Early warning signals indicate climate change-induced stress in Norway spruce in the Eastern Carpathians

Research output: Contribution to journalResearch articleContributedpeer-review



Climate change is affecting forest ecosystems globally, in particular through warming as well as increases in the frequency and intensity of extreme events. Norway spruce (Picea abies (L.) Karst.) is one of the most important coniferous tree species in Europe. In recent extremely dry years in Central Europe, spruce suffered and large dieback has been observed. In parts of Eastern Europe, however, no large-scale decline in spruce has been re- ported so far, though anticipated changes in climate pose the question how the future of these forests may look like.
To assess the current state of spruce forests in Eastern Europe, we established a tree-ring network consisting of 157 Norway spruce chronologies (from >3000 trees) of different ages distributed along elevational transects in the Eastern Carpathians, Romania. We evaluated early warning signals of climate change-induced stress, i.e. (1) growth decline, (2) increased sensitivity of tree growth (assessed over the statistics first-order autocorrelation and standard deviation), and (3) increased growth synchrony.
A pronounced growth decline was observed over the last two decades, which was strongest in younger stands and at lower elevations. However, growth sensitivity and synchrony did not show consistent patterns, suggesting that forest decline may not be immediately imminent. Overall, our findings highlight an increased vulnerability of spruce in the Eastern Carpathians. With ongoing climate change, spruce dieback may be expected in this part of Europe as well.


Original languageEnglish
Article number169167
JournalScience of the total environment
Publication statusPublished - 20 Feb 2024

External IDs

Scopus 85180533549
ORCID /0000-0002-5218-6682/work/151438948
Mendeley 60d9919c-dc78-3a18-b5ef-a050c63ca025


Sustainable Development Goals


  • Basal area increment, Climate change, Drought response, First-order autocorrelation, Growth decline, Growth synchrony, Standard deviation