No Future Growth Enhancement Expected at the Northern Edge for European Beech due to Continued Water Limitation
Authors: Klesse Stefan , Peters Richard L. , Alfaro‐Sánchez Raquel , Badeau Vincent , Baittinger Claudia , Battipaglia Giovanna , Bert Didier , Biondi Franco , Bosela Michal , Budeanu Marius , Čada Vojtěch , Camarero J. Julio , Cavin Liam , Claessens Hugues , Cretan Ana‐Maria , Čufar Katarina , de Luis Martin , Dorado‐Liñán Isabel , Dulamsuren Choimaa , Espelta Josep Maria , Garamszegi Balazs , Grabner Michael , Gricar Jozica , Hacket‐Pain Andrew , Hansen Jon Kehlet , Hartl Claudia , Hevia Andrea , Hobi Martina , Janda Pavel , Jump Alistair S. , Kašpar Jakub , Kazimirović Marko , Keren Srdjan , Kreyling Juergen , Land Alexander , Latte Nicolas , Lebourgeois François , Leuschner Christoph , Lévesque Mathieu , Longares Luis A. , del Castillo Edurne Martinez , Menzel Annette , Merela Maks , Mikoláš Martin , Motta Renzo , Muffler Lena , Neycken Anna , Nola Paola , Panayotov Momchil , Petritan Any Mary , Petritan Ion Catalin , Popa Ionel , Prislan Peter , Levanič Tom , Roibu Catalin‐Constantin , Rubio‐Cuadrado Álvaro , Sánchez‐Salguero Raúl , Šamonil Pavel , Stajić Branko , Svoboda Miroslav , Tognetti Roberto , Toromani Elvin , Trotsiuk Volodymyr , van der Maaten Ernst , van der Maaten‐Theunissen Marieke , Vannoppen Astrid , Vašíčková Ivana , von Arx Georg , Wilmking Martin , Weigel Robert , Zlatanov Tzvetan , Zang Christian , Buras Allan 
Published: October 2024

With ongoing global warming, increasing water deficits promote physiological stress on forest ecosystems with negative impacts on tree growth, vitality, and survival. How individual tree species will react to increased drought stress is therefore a key research question to address for carbon accounting and the development of climate change mitigation strategies. Recent tree‐ring studies have shown that trees at higher latitudes will benefit from warmer temperatures, yet this is likely highly species‐dependent and less well‐known for more temperate tree species. Using a unique pan‐European tree‐ring network of 26,430 European beech (Fagus sylvatica L.) trees from 2118 sites, we applied a linear mixed‐effects modeling framework to (i) explain variation in climate‐dependent growth and (ii) project growth for the near future (2021–2050) across the entire distribution of beech. We modeled the spatial pattern of radial growth responses to annually varying climate as a function of mean climate conditions (mean annual temperature, mean annual climatic water balance, and continentality). Over the calibration period (1952–2011), the model yielded high regional explanatory power (R2 = 0.38–0.72). Considering a moderate climate change scenario (CMIP6 SSP2‐4.5), beech growth is projected to decrease in the future across most of its distribution range. In particular, projected growth decreases by 12%–18% (interquartile range) in northwestern Central Europe and by 11%–21% in the Mediterranean region. In contrast, climate‐driven growth increases are limited to around 13% of the current occurrence, where the historical mean annual temperature was below ~6°C. More specifically, the model predicts a 3%–24% growth increase in the high‐elevation clusters of the Alps and Carpathian Arc. Notably, we find little potential for future growth increases (−10 to +2%) at the poleward leading edge in southern Scandinavia. Because in this region beech growth is found to be primarily water‐limited, a northward shift in its distributional range will be constrained by water availability.