Julia Roberts and Dr. David Vandermast Elon University

Introduction American beech (Fagus grandifolia) Beech gaps Beech bark disease (BBD) Insect-fungal complex (Cryptococcus fagisuga, and Nectria coccinea) Photo by: David Vandermast

Introduction (cont’d) Fungal infection after insect infestation Three phases: Invasions and buildups Small beech trees in aftermath forests Demographics change to adjust Boston in 1929; GRSM in 1993 Permanent plots sampled during summers 2000 and 2008 Photo by: David Vandermast

Purpose of study To understand how beech bark disease is altering the community composition and structure of tree-sized stems in high-elevation beech gaps in the Great Smoky Mountains National Park

Hypotheses 1) Since 2000, BBD will continue to cause the loss of tree-sized (dbh ≥ 10 cm) beech stems as measured by density and basal area (BA) 2) Beech gaps with the highest mortality in 2000 would show evidence of recovery (the development of aftermath forests)

Methods 11 permanent plots in high-elevation forests in GSMNP Identified individual trees using tree “maps” created in 1985 Photo by: David Vandermast

Locations of permanent plots in high-elevation beech forests

Methods (cont’d) Visited 11 permanent plots (total area = 1.39 ha) in high-elevation beech forests Recorded DBH and identity of all living tree (DBH ≥ 10cm) species during summer 2008 Compared results to community composition recorded in summer 2000 Paired Wilcoxon ranked sign tests in Sigma stat 3.1

Results Across all 11 plots, BA declined by 10% and stem numbers declined by 14% (though neither change was statistically significant) Roughly half of all plots gained BA and stems Losses in BA and stems sustained by declining plots were statistically significant as were the gains realized by the plots with increases

Plots that gained stems and BA Five plots that gained stems also gained basal area One plot gained one stem but lost basal area The average gain in stems was 12.4% (p = 0.004) The average gain in basal area was 16.3% (p = 0.03)

Plots that lost stems and BA Five plots that lost stems also declined in basal area As mentioned above, one plot lost BA but gained one stem Average loss of stems was 24.6% (p = 0.004) Average loss of basal area was 43.5% (p = 0.04)

SpeciesRDRBARDRBA Fraser fir Striped maple Sugar maple Buckeye Serviceberry Yellow birch American beech Silverbell0.1 Red spruce Black cherry No. red oak Hemlock Relative densities and basal areas of tree-sized (dbh ≥ 10 cm) stems in 11 high-elevation beech plots

Discussion There continued to be overall declines in BA and stem #s from However, some beech gaps show signs of recovering from BBD Beech forests in GRSM are a mosaic of dying and recovering patches Plots with increasing stem numbers demonstrated the structural and compositional characteristics expected of aftermath forests

Acknowledgments Elon University Honors Program Great Smoky Mountains National Park for license and camping Sarah Galliher, Alexandra Kay – field assistance and moral support!

Questions?