Extended Data Fig. 4: Characteristics of forest islands.

a, Photograph of the anthropic landscape dotted with forest islands in the Barba Azul nature reserve. b, Histogram showing the distribution of the diameter of forest islands. The left side of the distribution is truncated at 25 m because smaller forest islands have not been mapped. c, Photograph taken at site 579, a natural forest island. Samples are taken every 10 cm, from top left (highest sample) to bottom right (deepest sample). Material is silt with no organic matter. d, Photograph taken at site 425, an anthropogenic forest island. The depth from which the sample was taken is 140 cm. e, Photograph taken at site 430, an anthropogenic forest island. The depth from which the sample was taken is 160 cm. Samples in d, e are representative of the whole profiles of sites 425 and 430, respectively (Extended Data Fig. 7). We obtained one core for each forest island that we visited.