Data and Code from: Sheltered or suppressed? Tree regeneration in unmanaged European forests

Tree regeneration is a key demographic process influencing long-term forest dynamics. It is driven by climate, disturbances, biotic factors, and their interactions. Thus, predictions of tree regeneration are challenging due to complex feedbacks along the wide climatic gradients covered by most tree species. We developed statistical models based on >50,000 recruitment events observed for 24 tree species in an extensive permanent plot network (6,540 plots from 299 unmanaged European temperate, boreal, and subalpine forests) covering a wide climatic gradient. 
This repository stores csv files with response and explanatory variables and R-Scripts that are needed to run the analysis and create the figures that are presented in the accompanying article titled \"Sheltered or suppressed? Tree regeneration in unmanaged European forests\" which was published in Journal of Ecology in 2023.
Our study shows that competition between trees towards climatic stress decreases systematically but depends ..., The files with the endings dbh7 and dbh10 show the variables for all plots with a size measurement threshold of a diameter at breast height (dbh) of 7 and 10 cm respectively.
Environmental Variables
data/processed_data/site_data_unique_plot_id2.csv

unique_plot_id2: ID of the forest sampling plot.

dds: the seasonal degree-day sum (DDS) is the integral under the temperature curve when ignoring temperatures be-low 5.5 °C (Allen 1976; Fischlin et al. 1995).

swb: the site water balance (SWB; cf. Speich 2019). The calculation of the SWB is explained in detail in Appendix A1 of the main article. The unit of the SWB is mm and refers to the amount of water which can be storred in the soil.

Allen, J. C. (1976). A modified sine wave method for calculating degree days. Environmental Entomology, 5(6), 388–396. https://doi.org/10.1093/ee/5.3.388
Fischlin, A., Bugmann, H., & Gyalistras, D. (1995). Sensitivity of a forest ecosystem model to climate parametrization schemes. Environmental Pollut..., Data description
These files are used as input for the scripts/fit_models.R script.

File
Description

data/processed_data/site_data_unique_plot_id2.csv
This file stores the environmental variables for temperature (degree day sum) and water balance. It serves as input for scripts/fit_models.R.

data/processed_data/stand_variables_dbh7.csvdata/processed_data/stand_variables_dbh10.csv

These files store the leaf area index (LAI_tot) and other variables which are used as predictors in the model and the Number of recruited trees for each inventory period and species in the. The file serves as input for scripts/fit_models.R.
The files with the endings dbh7 and dbh10 show the variables for all plots with a size measurment threshold of a diameter at breast height (dbh) of 7 and 10 cm respectivtly.

data/raw_data
This folder stores files needed as input for creating the figures of the manuscript.

data/raw_data/expectations.csv

This file contains information which is needed to run t...