Influence of stand density and canopy structure on the germination and growth of Scots pine (Pinus sylvestris L.) seedlings

Abstract

Since the natural regeneration of Scots pine forests is known to be difficult, the effects of canopy structure and environmental variables such as light on germination, seedling growth, and mortality need to be well understood. The knowledge on the relationships between canopy structure, environmental variables, and seedling growth have been helpful for forest managers to formulate silvicultural prescriptions that enhance seedling recruitment. In this study, the influences of stand basal area (BA) (m2 ha-1), leaf area index (LAI), light transmittance (LT), and height-to-crown base (HCB) on germination and seedling growth were explored in a naturally regenerated Scots pine forest in Kastamonu, Turkey. The number of germinants was observed following germination, and total root-collar diameter (RCD) and height of seedlings were monitored after five growing seasons following germination. BA, LAI, LT, and HCB were also examined to determine which variable has more influence on Scots pine seedlings. All variables (i.e., BA, LAI, LT, and HCB) had significant influence on the total seedling growth over a 5-year period. LT was the most significant predictor for total RCD growth and height growth of Scots pine seedlings. The data support the importance of light transmittance through the canopy, along with vertical canopy structure (i.e., HCB) when considering seedling development under a stand canopy.