Red lists, Whitebeams and Green ambitions

Posted on by Emily Beech

GTC doesn’t just do practical tree conservation; before we can start protecting, or encouraging our partners to do so, we need to find out which trees need our help. To that end, the whitebeam (Sorbus) experts of Europe recently convened in Zagreb, Croatia to review draft red list assessments produced by the GTC. Over 190 assessments were agreed upon over the four-day workshop.


Sorbus experts discuss some herbarium specimens in a variety of languages. Credit: Malin Rivers/BGCI

The task at hand

When confronted with the task of red listing the trees and shrubs of Europe, we were unsure where to start. So following the expression ‘bigger is better’, we started with one of the largest groups on our list of European trees: the Sorbus genus. Part of the Rosaceae family, Sorbus in English are commonly known as whitebeams, rowans or service trees. It is a genus of deciduous trees and shrubs found across the temperate regions of the world.

After delving into the taxonomy of the Sorbus genus in Europe, it was clear that there were far more species than we first anticipated. Our final list grew and grew until we had 190 species to assess – and all in just 2 months.

Before the workshop, GTC drafted red list assessments for every species. To do this, we assembled information from scientific literature, floras and books to find information on the distribution, population size, trends and threats to these species. Using all of this information, we made preliminary conservation assessments of all the European Sorbus species. This method of categorising allows conservationists to prioritise species most in need of conservation action.

Four nights in Zagreb

In early June, eight Sorbus experts from across Europe gathered in Zagreb, Croatia for an intense four day workshop to review of all 190 draft assessments. These experts spend much of their time in the field, often finding and describing new species of Sorbus and know everything there is to know about these species. Their collective brains contain the most up to date information on Sorbus population numbers and local threats, so they are the best-placed people to determine the current state of each species and their distributions.

Not only did the workshop allow us to make sure we had the most accurate information for our red list assessments, many of these experts had collaborated over email on the very papers we had used to compile our red list assessments but they had never met face to face. So this was a great opportunity for the group to network and discuss the most pressing issues facing their genus.

Sorbus aria

Wild Sorbus aria (Least Concern), found in the hills above Zagreb, Croatia. Credit: Emily Beech/BGCI

Four days of Sorbus talk ended with 190 complete Sorbus red list conservation assessments, covering the entire European region. The complete red list assessments for European Sorbus species will be available on our website in early 2017 – so watch this space.

To celebrate, we headed into the hills above Zagreb in search of wild Sorbus. We were not disappointed. We found several Sorbus aria trees (one of Europe’s more widespread species) as well as many other interesting European plant species.

Where do we go from here?

After weeks of immersion in the world of Sorbus, the workshop was over. However for conservationists working on threatened Sorbus species, this is just the start.

Once we have identified the threatened species, conservation action planning comes into play. This may be at the government level, influencing policy, or at the local level, informing the choices that are made on the ground to improve the conservation status of a species and protect it from extinction.

Our workshop identified that almost 75% of European Sorbus are threatened with extinction. This high number of threatened species most likely reflects a change across Europe in farming and woodland practices. Previously woods would have been coppiced and grazed, creating gaps in the canopy for light-loving Sorbus. As these practices are slowly being abandoned throughout the continent and forests are left to regenerate, Sorbus species are confined to the woodland edges or rocky outcrops where other species cannot grow.

Not everybody considers Sorbus species as a high priority for conservation action because they can evolve quickly and readily form new species. However, conservation action for Sorbus – involving creating space in the canopy by selectively removing commoner species – can be achieved on a relatively low budget giving Sorbus the chance to flourish in tandem with forest regeneration.

Moreover, if the revival of such management can be targeted to priority sites – e.g. areas containing range restricted Sorbus – it could also serve to bring the rarest and most threatened Sorbus back from the brink of extinction. The hope is these assessments will inspire both national policy makers and local conservation practitioners to take action to keep the amazing Sorbus diversity alive and well.

Moving forward

Now to red list the other trees and shrubs of Europe. The GTC team will next dedicate our time to red listing a further 300 unevaluated trees and shrubs of Europe to identify which other trees are in need of conservation action.


Red List assessments and distribution maps for European Sorbus species are currently being finalised and will be available on the IUCN Red List website in early 2017, and the resulting publication ‘European Red List of the trees and shrubs of Europe’ will be published later that year.

This work is part of IUCN’s EU LIFE project, for which GTC is assessing the trees and shrubs of the pan European region. The project is also funding the red listing of a number of other groups including saproxylic beetles, molluscs, mosses and ferns, all contributing to the European Red List.

This work contributes directly to the ‘Global Tree Assessment’, an initiative run by BGCI and the IUCN/SCC Global Trees Specialist Group to assess all the world’s trees by 2020.

For more information about GTC’s contribution to red listing efforts, click here.

Sorbus experts of Europe gather in Zagreb to agree on European Red List assessments. Credit: Per Salvesen


Written by Emily Beech

Emily is a Tree Red List Manager at Botanic Gardens Conservation International (BGCI), working on the Global Tree Assessment, managing conservation assessment projects across the world, including in Madagascar, Central America and Oceania.

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