Multi-millennial ecological resilience and disturbances of an old-growth beech forest in the Eastern Carpathians

The growing uncertainty about the impacts of climate change and increasing disturbances on terrestrial ecosystems highlights the need to evaluate their resilience. Old-growth forests are particularly vulnerable to these changes. This study explores the dynamics and ecological resilience over the last 2700 years in an old-growth beech forest in the Eastern Carpathians, employing a multiproxy approach integrating pollen analysis, macro charcoal influx, fungal spores, and biomarkers. The research focuses on how vegetation reacted to disturbances (fire, fungal outbreaks, and human-related activities) and its response to these changes. The sedimentary record from Lake Morské oko reveals a stable forest community dominated by beech under low disturbance regimes, characterised by fires and fungal outbreaks. However, an increase in human impact around 1150 cal yr BP, shown by macro-charcoal influx and coprophilous fungi spores, introduced grazing and fire practices that shifted forest composition towards stress-tolerant and light-demanding species like birch and hazel. Despite the forest's resilience and partial recovery following reduced disturbances, modern pressures, such as climate change, fires, and prolonged anthropogenic impact, have further shifted the species composition of this community. The findings highlight the high ecological resilience of old-growth forests under low to moderate disturbances while also emphasising their susceptibility to intensified human activity, fires and climate change. This research highlights the importance of conservation strategies that mitigate human pressure and prioritise the regeneration of late-successional species such as beech. Findings from this long-term ecological analysis provide direction for the management and protection of these ecosystems against global environmental change.