Delayed plant genetic responses to forest edge dynamics and their conservation implications

Area of Science:

• Ecology
• Evolutionary Biology
• Conservation Genetics

Background:

• Forest dynamics significantly influence understory plant populations.
• Predicting long-term viability and conservation requires understanding genetic responses.
• Broad-leaved enchanter's nightshade (Circaea lutetiana) is a key clonal forest understory species.

Purpose of the Study:

• Investigate genetic extinction debt and colonization credit in Circaea lutetiana across Europe.
• Examine how population size, latitude, and historical forest changes affect genetic diversity.
• Assess the equilibrium of C. lutetiana populations with current forest configurations.

Main Methods:

• Utilized pooled genotype-by-sequencing data from 40 populations.
• Analyzed forest edge and core populations across the European range.
• Correlated genetic diversity metrics with historical forest configuration, population size, and latitude.

Main Results:

• Historical forest configuration significantly shaped current genetic diversity.
• Long-established forest edges showed 9% reduced allelic richness (extinction debt).
• Recently afforested areas exhibited 10% lower allelic richness (colonization credit).

Conclusions:

• Circaea lutetiana populations exhibit lagged genetic responses to forest changes over long periods.
• Population size and connectivity are crucial mediators of genetic diversity, impacting vulnerability.
• Results emphasize the need for history-informed conservation and restoration strategies for forest understory species.