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 &gt;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., &amp; 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...树木更新是影响森林长期动态的关键种群统计过程。其驱动因子涵盖气候、干扰、生物因子及其相互作用。鉴于多数树种所覆盖的广泛气候梯度下存在复杂反馈机制，树木更新的预测颇具挑战性。我们基于覆盖大范围气候梯度的大型永久样地网络（包含来自299片未管理欧洲温带、寒带及亚高山森林的6540个样地）中24个树种的5万余株幼树补充事件，开发了统计模型。 本数据集仓库存储了响应变量与解释变量的CSV文件，以及用于运行分析、复现论文配图的R脚本，对应2023年发表于《Journal of Ecology》的论文"Sheltered or suppressed? Tree regeneration in unmanaged European forests"（《庇护还是抑制？未管理欧洲森林的树木更新》）。 本研究表明，树木对气候胁迫的竞争作用呈系统性减弱趋势，但该效应取决于……，文件后缀为dbh7与dbh10的数据集，分别对应胸径（diameter at breast height, DBH）阈值为7厘米与10厘米的全部样地变量。 ### 环境变量 data/processed_data/site_data_unique_plot_id2.csv unique_plot_id2: 森林样地采样的唯一标识ID。 dds: 季节积温总和（seasonal degree-day sum, DDS）指忽略5.5℃以下温度时的温度曲线积分（Allen 1976; Fischlin et al. 1995）。 swb: 立地水平衡（site water balance, SWB；参见Speich 2019）。立地水平衡的计算方法详见主论文附录A1，其单位为毫米，代表可储存于土壤中的水量。 Allen, J. C. (1976). 一种计算积温的改进正弦波法. 《环境昆虫学》, 5(6), 388–396. https://doi.org/10.1093/ee/5.3.388 Fischlin, A., Bugmann, H., & Gyalistras, D. (1995). 森林生态系统模型对气候参数化方案的敏感性. 《环境污染物……》 ##### 数据说明 这些文件将作为scripts/fit_models.R脚本的输入数据。 | 文件 | 描述 | | ---- | ---- | | data/processed_data/site_data_unique_plot_id2.csv | 本文件存储了温度（积温总和）与水平衡相关的环境变量，可作为scripts/fit_models.R脚本的输入数据。 | | data/processed_data/stand_variables_dbh7.csv<br>data/processed_data/stand_variables_dbh10.csv | 这两个文件存储了叶面积指数（leaf area index, LAI_tot）及其他模型预测因子，同时包含各清查周期内各物种的幼树补充株数，可作为scripts/fit_models.R脚本的输入数据。文件后缀为dbh7与dbh10，分别对应胸径（DBH）阈值为7厘米与10厘米的全部样地变量。 | | data/raw_data | 该文件夹存储了绘制论文配图所需的输入文件。 | | data/raw_data/expectations.csv | 本文件包含运行t...所需的相关信息（原文未完整披露）。