Disney Wilderness Preserve (DSNY)

Disney Wilderness Preserve (DSNY)

Jordan Luongo, Jim Clark

15-16 June 2018

-81.399 W, 28.093 N

Sampling at the DSNY NEON site was facilitated by Guy Fausnaught at NEON and Beatriz Pace-Aldana, the Research Coordinator, plant and GIS specialist at the Disney Wilderness Preserve.  From 15-16 June we installed seed traps and collected data on cone production at three NEON plots: 6, 8, 10.  Tree cover on other plots was too sparse to warrant seed monitoring.

Monthly effective precipitation over the last five years (left) and annual values since 1960 (right). At left are shown summer surpluses in blue and winter deficits in orange. At right are annual anomalies in minimum winter temperature and annual deficit.

Formerly ranchland, the Disney Wilderness Preserve has been restored to Pine savanna under ownership of The Nature Conservancy. Previously, most of the preserve consisted of flatwoods open to cattle and excluded from fire.  Frequent fire and invasive species removal restored the flatwoods/savannahs with more herbaceous groundcover.  Prescribed burning at 3-yr intervals promotes pine savannas, which is interspersed with cypress swamps and some hardwood stands.  TNC is actively managing to minimize invasive species and restore red-cockaded woodpecker to the site.  The dominant slash pine (Pinus elliotii) and longleaf (P. palustris) form a sparse canopy over palmetto (Serenoa repens) and rhizomatous dwarf shrubs, including dwarf live oak (Quercus minima), runner oak (Q. elliottii), blueberry (Vaccinium) and grass species, include wiregrass (Aristida stricta).  We observed a single loblolly pine (P. taeda).  Much of the mesic flatwoods remain saturated from May to September from almost daily afternoon thunderstorms, sometimes short-duration, often high-intensity.

Pine savanna with seed traps at plot 10

Beatriz discussed options for accommodating our seed traps during controlled burns, which can come with limited notice.  She generously offered to facilitate moving traps aside during burns and contacting us on how to redeploy them.

Cone counts supplement mast estimates from seed trap data.  Throughout this site, pines support sparse foliage and cone production.  Female cones fertilized in spring develop over the current and subsequent growing season to release seeds in autumn and winter of the following year. Sparse canopies facilitated direct cone counts, in two cohorts.  Open cones at the time of our visit in 2018 released seeds in winter of 2017.  Consistent with previous convention, we call this the “2017 seed year”.  Fully developed but unopened cones on trees at the time of our visit were initiated in spring 2017 and will release seed beginning in autumn/winter of 2018.  Undeveloped cones were initiated in 2018 and too small to observe from the ground.  From cone counts, it became clear that 2017 was a relatively strong seed year. From sparse unopened cones we expect small seed crops in 2018.

Plot 6 burned this year

On all plots, we mapped all trees within the NEON 40×40 area.  Having been burned the week before our arrival, Plot 6 presented us with blackened soils and stems. Already there was evidence of regrowth of palmetto and grasses.  Despite near complete consumption of understory foliage during the burn, it was clear that palmetto was a dominant species. We installed six seed traps and counted cones on trees.

At the southern end of the site, plot 8 supported a diverse understory beneath a sparse slash pine overstory.  Here again, we installed six seed traps and completed cone counts.

Plot 10 represents palmetto-dominated savanna, with palmetto, several shrub oaks, Vaccinium, and grasses.  The water table was at the surface, but there was no standing water within the plot.  We installed 6 seed traps and counted cones from the three cohorts on trees within 20 m of the plot center.

Maps above show trees sampled by NEON, DUKE, and locations of six seed traps.  USDA species codes are used.