Tracing the origin of Oriental beech stands across Western Europe and reporting hybridization with European beech : implications for assisted gene flow

The benefits and risks of human-aided translocation of individuals within the species range, assisted gene flow (AGF), depend on the genetic divergence, on the rate and direction of hybridization, and on the climate transfer distance between the host and donor populations. In this study, we explored the use of Oriental beech (Fagus sylvatica subsp. orientalis), growing from Iran to the Balkans, for AGF into European beech populations (F. sylvatica subsp. sylvatica) that increasingly suffer from climate warming. Using samples from natural populations of Oriental and European beech and microsatellite loci, we identified 5 distinct genetic clusters in Oriental beech with a divergence (FST) of 0.15 to 0.25 from European beech. Using this knowledge, we traced the origin of 11 Oriental beech stands in Western Europe established during the 20th century. In two stands of Greater Caucasus origin, we found evidence for extensive hybridization, with 18% and 41% of the offspring having hybrid status. Climate data revealed higher seasonality with warmer and drier summers across the native Oriental beech sites in comparison to the planting sites in Western Europe. Accordingly, we found that bud burst of Oriental beech occurred four days earlier than in European beech. Overall, our results suggest that AGF of Oriental beech could increase the genetic diversity of European beech stands and may foster introgression of variants adapted to expected future climatic conditions. Our study showcases the evaluation of the benefits and risks of AGF and call for similar studies on other native tree species

Waldlabor Zürich: Das Reallabor für angewandte Forschung und umfassenden Wissenstransfer zu Waldthemen nimmt Gestalt an

Inmitten der Stadt Zürich entsteht ein großräumig und langfristig angelegtes Reallabor für Wissenstransfer rund um die Themen Waldökosystem und Waldbewirtschaftung. Aus der ursprünglichen Idee eines ,,Kommunikationswaldes“, um der breiten Bevölkerung Wald und Waldbewirtschaftung näherzubringen, entwickelt sich nach und nach eine integrale Plattform. Diese vereint sowohl Forschung, Lehre und Wissenstransfer als auch die waldbezogenen naturwissenschaftlichen, geisteswissenschaftlichen und technischen Disziplinen ‐ und nicht zuletzt die transdiziplinären Stakeholder-Ebenen Forschung, Behörde, Praxis und Öffentlichkeit. Der Ansatz eines iterativen Bottom-up-Prozesses birgt Chancen für die Lösung komplexer Umweltprobleme und stellt gleichzeitig alle Beteiligten vor erhebliche Herausforderungen.ISSN:0940-555

Die Schwarzpappel in der Schweiz: Verbreitung und Verjüngung

ISSN:1664-814

Impacts of climate warming, pollution, and management on the vegetation composition of Central European beech forests

Over the past century, climate warming, nitrogen deposition, acidic rain, widespread disturbance events, adaptive management, and natural stand maturation have substantially altered the composition and structure of forests. However, the absence of historical data on the environment makes it difficult to prove these long-term effects. Ecological indicator values based on plant species characteristics offer a promising approach to detect presumed changes at relevant spatial scales (i.e., site level). In this study, we discerned the shifts in taxa composition of principal Central European beech forests and their associated environmental drivers by integrating three data sources: (1) 254 historical (1937 – 1948) and resurveyed (2019 – 2022) vegetation relevés of beech-dominated forests sites in the Swiss Jura mountains, (2) derived ecological indicator values for vascular plants regarding temperature, soil moisture, micro-climatic conditions, soil nutrients, pH, humus layer, and light availability, and (3) related data on disturbance/management intensity in these forest sites over the past 75 years, categorized as ‘undisturbed’ and ‘disturbed’ sites. We found a significant decrease in alpha diversity (taxa richness per site) on ‘undisturbed’ sites (loss of 7.0 ± 1.48 taxa) but stability on ‘disturbed’ sites (gain of 2.1 ± 5.71 taxa). Both beta (Jaccard dissimilarity) and gamma diversity (overall taxa richness) increased over the study period. The average ecological indicator values per site (EIV¯ s) consistently indicated climate warming impacts on all sites ranging from 390 to 1480 m a.s.l., while effects of acidic rain on soil pH and nitrogen deposition on soil fertility were negligible, except in densely populated lowland forest areas. The EIV¯ s for light and micro-climatic conditions differed between ‘undisturbed’ and ‘disturbed’ sites, indicating darker and more oceanic, and more open and continental conditions, respectively. The decrease in alpha diversity on ‘undisturbed’ sites corresponded primarily with reduced light availability, suggesting that stand maturation is the main driver of taxa loss while climate warming and pollution mainly affected composition rather than taxa richness. In contrast, the rise in beta and gamma diversity likely stems from changes in forest management and disturbance regimes, which have increased structural diversity with various micro-climatic niches enriching the taxa pool. In conclusion, our study demonstrates the ability to differentiate the profound effects of climate warming and pollution agents on forest composition and underscores the critical role of adaptive management in mitigating these impacts. By fostering structural diversity and biodiversity, adaptive management enhances the resilience of forests, enabling them to better adapt to evolving environmental conditions.ISSN:1470-160XISSN:1872-703

Impacts of climate warming, pollution, and management on the vegetation composition of Central European beech forests

Over the past century, climate warming, nitrogen deposition, acidic rain, widespread disturbance events, adaptive management, and natural stand maturation have substantially altered the composition and structure of forests. However, the absence of historical data on the environment makes it difficult to prove these long-term effects. Ecological indicator values based on plant species characteristics offer a promising approach to detect presumed changes at relevant spatial scales (i.e., site level). In this study, we discerned the shifts in taxa composition of principal Central European beech forests and their associated environmental drivers by integrating three data sources: (1) 254 historical (1937 – 1948) and resurveyed (2019 – 2022) vegetation relevés of beech-dominated forests sites in the Swiss Jura mountains, (2) derived ecological indicator values for vascular plants regarding temperature, soil moisture, micro-climatic conditions, soil nutrients, pH, humus layer, and light availability, and (3) related data on disturbance/management intensity in these forest sites over the past 75 years, categorized as ‘undisturbed’ and ‘disturbed’ sites. We found a significant decrease in alpha diversity (taxa richness per site) on ‘undisturbed’ sites (loss of 7.0 ± 1.48 taxa) but stability on ‘disturbed’ sites (gain of 2.1 ± 5.71 taxa). Both beta (Jaccard dissimilarity) and gamma diversity (overall taxa richness) increased over the study period. The average ecological indicator values per site (EIV‾s) consistently indicated climate warming impacts on all sites ranging from 390 to 1480 m a.s.l., while effects of acidic rain on soil pH and nitrogen deposition on soil fertility were negligible, except in densely populated lowland forest areas. The EIV‾s for light and micro-climatic conditions differed between ‘undisturbed’ and ‘disturbed’ sites, indicating darker and more oceanic, and more open and continental conditions, respectively. The decrease in alpha diversity on ‘undisturbed’ sites corresponded primarily with reduced light availability, suggesting that stand maturation is the main driver of taxa loss while climate warming and pollution mainly affected composition rather than taxa richness. In contrast, the rise in beta and gamma diversity likely stems from changes in forest management and disturbance regimes, which have increased structural diversity with various micro-climatic niches enriching the taxa pool. In conclusion, our study demonstrates the ability to differentiate the profound effects of climate warming and pollution agents on forest composition and underscores the critical role of adaptive management in mitigating these impacts. By fostering structural diversity and biodiversity, adaptive management enhances the resilience of forests, enabling them to better adapt to evolving environmental conditions