Floristic changes following the chestnut blight may be delayed for decades.

Area of Science:

• Forest Ecology
• Botany
• Conservation Biology

Background:

• American chestnuts and oaks were codominant in Shenandoah National Park before the chestnut blight.
• Previous surveys indicated oaks were replacing chestnuts, with a notable decline in chestnut presence.

Purpose of the Study:

• To resurvey forest composition in White Oak Canyon, Shenandoah National Park, after the loss of American chestnuts.
• To assess long-term changes in forest structure and species abundance over multiple decades.

Main Methods:

• Resurveyed 10 established sites from a 1977 survey in White Oak Canyon.
• Recorded canopy and understory trees, including those growing above remnant chestnut sprouts.
• Compared current forest composition with historical survey data from the 1920s and 1977.

Main Results:

• The forest canopy has changed substantially since 1977, with increased abundance of birch and maple.
• Hemlock populations declined, and oaks became less common in the canopy.
• Early to mid-successional trees have largely replaced oaks and hemlocks.
• Chestnut sprouts have significantly decreased since 1977, likely due to repeated diebacks.
• Chestnut persistence was associated with red oak presence and limited understory competition, while rare in birch/hemlock sites.

Conclusions:

• Forest composition changes following the American chestnut loss may be more profound than previously understood.
• The long-term ecological impact of losing a codominant species like the American chestnut is still being determined.
• Specific microhabitat conditions influence the persistence of remnant American chestnut sprouts.