Divergent growth patterns and climate constraints of Scots pine across three typical climate types in Eurasia

Global large-scale afforestation is seen as an effective strategy to restore ecosystems and mitigate climate change by sequestering carbon. However, ongoing global warming and hotter droughts have triggered forest dieback, growth decline, and increased mortality in plantations subjected to chronic climate stress. Scots pine (Pinus sylvestris L.) is one of the conifer species with the widest distribution on Earth and has been widely planted across Eurasia under contrasting climatic conditions. Here, we investigated how forecasted climate change may affect Scots pine plantations under Mediterranean conditions in Spain, under temperate-continental climate conditions in Romania, and in the temperate monsoon climate of Northeast China. We used dendrochronology to analyze tree growth and stands’ responses to extreme droughts using resilience indices. Additionally, we inferred the main climate constraints of growth using the Vaganov–Shashkin-Lite (VS-Lite) model. Our results showed that Scots pine in the driest and warmest sites in Spain had lower resistance but exhibited higher resilience, although 36% of planted forests failed to recover within four years. Resilience trends declined during three extreme drought events in the more humid climates of Romania and NE China. Warming-induced droughts negatively impacted growth in Spain, while a warm spring compensated for it and probably advanced the growth onset. The VS-Lite model verified that the radial growth of Scots pine was mainly constrained by soil moisture (69.3%) in dry Spain, especially during the growing season (over 85%), whereas temperature played a more significant role in Romania (54.8%) and NE China (59.9%), highlighting regional differences in climate-growth relationships. By identifying these region-specific constraints, we aim to reduce the uncertainties regarding the future viability of Scots pine plantations. Future studies should refine models by integrating long-term drought impacts and local climate dynamics to improve predictions and better guide forest management strategies across diverse climatic zones.