Abstract
We present a unique dataset of historical tropical tree phenology observations at two sites from different bioclimatic regions across the Congo Basin. We cover both the Atlantic Mayombe forest and the tropical forest in the central Congo Basin. To our knowledge this is the complete extant historical (1937–1957) phenology data across the Congo basin. The data contains ~10 million observations of 876 species, across 6339 individuals, and phenology metrics including leaf, flowering, and fruiting phenology. The data were recovered through expert transcription and validated community science based crowdsourcing. These data may provide a reference baseline and key information on how tree species are responding to a changing climate.
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Data availability
The manuscript’s database is made available as a Zenodo Digital Repository (https://doi.org/10.5281/zenodo.16789580). The original digitized tables, and the citizen science (raw) transcriptions are available as zipped archives (https://doi.org/10.5281/zenodo.14906306 and, https://doi.org/10.5281/zenodo.14900505 respectively).
Code availability
The code and workflow used during ‘Jungle Rhythms’ community science project are available as an R project (https://doi.org/10.5281/zenodo.7650294).
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Acknowledgements
Historical phenological data recovery was supported by the Institut National pour l’Étude et la Recherche Agronomiques (INERA). Initial digitization was funded through the COBIMFO project funded by the Belgian Science Policy Office (Belspo; contract no. SD/AR/01 A). We thank all citizen scientists for their combined efforts in transcribing data in the “Jungle Rhythms” Zooniverse project. Postdoctoral funding for EK was granted by the BOF Special Research Fund, Ghent University, Belgium. KH acknowledges funding through the Belgian Science Policy office COBECORE project (BELSPO; grant BR/175/A3/COBECORE), the European Union Marie Skłodowska-Curie Action (project number 797668) and the NSF Macrosystems Biology programme (Award Numbers: EF-1065029) in supporting transcription efforts. Consolidation and post-processing of the data was funded by BlueGreen Labs (BV).
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K.H. supervised and led phenological data recovery of the Yangambi phenology data with support of E.R.K. and E.K.Y. M.K. supported the Zooniverse community science project setup. H.B., and J.V.d.B. supervised the Luki data recovery. E.K., T.D.M., P.S. and S.J. assembled critical species meta-data. E.K. and K.H. performed data analysis and wrote the first draft of the paper. All authors provided valuable insights, logistical and political support. All authors read and commented on the manuscript.
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Hufkens, K., Kearsley, E., Stoffelen, P. et al. Historical tree phenology data across contrasting sites in the Congo Basin. Sci Data (2026). https://doi.org/10.1038/s41597-025-06542-z
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DOI: https://doi.org/10.1038/s41597-025-06542-z
