Effects of habitat fragmentation on genetic diversity and reproduction in Fagus crenata populations

2015 Fiscal Year Final Research Report

• Project/Area Number: 25292087
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Forest science
• Research Institution: Nagoya University
• Principal Investigator: TOMARU Nobuhiro 名古屋大学, 生命農学研究科, 教授 (50241774)
• Co-Investigator(Kenkyū-buntansha): HARA Masatoshi 千葉県中央博物館, 生態・環境研究部, 主席研究員 (20250144) ; KODANI Jiro 石川県農林総合研究センター(林業試験場), 森林環境部, 主任研究員 (40450811) ; IDA Hideyuki 信州大学, 学術研究院教育学系, 准教授 (70324217) ; OKADA Mitsuhiro 長野県林業総合センター, 育林部, 主任研究員 (90450816) ; SHIMIZU Kayo 長野県林業総合センター, 育林部, 研究員 (00631714) ; KOYAMA Yasuhiro 長野県林業総合センター, 指導部, 担当係長 (00450817)
• Research Collaborator: INANAGA Michiko 秋田県立大学, 木材高度加工研究所, 特任助教 (30757951)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ブナ / 生育地の断片化 / 小集団 / 孤立 / 遺伝的多様性 / 近親交配 / 結実 / 絶滅リスク

Outline of Final Research Achievements

Habitat fragmentation poses a serious threat to populations through the effects caused by reduced population size and increased isolation. Fagus crenata is the dominant species in cool temperate deciduous broadleaved forests (beech forests) in Japan, which have been fragmented by historical human activities. We studied the effects of habitat fragmentation on genetic diversity and reproduction in F. crenata populations. The sampled small populations showed low genetic diversity within populations, high genetic differentiation, and a high level of inbreeding compared to the sampled large populations. The sterile rate from flowering to fruiting, the proportion of sound seeds, and the germination rate were higher, lower, and lower, respectively, for the small populations than for the large populations. These findings indicate that small population size and population isolation have adverse effects on the persistence of F. crenata populations.

Free Research Field

森林遺伝学