Terrestrial vegetation monitoring at Timucuan Ecological and Historic Preserve: 2019 data summary—Version 2.0
Authors: Boyle Maxwell , Rico Elizabeth 
Published: February 2022

The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the nationwide Inventory and Monitoring Program of the National Park Service (NPS). The vegetation community vital sign is one of the primary-tier resources identified by SECN park managers, and it is currently conducted on 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks’ natural vegetation. 2019 marks the first year of conducting this monitoring effort on four SECN parks, including Timucuan Ecological and Historic Preserve (TIMU). A total of 23 vegetation plots were established in the park in May and June. Data collected in each plot include species richness across multiple spatial scales, species-specific cover and constancy, species-specific woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches (in)]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Timucuan Ecological and Historic Preserve in 2019. Data were stratified across three dominant broadly defined habitats within the park (Coastal Plain Nonalluvial Wetlands, Coastal Plain Open Uplands and Woodlands, and Maritime Upland Forests and Shrublands) and three land parcels (Cedar Point, Theodore Roosevelt, and Thomas Creek). Noteworthy findings include: A total of 157 vascular plant taxa (species or lower) were observed across 23 vegetation plots, including nine species not previously known from the park. Three plots were located in the footprint of the Yellow Bluff Fire, and were sampled only two weeks following the fire event. Muscadine (Muscadinia rotundifolia), cat greenbrier (Smilax glauca), water oak (Quercus nigra), and swamp tupelo (Nyssa biflora) were the most frequently encountered species in Coastal Plain Nonalluvial Wetland habitat; saw palmetto (Serenoa repens), slash pine (Pinus elliottii), and gallberry (Ilex glabra) were the most frequently encountered species in Coastal Plain Open Upland and Woodland habitat; and Darlington oak (Quercus hemisphaerica), Spanish moss (Tillandsia usenoides), and red bay (Persea borbonia) were the most frequently encountered species in Maritime Upland Forests and Shrublands. There were no exotic species of the Florida Exotic Pest Plant Council list of invasive plants (FLEPPC 2020) observed on any of these plots. Both red bay and swamp bay (Persea palustris) were largely absent from the tree stratum in these plots; however, they were present (occasionally in high abundance) in the seedling and sapling strata across all habitat types. Buckthorn bully (Sideroxylon lycioides)—listed as Endangered in the state of Florida by the Florida Department of Agriculture and Consumer Services (FDACS 2020)—was observed in three Maritime Upland Forest and Shrubland plots. The tree strata in each broadly defined habitat were dominated by the following species: Coastal Plain Nonalluvial Wetlands-loblolly bay (Gordonia lasianthus) Coastal Plain Open Uplands and Woodlands-longleaf pine (Pinus palustris) Maritime Upland Forests and Shrublands-oaks (Quercus sp.) Most stems within the tree strata exhibited healthy vigor and only moderate dieback across all habitat types. However, there was a large amount of standing dead trees in plots within Maritime Upland Forests and Shrublands. Downed woody biomass (fuel loads) were highest in the Cedar Point and Thomas Creek land parcels.