Bareroot versus container stocktypes: a performance comparison

摘要

This review examines the published work on bareroot and container stocktypes in forest restoration programs. The objective was to define overall trends between these two stocktypes and describe what they mean in terms of available information on their nursery and field performance. Stock quality assessments show bareroot seedlings have larger shoot systems because they are typically grown at lower densities, and in many instances longer timeframes, than container seedlings. Container systems typically produce seedlings having a lower shoot to root ratio and a greater root growth potential, conferring greater drought avoidance potential. However, assessments of stress resistance and nutrition found no conclusive evidence that either stocktype has a performance advantage, other than the container plug acting as a source of water and nutrient storage available for outplanting performance. Bareroot seedlings are more sensitive to handling practices of lifting, storage, transport and planting and these practices can negatively affect their performance. Container seedlings can have a higher level of field survival which is related, in part, to their greater drought avoidance potential, thereby overcoming planting stress. Bareroot and container seedlings have comparable survival rates on sites with minimal planting stress. Once seedlings are established, bareroot and container seedlings can have comparable field performance. In many instances where plant competition is the main limiting site variable, larger sized bareroot and container stocktypes have the best chance for successful stand establishment. The lack of a natural root form and root distribution for both stocktypes is a debated mechanical stability issue, though risks of windthrow have not been consistently demonstrated for either stocktype.