Summary: This type represents one of two described phases of wet prairie or open savanna which are endemic, or nearly so, to the Apalachicola National Forest. This type has been referred to as the "Verbesina phase" and is presumably drier and found on clayier soils. While both types are dominated by Aristida beyrichiana, this type supports Verbesina chapmanii, a panhandle Florida endemic, and lacks significant amounts of Pleea tenuifolia and Sarracenia species. A rich herbaceous layer is present, among which Ctenium aromaticum is an abundant grass. An emergent layer of Hypericum spp. may be present if fires have been only infrequent. Preliminary data suggest that Muhlenbergia expansa, Lobelia brevifolia, and Fuirena breviseta may be indicative of this type as well.
Environment: According to Clewell (1971), this savanna type occurs on heavy loam soils in contrast to savannas with sandier soils. Soils underlying these sites in northern Florida are poorly drained Ultisols or Aquults. A seasonally high water table is perched near the soil surface during periods of heavy rainfall due to the presence of an argillic horizon which is slowly permeable to downward percolating water. A combination of high clay content and standing water contributes to sparse overstories.
Vegetation: This association is dominated by Aristida beyrichiana and supports a diverse mixture of wetland graminoids and forbs. Sarracenia spp., especially Sarracenia flava and Sarracenia psittacina, as well as Pleea tenuifolia are present but with low relative abundance values (NatureServe unpubl. data). Other species may include Agalinis filicaulis, Aletris obovata, Andropogon mohrii, Bigelowia nudata, Dichanthelium spretum, Eriocaulon decangulare, Fuirena breviseta, Helianthus heterophyllus, Lobelia brevifolia, Lophiola aurea (= Lophiola americana), Muhlenbergia expansa, Rhexia alifanus, Rhynchospora inundata, Rhynchospora latifolia, Rhynchospora macra, Rhynchospora oligantha, Rhynchospora plumosa, and Scleria reticularis. Other species which may be present include Rudbeckia graminifolia, Carphephorus pseudoliatris, Gentiana pennelliana, Calopogon pallidus, Andropogon arctatus, Asclepias viridula, Rhynchospora compressa, Liatris spicata, and Rhexia lutea (A. Schotz pers. comm.).
Comments: This type was originally based on the work of Clewell (1971) who suggested two savanna types on the Apalachicola National Forest, a Verbesina phase of wet savannas occurred on heavy loam soils in contrast to the Pleea phase which was found on sandy surface soils. For unknown reasons, in a later work Clewell (1981) did not recognize this distinction and referred only to "grass-sedge savannahs." This association is characteristic of the Post Office Bay area on Apalachicola National Forest.
Conservation Ranking & Rare Species
GRank: G2 (97-11-22): This saturated herbaceous flatwoods association is found in a restricted range and specific set of habitat conditions. It is a grassy wet prairie which has a very narrow distribution, and is endemic, or nearly so, to the Apalachicola National Forest. Many of the species found here are endemic, or nearly so, to this association. Several examples of this vegetation type are known to have been destroyed, but its current extent (less than 10,000 acres) is thought to be relatively stable. This vegetation is highly dependent on fire, and succession to woody plant dominance takes place when fire is removed. This uncommon community is threatened by alteration of the hydrology (ditching and draining), domestic animal grazing, and alteration of fire regimes through fire exclusion and suppression. These factors, along with land conversion to commercial forest plantations or agriculture, have decreased the occurrence of this type. Prescribed burning, which mimics historic fire seasonality and periodicity, and the maintenance of watershed integrity to ensure seepage conditions are important for management of this community.