Development and long-term dynamics of old-growth beech-fir forests in the Pyrenees: Evidence from dendroecology and dynamic vegetation modelling

• Natural and human disturbances in old forests with contrasting management history. Forest dynamics analysed dendroecology a dynamic vegetation model. Persistence dominance of shade-tolerant species under low disturbance rates. Management legacies affect composition structure, increasing fir abundance. induce temporal fluctuations beech Ecological knowledge on long-term forest development has been primarily derived from the study old-growth forests. Centuries have decreased extent temperate Europe altered managed Disentangling effects past climate current is crucial for understanding global change. In this study, we investigated recruitment two Western Pyrenees (Spain) history: an long-untouched forest, both dominated by Fagus sylvatica (European beech) Abies alba (Silver fir). We used dendroecological methods seven plots to analyse growth patterns histories these benchmarked data model ForClim examine natural human-induced development, structure composition. Disturbance regimes differed between forests, but none showed evidence stand replacing disturbances, either or induced. Low rates continuous over last 400 years. contrast, was intensively disturbed 1700–1780, probably logging, lower thereafter. Beech preferentially occurred after more intense despite high shade tolerance fir. Higher abundance than appeared be related its disturbances. closely simulated potential fir, overestimated presence less species. Previously observed local decline may result successional processes logging. Within ?200 years logging cessation, some structural attributes converged towards legacy still affected structure. beech-fir abundance, tendency advanced developmental stages