DOI: 10.5061/dryad.7h44j105d
title: Vulnerability to climate changes of tropical forests across Africa

description: Aim: Global climate projections identify tropical regions as hotspots of
 climate change during the 21st century. The few ground data in tropical
 Africa confirm significant warming and drying over the last decades, but
 how plant communities will tolerate these new climate conditions remain
 vastly uncertain. In this study, we assess the climatic vulnerability of
 tropical moist forests across Africa. Location: Tropical Africa. Methods:
 We mapped climate change exposure across the tropical moist forest biome,
 focusing on mean annual temperature (MAT), mean annual precipitation
 (MAP), and climatological water deficit (CWD) using climate projections
 for 2085 from five regional models under RCP4.5 and RCP8.5. Using
 occurrence records for 3,536 tree and shrub species, we estimated species’
 climatic limits and safety margins, then averaged these margins at the
 community level. Finally, we combined exposure and safety margins to
 assess species- and community-level risk by 2085. Results: Under RCP4.5,
 corresponding to an average warming of 2.4°C by 2080, 92% of species
 (3,256) could be at risk in at least one community where they occur. This
 rate increases to 96% (3,405 species) under RCP8.5, with an average
 warming of 4.3°C. In all scenarios, the most at-risk communities are
 concentrated in low-elevation regions, where species have few
 opportunities to migrate if their climatic limits are exceeded. The high
 risk across the forest biome results from the combination of significant
 and widespread temperature increases and the relatively narrow safety
 margins of the species. Specifically, 50% of species have an average
 safety margin below 1.6°C above baseline temperatures, suggesting they are
 already near their tolerance limits. Main conclusions: Beyond refining our
 understanding of the vulnerability of tropical moist forests across
 Africa, our results have far-reaching implications for conservation,
 allowing to target species and communities of interest for further
 monitoring and conservation efforts.
description: # Vulnerability to climate changes of tropical forests across Africa
 [https://doi.org/10.5061/dryad.7h44j105d](https://doi.org/10.5061/dryad.7h44j105d) ## R_code_final.zip This repository contains species occurrence data, spatial layers, and R scripts used to reproduce the main results of the article: **Vulnerability to climate change of tropical forests across Africa**. ### **climatic_data/** Climate layers (baseline and projections under RCP4.5 / RCP8.5): * **CWD** (*Climatic Water Deficit*) – in **mm** * **MAP** (*Mean Annual Precipitation*) – in **mm** * **MAT** (*Mean Annual Temperature*) – in **°C**\ Also includes **exposure layers** for each variable (files prefixed with `expo_`, e.g. `expo_mat_rcp45.tif` for MAT under RCP4.5). ### communities_grid/ Polygons/pixels representing forest communities: * **communities**: community boundaries (polygons/pixels) * **forest_communities**: communities including species occurrences ### floristic_data/ Tree and shrub occurrences extracted from RAINBIO ([https://gdauby.github.io/rainbio/download_page.html](https://gdauby.github.io/rainbio/download_page.html)). The file `rainbio_selected.csv` contains information on species occurrences. The key variables included are: * **tax_sp_level**: binomial scientific name of the species * **ddlat**: latitude * **ddlon**: longitude * **growth_form_level_1_1_3**: species growth form (tree, shrub, etc.) * **final_accuracy**: spatial accuracy of the occurrence coordinates ### output_data/ Results generated by R scripts (CSV), e.g.: * `table_safety_margin_sp.csv`: climate safety margins for species. ### output_maps/ Maps generated by the analyses. The naming convention of the output maps is as follows: * First, the **vulnerability index** (e.g. *Exposure*), * then the **climate variable** (e.g. *CWD*), * followed by the **climate scenario** (e.g. *RCP4.5*). For example: **Exposure_CWD_RCP45**. ### shp_africa/ Base shapefiles (African boundaries and reference layers), e.g.: * `africa_cropped.*`: cropped African boundaries used to delimit analysis extent * `ATMF_sf.*`: African Tropical Moist Forest (ATMF) grid cells used in spatial analyses (in main folder) ### R scripts * **1_climate_safety_margin_analysis.R** — computes climate safety margins for tree and shrub species. * **2_climate_exposure_analysis.R** — analyzes spatial exposure of communities to projected climate changes. * **3_climate_risk_by_community.R** — assesses climate risk scores for each community. ### Software requirements * **R** (version ≥ 4.0) * Packages: `sf`, `terra`, `dplyr`, `ggplot2` ### Data sources The floristic data were derived from RAINBIO, available at:  [https://gdauby.github.io/rainbio/download_page.html](https://gdauby.github.io/rainbio/download_page.html) The climate date were derived from AFRICLIM 3.0, available at: [https://webfiles.york.ac.uk/KITE/AfriClim/](https://webfiles.york.ac.uk/KITE/AfriClim/) ## Change Log * **September 2025** : The ` R_code_final` folder has replaced  `data_VULNERABILITY_TFA_DivDis_24_02_25.zip` and README updated