Amazon plant diversity revealed in verified research

The first ever verified checklist of plant diversity in the Amazon has revealed unexpected data providing an exciting and solid new foundation for future research and exploration into the ecology and evolution of one of Earth’s most species-rich regions. Published today (Tuesday, September 19) in the Proceedings of the National Academy of Sciences ( ), the research paper "Challenging checklists: counting plant species in the Amazon" sets out a clearer picture of exactly what does grow in this biodiversity hot spot.

In cataloguing 14,003 species of seed plants - flowering plants and cycads - from the Amazon basin, the team of taxonomists from 32 research institutes in Amazonian countries, Europe, and USA, discovered fewer than half of the plant species - just 6,797 - to be trees, a number lower than expected against suggestions in previously published work. At the same time, herbs, shrubs and epiphytes - plants that grow on other plants - were more diverse than anticipated: symptomatic of having often been overlooked in studies of tropical diversity.

Now, this taxonomically verified plant list can deliver a solid basis for researching into the needs of  these diverse forest communities in response to climate and other environmental change. It has been achieved thanks to collaboration by experts in herbaria and museums around the world.

Dr Sandra Knapp, of the Natural History Museum, London, who contributed to the project, explained: “This study shows how the infrastructure of both museum collections and the people who work on them, working collaboratively across countries, are essential for understanding the diverse forests of the Amazon basin. By establishing a taxonomically verified baseline for Amazonian plants, we have solid basis for conservation, but also for studies of the evolution and ecology of these extraordinary and wonderful forests.”

This Open Access Baseline list is made possible by recent advances both in the study of the Amazon flora and also by the digitisation of herbarium specimens, along with new availability of data on the names and occurrences of plants in these forests. Innovative efforts such as the ongoing Flora do Brasil 2020 and the Catálogo de Plantas de Colombia, funded by their respective governments, alongside local knowledge and studies, are key to advancing knowledge of Amazonian plant diversity.

At the vanguard of this research is the Royal Botanic Garden Edinburgh, from where Dr Tiina Särkinen added: “These platforms represent the accumulation of years of  study into the plants of the Amazon and this is a real moment of celebration for the botanical community. The checklist reflects hundreds of years of field work and exploration in the region and centuries of taxonomic study around the world’s herbaria by countless researchers.”

The significance of the research paper was underlined by Dr Domingos Cardoso Salvador’s, of Federal University, Brazil, who led the study and concluded that this moment was the start of a new chapter:

“Publication of this list does not mean that the Amazonian flora is completely known. Many new plant species are discovered each year, both in the field and in museum and herbarium collections, and much of the vast Amazon area still remains poorly or completely unexplored. Taxonomic research clarifies species identities and boundaries. Verified lists depend on museum and herbarium collections – these have been likened to the ‘Natural History Large Hadron Collider’ – but people matter too. Without taxonomic expertise, plant collecting in the wild, and long-term studies, our ignorance of what lives where and how it is changing means we risk damaging that which we had it in our power to save, by just not knowing.”

The Royal Botanic Garden Edinburgh is a charity (registration number SC007983)