Geobotanists from St Petersburg University warn about the threat of extinction of the natural flora of Abkhazia due to Asian oaks

The research findings are published in the Russian Journal of Biological Invasions.

During the Russian Empire, the territory of present-day Abkhazia was considered a promising resort. To this end, exotic plants, unusual for the region, were imported from various continents to Sukhumi and other towns such as New Athos and Gagra. Most of them took root on the Black Sea coast of Abkhazia, as there are three climatic borders that create unique opportunities for introduction. 

The process of importing exotic plants to Abkhazia began as early as the 19th century, but it was most active in the early 20th century with the development of the resort area of the Black Sea coast. At that time, the area was being transformed into a privileged resort, and outstanding garden architects, botanists and dendrologists were working on it.

Among the scientists who carried out such work in Sukhumi were the researcher and landscape architect Pavel Tatarinov, and the botanists Alfred Kolakovskii, Nikolai Albov and Aleksandr Kolesnikov.

In the 21st century, however, scientists began to notice the aggressive behaviour of some introduced plants that had not previously shown such characteristics. Some introduced species began to outcompete and displace local flora. It turned out that the catalyst for this process was climate change, which in recent years has caused global warming in some latitudes and abnormal rainfall and hail in others. 

For example, temperate latitudes have become one degree warmer on average in recent years, while tropical and high latitudes have seen an increase in precipitation. Scientists attribute this to anthropogenic activities, particularly the release of toxic elements from industrial plants.

Yana Virolainen is Senior Research Associate in the Department of Atmospheric Physics at St Petersburg University and Researcher in the Ozone Layer and Upper Atmosphere Research Laboratory at St Petersburg University. She spoke about the problem of climate change, possible solutions and the consequences of this phenomenon in St Petersburg University’s Heinrich Terahertz podcast.

The geobotanists from St Petersburg University have been studying the behaviour of the myrsina-leaved oak (Quercus myrsinifolia Blume), which has become widespread on some mountain slopes over the past 20 years. The plant of Japanese-Chinese origin, brought to Abkhazia in imperial times, has long been used in landscaping and has not shown any invasive properties, i.e. it does not threaten other species by spreading. 

"This evergreen tree can reach a height of 20 metres and densely covers the area below with its extensive crown, creating shade for other plants. We noticed the aggressive influence of oaks on neighbouring areas and investigated this process. It turns out that the plant is now significantly expanding its zone of influence and displacing local flora. For example, juveniles from three or four adult trees can easily occupy an area on slopes five times larger than that originally occupied by their mother plants," said Irina Antonova, the author of the study, Associate Professor in the Department of Geobotany at St Petersburg University. 

The oaks not only shade other plants from the sun, but also produce a large number of acorns, which quickly germinate and take over the nearest areas. According to the University’s scientists, the rapid spread and suppression of native plants is facilitated by the drained soils of Abkhazia’s mountain slopes, which are favourable for growth.

St Petersburg University is actively developing cooperation with the Abkhazian State University. A delegation from the Abkhazian State University recently visited St Petersburg University and discussed a project to create a modern sport, fitness and research complex.

According to the researchers from St Petersburg University, such a rapid spread of such plants seriously threatens the existence of natural plant communities in future. At the same time, the foothills of Abkhazia are a unique floral community with many relict and rare species. 

The solution to the problem may be to start active monitoring of the areas, and modelling the behaviour of different introduced trees under conditions of climate change. Such an approach will make it possible to theoretically determine: the strength and speed of the spread of woody (and not only woody) plants, the factors that inhibit their growth and spread; and other important characteristics of the behaviour of introduced trees in relation to the local flora.

St Petersburg University heads the list of research organisations in Russia in the number of publications in Scopus-indexed journals on subjects related to the green transition. Also, the University has recently opened a centre to develop solar energy and carbon neutralisation solutions.

According to the scientists’ observations, it is not only oaks that have changed their behaviour towards aggressive expansion. In Abkhazia, the Canadian goldenrod (Solidago canadensis L.), cultivated in Russia as an ornamental plant and vigorously invading the meadows of the foothills, proved to be the most aggressive. Another example is the American shrub eastern baccharis (Baccharis halimifolia L.), which densely covers previously abandoned tea fields and is no less active in destroying natural vegetation due to its rapid spread.

St Petersburg University, the oldest university in Russia, was founded on 28 January (8 February) 1724. This is the day when Peter the Great issued a decree establishing the University and the Russian Academy of Sciences. Today, St Petersburg University is an internationally recognised centre for education, research and culture. In 2024, St Petersburg University celebrates its 300th anniversary. 

The plan of events during the celebration of the anniversary of the University was approved at the meeting of the Organising Committee for the celebration of St Petersburg University’s 300th anniversary. The meeting was chaired by Dmitry Chernyshenko, Deputy Prime Minister of the Russian Federation. Among the events are: the naming of a minor planet in honour of St Petersburg University; the issuance of bank cards with a special design; and the branding of the aircraft of the Rossiya Airlines to name just a few. To mark the 300th anniversary of St Petersburg University, a postage stamp depicting the Twelve Collegia building and the monument to Count Sergey Uvarov was issued. 

By the decision of the Governor of St Petersburg Alexander Beglov, 2024 is a year of the 300th anniversary of St Petersburg University in St Petersburg. On the day of the University’s 300th anniversary torches were lit on the Rostral Columns on the Spit of Vasilyevsky Island. St Petersburg University flags were raised on the Palace Bridge. The city public transport was decorated with the University’s symbols. New tourist maps will feature the locations of the University buildings, with thematic and historical materials about the University placed nearby. During St Petersburg’s City Day celebrations in May 2024, St Petersburg University will be a participating venue. The traditional ‘Scarlet Sails Festival’ will also be dedicated to the anniversaries of St Petersburg University and the Russian Academy of Sciences. Additionally, the University has launched a website dedicated to the upcoming holiday. The website contains information about outstanding University staff, students, and alumni; scientific achievements; and details of events held as part of the celebration of the 300th anniversary of the University.