Global Quantitative Review of Container Effects on Nursery Growth and Field Survival in Forest Seedlings

Purpose of review Container type, volume, depth, and cultivation density represent key and economically relevant decisions for forest nurseries, as they directly shape seedling traits and outplanting performance. Despite numerous studies, existing knowledge remains fragmented and context-specific, limiting the development of general, evidence-based guidelines. This review examines how these container variables influence seedling morphology in the nursery and outplanting survival across taxonomic plant groups, seedling ages, and planting environments. Recent findings We found that larger container volume and depth increase proportionally more root than shoot growth resulting in reduced shoot-to-root mass ratio (S:R), whereas increasing cultivation density reduces seedling biomass and increases S:R. These patterns are more pronounced in cell containers and in ≤ 1 year-old seedlings. Container depth enhances root development particularly in angiosperms. Larger volume and deeper containers improve outplanting survival, espe- cially in cell containers, in ≤ 1 year-old plants, angiosperms, and in harsher, forest planting sites. Planting site aridity does not modulate the effects of container properties on survival. Interestingly, outplanting survival is influenced by both direct effects of container characteristics and indirect pathways mediated by morphology, which differ between angiosperms and gymnosperms. Summary Container characteristics are major drivers of seedling morphology in the nursery and early field survival. These findings support prioritizing larger containers and cell containers for ≤ 1 year-old stock to optimize performance under harsh planting sites. Increasing container depth promotes larger seedlings by enhancing root growth in large-seeded, taproot- forming angiosperms, whereas survival in gymnosperms appears to be more influenced by cultivation density. This review provides a quantitative basis for improving container selection and nursery decision-making in forest plantings.