Monday, August 2, 2010
Exhibit Hall A, David L Lawrence Convention Center
Sarah T. Lumban Tobin1, Debbie L. Miller2 and Mack Thetford1, (1)West Florida Research and Education Center, University of Florida, Milton, FL, (2)West Florida Research and Education Center, University of Florida/Milton Campus, Milton, FL
Background/Question/Methods Woody vegetation increases the stability of barrier islands and provides important services to wildlife and humans. In addition to harsh and variable daily and seasonal environmental conditions, barrier islands in the eastern United States are subject to the brunt of tropical storms. Barrier islands throughout the Gulf of Mexico have recently experienced an increased frequency and intensity of hurricanes, potentially associated with climate change. Altered environmental gradients and disturbance regimes increase the need to understand limitations to woody species regeneration in coastal systems. We evaluated the effect of microsite(swale depression or swale ridge), vegetation cover (absent or present) and seed placement (surface or buried) in caged and uncaged locations on presence and germination eight weeks after placement of
Quercus geminata and
Quercus myrtifolia acorns in association with barrier island ephemeral wetlands (swales). Fifteen acorns were buried or placed on the surface within each microsite, vegetation cover, and cage treatment combination in each of 6 replicate sites for a total of 1440 acorns. We also evaluated the effect of soil moisture (wet or dry), salinity (0,8,15 or 22 ppt) and seed placement (surface or buried) on
Quercus geminata and
Quercus myrtifolia germination
in the greenhouse.
Results/Conclusions There was a high rate of acorn loss in the field; presence of Quercus geminata was 16.7% without cages and presence was influenced by microsite, vegetation and burial. Less than 1% of Quercus myrtifolia was present without cages. Germination of Quercus geminata was 15% of acorns present and was not influenced by microsite, vegetation cover or burial. Germination of Quercus myrtifolia was 75% of acorns present and was marginally increased by burial. Germination of Quercus in the greenhouse was influenced by salinity and burial with salinity 0 ppt having higher germination rates than 8, 15 and 22 ppt salinities and buried acorns having higher germination than acorns placed on the surface of the soil at low salinities. Soil moisture increased germination at higher salinities (15 and 22 ppt). Information on woody plant establishment under various environmental conditions provides insight into consequences of altered environmental gradients and disturbance regimes associated with climate change.
