Abstract
We present the first cross-continental comparison of the flowering and fruiting phenology of tropical forests across Africa. Flowering events of 5446 trees from 196 species across 12 sites and fruiting events of 4595 trees from 191 species across 11 sites were monitored over periods of 6 to 29 years and analyzed to describe phenology at the continental level. To study phenology, we used Fourier analysis to identify the dominant cycles of flowering and fruiting for each individual tree and we identified the time of year African trees bloom and bear fruit and their relationship to local seasonality. Reproductive strategies were diverse, and no single regular cycle was found in >50% of individuals across all 12 sites. Additionally, we found annual flowering and fruiting cycles to be the most common. Sub-annual cycles were the next most common for flowering, whereas supra-annual patterns were the next most common for fruiting. We also identify variation in different subsets of species, with species exhibiting mainly annual cycles most common in West and West Central African tropical forests, while more species at sites in East Central and East African forests showed cycles ranging from sub-annual to supra-annual. Despite many trees showing strong seasonality, at most sites some flowering and fruiting occurred all year round. Environmental factors with annual cycles are likely to be important drivers of seasonal periodicity in trees across Africa, but proximate triggers are unlikely to be constant across the continent.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 418-430 |
| Number of pages | 13 |
| Journal | Biotropica |
| Volume | 50 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 2018 |
Bibliographical note
Funding Information:We thank ESA CCI Land Cover project for permission to use the land cover data to create our map. Thanks are due to the following organizations and individuals for assistance with funding, permits, permissions and fieldwork at each of the sites: Amani: Permits and permissions from COSTECH and Amani Nature Reserve; fieldwork from University of Dar es Salaam, Roosevelt University and the Field Museum, Thomas Challange, Bakari Mtui, and Mwanaidi Kijazi. Gombe: We thank the Tanzania Wildlife Research Institute (TAWIRI) and Commission on Science and Technology (COSTECH) for permission to conduct this research and Gen Yamakoshi, who initiated collection of phenological data at Gombe. We thank the Jane Goodall Institute, NSF grants IOS-1052693 and BCS-0648481, the University of Minnesota, Harris Steel, and Duke University for supporting field-work and data entry. Kibale: Funding from Canada Research Chairs Program, Wildlife Conservation Society, Natural Science and Engineering Research Council of Canada, National Geographic, National Science Foundation, and Fonds Québécois de la Recherche sur la Nature et les Technologies. Fieldwork: Richard Wrangham. Lope: Funding from the International Centre for Medical Research in Franceville (CIRMF) (1986–2010), the University of Stirling (1986–present), and Gabon’s National Parks Agency (ANPN) (2011–present). Permission and permits from the CIRMF Scientific Council and the Ministry of Water and Forests (1986–2010) and by ANPN and the National Centre for
Funding Information:
We thank ESA CCI Land Cover project for permission to use the land cover data to create our map. Thanks are due to the following organizations and individuals for assistance with funding, permits, permissions and fieldwork at each of the sites: Amani: Permits and permissions from COSTECH and Amani Nature Reserve; fieldwork from University of Dar es Salaam, Roosevelt University and the Field Museum, Thomas Challange, Bakari Mtui, and Mwanaidi Kijazi. Gombe: We thank the Tanzania Wildlife Research Institute (TAWIRI) and Commission on Science and Technology (COSTECH) for permission to conduct this research and Gen Yamakoshi, who initiated collection of phenological data at Gombe. We thank the Jane Goodall Institute, NSF grants IOS-1052693 and BCS-0648481, the University of Minnesota, Harris Steel, and Duke University for supporting fieldwork and data entry. Kibale: Funding from Canada Research Chairs Program, Wildlife Conservation Society, Natural Science and Engineering Research Council of Canada, National Geographic, National Science Foundation, and Fonds Québécois de la Recherche sur la Nature et les Technologies. Fieldwork: Richard Wrangham. Lopé: Funding from the International Centre for Medical Research in Franceville (CIRMF) (1986–2010), the University of Stirling (1986–present), and Gabon's National Parks Agency (ANPN) (2011–present). Permission and permits from the CIRMF Scientific Council and the Ministry of Water and Forests (1986–2010) and by ANPN and the National Centre for Research in Science and Technology (CENAREST) (2011–present). We also thank Richard Parnell, Liz Williamson, Rebecca Ham, and Patricia Peignot for significant periods of data collection. M'Baïki: Fieldwork by ARF Project (Appui la Recherche Forestière) funded by six partners: AFD (Agence Française de Développement), CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement), ICRA (Institut Centrafricain de Recherche Agronomique), MEFCP (Ministère centrafricain des Eaux, Forêts, Chasse et Pêche), SCAC/MAE (Service de Coopération et d'Actions Culturelles, Ministère des Affaires Etrangères), and SCAD (Société Centrafricaine de Déroulage). Mbeli Bai: Funding from the Columbus Zoo and Aquarium, Cincinnati Zoo and Botanical Garden, Cologne Zoo, Disney Worldwide Conservation Fund, Dublin Zoo, Sea World and Busch Gardens Conservation Fund, Toronto Zoo, Wildlife Conservation Society, and Woodland Park Zoo. Permits from the Ministry of Sustainable Development, Forest Economy and Environment and the Ministry of Scientific Research of the Republic of Congo. Taï: Funding from Max Planck Institute for Evolutionary Anthropology. Permits from the Ministère de la Recherches Scientifiques, the Ministère de l'Environnement et des Eaux et Forêts, and the Office Ivoirien des Parcs et Réserves. Support in the field from the staff of the Taï Chimpanzee Project, Centre Suisse de Recherche Scientifique, C. Boesch, D. P. Anderson, and Z.B. Goné Bi.
Funding Information:
Research in Science and Technology (CENAREST) (2011–present). We also thank Richard Parnell, Liz Williamson, Rebecca Ham, and Patricia Peignot for significant periods of data collection. M’Ba€ıki: Fieldwork by ARF Project (Appui la Recherche Forestière) funded by six partners: AFD (Agence Fran©caise de Développement), CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement), ICRA (Institut Centrafricain de Recherche Agronomique), MEFCP (Ministère centrafricain des Eaux, Forêts, Chasse et Pêche), SCAC/MAE (Service de Coopération et d’Actions Culturelles, Ministère des Affaires Etrangères), and SCAD (SociétéCen-trafricaine de Déroulage). Mbeli Bai: Funding from the Columbus Zoo and Aquarium, Cincinnati Zoo and Botanical Garden, Cologne Zoo, Disney Worldwide Conservation Fund, Dublin Zoo, Sea World and Busch Gardens Conservation Fund, Toronto Zoo, Wildlife Conservation Society, and Woodland Park Zoo. Permits from the Ministry of Sustainable Development, Forest Economy and Environment and the Ministry of Scientific Research of the Republic of Congo. Ta€ı: Funding from Max Planck Institute for Evolutionary Anthropology. Permits from the Ministère de la Recherches Scientifiques, the Ministère de l’Environnement et des Eaux et Forêts, and the Office Ivoirien des Parcs et Réserves. Support in the field from the staff of the Ta€ı Chimpanzee Project, Centre Suisse de Recherche Scientifique, C. Boesch, D. P. Anderson, and Z.B. GonéBi.
Publisher Copyright:
© 2018 The Association for Tropical Biology and Conservation
Keywords
- Africa
- annual cycles
- flowers
- fruits
- phenology
- seasonality
- tropical forest