A major step forward in the need to improve conservation efforts on the plants of the Andes has been reflected in a new scientific paper by leading scientists from the Royal Botanic Garden Edinburgh (RBGE), Royal Botanic Gardens, Kew, the University of Oxford and Montana State University, USA. The results of the study Contrasting plant diversification histories within the Andean biodiversity hotspot by Pennington et al, published by PNAS, means botanists and systematists can now move more quickly towards the preservation of a previously neglected region meriting international concern.
Headed up by Professor Toby Pennington of RBGE, who worked with Dr Tiina Sarkinen (RBGE, University of Oxford), Dr Colin Hughes (University of Oxford), Dr Gwilym Lewis (RBG Kew), Dr Bente Klitgaard (RBG Kew) and Professor Matt Lavin (Montana State University), the research not only demonstrates that Andean dry forests are considerably older than previously thought, but that they also hold many species that remain unknown to science.
“The purpose of the paper is to demonstrate the unique biological history of tropical dry forests in the Andes” explained Toby Pennington. “Dry forests are the most threatened tropical forests on the planet, but have been drastically understudied compared to rain forests. The ultimate aim of the paper is to raise the conservation profile of these dry forests in the Andes where they are in urgent need of protection”.
During the project the team discovered that the leguminous shrub species Cyathostegia mathewsii is more than 10 million years old and that populations, found in four separate valleys in Ecuador and Peru, have been isolated from each other over millions of years. The stability of the dry forests over the past 10 million years, during which the dynamic mountain uplift events and historical climate changes have taken place in the Andes, seems remarkable, according to Pennington. The long evolutionary history of these dry forests is in stark contrast to other Andean vegetation types which are more recent in age. The fact these Andean dry forests contain a living “museum” of diversity highlights the urgent need for protection.
Tiina Sarkinen has also shown, in her PhD studies, that the longevity of the genus Cyathostegia is not exceptional, but that a number of other plants in Andean dry forests have also been present for millions of years.
“The data show clearly that the dry forests have a long history in contrast to the other vegetation types in the Andes” she said. “Our studies are the first steps in understanding the true diversity of the forests, but we still need baseline data such as complete species lists for these forests. More than a third of the plants occur nowhere else on the planet and we continue to discover new species every field trip”.
This research partnership between RBG Kew and RBGE dates back to 1991 when Toby Pennington was trained, during his PhD fieldwork, by Gwilym Lewis in Brazil.
They have since collaborated at various levels, including in 1997 when Gwilym and Bente Klitgaard, who were working on dry forests in Ecuador, invited Toby and Dr Vanessa Plana to participate in fieldwork. This was the first time Toby saw the Cyathostegia mathewsii which is the subject of the PNAS paper: “We knew this to be an interesting plant. It was thought to be very restricted and confined to south Ecuador and north Peru, but we later discovered populations in two other dry valleys”, he added. “It was also on this trip that we discovered its highly unusual flowers to be pollinated by beetles: the latter a surprising observation for a member of the legume family”.
Pennington confirmed the significance of such partnerships on international conservation: “Understanding plant diversity is a challenge in the Tropics, where most species occur – there are 45,000 species of plants in the Andes alone. We work together with experts from the Universidad Nacional Agraria La Molina in Lima, Peru, and our aim is that our collaborative study brings these unique forests to the global map of conservation priorities”.