Extending effect of a wind disturbance: mortality of Abies sachalinensis following a strong typhoon in a natural mixed forest

ABSTRACT

Strong wind constitutes the major force behind disturbance of northern Japanese forests. Canopy gaps induced by disturbance are responsible for subsequent recovery of the stand (i.e. enhancement of growth and recruitment). There is also a possibility that a sudden change in stand structure, involving significant microclimatic alterations, results in further stand degradation. We therefore examined a hypothesis proposing that wind disturbance causes indirect and delayed negative effects on the demography of Abies sachalinensis, a dominant conifer species of northern Japanese natural mixed forests. Data for all trees in a 3-ha study stand with diameter at breast height ≥10 cm were recorded for over 10 years, including the period of severe wind disturbance induced by Typhoon Songda in 2004. We found that the total amount of dead A. sachalinensis in the post-disturbance period was equivalent to that in the wind disturbance. The mortality of the species was generally high in larger trees. Within 1–2 years immediately after the disturbance, dead trees frequently presented the uprooted form despite there being no record of strong winds, suggesting that the physical influence of the disturbance persisted. Moreover, these dead trees showed spatial association with trees in the surrounding trees that died due to strong wind. In contrast, most A. sachalinensis trees that died 3–8 years later showed growth reduction after the disturbance. We conclude that a strong wind disturbance can have long-term influence on the stand dynamics, during which the possible cause of tree deaths changes gradually from physical damage to physiological stress.

KEYWORDS:

• Sakhalin fir
• demography
• spatial patterns
• windthrow
• Typhoon Songda

Acknowledgements

We sincerely thank K. Yasue for his instruction for the annual ring analysis. Thanks are extended to Y. Ohno, T. Hiura, S. Uemura and M. Kobayashi for their critical advices on this study. We also thank technical staff of the Uryu Experimental Forest, for their assistance in the field work, and members of the Nayoro laboratory (especially T. Inoue, F. Takeuchi, H. Umegane, I. Asada and N. Hyodo) for their valuable supports for this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the research project fund from the Ministry of Education, Culture, Sports, Science and Technology of Japan (No. 26450187 and 26450205).