20.500.12556/DiRROS-31916 Divergent growth and wood anatomical responses of European larch and Swiss stone pine to climate variability at alpine treeline ecotones Climate change is reshaping high-elevation forests in the European Alps, with species- and site-specific differences in the climate sensitivity of conifers being increasingly reported in treeline ecotones. However, a detailed understanding of how two dominant and co-occurring species, Larix decidua and Pinus cembra, respond to climate variability at inter- and intra-annual temporal scales and across treeline ecotones with different environmental settings is lacking. To address this gap, we analyzed chronologies of wood anatomical traits (earlywood lumen area, EWLA, and latewood cell wall thickness, LWCWT), tree-ring widths, and basal area increments (BAI) from five treeline ecotone sites across three Alpine regions with differing moisture regimes. We assessed climate-growth correlations, pointer years, long-term growth trends, and interspecific differences in absolute radial growth and wood anatomical traits. Our results show that, next to temperature, precipitation and atmospheric drought (vapor pressure deficit) are important drivers of growth variability. Pointer-year analyses clearly showed the differential response of the two species: growth and wood anatomy of P. cembra strongly depended on moisture, especially at drier sites, while L. decidua responded more consistently to temperature. Growth trajectories diverged between species: L. decidua showed consistently positive BAI, EWLA, and LWCWT trends, whereas P. cembra exhibited site- and trait-dependent positive, stable, or declining growth trends. Generalized additive mixed models indicated that for BAI, these differences could partly be attributed to species-specific climate effects, while effects on EWLA trends were mostly of structural origin for both species. LWCWT trends differed between species and sites despite broadly similar late-season climatic effects, pointing to additional species- and site-specific temporal dynamics. Notably, clear interspecific differences emerged in wood anatomical traits: although both species had a similar mean ring width, L. decidua consistently exhibited larger EWLA and LWCWT. Our findings highlight the contrasting mechanistic and ecological strategies of the two species, i.e., the isohydric, drought-sensitive, conservative P. cembra versus the anisohydric, efficiency-oriented and more temperature-limited L. decidua. Continued warming and intensifying drought may contribute to divergent growth trajectories between mature L. decidua and P. cembra especially in drier areas, with potential implications for future forest composition and growth dynamics in Alpine treeline ecotones. climate change climate-growth relationships earlywood Larix decidua Pinus cembra quantitative wood anatomy podnebne spremembe odnosi med podnebjem in rastjo zgodnji les Larix decidua Pinus cembra anatomija lesa true false true Angleški jezik Slovenski jezik Znanstveno delo 2026-08-18 13:24:54 2026-08-18 13:24:54 2026-08-19 03:46:20 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 18. 8. 2026; str. 1-17 [article no.] ǂ 1813904 Vol. 17 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630*81 1664-462X 10.3389/fpls.2026.1813904 288070915 https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2026.1813904/full 1 7147be34-9af7-11f1-af5a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=49652 fpls-17-1813904.pdf fpls-17-1813904.pdf 1 D2B5A44884D894F81320E9EAE8614467 b27c4ed0cd236123d06e482d480913339bd43a423456df3b6cadbe5f23956b46 8da3f4f0-9af7-11f1-af5a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=49653 Gozdarski inštitut Slovenije 0 0 0