprocessor, under historical (2010) and future (2050 and 2090) climate conditions. Outputs represent decadal averages: 2005–2014 for 2010, 2045–2054 for 2050, and 2085–2094 for 2090. The vegetation carbon stock includes total carbon stored in tree organs (leaves, stems, branches, and roots). Each file also includes information on stand age cohorts under four forest management scenarios. For methodological details and the national-scale simulation framework, refer to the publication below. ReferenceToriyama, J., Hashimoto, S., Nakao, K., Saitoh, T.M., Nishizono, T., Uchiyama, K., Araki, M.G., Murakami, W., & Hirata, Y. (2025).Management strategies for shrinking and aging tree plantations are constrained by the synergies and trade-offs between carbon sequestration and other forest ecosystem services. Journal of Environmental Management, 373, 123762. https://doi.org/10.1016/j.jenvman.2024.123762 Variables in CSV FilesFiles: ssp126.csv (79 MB), ssp585.csv (79 MB), latlong.csv (1.5 MB) meshcode: Identifier of the mesh (i.e., grid cell, based on Japan’s third-order mesh system) gcm: GCM used; abbreviated as acc (ACCESS-CM2), ipsl (IPSL-CM6A-LR), miroc (MIROC6), mpi (MPI-ESM1-2-HR), and mri (MRI-ESM2-0) manag: Management scenario (1–4), corresponding to CL+PH, CH+PH, CL+PL, and CH+PL, respectively, as defined in Toriyama et al. (2025):- CL and CH: Low and high cutting intensities (5% and 15% per decade for cedar stands aged >30 years)- PL and PH: Low and high planting rates (25% and 75% of the harvested area) npp1, npp2, npp3: Annual NPP (kgC m⁻² year⁻¹) for 2010, 2050, and 2090, respectively nep1, nep2, nep3: Annual NEP (kgC m⁻² year⁻¹) for 2010, 2050, and 2090, respectively vegec1, vegec2, vegec3: Vegetation carbon stock (kgC m⁻²) for 2010, 2050, and 2090, respectively age1, age2, age3: Stand age cohort class in 2010, 2050, and 2090, respectively- Positive integers (1 to 17): Age classes of Japanese cedar stands (e.g., 1 = 1–10 years, 2 = 11–20 years, ..., 17 = 161–170 years)- Negative integers (-1 to -12): Age classes of secondary broadleaf forests (e.g., -1 = 1–10 years, ..., -12 = 111–120 years)- –99: Represents a steady-state condition for broadleaf forests (spin-up equilibrium) lat: latitude of center of the mesh (north latitude) long: longitude of center of the mesh (east longitude) AcknowledgementsThis dataset was produced with support from the Environment Research and Technology Development Fund (JPMEERF25S12423, Theme S–24–2(3)) of the Environmental Restoration and Conservation Agency (ERCA), provided by Ministry of the Environment, Japan, and from KAKENHI Grant No. 24K01818 of the Japan Society for the Promotion of Science (JSPS). The underlying research was also supported by the ERCA-funded project “Comprehensive Research on Projection of Climate Change Impacts and Evaluation of Adaptation” (Theme S–18–2(3)), and by KAKENHI Grant No. 21H02245 of JSPS. Biome-BGC version 4.2 and MT-CLIM version 4.3 were developed by the Numerical Terradynamic Simulation Group at the University of Montana. Parameterization for Japanese cedar stands was facilitated by flux data from the KHW site (FFPRI FluxNet database) and the TKC site (Center for Environmental and Societal Sustainability, Gifu University). The use of National Forest Resources Database (third-order mesh, 2008 version) was supported by the Forestry Agency of Japan.