Back to seedlings: rethinking the slow-fast continuum across tree life stages.

Abstract

Forest dynamics have traditionally been interpreted through the lens of adult trees, yet most mortality occurs during the seedling stage, shaping future forests. A central assumption in ecology is that demographic trade-offs, such as the slow-fast continuum, operate consistently across ontogeny. However, increasing evidence challenges this view. Seedlings experience high pest-driven mortality, strong environmental filtering, and stochastic variation in dispersal and microsite conditions, which can decouple early-life performance from adult demography. We synthesize recent developments suggesting that seedling trade-offs may either reflect a scaled-down version of adult dynamics or diverge into alternative axes, such as the recruitment-stature axis. Recognizing these shifts is important, as climate change is likely to further reshape the regeneration process and alter community assembly in future forests.