Abstract Detail

Ecophysiology

Restoring the Roan: Red Spruce Forest Understory Responses to Canopy Gaps at Roan Mountain, NC.

Red spruce-Fraser fir dominated forests are considered threatened at the southern extreme of their range in the North Carolina Appalachians and are known to support a variety of rare and endemic species. This study explored the effectiveness of different sizes of canopy gaps in boosting seedling and understory growth and recruitment in these forests at Roan Mountain, NC, with the goal of identifying a successful management strategy for red spruce that mirrors historically natural processes. Seedling survival and soil respiration were monitored over the first growing season after gap creation (June-October 2021) to gain insight into gap effects on seedlings and CO₂ exchange. Soil rings, half of which were scarified to mimic squirrel foraging activity, were established in center and edge of five 10m-diameter gaps, five 3.5m-diameter gaps, and four nearby uncut patches. 1x1m quadrat monitoring at the beginning, middle, and end of the growing season revealed a >90% survival rate of red spruce and Fraser fir seedlings in all plots that contained clusters of them, indicating no immediate negative effect of any gap size on seedling health. Preliminary analysis of weekly soil respiration observations indicates that mean soil CO₂ efflux was significantly lower in 10m multi-tree gaps than in either 3.5m single-tree or uncut areas and that edges of multi-tree gaps had significantly higher efflux than gap centers when soil was scarified. Time had strong effects on soil respiration in all cases, with peak efflux occurring from late July through late August in all cases. This information suggests that multi-tree canopy gaps 10m or greater in diameter may have negative effects on root and microbe processes in these forests that diminish toward the gap edge compared to the regeneration already occurring in the understory. Single-tree 3.5m gaps may be the most beneficial management tool for stimulating red spruce and Fraser fir growth with minimal mortality over multiple seasons.

1 - Western Carolina University, Biology, 112 Loch Pointe Drive, Cary, NC, 27518, USA

Keywords:
ecophysiology
restoration
plant ecology.

Presentation Type: Oral Paper
Number: EPH1004
Abstract ID:358
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize,Physiological Section Best Paper Presentation