Demography of scrub plum (Prunus geniculata) at Carter Creek, Lake Wales Ridge National Wildlife Refuge, 2001-2013, in relation to fire and felling

At the Carter Creek unit of the Lake Wales Ridge National Wildlife Refuge, we collected demographic data annually on scrub plum (Prunus geniculata), a federally endangered shrub. We initially selected 903 plants (tagged and GPS'd) distributed among 12 management units in February 2001, a minimum of 65 plants per management unit. We worked with United States Fish and Wildlife Service (USFWS) staff and a crew from The Nature Conservancy (TNC) to impose three management treatments on a unit basis (4 replicate units) in 2001 (finishing in August): control, chain-saw felling of large oaks, and chain-saw felling followed by prescribed burns. The treatments also served as the basis for vegetation sampling and demographic research on other species (Rickey et al. 2013). Beginning in 2001 and continuing through 2008, we collected annual data (in February) on each marked plant, including survival status, life history stage, height, maximum crown diameter, and reproductive structures. We also scoured areas near plants for new seedlings. We subsampled plants from 2009-2012, and then re-censused all plants in 2013. We also noted fire severity in 2001, 2007, and 2009 in four categories for each plant. Analyses through 2007 (Menges and Weekley 2013) showed that scrub plum had extremely high annual survival (98%) but minimal seedling recruitment. Scrub plum had high survival in all four burn treatments, although severely burned plants were more likely to die. Fire benefited scrub plum as plants resprouted vigorously, increased stem numbers post-fire, and had higher flower production 2-3 years after fires. Between fires, plants increased in height and diameter but retained fewer stems. We concluded that chainsaw felling of oaks did not have strong effects on scrub plum and could be a useful management tool, but we also emphasized the primacy of fire as an ecological disturbance and management treatment in this sandhill ecosystem.