Biological legacies influence seedling survival and growth in post‐fire restoration of Patagonian Nothofagus pumilio forests

High‐severity wildfires increasingly affect the subantarctic forests of southern Patagonia, where fires have left extensive areas with limited natural regeneration in forests dominated by Nothofagus pumilio (lenga). In Torres del Paine National Park, repeated large fires have created degraded landscapes in which seedling establishment is constrained by harsh microclimatic conditions. Since 2012, nucleation‐based reforestation has been implemented across more than 470 ha using planting clusters associated with biological legacies such as shrubs, fallen logs, and standing dead trees. Although these structures are assumed to function as nurse elements, their spatial configuration and relative influence on seedling performance remain poorly quantified. We evaluated how legacy identity, proximity, and lateral coverage influence N. pumilio seedling survival and growth 2 and 5 years after planting. Using microsite‐scale measurements and linear mixed‐effects models, we assessed the effects of legacy structure on survival, maximum height, and cumulative growth. Proximity to shrubs and fallen logs significantly increased survival and growth, particularly within distances of approximately 1.5–3.5 m and under moderate to high lateral coverage. Nuclei dominated by a single substantial legacy performed better than those surrounded by dispersed or structurally mixed elements. Practical implication : Microsite configuration is a key determinant of restoration success. Practitioners can enhance seedling survival and growth in post‐fire subantarctic forests by positioning planting nuclei approximately 1.5–3.5 m from large shrubs or fallen logs, prioritizing microsites dominated by a single structurally substantial legacy over spatially dispersed configuration.