DOI: 10.5061/dryad.r87p0
title: Data from: Forest extent and deforestation in tropical Africa since 1900

description: Accurate estimates of historical forest extent and associated
 deforestation rates are crucial for quantifying tropical carbon cycles and
 formulating conservation policy. In Africa, data-driven estimates of
 historical closed-canopy forest extent and deforestation at the
 continental scale are lacking, and existing modelled estimates diverge
 substantially. Here, we synthesize available palaeo-proxies and historical
 maps to reconstruct forest extent in tropical Africa around 1900, when
 European colonization accelerated markedly, and compare these historical
 estimates with modern forest extent to estimate deforestation. We find
 that forests were less extensive in 1900 than bioclimatic models predict.
 Resultantly, across tropical Africa, ~ 21.7% of forests have been
 deforested, yielding substantially slower deforestation than previous
 estimates (35–55%). However, deforestation was heterogeneous: West and
 East African forests have undergone almost complete decline (~ 83.3 and
 93.0%, respectively), while Central African forests have expanded at the
 expense of savannahs (~ 1.4% net forest expansion, with ~ 135,270 km2 of
 savannahs encroached). These results suggest that climate alone does not
 determine savannah and forest distributions and that many savannahs
 hitherto considered to be degraded forests are instead relatively old.
 These data-driven reconstructions of historical biome distributions will
 inform tropical carbon cycle estimates, carbon mitigation initiatives and
 conservation planning in both forest and savannah systems.
description: Probability of forest
 for 1900, 70% tree coverThis raster contains the
 median modelled probability of forest for the year 1900 and computed using
 a tree cover threshold of 70%.Proba_for_1900_70TC.tifProbability of forest for 2000, 70% tree coverThis raster contains the median modelled probability of forest for the year 2000 and computed using a tree cover threshold of 70%.Proba_for_2000_70TC.tifForest and savanna distribution for 1900, 70% tree coverThis raster contains the modelled distribution of forest (coded 1) and savanna (coded 0) for the year 1900, and using a probability threshold of 0.5 and for 70% tree cover threshold.Forest1900_thres05_70TC.tifForest and savanna distribution for 2000, 70% tree coverThis raster contains the modelled distribution of forest (coded 1) and savanna (coded 0) for the year 2000, and using a probability threshold of 0.5 and for 70% tree cover threshold.Forest2000_probthres05_70TC_UNC.tifForest changes between 1900 and 2000, 70% tree coverThis raster contains the changes in forest area between 1900 and 2000, for 70% tree cover threshold. The corresponding codes are: 0=savanna, 1=deforestation, 2=afforestation and 3=forest.Forest_change_70TC.tifProbability of forest for 1900, 75% tree coverThis raster contains the median modelled probability of forest for the year 1900 and computed using a tree cover threshold of 75%.Proba_for_1900_75TC.tifProbability of forest for 2000, 75% tree coverThis raster contains the median modelled probability of forest for the year 2000 and computed using a tree cover threshold of 75%.Proba_for_2000_75TC.tifForest and savanna distribution for 1900, 75% tree coverThis raster contains the modelled distribution of forest (coded 1) and savanna (coded 0) for the year 1900, and using a probability threshold of 0.5 and for 75% tree cover threshold.Forest1900_thres05_75TC.tifForest and savanna distribution for 2000, 75% tree coverThis raster contains the modelled distribution of forest (coded 1) and savanna (coded 0) for the year 2000, and using a probability threshold of 0.5 and for 75% tree cover threshold.Forest2000_thres05_75TC.tifForest changes between 1900 and 2000, 75% tree coverThis raster contains the changes in forest area between 1900 and 2000, for 75% tree cover threshold.The corresponding codes are: 0=savanna, 1=deforestation, 2=afforestation and 3=forest.Forest_change_75TC.tifProbability of forest for 1900, 65% tree coverThis raster contains the median modelled probability of forest for the year 1900 and computed using a tree cover threshold of 65%.Proba_for_1900_65TC.tifProbability of forest for 2000, 65% tree coverThis raster contains the median modelled probability of forest for the year 2000 and computed using a tree cover threshold of 65%.Proba_for_2000_65TC.tifForest and savanna distribution for 1900, 65% tree coverThis raster contains the modelled distribution of forest (coded 1) and savanna (coded 0) for the year 1900, and using a probability threshold of 0.5 and for 65% tree cover threshold.Forest1900_thres05_65TC.tifForest and savanna distribution for 2000, 65% tree coverThis raster contains the modelled distribution of forest (coded 1) and savanna (coded 0) for the year 2000, and using a probability threshold of 0.5 and for 65% tree cover threshold.Forest2000_thres05_65TC.tifForest changes between 1900 and 2000, 65% tree coverThis raster contains the changes in forest area between 1900 and 2000, for 65% tree cover threshold. The corresponding codes are: 0=savanna, 1=deforestation, 2=afforestation and 3=forest.Forest_change_65TC.tifConfidence levels for 1900 and 70% tree coverRaster containing the confidence levels in defining forest and savanna distribution and boundaries for 1900 for forest defined as 70% tree cover threshold and for a probability &gt; 0.5. The confidence levels are expressed between 0 (less confident), and 1 (more confident).Forest1900_probthres05_70TC_UNC.tifConfidence levels for 2000 and 70% tree coverRaster containing the confidence levels in defining forest and savanna distribution and boundaries for 2000 for forest defined as 70% tree cover threshold and for a probability &gt; 0.5. The confidence levels are expressed between 0 (less confident), and 1 (more confident).Forest2000_probthres05_70TC_UNC.tifConfidence levels for 1900 and 75% tree coverRaster containing the confidence levels in defining forest and savanna distribution and boundaries for 1900 for forest defined as 75% tree cover threshold and for a probability &gt; 0.5. The confidence levels are expressed between 0 (less confident), and 1 (more confident).Forest1900_probthres05_75TC_UNC.tifConfidence levels for 2000 and 75% tree coverRaster containing the confidence levels in defining forest and savanna distribution and boundaries for 2000 for forest defined as 75% tree cover threshold and for a probability &gt; 0.5. The confidence levels are expressed between 0 (less confident), and 1 (more confident).Forest2000_probthres05_75TC_UNC.tifConfidence levels for 1900 and 65% tree coverRaster containing the confidence levels in defining forest and savanna distribution and boundaries for 1900 for forest defined as 65% tree cover threshold and for a probability &gt; 0.5. The confidence levels are expressed between 0 (less confident), and 1 (more confident).Forest1900_probthres05_65TC_UNC.tifConfidence levels for 2000 and 65% tree coverRaster containing the confidence levels in defining forest and savanna distribution and boundaries for 2000 for forest defined as 65% tree cover threshold and for a probability &gt; 0.5. The confidence levels are expressed between 0 (less confident), and 1 (more confident).Forest2000_probthres05_65TC_UNC.tif