Publication in “Nature”

Prof. Bogdan Jaroszewicz of the Białowieża Geobotanical Station at the Faculty of Biology, University of Warsaw, is a co-author of an international study whose findings have been published in the journal “Nature”. The study shows that vegetation in Europe is not keeping pace with the rate of climate warming. Analyses have shown that forests, meadows, and mountain peaks respond to temperature changes at different rates, leading to the formation of what is known as a “climate debt.”

The species composition of European plant communities is undergoing gradual changes caused by climate warming. Species tolerant of cooler climates are gradually giving way, while thermophilic species are expanding. An international team of scientists, including Prof. Bogdan Jaroszewicz of the Białowieża Geobotanical Station at the UW’s Faculty of Biology, has for the first time compared how these changes are unfolding in different types of environments: forests, meadows, and mountain peaks. The research findings were published in the journal “Nature”.

Climate debt

A comparison of current and historical species compositions of plant communities revealed that the three ecosystem types studied respond to climate warming in different ways. “This publication was made possible by analysing over 6,000 plant inventories conducted at least twice, with intervals ranging from a dozen to several dozen years, which allowed us to demonstrate the nature of biodiversity changes across many locations in Europe, from Ireland to Ukraine and from Norway to Spain,” says Prof. Bogdan Jaroszewicz.

A key finding was that the rate of change in plant communities is slower than the rate of climate warming.

“This results in a ‘climate debt,’ which is the difference between the current state of vegetation, i.e., its species composition, and the state estimated based on current climatic conditions,” explains the scientist.

The consequence of climate debt is a high probability of more rapid changes in vegetation composition in the future, as species catch up in their geographic distributions. The pace of these changes will vary depending on local conditions.

Mountains are changing the fastest

A new finding is that the response of vegetation in the three ecosystem types studied to climate warming differs. Vegetation on mountain peaks is changing about five times faster than that in forests and grasslands, which is consistent with the highest rate of warming observed in the mountains. Changes in the composition of mountain peak vegetation are mainly driven by the gradual extinction of cold-tolerant species, due to their limited ability to migrate to cooler regions.

In grassland ecosystems, the change is mainly driven by the expansion of thermophilic species. In forests, however, the process is more complex and involves both the retreat of cold-tolerant species and the expansion of thermophilic species.

– These new findings help us better understand the processes responsible for the changes occurring in Europe’s natural environment over the past few decades. They show that each type of environment reacts in its own way and that, to explain these differences, more factors than just temperature alone must be taken into account, including land management practices, soil condition, environmental pollution, and changes in the amount and nature of precipitation,” –  concludes prof. Bogdan Jaroszewicz.