From February 26 to March 11, 2018, a fourth field campaign will take place. We unexpectedly received opportunity to start renaturation (reforestation) on pasture land near Boca do Acre. Saplings have been planted in late 2017. We shall document the site (drone-based orthophotography) and take some additional samples. In addition, re-sampling Làbrea is on the agenda, since it was inaccessible (inundations) a year ago.