Data from: Convergence and variation in tree growth trends at the aggregate level
Data files
Nov 04, 2025 version files 2.47 MB
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README.md
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submit_mian_data_and_code_(2).zip
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Abstract
Individual trees in natural forests often exhibit complex, inconsistent, and variable growth trajectories influenced by genetics, climate change, and uneven stand structure. These growth divergences pose a challenge in predicting the overall growth trend of trees at the aggregate level.
Here, we propose a radius-driven metabolic growth model (IGMR) to explain the radial growth of trees. The IGMR suggests that the best radial growth trajectory (BGT) at the aggregate level varies within a predictable range and can be derived from the maximum radius and total growth time of an individual tree.
Analyses based on a global database confirmed the applicability of the IGMR and found that the average radial growth trend closely follows half of the BGT, with the strength of this association potentially related to functional trait trade-offs.
Further analyses show that climate change and uneven stand structure may cause the overall growth trajectory to undergo more drifts (changes in growth rate only) than adaptations (changes in maximum size).
Synthesis: Our results reveal not only a convergent growth trajectory in tree size (or radius) at the aggregate level, but also suggest that climate regulates the tree growth–climate relationship by influencing the height (i.e., maximum radial growth rate) of this unimodal trajectory, whereas the length (i.e., with maximum tree radius) of the trajectory shows greater dependence on species. These findings further imply that climate change is more likely to affect the forest’s maximum carbon sequestration capacity through shifts in community composition, rather than through direct changes in individual tree growth rates.
1. Overview
This dataset was compiled to investigate large-scale patterns and drivers of tree radial growth across multiple regions. It integrates tree-ring measurement data from the NOAA International Tree-Ring Data Bank (ITRDB) and processed climate variables derived from WorldClim v2.1.
All data were curated, filtered, harmonized, and aggregated to meet the analytical objectives of the study, resulting in a final dataset containing more than 130,000 individual records.
Note: The WorldClim data included here are processed derivatives (summaries and extracted site-level values), not the original raster files. These derived variables are consistent with Dryad’s CC0 license requirements, as they represent newly generated, value-added data.
2. Data Availability
- Data and code underlying Figure 1 are not included, as they overlap with an ongoing unpublished study. Relevant files will be made available in a future update.
- data2cfa_new2.csv → used to generate Figure 2.
- Datasets used for Figure 3:
- f.csv → Figure 3A
- f2.csv → Figures 3B and 3C
- f4.csv → Figure 3D
3. Data Sources
1. Tree radial growth data:
NOAA International Tree-Ring Data Bank
https://www1.ncdc.noaa.gov/pub/data/paleo/treering/measurements/
2. Climate data:
Derived from WorldClim v2.1
https://www.worldclim.org/data/worldclim21.html
Only derived site-level variables (mean values and summary statistics) are included, not original raster products.
4. File Descriptions
1. data2cfa_new2.csv
Contains site-level or population-level metrics used for analyses and for producing Figure 2.
2. f.csv, f2.csv, f4.csv
Contain subsets of data used for generating Figure 3 (panels A–D). Each file includes tree growth, climate, and metadata variables.
3. main_analysis.R
R script for loading data, cleaning, calculating summary metrics, and generating Figures 2–3.
Software requirements: R ≥ 4.3; packages: dplyr, tidyr, ggplot2, lme4, nlme, ggpubr, sf, terra.
Variable Definitions
Tree Growth Variables
| Variable | Description | Unit / Notes |
|---|---|---|
| mean_mean.f | Population mean growth rate over the entire history | mm yr⁻¹ |
| age_mean.f | Population mean age | years |
| mean_max.f | Maximum population growth rate over the entire history (99th percentile) | mm yr⁻¹ |
| rc_max.f | Maximum tree radius in the population | mm |
| age_max.f | Maximum age in the population | years |
| No.file | Number of cores (tree-ring samples) for each tree | — |
| mean_c_mean.f | Population mean growth rate over the last 20 years | mm yr⁻¹ |
| max_mean.f | Mean of individual maximum growth rates in the population | mm yr⁻¹ |
| rc_mean.f | Population mean radius | mm |
| mean_c_max.f | Maximum population growth rate over the last 20 years | mm yr⁻¹ |
| treeid | Individual tree ID | — |
| rc | Individual current radius | mm |
| age | Individual current age | years |
| mean_c | Individual mean growth rate over the last 20 years | mm yr⁻¹ |
| mean_csd | Standard deviation of individual growth rate | mm yr⁻¹ |
Metadata and Site Variables
| Variable | Description | Unit / Notes |
|---|---|---|
| species | Tree species code (abbreviated Latin name) | For specific details, please refer to the Species Description |
| latitude | Latitude of sampling site | decimal degrees |
| longitude | Longitude of sampling site | decimal degrees |
| elevation | Elevation of sampling site | meters |
| region | Broad geographic region | e.g., continent, country, or study region |
| type | Data type / category | e.g., tree-ring width |
Climate Variables
| Variable | Description | Unit |
|---|---|---|
| AMT (bio1) | Annual Mean Temperature | °C |
| MDR (bio2) | Mean Diurnal Range (monthly max – min temperature) | °C |
| ISO (bio3) | Isothermality (bio2/bio7 × 100) | % |
| TSE (bio4) | Temperature Seasonality (SD × 100) | °C × 100 |
| MTWAM (bio5) | Max Temperature of Warmest Month | °C |
| MTCM (bio6) | Min Temperature of Coldest Month | °C |
| TAR (bio7) | Temperature Annual Range (bio5 – bio6) | °C |
| MTWEQ (bio8) | Mean Temperature of Wettest Quarter | °C |
| METDQ (bio9) | Mean Temperature of Driest Quarter | °C |
| MTWAQ (bio10) | Mean Temperature of Warmest Quarter | °C |
| METCQ (bio11) | Mean Temperature of Coldest Quarter | °C |
| AP (bio12) | Annual Precipitation | mm |
| PWEM (bio13) | Precipitation of Wettest Month | mm |
| PDM (bio14) | Precipitation of Driest Month | mm |
| PS (bio15) | Precipitation Seasonality (Coefficient of Variation) | % |
| PWEQ (bio16) | Precipitation of Wettest Quarter | mm |
| PDQ (bio17) | Precipitation of Driest Quarter | mm |
| PWAQ (bio18) | Precipitation of Warmest Quarter | mm |
| PCQ (bio19) | Precipitation of Coldest Quarter | mm |
| SH (rcv.cv.f) | Coefficient of Variation of Tree Radial Growth | dimensionless |
Species Description
| Species | Full name |
|---|---|
| PCGL | Picea glehnii |
| PCSI | Picea sitchensis |
| TSME | Tsuga mertensiana |
| PCMA | Picea mariana |
| CHNO | Chamaecyparis nootkatensis |
| PIPA | Pinus palustris |
| PIHE | Pinus heldreichii |
| PIHA | Pinus halepensis |
| CDAT | Cedrus atlantica |
| PINI | Pinus nigra |
| PINE | Pinus nigra ssp. nigra |
| PIEC | Pinus echinata |
| TADI | Taxodium distichum |
| JUVI | Juniperus virginiana |
| QUST | Quercus stellata |
| QUAL | Quercus alba |
| NOPB | Nothofagus pumilio |
| NOPD | Nothofagus dombeyi |
| NOPU | Nothofagus pumilio |
| FICU | Fitzroya cupressoides |
| CEAN | Cedrus deodara |
| JUAU | Juglans australis |
| NOBE | Nothofagus betuloides |
| CESP | Abies spectabilis |
| ARAR | Araucaria araucana |
| PIUV | Pilgerodendron uviferum |
| AUCH | Austrocedrus chilensis |
| ATSE | Athrotaxis cupressoides |
| PHAS | Phyllocladus aspleniifolius |
| LGFR | Lagarostrobus franklinii |
| CACO | Callitris columellaris |
| ATCU | Athrotaxis cupressoides |
| QUPE | Quercus petraea |
| QUSP | Quercus sp. |
| PIPO | Pinus ponderosa |
| PIED | Pinus edulis |
| PSME | Pseudotsuga menziesii |
| PIST | Pinus strobus |
| PISF | Pinus sylvestris |
| PCEN | Picea engelmannii |
| QURO | Quercus robur |
| CEMC | Centrolobium microchaete |
| PISY | Pinus sylvestris |
| PCAB | Picea abies |
| TSDU | Tsuga dumosa |
| PCSP | Picea smithiana |
| PIWA | Pinus wallichiana |
| PIRO | Pinus roxburghii |
| LAGR | Larix gmelinii |
| JURE | Juniperus turkestanica |
| PILE | Pinus heldreichii |
| PIFL | Pinus flexilis |
| PIJE | Pinus jeffreyi |
| PIBA | Pinus balfouriana |
| PICO | Pinus contorta |
| PILA | Pinus lambertiana |
| QUCF | Quercus coccinea |
| LIDE | Larix decidua |
| ABCO | Abies concolor |
| ABMA | Abies magnifica |
| PIAL | Pinus albicaulis |
| PSMA | Pseudotsuga macrocarpa |
| QUDG | Quercus douglassii |
| QULO | Quercus lobata |
| JUOC | Juniperus occidentalis |
| PLRA | Platanus racemosa |
| PILO | Pinus longaeva |
| PIMR | Pinus merkusii |
| CADE | Cedrus deodara |
| ABAM | Abies amabilis |
| PIBN | Pinus banksiana |
| ABBA | Abies balsamea |
| ABLA | Abies lasiocarpa |
| QUMA | Quercus macrocarpa |
| PIRE | Pinus resinosa |
| THOC | Thuja occidentalis |
| LALY | Larix lyallii |
| PIAM | Pinus armandii |
| JUPR | Juniperus przewalskii |
| PCSH | Picea schrenkiana |
| PCLI | Picea likiangensis |
| LASI | Larix sibirica |
| PCTI | Picea smithiana |
| PITB | Pinus tabuliformis |
| PCPU | Picea pungens |
| PIBR | Pinus brutia |
| CEBR | Cedrela odorata |
| ABSP | Abies spectabilis |
| FASY | Fagus sylvatica |
| QULY | Quercus lyrata |
| PICE | Picea engelmannii |
| LITU | Liriodendron tulipifera |
| TSCA | Tsuga canadensis |
| QUPR | Quercus prinus |
| QUVE | Quercus velutina |
| TEGR | Tectona grandis |
| PISP | Pinus sp. |
| PIPN | Pinus pinea |
| PIPI | Pinus pinaster |
| LADE | Larix decidua |
| HEHE | Hevea brasiliensis |
| QUCE | Quercus cerris |
| PCGN | Picea glauca |
| CHOB | Chamaecyparis obtusa |
| CMJA | Cunninghamia lanceolata |
| PIKO | Pinus koraiensis |
| JUSP | Juniperus scopulorum |
| JUTU | Juniperus turkestanica |
| PIRI | Pinus rigida |
| TAMU | Taxodium mucronatum |
| ABPI | Abies pindrow |
| QURU | Quercus rubra |
5. R Code Description
All analyses were conducted in R (≥4.3). The scripts generate Figures 2–3 based on IGMR predictions and climate-structure relationships.
1. figure2ABCD.R
- Generates Figure 2 panels A–D:
\- 2A–B: Predicted recent mean (A) and maximum (B) radial growth rates of populations vs IGMR predictions.
\- 2C: Relationship between population mean growth rates and their standard deviation.
\- 2D: Relationship between tree size heterogeneity and deviation of recent growth from theoretical predictions.
- Includes model fitting, residual checks, and plotting.
2. figure3A.R, figure3B.R, figure3C.R, figure3D.R
- Generate Figure 3 panels A–D:
\- 3A: Effects of climate and size heterogeneity on maximum radius (rc_max.f)
\- 3B: Effects on maximum growth time (age_max.f)
\- 3C: Effects on mean radial growth rate (mean_mean.f)
\- 3D: Effects on maximum radial growth rate (mean_max.f)
- Fit linear mixed-effects models or nonlinear quantile regressions with climate variables and structural heterogeneity as predictors.
- Extract model coefficients, significance, and generate summary plots.
Workflow Summary:
1. Load and clean the dataset
2. Standardize growth and climate variables (z-scores)
3. Calculate population-level summary metrics
4. Fit IGMR predictions (Figure 2)
5. Fit climate-structure models (Figure 3)
6. Export figures using ggplot2 and cowplot
6. License and Data Use
All data are released under CC0 1.0 Public Domain Dedication, permitting unrestricted reuse, redistribution, and modification.
Derived climate variables were computed from publicly available WorldClim v2.1 datasets (CC BY 4.0), only aggregated, derived outputs are included, not the original raster files.
7. Citation
Data and code supporting the results of this study are available in the Dryad Digital Repository at https://datadryad.org/dataset/doi:10.5061/dryad.1c59zw495 (Shu & Wang, 2025).
