Early establishment of spruce (Picea glehnii [Fr. Schm.] Masters) seedlings on disturbed soil with the aim of assisted natural regeneration

ABSTRACT

To examine the potential for natural regeneration of Picea glehnii, seeds and current-year seedlings were evaluated at a scarification site. Three surface-soil treatments of different scarification intensity were used: removed, organic soil was mostly removed from the site; remained, some soil remained at the site; and replaced, the soil was removed but replaced. Seeds were sown in the fall, and samples were collected in the following spring to examine the rot rate by fungi. Germination, mortality, growth, and mycorrhiza formation rate of the seedlings were recorded in the first growing season. The seed rot rate was generally low, and no significant differences among surface-soil treatments were observed. The germination rate was higher in the removed treatment than in the other treatments, but seedling survival was lower, and the final seedling density was similar to that in the replaced treatment. Seedling total weight and ectomycorrhizal formation rate were higher in the replaced treatment than in the removed treatment, suggesting that the higher amount of organic soil at the site led to better growth at least in the first growing season. Correlation analysis indicated that a high soil moisture content associated with the presence of organic soil contributed to survival and growth.

KEYWORDS:

• Germination
• growth and survival
• ectomycorrhiza formation
• pathogenic fungi
• soil scarification

Acknowledgements

We would like to thank scientific editor and two anonymous reviewers for their valuable comments and suggestions. We sincerely thank technical staff of the Uryu Experimental Forest for their assistance in the field work, and members of the Nayoro and Sapporo laboratories of Hokkaido University Forests for their supports for this study. Thanks are extended to Makoto Kobayashi for his critical reading of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.