The UNF Digital Preserve
Presented by the
UNF Environmental Center
Habitats on the Preserve
The Sawmill Slough Preserve acts as an urban island environment and refuge for native plants and animals as Jacksonville continues to grow. The Preserve contains at least eight different natural communities, in congruence with definitions according to the Florida Natural Areas Inventory (FNAI). This diversity of ecosytems within a relatively small area greatly influences the natural biodiversity of flora and fauna present in the Preserve. Habitats within the Preserve are maintained by restoration efforts such as pest plant control and prescription burns. For instance, the wet prairie community is actively managed with tree thinning and fire to promote growth of a variety of orchids and carnivorous plants which are threatened by a closing canopy and competitive exclusion from surrounding vegetation. Threatened longleaf pine and sandhill communities are especially dependent on fire to flourish. Furthermore, sections of the seepage stream system flow through swampy areas and transition into blackwater streams with dark tannin accumulation. This transition may be influenced by rainfall which alters the flow through the system. The Preserve also contains retention ponds of various ages that provide habitat for native fishes, reptiles and amphibians. Fragments of woodlands like this can no longer remain in their natural state without management. Recreation, pollution from neighbors, pest plants and reduction of burning all help degrade the space.
High Pine and Scrub
- Sandhill: xeric upland consisting of deep sand substrate; frequent fire (1-3 years); savannah of widely spaced longleaf pine and/or turkey oak with wiregrass understory.
- Wet Flatwoods: seasonally inundated flatland with sand substrate; frequent fire (2-4 years for grassy composition, 5-10 years for shrubby composition); closed to open pine canopy with grassy or shrubby understory; slash pine, pond pine, gallberry, fetterbush, sweetbay, cabbage palm, wiregrass, toothache grass.
- Mesic Flatwoods: mesic flatland with sand substrate; frequent fire (2-4 years); open pine canopy with low shrubs and herbs; longleaf pine and/or slash pine, saw palmetto, gallberry, live oak, wiregrass.
Freshwater Non-Forested Wetlands
- Wet Prairie: saturated and occasionally inundated flatland with sand/clayey sand substrate; frequent fire (2-3 years); treeless, dense herbaceous community with few shrubs; wiregrass, maidencane; cutthroat grass, wiry beaksedges, pipewort, toothache grass, pitcher plants, yellow-eyed grass.
Freshwater Forested Wetlands
- Dome Swamp: seasonally inundated with still water in shallow isolated depression in sand/marl/limestone substrate with peat accumulation toward center; occurring within a fire-maintained community; occasional/rare fire; forested canopy often tallest in center; cypress, tupelo.
- Bottomland Forest: occasionally inundated flatland with sand/clay/organic substrate; usually connected or adjacent to a riverine community; rare or no fire; dense canopy of mixed hardwoods, deciduous or mixed deciduous/evergreen; tuliptree, sweetbay, water oak, sweetgum, diamond-leaved oak, red maple, loblolly pine, spruce pine, white cedar.
- Blackwater Stream: perennial or intermittent/seasonal watercourse characterized by tea-colored water with a high content of particulate/dissolved organic matter derived from drainage through swamps and marshes; generally lacks alluvial floodplain.
- Seepage Stream: upper perennial or intermittent/seasonal watercourse with clear to lightly colored water derived from shallow groundwater seepage.
Sandhill © Chuck Hubbuch
Mesic Flatwoods © Justin Lemmons
Dome Swamp © Justin Lemmons
Bottomland Forest © Justin Lemmons