Clarification on changes in the growth pattern of coniferous canopy trees after temporarily blown strong winds

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05732
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Seki Takeshi 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 (40353742)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 上層木 / 林冠木 / エゾマツ / トドマツ / 樹高成長 / 枝 / 樹冠発達 / 強風

Outline of Final Research Achievements

With the recent increase in extreme climatic phenomena, in order to detect the effect of a temporary strong wind, including a typhoon, on the medium-to-long-term growth of trees with no physical scars, the trajectory of the elongation of the top of the trunk and branch axes was investigated for Picea jezoensis and Abies sachalinensis canopy trees in a natural forest in Hokkaido. In the forest in Hokkaido, where a 2004 typhoon caused severe damage to the island, no rapid change in the growth trajectory was detected for the canopy trees investigated. However, in the course of tree growth, including the period before the typhoon, a continuing increase in the density of branches was detected in the top part of tree crowns. Since light conditions for needles are influenced by the density of nearby branches, the increase suggests that a decrease in photosynthetic production continues in the top part of tree crowns.

Free Research Field

森林生態学

Academic Significance and Societal Importance of the Research Achievements

本研究は、気象観測施設から3 km以内に位置する天然林の樹木について過去の成長履歴を復元していることから、天然林の樹木の成長に強風が中長期的に及ぼす影響を予測する上で、気象観測施設のデータを用いた解析方法向上に寄与する。また、先行研究の多くでは樹木の成長履歴復元に幹の肥大成長における情報を用いているが、本研究は風に直面している群落上層での幹の伸長成長および枝の分枝・伸長成長の観点からの予測方法向上に寄与する。研究の過程で得られた、幹の先端付近での枝の混み合いの変化についての結果は、森林群落の上層木の成長予測における構成要素となることから、天然林の中長期的推移を予測する上で有効な情報となる。