Our new study reveals that 31.7% of tropical Africa’s vascular plant species could be threatened with extinction and published in the journal Science Advances on 20 November 2019. Using a new approach based on the key elements of the assessment process used by the International Union for Conservation of Nature (IUCN), we have been able to assess the potential conservation status of tropical flora on the scale of a continent.
Stévart, T., Dauby, G., Lowry, P.P., Blach-Overgaard, A., Droissart, V., Harris, D.J., Mackinder, B.A., Schatz, G.E., Sonké, B., Sosef, M.S.M., Svenning, J.-C., Wieringa, J.J., Couvreur, T.L.P., 2019. A third of the tropical African flora is potentially threatened with extinction. Science Advances 5, eaax9444.
https://advances.sciencemag.org/content/5/11/eaax9444 [open access]
Given the anthropological and climate threats facing nature, the conservation of tropical biodiversity is a major challenge. To encourage the implementation of better biodiversity management practices, countries and international agreements on biodiversity refer to the assessments of species “at risk of extinction” performed by the IUCN as part of a standardised procedure (See Red List of Threatened Species). This approach remains the most comprehensive and objective means of identifying species in need of protection.
However, while the conservation status of the majority of vertebrate species has been assessed, the same cannot be said for plants, although they are critical to earth ecosystems. This is especially true in tropical regions where the flora is very diverse but remains poorly documented.
6,990 Potentially Threatened Species
In this study, we developed a new fast and automatic approach based on key elements of the conservation assessment process used by the IUCN. Their objective was to provide relevant information on the conservation status of a large number of plant species at broad scales, in the form of Preliminary Automated Conservation Assessments (PACA).
We then applied this methodology to the RAINBIO database, which contains over 600,000 georeferenced occurrences of plants in tropical Africa across more than 20,000 vascular plant species.
After classifying these species into six categories – which include species that are “probably or potentially threatened”, those that are “potentially rare” and those that are “potentially not threatened” – we reveal that almost a third (31.7%) of the 22,036 vascular plant species studied are potentially threatened with extinction, and an additional 33.2% are potentially rare (they could be threatened in the near future).
Facilitating Large-Scale Biodiversity Assessments
After determining the most endangered species, we also identified four regions in Africa that are particularly exposed: Ethiopia, central Tanzania, the south of the Democratic Republic of the Congo and the West African tropical rainforests.
We highlight the advantages of this approach, based on the preliminary automated conservation assessments, in terms of cost reduction, time saving and the potential to carry out large-scale assessments.
From November 11th till 16th 2019, I went to south-western Ecuador (Azuay Province) to collect the wild retaliative of the only domesticated south American palm Bactris gasipaes or Chonta. The wild relative, known locally as Chontilla (variety chichagui), grows naturally along the western coast and Andes of Ecuador. In the southern part it grows in the drier regions, and the cultivated variety is absent. The wild type is characterized by small rounded fruits (in contrast to the domesticated on with large oval fruits, a clear domestication syndrome). The southern part of western Ecuador has suffered tremendous deforestation and finding small pockets of forests is very challenging, not just because they are rare, but the ones that do exist are generally places where humans cannot access easily... that is steep slopes! It is icredible that there are hardly no forests reserves there a special mention is Jocotoco Buenaventura reserve, wow, it is great and some great forests there, in addition to birds http://jocotoursecuador.com/destination/buenaventura-reserve/).
From 28th Feb. to 12 March 2019, with my PhD student Léo-Paul and Université de Yaoundé I student Narcisse Kamdem, we traveled for two days to the far East of Camereroon, 60 km south of Yokadouma.
There were very few collections of Annonaceae from this region. The roads were in bad state and the rainy season was upon us. This led to a hard field trip. Luckily we were hosted by ALPICAM who were very generous and helpful. A lot of trees had fallen on the raod so at one point we were lumberjacks rather than botanists. But fate was on our side as several of the fallen trees were Annonaceae in flower or fruit!
Together with Terry Sunderland, and in collaboration with my PhD student Suzanne Mogue, we just published the Flore du Gabon Palms treatment. 34 species are described in French and illustrated, in addition to easy keys to all Gabonese species.
it can be ordered through Margraf Publishers:
Check out my podcast interview with Matt from In Defense of Plants, where I talk about my research on tropical rain forests, Annonaceae and palms! PODCAST HERE
In general the podcasts are really great for anybody intrested in plants! Thanks to Matt for inviting me and the great conversation we had. Check out the website here for more!
Within a review paper I am co authoring, I digitized the biogeographical regionalization results of Linder, H.P., de Klerk, H.M., Born, J., Burgess, N.D., Fjeldså, J., & Rahbek, C. (2012) The partitioning of Africa: statistically defined biogeographical regions in sub-Saharan Africa. Journal of Biogeography, 39, 1189–1372.
This paper uses extensive distribution data from vertebrates (birds, mammals, amphibians and snakes) and plants to generate common bioregions across tropical Africa. In total seven distinct bioregions are statistically identified, five of which are further subdivided into 15 subregions. I make the resulting shape file available for free of use, under the condition that the original work is properly cited (see citation above). This file was generated using QGIS.
Below you have a view of the result with subregions indicated.
Shape file available here compressed into a zip file (8 kb).
In July 2018, I went into the field with PhD student Sebastian Escobar (Aarhus University, Denemark) and my colleague from the Pontificia Universidad Catolica del Ecuador Rommel Montufar, expert in Neotropical palms and their uses. The aim was to sample tagua, or vegetable ivory (Phytelephas aequatorialis) in the regions of Manabi, Los Rios and Santo Domingo. This species is endemic to western Ecuador and is used to make buttons or crafts. The leaves (called cade) are used for thatching. Because of the important deforestation in western Ecuador, this species is highly fragmented on most of its distribution. Small forest fragments provide important refugia for this species and many other plants and animals.
We spent a week driving through dry and wet forests of western Ecuador, collecting tagua. The aim is to study the phylogeography of tagua, and understand how it reacted to past fragmentation, especially during the last glacial maximum. Sebastian's project also aims to understand the ecological dynamics of fruit dispersion and its social economic importance in the region.
Yesterday 1st February 2018, we welcomed Andrew to our lab! Welcome!
Andrew undertook his PhD in evolutionary biology at Imperial College London, on the evolution of annual killifish (Austrolebias) and other Cyprinodontiformes. He then undertook several Postdoctoral Research Fellows in plant genomics at Royal Botanic Gardens, Kew, working on hazelnut production in Turkey, demographic history of the sea campion, Silene uniflora and analyzing genomic data fora range of projects on Madagascan plants (including some palms!).
He will be here in Montpellier for 2 years and will work on the comparative phylogeography of several co distributed rain forest plant species (Annonaceae and palms) across Central Africa, part of the AFRODYN project.
Next stop: Cameroon for some field work and hands on discussions about rain forest evolution!
Check out one of his intresting papers from his PhD:
Helmstetter, A.J., Papadopulos, A.S., Igea, J., Van Dooren, T.J., Leroi, A.M., & Savolainen, V. (2016) Viviparity stimulates diversification in an order of fish. Nature communications, 7, 11271.
Our paper introducing our new R package called ConR: Conservation with R is out in Ecology and Evolution.
ConR allows people to undertake preliminary conservation assessments for hundreds of taxa at a time. The package was specifically aimed to use IUCN criteria, in particular criteria needed for category B assessments. It is particularity suited to analyse large scale datasets containing many taxa, for example at country or even continental level. The output (tabular and graphical) provides an overview of threatened versus non threatened species, useful for identifying taxa or areas of conservation importance. In parralelel, ConR can be used to generated all the needed parameters to undertake full IUCN assessments, for example within the framework of Red Listing workshops or for monographic studies.
However, ConR output should not be taken as final IUCN ready assessments.
This package was mainly implemented by Gilles Daudy in R. The package comes with a complete and detail tutorial.
This article is a direct output of the RAINBIO project. The article is OPEN ACCESS
Below an example of one graphical output from ConR.
Dauby, G., Stévart, T., Droissart, V., Cosiaux, A., Deblauwe, V., Simo-Droissart, M., Sosef, M.S.M., Lowry II, P.P., Schatz, G.E., Gereau, R.E., & Couvreur, T.L.P. (2017) ConR: an R package to assist large scale multi-species preliminary conservation assessments using distribution data. Ecology and Evolution, 7, 11292–11303
Research Area and Project Description: This postdoc is part of the project “Central AFrican Rain fOrests: past DYNamics and future resilience” (AFRODYN), funded by the French ANR. AFRODYN aims to understand the evolutionary dynamics of central African rain forests using a multispecies approach and an unprecedented DNA sequence dataset for African plant species. The overall objectives of AFRODYN are to 1) test different hypotheses of Central African rain forests dynamics in the past within and between species using a statistical comparative phylogeographic approach and 2) infer the potential resilience of this ecosystem to future climate change. Specifically, the post doc will be in charge of analyzing a large dataset of ~800 exons (ca. 200 kpb) captured for over 600 individuals of six different plant species (palms and Annonaceae) sampled across central Africa. This dataset is partly already available and no lab work is required. Finally, the postdoc is expected to contribute ideas and concepts to the project and lead at least two high-quality papers in this research area, contribute to the project’s public outreach, as well as collaborate with other team members, including students and sharing skills.
Thomas Couvreur, researcher in tropical biodiversity evolution