Patterns of Branch Growth and Death in Crowns of Sakhalin Spruce, Picea glehnii (F. Schmidt) Mast

• Published in: Forests
• Main Authors: Lei Chen, Akihiro Sumida
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2017
• Subjects: branch autonomy; correlative inhibition; growth and death; light intensity; Sakhalin spruce; Sakhalin
• Online Access: https://doi.org/10.3390/f8010026

The development of crown architecture strongly affects tree growth and survival. Growth and death of primary branches (those branching off from the main stem) and secondary branches (those from a primary branch) in the lowest part of the crown were investigated for Picea glehnii in an even-aged plantation. Probability of death of a primary branch decreased as the length between its basal location and the crown base (LCB) increased (p = 0.04), but this probability was not significantly related to the relative photosynthetic photon flux density (rPPFD) above the primary branch (p = 0.18). The probability of producing one or more current-year shoots on a primary branch increased with increasing rPPFD above the primary branch (p = 0.01); however, this probability was unrelated to LCB (p = 0.29). Secondary branches at the distal part of a primary branch produced more current-year shoots and exhibited a lower probability of death than proximal branches (p < 0.01), probably because rPPFD above the distal secondary branches was greater than the proximal branches (p < 0.01). Our results suggest that, while local light conditions are relevant to shoot production and shoot death on a primary branch, the death of an entire primary branch may be related to some morphological attributes concerning the length to the crown base.