Abstract Detail

Ecological Section

Spiegel, Kimberly S. [1], Leege, Lissa M. [1].

Impacts of Laurel Wilt Disease on Redbay (Persea borbonia) Population Structure and Forest Communities in the Coastal Plain of Georgia, USA.

Laurel wilt disease, a fungal vascular wilt disease vectored by the non-native redbay ambrosia beetle (Xyleborus glabratus), has caused mortality of redbay (Persea borbonia) in the coastal plain of Georgia, USA, since 2003. This recently introduced disease is spreading 30-100 km/year and little research has been done to study its impacts on redbay population structure and forest communities. Healthy and impacted populations of redbay and their associated communities were compared in five sites infested with laurel wilt disease and three un-infested sites in five counties in GA, USA. Tree layer was sampled in 8-10 randomly selected 10x10 m plots. Shrub layer was sampled in 4-5 2x2 m plots randomly selected within tree plots, and herb layer was sampled in 1x1 m plots nested in each shrub layer plot. Our research showed that only 8% of redbay trees >3 cm DBH were alive in infested sites, compared to 80% of trees alive in control sites. Live redbay trees had 2.1 times greater average DBH in control sites. Dead primary tree stems had 2.9 times more average stump sprouts per tree in infested sites. Importance values (IV) of redbay at the tree layer were approximately 5 times greater in control sites. In contrast, importance values of redbay were 2 times greater at the shrub layer and 1.6 times greater at the herb layer in infested sites. Photosynthetically active radiation (PAR) was 4.8 times greater at infested sites due to loss of redbay canopy. Laurel wilt disease impacted trees >3 cm DBH which resulted in lower IVs at the tree layer. Higher IVs at the shrub and herb layer are evidence of regeneration in the understory due to increased light availability and the number of stump sprouts generated at dead primary stems. Laurel wilt disease has affected populations of redbay and forest communities in Georgia, and future research may show further shifts in population and community structure.

Broader Impacts:

1 - Georgia Southern University, Biology, P.O. Box 8042, Statesboro, GA, 30460, USA

Keywords:
Persea borbonia
laurel wilt disease
redbay.

Presentation Type: Oral Paper:Papers for Sections
Session: 21
Location: 552A/Convention Center
Date: Monday, August 2nd, 2010
Time: 4:00 PM
Number: 21002
Abstract ID:122