The increasing drought sensitivity of silver fir (Abies alba Mill.) is evident in the last two decades

Abstract

Silver fir (Abies alba Mill.) is still counted among drought-tolerant tree species. However, its ability to cope with the recent extremely dry period has not yet been sufficiently studied. The objective of research was to analyse differences in the climate-growth response between silver fir, Norway spruce (Picea abies L. Karst.) and European larch (Larix decidua Mill.) growing in areas with large-scale disintegration of spruce stands. In 2019-2021, the increment cores were sampled at 16 sites along the altitudinal gradient of 340-775 m a.s.l. in different regions of the Czech Republic affected by bark beetle outbreak. The radial growth pattern of fir was compared with that of spruce or larch growing under the same site conditions. In fir, the missing rings were frequently recorded during the period of peak SO 2 pollution load in 1966-1985, but they were rarely identified in recent years. In spruce and larch, missing rings were less common and occurred mainly in the recent dry period after 2015. Fir was less sensitive to summer drought compared to larch and especially to spruce, which showed high sensitivity to summer drought regardless of the altitude. The significant positive response of fir to summer precipitation was recorded at sites up to 450 m a.s.l., however, its sensitivity to drought has increased in the last two decades. Hence, when considering the wider use of fir, it is necessary to respect its ecological requirements as much as possible in order to preserve its vitality and production potential in changing climatic conditions.

Major tree species of Central European forests differ in their proportion of positive, negative, and nonstationary growth trends

“…Silver fir outperformed all other investigated tree species with respect to growth trends, displaying a clear prevalence of stationary positive growth trends. This advantage can be attributed to factors such as the extension of the growing season and the species' lower sensitivity to summer drought compared to spruce (Vejpustková et al., 2023). Additionally, silver fir benefits from reduced acidification, particularly when compared to the 1970s–1980s period (Oulehle et al., 2022).…”

Silver Fir (Abies alba Mill.): Review of Ecological Insights, Forest Management Strategies, and Climate Change’s Impact on European Forests

“…Annual disturbance-based tree mortality of silver fir has been accelerating and was the highest (compared to Norway spruce, Douglas-fir, European beech, and oak) in Germany during the period of 1929-2014 [257]. Extensive mortality of fir trees was observed after the drought in 2018 in Czechia [258]. Natural and anthropogenic disturbances play a principal role in the dynamics of forest ecosystems and influence stand structure and regeneration processes.…”

“…Annual disturbance-based tree mortality of silver fir has been accelerating and was the highest (compared to Norway spruce, Douglas-fir, European beech, and oak) in Germany during the period of 1929-2014 [257]. Extensive mortality of fir trees was observed after the drought in 2018 in Czechia [258].…”

Tree-Level Climate Sensitivity Reveals Size Effects and Impending Growth Decline in Silver Fir Affected by Dieback

“…Key limiting factors for its development include low summer temperatures, insufficient humidity during the growing season, and frost during its early germination stages [10]. Recent studies underscore the increasing significance of drought as a limiting factor for the species' development [11,14].…”

“…Silver fir decline has occurred periodically in Europe since 1500 [9]. In the rear edge of the species, located about the ecotone of the Mediterranean region, dieback symptoms have been related to warming and extreme drought events but also contributing factors such pathogens and the legacy of management (clear-cut logging with short regeneration periods, the abrupt removal of shelter trees, and plantation without shelter trees) [10][11][12][13][14].…”