An alternative of soil scarification treatment for forest restoration: effects of soil replacement

Abstract

We examined an alternative natural regeneration practice with a scarification treatment, in which removed soil is replaced on the scarified area, in northern Japan. The effect of the soil replacement on tree establishment was quite obvious; the basal area of trees, composed mostly of Betula ermanii, in the soil-replaced site was about 150-fold greater than that of the normally treated site. The greater growth rates together with higher density, both of which seemed to be enhanced by improved (i.e., deeper, tender, and nutrient-rich) soil properties, produced the marked difference to the normally treated site. The expected enhancement of species diversity owing to utilizing buried seeds in the replaced soil was not found. The current study revealed that the soil replacement could substantially improve forest restoration management with emphasis on biomass production for large nonwooded sites.

Keywords:

• Betula ermanii
• Natural regeneration
• Site preparation
• Soil properties
• Tree growth

Acknowledgments

We would like to thank anonymous reviewers for their helpful comments and suggestions. We thank the staff of the Uryu Experimental Forest for their assistance in the fieldwork. Thanks are also extended to H. Shibata and M. Noguchi for their valuable suggestions. This study was partly supported by research funds in aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan (no. 14760095, 17580123).