Long-term effects of environmental change and species diversity on tree radial growth in a mixed European forest

Norway spruce (Picea abies), European beech (Fagus sylvatica), silver fir (Abies alba) and Scots pine (Pinus sylvestris) typically co-occur in European forests, but show contrasting response to climate and environmental change. Sustainable forest management therefore depends on species- and regional-specific information. Here, we use tree-ring width measurements of 334 beech, 280 fir, 144 spruce and 63 pine trees from 75 inventory plots in Slovakia to assess the predominant climatic factors that control radial stem growth of Europe’s economically most important forest species. All four species exhibit significant shifts in stem growth over the past 100 years. Ring width patterns were, however, not significantly affected by tree species diversity and site elevation. The resistance, resilience and recovery of all species to the extreme summer droughts between 1950 and 2003 suggest that spruce is the species most unsuitable for the predicted warmer and drier future. Silver fir may benefit from warmer conditions, although we cannot conclude that it will not suffer from predicted increased frequency of climate extremes. Forest management in this locality should aim to avoid significant loss of forest cover by replacing Norway spruce monocultures with mixed stands of silver fir and European beech

Harmonised projections of future forest resources in Europe

Data PaperAbstract • Key message A dataset of forest resource projections in 23 European countries to 2040 has been prepared for fores trelated policy analysis and decision-making. Due to applying harmonised definitions, while maintaining country-specific forestry practices, the projections should be usable from national to international levels. The dataset can be accessed at https://doi.org/10.5061/dryad.4t880qh. The associated metadata are available at https://metadata-afs.nancy.inra.fr/ geonetwork/srv/eng/catalog.search#/metadata/8f93e0d6-b524-43bd-bdb8-621ad5ae6fa9info:eu-repo/semantics/publishedVersio

A high proportion of norway spruce in mixed stands increases probability of stand failure

The decline of pure spruce forests in the Beskydy Mountains in the Czech Republic and Slovakia is mainly driven by bark beetle attacks and storm events. Salvage-harvest records based on timber volume on the forest-stand level document the extent of stand failure processed by salvage logging. On the basis of these records, the stand failure proportion was expressed as the proportion of timber volume processed by salvage harvest divided by the standing timber volume over a period of 10 years (sf). Two null hypotheses to be tested are that sf is not influenced by (H1) the size of trees expressed by mean stand age (age) or alternatively by mean stand diameter (dbh); and (H2) the volume proportion of spruce within the stand (spp). The dataset was evaluated as a total and separately for the three site types, each for spruce, beech, fir, larch, pine, and other broadleaved species. The dataset was analysed using a binary logistic regression. The sf increased with age, dbh, and the spp. Pure spruce stands with high age and high dbh on mountain sites are associated with the highest sf. However, a slight admixture of 25% tree species other than spruce was shown to stabilise the stands significantly. Species other than spruce in a minor admixture to spruce stands were destabilised by the breakdown of spruce stands. For a realistic financial evaluation of forest-stand management, managers should consider the risk of stand failure, and reduce the risk by increasing species admixture in the spruce forest stands

Harmonised projections of future forest resources in Europe

• Key message A dataset of forest resource projections in 23 European countries to 2040 has been prepared for forest-related policy analysis and decision-making. Due to applying harmonised definitions, while maintaining country-specific forestry practices, the projections should be usable from national to international levels. The dataset can be accessed at https://doi.org/10.5061/dryad.4t880qh . The associated metadata are available at https://metadata-afs.nancy.inra.fr/geonetwork/srv/eng/catalog.search#/metadata/8f93e0d6-b524-43bd-bdb8-621ad5ae6fa9