Risk assessment of decay on Sakhalin-fir consequent of wounds on stems or roots injured by logging machines

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07861
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Forest science
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Yamaguchi Takehiro 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (00353897)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: トドマツ / 林業機械作業 / 腐朽菌 / 機器・根系損傷 / レンガタケ / カワラタケ / 条件付き推測樹木法

Outline of Final Research Achievements

As the harvest operations using logging machinery are more common, there is concern about decay damage consequent on mechanical wounds to stem or root systems on Sakhalin fir (Abies sachalinensis), a major tree species in Hokkaido, northern Japan. We investigated the advance of decay caused by the wounds on the stem and root system on the fir using a nondestructive decay-detecting device. The rate of decay advance was estimated from the passed years after the wounding. The fungi isolated from the decayed wood were identified. Heterobasidion orientale was the most dominant species within the fungi isolated from the decayed wood. In addition, H. orientale was inoculated into the fir with partly removing the bark on the stem, and the ability of decay advance was estimated. Based on these results, we assessed the risk of decay damage consequent on mechanical wounds by logging machinery. Area of wound was found the most important factor for the advance of decay.

Free Research Field

森林病理学、腐朽菌学

Academic Significance and Societal Importance of the Research Achievements

林業機械によるトドマツ幹・根系の損傷がもたらす腐朽被害に関わる腐朽菌として、北海道内でもレンガタケが多く関与しており最も警戒すべき腐朽菌であること、その他にも多様な腐朽菌が関与していることが明らかとなった。接種試験によりレンガタケの腐朽進展能力を実験的に明らかにすることができた。また、剥皮処理後に接種を行うことでレンガタケやカワラタケの腐朽が格段に進展することが判明し、今後の接種試験に応用できる可能性が示された。これらの結果をもとに腐朽被害発生リスク評価を試みることで、腐朽を低減する作業指針などに利用できる可能性が示唆された。