Investigating the resilience of Japan's cool climate forests to past and ongoing climate change

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H06197
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Forest science
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Worth James 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 (30770771)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: forest / climate change / genetic diversity / hybridisation

Outline of Final Research Achievements

Overall the study designed the first nuclear and chloroplast genetic markers for Japanese Tsuga species, the temperate T. sieboldii and subalpine T. diversifolia. Range-wide population genetic studies of both species found significant genetic structure with the most diverged populations being the southern and northern most occurrences in both species. Genetic markers also were used to discover the southernmost population of T. diversiolia at Mt Ishizuchi, Ehime Prefecture, which consists of a mixed stand of both species. Although not identified using SSRs, RAD-seq data found evidence for low levels of past hybridisation between the two Tsuga species in southern edge populations.
For Fagus crenata, whole chloroplast genome sequencing revealed two strongly diverged clades, one in western Japan that is closest to Chinese Fagus species and the other in eastern Japan with uncertain affinity. RAD-seq data for 354 samples from four elevational clines has been obtained and analysis is ongoing.

Free Research Field

樹木分子遺伝

Academic Significance and Societal Importance of the Research Achievements

Genetic isolation, hybridisation　and competition with the temperate T. sieboldii threaten the long term viability of southern range-edge populations of the major Japanese subalpine tree Tsuga diversifolia.