Legacy of Past Disturbance on Genetic Diversity in Tree Species

A new study from the Forestry and Forest Products Research Institute in Japan examines the impact of past anthropogenic disturbance on the genetic diversity of tree species, with a focus on the Tasmanian palaeoendemic conifer Lagarostrobos franklinii. The research, which was peer-reviewed and published in Heredity, reveals that genetic differentiation is relatively high for conifers, with cryptic divergence between populations geographically close but in differing river catchments likely reflecting postglacial dispersal from distinct Last Glacial refugia and low levels of gene flow.

Key Takeaways:

• The study found that genetic differentiation is relatively high for conifers, with Fst values of 0.113 and 0.143 for nuclear SSR and MIG-seq, respectively.
• Cryptic divergence between populations geographically close but in differing river catchments was observed, likely reflecting postglacial dispersal from distinct Last Glacial refugia and low levels of gene flow.
• Population level genetic diversity was greatest in the core of the range, with no significant correlation with the history of post-colonial human disturbance (i.e., primary vs. non-primary stands).
• A significant decline in allelic richness with increasing elevation was observed, contrary to expectations.
• The study demonstrates that genetic tools can be invaluable in characterizing species-specific impacts of disturbance and guiding conservation efforts.
• The researchers used a novel combination of 8 nuclear SSRs and MIG-seq-based single nucleotide polymorphisms to analyze genetic diversity in 33 populations of L. franklinii.

Statistics:

• 33 populations of L. franklinii were genotyped using 8 nuclear SSRs and MIG-seq-based single nucleotide polymorphisms.
• 871 samples were genotyped using nuclear SSRs.
• 254 samples were genotype using MIG-seq.
• Fst value for nuclear SSR differentiation was 0.113.
• Fst value for MIG-seq differentiation was 0.143.
• Allelic richness declined with increasing elevation.

Sources:

• Forestry and Forest Products Research Institute, Ibaraki, Japan (no date)
• Heredity, 2025 (Springernature, Campus, 4 Crinan St, London, N1 9XW, England)
• NewsRx (https://www.newsrx.com/)
• Cite: NewsRx. Researchers at Forestry and Forest Products Research Institute Release New Data on Science (Last Glacial and Holocene dynamics override post-colonial disturbance in shaping genetic diversity of a heavily exploited palaeoendemic conifer, ...). Science Letter. October 31, 2025; p 2234.