Wild tulips fight to survive in their ancestral home

Tulips are one of the world’s most well known spring flowers. Like all other garden plants, they have natural ancestors, and surprisingly these do not grow in the Netherlands—the country that exports the majority of horticultural tulips. In fact, most wild tulips can be found in the steppes, semi-deserts, and mountains of Central Asia, where over half of all known species of wild tulip grow. The number of wild tulips is dwarfed by the tens of thousands of horticultural varieties, yet the large number of species found in Central Asia makes this region a diversity hotspot for this plant group.

These wild tulip species harbour genetic resources that may be crucial for future breeding efforts, especially with respect to disease resistance and tolerance to climate change. They also act as indicators of overall ecosystem health, i.e. they provide an impor- tant signal if their habitat is being damaged. The flowers provide important resources and homes for insects, most notably supporting the insect populations that may also pollinate crop plants. Furthermore, wild tulips hold significant cultural value in this region, with local communities often possessing knowledge about where they occur close to their settlements. Therefore, they are a valuable asset, especially to local communities. However, limited understanding of natural diversity, the impact of climate change, and the effects of environmental disturbance have made it challenging to develop a solid conservation plan for these plants.

Since 2018, a team led by Fauna & Flora International has been proactively working on solving some of these issues. Specifically, I— Brett Wilson, a PhD student at the University of Cambridge and Dr. Sam Brockington the Curator of Cambridge University Botanic Garden—have been part of a research team that focuses on using technical knowledge and local expertise shared across organisations, to tackle these challenges. Sam and I have been working most closely with Bioresurs—a Kyrgyz conservation NGO, the National Academy of Sciences of the Kyrgyz Republic, and the Gareev Botanical Garden in Bishkek, Kyrgyzstan. Additionally, we have also developed collaborations across the region, including in Uzbekistan, Tajikistan, and Kazakhstan. This includes a range of botanic gardens where we have actively expanded tulip collections, not only for public viewing but also for both scientific and conservation purposes—an often-overlooked role of global botanic garden plant collections.

The first task for our team was to improve our knowledge of tulip taxonomy. Without this fundamental information, conservationists struggle to appropriately target and obtain funding as well as carry out mitigation and management. In recent decades, it has become easier and cheaper to sequence DNA, and to use this information to infer whether the target plants are distinct species, and how these species are related to one another. Simultaneously, there has also been an increase in sources of tulip material, especially across the global botanic garden network.

Over the past four years, our team has collected and sequenced DNA from leaf material sourced from: an array of wild tulip populations in Central Asia, the living collections of several botanic gardens, and herbarium material—some of which was collected nearly a century ago. This allowed us to survey over 86 percent of all currently recognised species, as well as many plants collected under old names that are no longer recognised as species. Through this huge effort, we discovered the existence of a new subgenus, and reorganised many sections to simplify these groupings. Based on the data, we were able to reinstate several species, declassify some that are no longer considered separate species, and we also discovered a new species which we formally described in the summer of 2022.

Genetic data can be used to explore the evolutionary history of a plant group across millions of years. Understanding the history of tulips is important as it can allow us to identify the geographic origin of this plant, as well as begin to understand where, when, and why it diversified. In turn, this can help us pinpoint the areas of distribution that are most important for conservation as well as specify which species are the most genetically unique. We were able to show that wild tulips originated in the broader Central Asia region with the most recent common ancestor estimated to have existed here around 23 million years ago. In addition, we discovered that this part of the world was crucial for the diversification of wild tulips throughout their history. The explosion of different tulip species in Central Asia could be linked to aridification, development of large mountain ranges, and global cooling. Strikingly, we were also able to show that tulips most likely moved out of the region through the Kazakh and Russian steppes into the Caucasus, from where they spread into the Middle East, Mediterranean, eastern Europe, and Iran. Very few species seem to have made it south out of Central Asia due to historical barriers such as deserts and seas. Crucially, all this work demonstrated that Central Asia is both historically and currently important for tulips, emphasising the need to conserve these flowers and their habitats in the region.

Central Asia has seen several decades of instability, with the collapse of the Soviet Union leading to economic issues, border disagreements, and political uncertainty. Thus, Central Asian countries often struggle to collaborate on policy and management approaches. This is a major problem for biodiversity, which doesn’t abide by borders or nationality. Although individual countries (e.g., Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan) have undertaken national assessments of tulip diversity, few studies have looked at the region as a whole.

It is important to work at a larger scale in order to predict and protect wild tulips from the effects of global threats such as climate change. We used a large dataset comprising the location points of tulip populations to predict the impact of different climate change scenarios. Our findings pointed to vast reductions of suitable tulip habitat by 2050, including inside designated reserves. Our study predicted that most species would only survive at higher altitudes. Overall, not only did this work highlight the threat of climate change to biodiversity in the region, but it also provided important information to help policymakers and conservationists take action to protect tulip diversity. This will hopefully act as a rallying call for greater regional collaboration on this and other conservation efforts—especially those related to large-scale threats, such as climate change.

We felt that a good starting point to promote regional cooperation would be making use of the IUCN Red List. The online resource aids in raising awareness and catalysing action by indicating the conservation status of specific species. In order to add wild tulips to the Red List, we created a network of experts from across Central Asia. This ensured better communication, sharing of data, and collaboration—linking up a wealth of country-specific information—so that researchers could conduct a more cohesive, border-spanning assessment of tulip populations. This process took place in several stages: writing initial draft reports for each species, obtaining inputs from regional experts (at a workshop held in Bishkek, Kyrgyzstan), asking an expert to review the reports, and finally, ensuring the reports met IUCN’s standard. These efforts led to collated information about the species’ population sizes, locations, threats, habitat, and required conservation action.

After around two years of hard work, we were able to ensure that reports for 53 species of wild tulips from Central Asia were published in December 2022. The reports showed that approximately 51 percent of all assessed Central Asian species are Threatened: six are Critically Endangered, six are Endangered, and 15 are Vulnerable species, with 14 other species considered Near Threatened. They highlight the precarious situation of wild tulips in Central Asia, especially as a result of livestock overgrazing and climate change. It is clear that urgent conservation attention is required, but we hope that the collaborations to date have brought together the people and information which will be fundamental in stopping the decline of these species.

At the moment, wild tulips continue to bloom in the Central Asian landscape every spring, yet our work shows that this may not always be the case. Although new species continue to be found in this mountainous haven, we may still be losing tulip diversity overall, potentially including many undescribed species. A stable taxonomic framework has now been established, which can hopefully underpin a wave of more effective research and conservation. Our partners have simultaneously been working on expanding botanic garden collections of wild tulips and promoting better management of pastures where they grow. We hope that our work will help preserve this beautiful flower in its native home, so that when spring rolls around once again, we will see the meadows, grasslands, and deserts alive with the colours of flowering tulips.

This article is from issue


2023 Sep