Springe direkt zu Inhalt

Between East and West

Scientists from the Berlin Botanic Garden and Botanical Museum, together with researchers in the Caucasus, are studying the diversity of plants in this region.

Dec 01, 2020

Mosaic of different habitats: Mountainous landscape in the North Caucasus (Karachay-Cherkessia, Russian Federation).

Mosaic of different habitats: Mountainous landscape in the North Caucasus (Karachay-Cherkessia, Russian Federation).
Image Credit: BGBM

The Caucasus is a region with spectacular landscapes and an unusually rich flora and fauna. One of the reasons for this is that the mountainous region between the Black and Caspian seas offers a huge range of habitats. The mountains of the Greater Caucasus, with peaks more than 5000 meters high, tower up in the north with glaciers, mountain meadows, and forests.

In contrast, forests and meadows on gentle hills are typical of the Lesser Caucasus in the south. The Colchis near the Black Sea is a rainy area, where numerous plants survived the ice ages due to a favorable climate, and dense forests thrive. And a similar history is shared by the Hyrcanian forests that grow near the southern shore of the Caspian Sea. Both forest regions are home to a large number of different trees and shrubs, some of them with ancestors from subtropical climates.

Open steppes shape the drier, continental landscapes in the eastern parts of the Caucaus and continue into huge areas on the other side of the Caspian Sea, continuing into Central Asia. It is not surprising that the Caucasus ecoregion is considered a treasure trove of global biodiversity. In an area of 580,000 square meters (one and one half times the size of Germany), there are an estimated 6,300 vascular plant species, and the flora of the Caucasus consists by no means solely of common plants. Professor Thomas Borsch, the director of the Botanic Garden and Botanical Museum (BGBM), points out, “About a quarter of the vascular plants in the Caucasus are endemics that do not occur anywhere else on Earth.”

Many Vascular Plants Are Unique to the Caucasus

This fascinating region has long been an exciting location for botanists. At the time of Adolf Engler, who as the director of the Berlin Botanic Garden at the end of the 19th century, made significant progress in researching the world’s plant diversity, there were already good relationships between botanists in Berlin and the Caucasus. These relationships were re-established after the fall of the Iron Curtain.

“If we want to understand the flora of the Caucasus, we need to investigate the entire region,” stresses Thomas Borsch. Thus, the Berlin team cooperates with research institutions from the Russian Federation as well as from Armenia, Azerbaijan, and Georgia. “In 2009 we launched the Caucasus Biodiversity Initiative together with partners in the region,” says Borsch. It provides a framework for projects with the aim of researching the plant diversity of the Caucasus, promoting scientific exchange and capacities in the Caucasus countries, and making knowledge available for the protection and sustainable use of Caucasian biodiversity.

Thomas Borsch in Georgia, examining a wild pear plant.

Thomas Borsch in Georgia, examining a wild pear plant.
Image Credit: G. Parolly

With support from the Volkswagen Foundation, the project “Developing Tools for Conserving the Plant-Diversity of the South Caucasus” took up its work in 2012. The participating research institutions are: the Takhtajan Botanic Institute and the Orbeli Institute of Physiology of the National Academy of Science of the Republic of Armenia; the Institute of Botany of the Azerbaijan National Academy of Sciences; the Botanic Garden in Baku, Azerbaijan; the Institute of Botany of the Ilia State University and the National Botanic Garden in Tbilisi, Georgia; the Botanic Garten in Batumi, Georgia; and the Georgian National Museum in Tbilisi.

“The plants examined in the project are as diverse as nature itself in the Caucasus”

The initial aim of this project was to investigate selected groups of plants with many species found in the Caucasus. These groups were to function as models. The scientists started with lichens and bluebells, the daisy family, the mint family, the carnation family, and wild pears (rose family). Wild pears play an important role as relatives of cultivated plants, especially since many of the wild species are adapted to warm and dry environmental conditions. Preserving them could be of practical importance for future cultivation of pears in times of climate change. “The plants examined in the project are as diverse as nature itself in the Caucasus,” says Borsch. The scientists were able to show, among other things, that there have been plant migrations between the East and the West for several million years. This was a major influence on the emergence of biodiversity in the Caucasus.

“The goals of the Caucasus cooperation are to convey and establish modern research methods, as well as to develop molecular laboratory capacities and collections such as herbaria or documented living plants in botanical gardens,” explains Thomas Borsch. Over the past ten years, thousands of samples have been collected on numerous joint field trips throughout the Caucasus region and deposited in the collections of the Caucasus countries as well as in the Botanic Garden and Botanical Museum in Berlin.

Digitizing the Collections

Through support from the Volkswagen Foundation, it was possible to improve technical capacities in Armenia, Azerbaijan, and Georgia and to begin digitizing the herbarium specimens. For this purpose, the scientists set up a database infrastructure that facilitates the exchange of data between the herbaria. In the future, the international team intends to continue digitizing the herbaria at institutions in the Caucasus and link them with databases of other important collections, for example, in the Russian Federation. Likewise, the collections from the Caucasus in the Botanic Garden and Botanical Museum in Berlin, which has the most extensive plant collections from the Caucasus in all of Germany, will be digitized and made accessible for further research. In a later step, the scientists want to create detailed distribution maps for the species.

In order to preserve and utilize the unique plant diversity of the Caucasus, it is necessary to first gain reliable knowledge on the species, their threats, and possible measures for their conservation and sustainable use. To this end, the BGBM and its partner organizations will continue to be involved in the joint Caucasus initiative in the coming years. As a long-term goal, the scientists have a vision firmly in view. They want to make this treasure trove of biodiversity accessible in a digital version. This will also be supported by international infrastructures such as the Global Biodiversity Information Facility (GBIF).

This text originally appeared in German on October 4, 2020, in the Tagesspiegel newspaper supplement published by Freie Universität.

Further Information

Prof. Dr. Thomas Borsch, Berlin Botanic Garden and Botanical Museum, Email: t.borsch@bgbm.org