State 1
Xeric Pine Sandhill WOODLAND / FOREST: intact native ground cover

See Community Phase Narratives

Community 1.1
Longleaf Pine Sandhill WOODLAND: uneven aged overstory, well developed herbaceous groundcover

Figure 11. Phase 1.1 Reference community: Longleaf pine sandhills of the northern LRU 154-1

Figure 12. Phase 1.1 Reference community: Longleaf pine sandhills of the southern LRU 154-2 (along the Lake Wales Ridge)

The pine canopy of the Northern variant of Phase 1.1 consists of widely spaced mature longleaf pines (P. palustris) intermixed with patches of regenerating longleaf pine seedlings and saplings. The uneven aged structure is typical of woodlands dominated by long-lived species with erratic but synchronous acorn production over large areas (Platt et al. 1988). Typical Phase 1.1-North pine stands are mosaics of even-aged longleaf pine “cohorts”, with dense patches of pine seedlings distributed in canopy gaps (Platt et al. 1988, Noel et al. 1998). Bare mineral soil and abundant light are required for longleaf pine seed germination, and these conditions are often present in canopy gaps immediately following fire. Midstory vegetation of Phase 1.1-North is generally sparse, consisting of patches of oaks, notably turkey oak (Quercus laevis) and sand live oak (Q. geminata). Other small statured oaks are often present, although usually in low abundance under conditions of frequent fire. These species include: myrtle oak (Q. myrtifolia), Chapman’s oak (Q. chapmanii) and bluejack oak (Q. incana). Sand post oak (Q. margaretta), an oak common in other sandhill communities, is notably infrequent compared to other sandhill communities of Florida (Carr et al. 2010). Chapman’s, myrtle and sand live oaks are able to persist for long periods in the ground cover in spite of frequent fires common in the reference site condition. These oak species have clonal life forms which allow horizontal clonal growth via rhizomes, and deep root systems (Abrahamson 1984). Groundcover vegetation of Phase 1.1-North sandhills is dominated by perennial bunch grasses which form a matrix of mostly continuous cover. Numerous plant species are common in the interstitial spaces between grass tussocks (Appendix 2.1). Estimates of Phase 1.1 species richness for the Northern LRU (154.1) are: 68 species /1000 m2 (Carr et al. 2010), and 59 species /400 m2 (ESI field work estimates: n=10, range= 32-87 species). Most ground cover plant species are sparsely distributed grasses and forbs, although low growing sub-shrubs are also significant (Carr et al. 2010; Appendix 2). Wiregrass (Aristida stricta var. beyrichiana) is a ubiquitous dominant bunchgrass in Phase 1.1 groundcover. Other common bunchgrasses include lopsided indiangrass (Sorghastrum secundum), little bluestem (Schizachyrium scoparium var. stoloniferum), pineywoods dropseed (Sporobolus junceus) and other bluestem species (Andropogon ternarius var. ternarius, A. gyrans var. gyrans). The southern variant of Phase 1.1 sandhills (LRU 154.2) differs from the northern variant in species composition and stand structure, as well as in natural disturbance dynamics. These distinctions are well documented in the literature, and Phase 1.1-South sandhills are variously referred to as: scrubby high pine, scrubby sandhills, high pine, turkey oak barrens, and southern ridge sandhills (Abrahamson et al. 1984, Myers and Ewel 1990, Myers and White 1998, USFWS 1999, Corogin 2008). 154-2 yellow sands sandhills differ in stand composition, with South Florida Slash pine (P. elliottii var. densa) replacing longleaf pine as the dominant canopy tree. Furthermore, 154-2 sandhills have more shrub cover in the midstory and ground cover, and less herbaceous cover (Abrahamson et al. 1984; Myers and White 1987, Reinhart and Menges 2004). Clonal scrub oaks (myrtle and Chapman’s oaks) and saw palmetto (Serenoa repens) are common and persistent in southern sandhills, in spite of frequent fire (Myers and White 1987). Florida scrub hickory (Carya floridana) and garberia (Garberia heterophylla), two Central Florida endemic shrubs, are abundant in southern sandhills, further distinguishing this community from the northern variant. Similarly, some grass species are common in the southern sandhills while uncommon or absent in 154-1, including pinescrub bluestem (Schizachyrium niveum) and corkscrew threeawn (Aristida gyrans). Furthermore, these sandhills provide habitat for numerous plant species which are narrowly endemic to the Lake Wales Ridge region (see Appendix 3). Ecological dynamics of Phase 1.1 sandhills are intrinsically linked to fire regimes, as frequent fire is necessary for perpetuation of this plant community. Estimates of pre-European settlement fire regimes for yellow sands sandhills vary between the northern and southern regions of MLRA 154. Presettlement fires of the northern sandhills (154-1) were frequent and relatively predictable; fire return intervals are predicted the order of three to four per decade (Jose et al. 2006, Platt 1999, Robbins and Myers 1992, Myers and White 1987). Fire regime of southern Phase 1.1 sandhills were more variable, having been estimated at once every 1 to 10 or 1 to 15 years (Myers 1990, Menges 1999, Reinhart and Menges 2004 ). The higher shrub and palmetto abundance, coupled with lower herbaceous cover in 154-2 sandhills affect the greater volatility of native fire regimes (Reinhart and Menges 2004). Other natural disturbances contribute to the ecological dynamics of Phase 1.1. Hurricanes and severe storms affect woody stand structure directly, and may impart indirect effects via changes in light availability and available fuels. In addition, storm damage may promote the uneven-aged structure of longleaf pine stands, via blow downs and increased mortality of mature trees. Lightning caused mortality of longleaf pines occurs frequently. Insects and pathogen infestation may kill pines, and on occasion may affect large stands of pines (i.e. southern pine beetle outbreaks, see Ecological Dynamics section).

Community 1.2
Longleaf Pine Sandhill WOODLAND: mature overstory, patchy scrub oaks, patchy native ground cover

Figure 13. Phase 1.2 Longleaf Pine Sandhill Woodland

Figure 14. Phase 1.2 Longleaf Pine Sandhill Woodland

Phase 1.2 resembles Phase 1.1 in species composition and overstory stand structure. Longleaf pine is the dominant canopy species, and mature longleaf pines are widely spaced throughout and basal area is similar to that of Phase 1.1. However, longleaf pine regeneration is diminished as a result of fire suppression, and the associated unavailability of bare ground and open conditions. Altered fire regimes promote accumulation of pine needles and thickening of surface litter and duff layers which in turn hinders longleaf pine seed germination (Varner et al. 2007). Conversely, oaks and other hardwoods increase in abundance in Phase 1.2, effectively “out competing” young longleaf pines for space and light and becoming prominent in the midstory and ground cover. Seedlings of the more shade tolerant and fire intolerant sand pine (P. clausa) may colonize in Phase 1.2 if seed source is available. Similar to Phase 1.1, the northern and southern Phase 1.2 variants may differ in dominant canopy pine species (longleaf pine vs. south Florida pine) and midstory composition. Similar to longleaf, south Florida slash regeneration is linked to post-fire conditions, and mature pines are fire tolerant (although less so than longleaf pine). Compared to the reference site condition, oak abundance of Phase 1.2 is higher. Species of oaks depend on geography and propagule source. In the Northern LRU Phase 1.2, turkey, bluejack and sand live oaks are prominent in the midstory. In addition to these oaks, Florida scrub hickory (C. floridana) and saw palmetto are also a prominent in Southern Phase 1.2 midstory. Sand pine may be present in Phase 1.2 sandhills depending on the availability of seed source. Mature pines of Phase 1.2 may have increased susceptibility to insect and pathology mortality, which is aggravated by higher pine density and hardwood encroachment (Palik and Pederson 1996). In addition, fuel accumulations from needle drop and hardwood growth exacerbate fire intensity, which in turn leads to higher pine mortality (Varner et al. 2007). Herbaceous ground cover is sparser and more patchily distributed in Phase 1.2 compared to Phase 1.1. Although the species composition of the ground cover remains similar, shifts in relative species abundances occur in response to increased hardwood encroachment and litter/duff accumulation (Myers 1985; Myers and White 1987). Species richness of Phase 1.2 is lower (mean spp /400 m2 = 44, range: 37-50, n=6; NRCS data 2013), reflecting sparser distribution of herbaceous plant populations due to fire suppression.

Community 1.3
Mixed Longleaf Pine - (Sand Pine) - Oak FOREST: no longleaf regeneration, patchy oak colonization, reduced herb cover

Figure 15. Phase 1.3 Mixed pine-oak Forest

Phase 1.3 describes Longleaf Pine Sandhill Woodlands following long periods of fire suppression (more than 10 years) or longer term alteration of native fire regimes (i.e. decades with occasional fire; fire return interval greater than 5 years). In this phase, increased of woody growth is concurrent with declines in herbaceous ground cover. Transition to pine-oak dominance may be exacerbated by selective logging and/or heavy grazing. Where seed sources are available, shade-tolerant sand pine may colonize. Stand structure in Phase 1.3 is dramatically different from that of Phase 1.1. Denser canopy and sub-canopy conditions attenuate light reaching the forest floor, as well as increases litter and duff accumulation which suppresses natural regeneration. Accordingly, thicker duff layers retain higher organic content and moisture availability (Hiers et al. 2007). Longleaf pine regeneration in Phase 1.3 is non-existent, as the soil surface is inhospitable to seedling germination. The canopy is increasingly even-aged as old longleaf pines die out and are replaced by even-aged sand pine or oak species. Similarly, encroachment of the mid- and under-story by oaks and palmettos is further accelerated from fire suppression, heavy grazing, and available propagule sources. Herbaceous ground cover of Phase 1.3 is significantly reduced in cover and species richness compared to that of Phase 1.1. Many of the small statured, heliophytic and sparsely distributed grass and forb species are extirpated. Patches of herbaceous vegetation remain, particularly in canopy gaps where light does reach the ground. Dominant bunchgrass tussocks may persist in these patches, along with some other remnant herbaceous plants. Small scale species richness is much lower compared to Phase 1.1, reflecting the paucity of small statured plant species relative to woody plant abundance. Increased pine and hardwood density in Phase 1.3 promote pine mortality from insect and pathogen infestations. Mature sand pines are particularly susceptible to wind throw and insect mortality. Furthermore, heavy accumulation of pine and oak leaf litter further suppresses the fine fuels necessary for the spread of low intensity fires.

Pathway 1.1A
Community 1.1 to 1.2

Longleaf Pine Sandhill WOODLAND: uneven aged overstory, well developed herbaceous groundcover

Longleaf Pine Sandhill WOODLAND: mature overstory, patchy scrub oaks, patchy native ground cover

Changes from historic frequent fire to regimes of either infrequent fire or complete fire suppression accelerates hardwood and sand pine encroachment (i.e. transition to Phase 1.2). Continued fire suppression affects transition to Phase 1.3 and eventually States 3 and/or 4. Heavy grazing reduces fine fuels needed to carry frequent low intensity ground fires, which lessens fire spread and accelerates woody plant invasion. In addition, heavy grazing will affect understory vegetation diversity, growth and reproduction, of palatable forbs and grasses. The following drivers contribute to this community pathway: Infrequent fire regimes are generally applied for land management objectives other than natural area conservation and restoration. These include, but not limited to, fuels reduction, forage management, tree plantation management, and site preparation (for crops and plantations). Included here are fire regimes with longer return intervals (> 3 years but < 15 years for LRU 154-1, and > 10 years and < 20 years for LRU 154-2). These prescribed fires generally occur in the dormant season in the southeastern Coastal Plain, although this category of infrequent fire regimes includes dormant and growing season prescribed fires. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. Heavy grazing describes grazing in excess of biomass and compositional recovery capacity of plant species or the plant community. Heavy grazing may affect large shifts in plant composition through loss of populations of palatable plants. Heavy grazing by cattle leads to the decline in palatable grasses such as lopsided indiangrass (Sorghastrum secundum), and causes increases in less palatable forage species (e.g. wiregrass, Aristida stricta var. beyrichiana). The over-utilization of forage species through heavy grazing can be caused under either continuous or rotational grazing systems.

Pathway 1.2A
Community 1.2 to 1.1

Longleaf Pine Sandhill WOODLAND: mature overstory, patchy scrub oaks, patchy native ground cover

Longleaf Pine Sandhill WOODLAND: uneven aged overstory, well developed herbaceous groundcover

Phase 1.2 describes a condition deviated from reference site condition via alteration of historical fire regime. Most plant populations typical of Phase 1.1 sandhills are still present in Phase 1.2, although shifts in relative abundances have occurred. Transition from Phase 1.2 to Phase 1.1 sandhills is possible through the reintroduction of frequent fire, without mechanical or chemical treatments for hardwood reduction. In addition, seasonal and moderate grazing may be reintroduced. Ground cover composition resembling that of Phase 1.1 will occur following one to several prescribed fires, and subsequent restoration of native fire regimes. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1-3 years for the North LRU (154-1) and 1-10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season. Prescribed grazing is the controlled harvest of vegetation with grazing or browsing animals, that are managed with the intent to balance forage production and animal demand to ensure proper utilization of forage species. Management may be continuous or rotational grazing systems, with proper forage/animal balance, composition of forage species will remain stable over extended periods. Regardless of the type of grazing management, deferment of areas or fields for 30 to 90 days during the growing season to allow for seed production, plant recruitment, and mitigation of grazing following other management practices (i.e. prescribed burning, brush management, etc.) is recommended for ground cover restoration.

Pathway 1.2B
Community 1.2 to 1.3

Longleaf Pine Sandhill WOODLAND: mature overstory, patchy scrub oaks, patchy native ground cover

Mixed Longleaf Pine - (Sand Pine) - Oak FOREST: no longleaf regeneration, patchy oak colonization, reduced herb cover

Continued fire suppression will eventually invoke increased hardwood and sand pine encroachment typical of the Phase 1.3. Heavy grazing can further reduce patchy ground cover and fine fuels needed to carry frequent fires, which exacerbates woody encroachment. Drivers that contribute to this transition: Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. Heavy grazing describes grazing in excess of biomass and compositional recovery capacity of plant species or the plant community. Heavy grazing may affect large shifts in plant composition through loss of populations of palatable plants. Heavy grazing by cattle leads to the decline in palatable grasses such as lopsided indiangrass (Sorghastrum secundum), and causes increases in less palatable forage species (e.g. wiregrass, Aristida stricta var. beyrichiana). The over-utilization of forage species through heavy grazing can be caused under either continuous or rotational grazing systems.

Pathway 1.3A
Community 1.3 to 1.2

Mixed Longleaf Pine - (Sand Pine) - Oak FOREST: no longleaf regeneration, patchy oak colonization, reduced herb cover

Longleaf Pine Sandhill WOODLAND: mature overstory, patchy scrub oaks, patchy native ground cover

Reintroduction of frequent low intensity fires (once every 1 to 3 years) promotes the transition of Phase 1.3 to Phases 1.1 or 1.2. However, mechanical or chemical treatments may be required prior to the reintroduction of fire for the purpose of woody biomass reduction. Depending on the density of oak and sand pine encroachment, selective logging can promote the open aspect of Phase 1.1 stand structure, plus open space for re-colonization of herbaceous ground cover and fine fuels to carry low intensity fires. Other mechanical treatments such as chopping or bulldozing may be used to reduced woody biomass; however, treatments indicated here do not include heavy ground disturbance or penetration which would extirpate native plant populations. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. This practice involves selective removal of pines via mechanical methods, usually for the purpose of improving residual stand conditions. These techniques can promote restoration of stand structure and composition to more uneven-aged conditions, and promote natural regeneration of longleaf pine where seed source is available. In the current model, this treatment does not include “high grading” of pine stands, which is a type of selective logging targeting only the most merchantable trees. Prescribed grazing is the controlled harvest of vegetation with grazing or browsing animals, that are managed with the intent to balance forage production and animal demand to ensure proper utilization of forage species. Management may be continuous or rotational grazing systems, with proper forage/animal balance, composition of forage species will remain stable over extended periods. Regardless of the type of grazing management, deferment of areas or fields for 30 to 90 days during the growing season to allow for seed production, plant recruitment, and mitigation of grazing following other management practices (i.e. prescribed burning, brush management, etc.) is recommended for ground cover restoration.

State 2
Xeric Pine Sandhill GRASSLAND or WOODLAND: altered canopy

See Community Phase Narratives

Community 2.1
Cut over pineland: intact native ground cover GRASSLAND (turkey oak barrens)

Figure 16. Phase 2.1 Cut over pineland with intact native groundcover

Phase 2.1 describes conditions following removal of pine and hardwood canopy and midstory of Phases 1.1, 1.2, and to some extent, Phase 1.3. This condition is a separate state in light of the considerable energy and expense needed to restore State 1 stand conditions (uneven-aged pine stands with oak midstory). Notably, State 2 is distinguished as having intact native ground cover vegetation which either resembles Phase 1.1 conditions or is restorable to Phase 1.1 conditions with reintroduction of frequent fire. Importantly, groundcover of State 2 has not been subject to ground penetration, i.e. plowing, tilling, disking, etc. Included in Phase 2.1 are old-fields (i.e. clear-cuts, not fallow crop lands) and native pasture lands. There is no canopy or mid-story stand structure in Phase 2.1. However, pine seedlings may be present depending on availability of seed sources. Ground cover diversity and species richness in Phase 2.1 resembles that of State 1 conditions. Because of the lack of soil tilling or plowing, a matrix of bunchgrasses remains in this phase, including wiregrass (A. beyrichiana). In addition to native perennial species typical of intact ground cover, native “weedy” plant species are often present. Weedy species colonize following clear cutting or other disturbances of the ground surface (not ground penetration). Residual ground cover following clear cutting may be sparse, depending on pre-cut conditions, and weedy species will often colonize the open spaces. The sudden increase in availability of light and moisture may trigger the rapid expansion of native bunchgrasses, particularly those in the genus Andropogon (bluestems). Frequent fire regimes are still intact in Phase 2.1, as periodic fire is necessary to encourage native ground cover persistence. Although grasses can provide the fine fuels necessary for low intensity ground fires, the absence of longleaf pine needle drop may slightly alter fire intensity and behavior.

Community 2.2
Plant pine WOODLAND with intact native groundcover (no till)

Figure 17. Phase 2.2

Phase 2.2 describes a woodland of planted pine (of any species native to Florida) overtopping intact native ground cover. On these excessively drained yellow sands, plant pine species typically include longleaf and sand pine. Although native ground cover remains intact, Phase 2.2 differs from reference site condition in stand structure (and perhaps overstory composition). Planted pines are generally even-aged and evenly spaced. Fire regimes are affected by Phase 2.2 stand structure. Fire behavior may be affected by heavy needle fall typical of densely planted longleaf pine, invoking hotter fires with greater scorch (Grace and Platt 1995). Alternatively, the paucity of fine fuels provided by grasses and other herbs may depress fire spread. Phase 2.2 has native ground cover vegetation, although the frequency and cover of component species will vary according to overstory density. In general, more densely planted stands will have sparser and patchier ground cover. As planted pines mature, light reaching ground level attenuates and heliophytic plants are replaced by more shade tolerant species. However native plant propagules remain in this densely shaded condition, and plant populations will rebound upon canopy opening (the transition to Phase 3.1 has yet occurred in this phase). In addition, weedy herbaceous species may be present in the ground cover.

Pathway 2.1A
Community 2.1 to 2.2

Cut over pineland: intact native ground cover GRASSLAND (turkey oak barrens)

Plant pine WOODLAND with intact native groundcover (no till)

The transition of Phase 2.1 to 2.2 occurs if native pines are planted (without the use of ground penetrating site preparation methods) and frequent fire regime remains intact. Fire maintains woodland conditions by precluding colonization of oaks and other hardwoods. This indicates all prescribed fire regimes (frequent and infrequent) with fire return intervals less than 15 years. This includes hand and mechanical planting of pine seedlings, as well as some methods which allow the natural reseeding from remnant mature pine trees. Typically, slash (P. elliottii) and sand (P. clausa) pine seedlings are densely planted in even aged stands for the purpose of pulpwood and saw timber production. Loblolly pine (P. taeda) may be planted for commodity production but is infrequent on Central Florida yellow sands.

Pathway 2.2A
Community 2.2 to 2.1

Plant pine WOODLAND with intact native groundcover (no till)

Cut over pineland: intact native ground cover GRASSLAND (turkey oak barrens)

The transition from Phase 2.2 to 2.1 can occur via clear-cut logging of canopy pines coupled with continued prescribed fire. Hardwood reduction treatment may be applied to enhance open, herbaceous-dominated ground cover vegetation. This indicates all prescribed fire regimes (frequent and infrequent) with fire return intervals less than 15 years. This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category.

State 3
Pine-Oak FOREST: remnant (non-apparent) herbaceous species population (propagules)

See Community Phase Narratives

Community 3.1
Pine and Xerophytic Oak FOREST: remnant (non-visible) propagules

Figure 18. Phase 3.1

Phase 3.1 describes a mixed pine-oak forest following a long period of fire suppression (on the order of decades without fire). The basis for distinction of this phase is the presence of native ground cover plant populations which may not readily visible. Importantly, this phase describes fire suppressed conditions in the absence of previous major soil disturbance in the form of plowing, tilling or disking. Canopy pines may include any native pine species; however, longleaf and sand pines are typical of fire suppressed pine-hardwood forests on yellow sands. Slash pines (P. elliottii) may be present if they were planted (i.e. successional from Phase 2.2). Canopy oaks may include xerophytic sand live oak, and laurel oak (depending on seed source). Scrub hickory (C. floridana) may be a prominent sub-canopy species in LRU 154-2. Clonal scrub oaks (myrtle and Chapman’s oaks) may be midstory components, depending on propagule availability. Ground cover vegetation is mainly invisible in Phase 3.1. Occasionally, small sprigs of wiregrass or shade tolerant native plants may be visible, particularly in canopy gaps. Despite the apparent absence of ground cover, dormant propagules persist in this phase and are able to recolonize the site following hardwood reduction and reintroduction of fire. Fuel conditions of this phase have dramatically deviated from those of reference site conditions. There are no fine fuels necessary to carry frequent low intensity ground fires. Under typical weather conditions this phase will not burn. Catastrophic wildfire may occur under extreme drought conditions.

State 4
Oak dominated FOREST (not Xeric Hammock – regionally restricted)

See Community Phase Narratives

Community 4.1
Laurel / Live Oak FOREST: native or non-native understory

Figure 19. Phase 4.1 - Laurel / Live Oak Forest with a variable understory

Phase 4.1 is a closed canopy oak forest with no herbaceous ground cover typical of State 1 sandhills. These conditions follow decades of fire suppression, and develop in regions with no source of scrub oaks and sand pine. Within the geographic range of this site, scrub oaks are infrequent or absent in part of the Northern LRU, including much of the Brooksville Ridge, western Alachua and Marion counties (Figure 1). The canopy of Phase 4.1 is dominated by sand live oak (Q. geminata) and laurel oak (Q. laurifolia). Southern live oak (Q. virginiana) may also occur, although this species is not typically common on excessively drained sands. No pines are present in the canopy or understory. Midstory can be dense or open, mainly harboring oak saplings. Under increasingly shady conditions, plant species typical of more mesic forests can invade the understory, such as cabbage palm (Sabal palmetto), cherry laurel (Prunus caroliniana), and greenbriar (Smilax spp.). Any native State 1 ground cover populations are extirpated. In addition, hardwoods typical of native longleaf pine sandhill midstory are absent (i.e. turkey and bluejack oaks, scrub hickory). In the absence of herbaceous ground cover vegetation and pine needles, there is no fine fuel to carry fire. Thick litter duff of hardwood leaves can build up and hold considerable moisture which further suppresses fire ignition. Catastrophic fire would only occur in extreme drought conditions, and result in canopy mortality. Similarly, strong winds and saturating rain associated with hurricanes may affect forest canopy. Laurel oaks have weak root systems (compared to live oaks) and are readily upturned (S. Carr, pers obs.).

State 5
Xerophytic Scrub SHRUBLAND / WOODLAND / FOREST

See Community Phase Narratives

Community 5.1
Early Successional Oak Scrub SHRUBLAND: no overstory, dense oak groundcover

Figure 20. Phase 5.1 : Early Successional Oak Scrub SHURBLAND dominated by clonal oaks, no pine canopy is present

Figure 21. Phase 5.1 : Early Successional Oak Scrub SHURBLAND with abundant sand pine regeneration

Phase 5.1 is characterized by dense growths of scrub oaks (myrtle, Chapman’s, and sand live oaks) and palmetto (saw and scrub palmetto). Canopy is absent in this early successional phase, either because sand pine seed source is unavailable or has not yet colonized the stand following disturbance. The dense establishment of clonal oaks disallows successful colonization of other pine species (longleaf and slash pines) which require abundance light and bare ground for germination. Scrub oaks in this phase reach 3 to 5 feet in height. Herbaceous ground cover of Phase 5.1 is very sparse or completely absent. Where it occurs, ground cover vegetation is patchily distributed. Because of the dominance of a few clonal oaks and paucity of herbaceous species, small scale diversity of Phase 5.1 is very low (average 19 species / 400 m2; range 12-36; n=6: NRCS inventory data 2013). Bunch grasses typical of longleaf sandhills are notably absent (i.e. wiregrass, indiangrass). The diversity and density of herbaceous plants are highest in the years immediately following fire (Menges and Hawkes 1998). Under historical conditions, composition and structure of Phase 5.1 scrub was maintained by fire regimes with return intervals of once every several decades (Myers 1985). Fires do ignite in scrubs in extreme drought conditions, and are typically are very hot and intense. Clonal scrub oaks and palmettos vigorously re-sprout, rapidly re-colonizing the post-fire environment (Abrahamson 1984; Freeman and Kobziar 2011). Recovery of plant diversity and cover occurs within 1 to 5 years following fire, although oak height growth continues for longer periods (Abrahamson 1984; Greenberg 2003; Schmalzer 2003). Non clonal plants, including herbaceous plants, are typically killed in hot fires. Some species which are prolific seeders (such as Florida rosemary), will recolonize post-fire.

Community 5.2
Late Successional Pine - Oak Scrub WOODLAND: mature sand pine overstory

Figure 22. Phase 5.2: Late Successional Pine - Oak Scrub WOODLAND

Figure 23. Phase 5.2: Late Successional Pine - Oak Scrub WOODLAND understory

Phase 5.2 is dominated by dense growths of scrub oaks (Q. myrtifolia, Q. chapmannii, Q. geminata) mixed with palmetto (saw and scrub palmetto), and a few other xerophytic hardwood species. Species composition of Phase 5.2 is very similar to that of Phase 5.1; the main difference between these phases is structural. A canopy of mature sand pines is present in Phase 5.2. Shrub growth is very dense and can reach 10 feet in height, although midstory is generally lower in stature under dense pine canopy. Sand pine canopies are typically even-aged, which is an artifact of seedling colonization following intense fire or logging (Laessle 1958). Sand pine canopies range from sparse to very dense. Herbaceous ground cover of Phase 5.2 is very sparse or absent. With prolonged fire exclusion, patches of open ground occur following death of individual oak clones. These patches often support abundant growth of fire intolerant fruticose lichens (members of the genus Cladonia). Dense surface accumulations of pine needles and hardwood leaves are also typical in the prolonged absence of fire. Phase 5.2 describes the late successional conditions of scrub communities which are adapted to infrequent and intense fires, on the order of two to three fires per century (FNAI 2010; Myers 1985). Coarse, woody fuels of Phase 5.2 only carry fire in extreme weather and drought conditions. If fire return interval is less than the typical lifespan of sand pine (60 to 70 years), fires will trigger regeneration of sand pine from serotinous cones. Sand pine can rapidly reseed post-fire conditions.

Community 5.3
Xeric Hammock FOREST: sand live oak canopy, dense midstory

Figure 24. Phase 5.3 Xeric Hammock FOREST: sand live oak canopy, dense midstory

Phase 5.3 describes late successional vegetation resulting from long term fire suppression of former scrub and xeric longleaf pine sandhill communities (FNAI 2010). This phase represents Xeric Hammock, a natural community type recognized by the Florida Natural Areas Inventory (FNAI 2010). Compositionally, Phase 5.3 closely resembles the scrub phases (Phases 5.1 and 5.2) in that the same clonal oak species are dominant (Q. myrtifolia, Q. chapmannii, Q. geminata). However, this phase is a forest with a closed canopy of sand live oak (Q. geminata), overtopping lower growths of clonal scrub oaks and hardwood seedlings. Sand pine is either absent, having failed to regenerate under densely forested conditions, or is present as a few old emergent trees. The mid- and under-story strata are overwhelmingly dominated by scrub oaks and palmetto. Other shrubs are sometimes irregularly distributed, including rusty staggerbush (Lyonia ferruginea), sparkleberry (Vaccinium arboreum), deerberry (V. stamineum), garberia (Garberia heterophylla), and Florida rosemary (Ceratiola ericoides). Herbaceous ground cover in Phase 5.3 is very sparse or absent. The forest floor is covered with oak leaf litter which holds considerable moisture, creating mesic conditions at ground level and further depressing native herbaceous growth as well as pine germination (FNAI 2010). The Phase 5.2 xeric hammock community itself is fire resistant. Fine fuels are absent, and hardwood litter retains ample moisture which deters fire spread. When fires do occur, they are severe and generally occur in extreme drought conditions. Unlike surface fires, these intense fires consume most standing biomass. In xeric hammocks, clonal oaks quickly re-sprout from extensive rhizome systems, impeding colonization of pines and herbaceous species.

Pathway 5.1A
Community 5.1 to 5.2

Early Successional Oak Scrub SHRUBLAND: no overstory, dense oak groundcover

Late Successional Pine - Oak Scrub WOODLAND: mature sand pine overstory

Fire suppression or very infrequent fire (on the order of once every 50+ years) allows the establishment of sand pine overstory and dense oak midstory, which are typical of Phase 5.2. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. Sand pine can colonize post-fire or fire suppressed conditions if seed source if available. In the absence of seed source, there is no sand pine regeneration.

Pathway 5.2A
Community 5.2 to 5.1

Late Successional Pine - Oak Scrub WOODLAND: mature sand pine overstory

Early Successional Oak Scrub SHRUBLAND: no overstory, dense oak groundcover

Phase 5.2 can transition to Phase 5.1 via natural disturbances of intense fire or strong winds associated with hurricanes or storms which result in sand pine mortality. Clear-cut logging results in canopy reduction which mimics the effects of intense fire and wind. Intense fires can reduce oak cover; however, clonal oaks and palmetto quickly resprout following fire unless extremely hot fire kills underground tissue of oak clones (Abrahamson and Abrahamson 1996). Strong winds are often associated with hurricanes, and occasionally affect large scale landscape disturbance in the Central Florida peninsula. Storm winds of this magnitude occur on the order of several times a century. Sand pine (P. clausa) is particularly susceptible to wind generated damage and mortality. Storm related sand pine mortality on a large scale can convert late successional sand pine scrub and xeric hammock to early successional oak scrub. Strong winds may affect other pine woodlands similarly, although longleaf pine sandhill communities are generally invulnerable to severe hurricane damage, in light of widely spaced and uneven aged longleaf pine stands. This category includes the death of mature sand pines due to natural processes. Sand pines typically occur in even aged populations and are short lived (about 70 years). Sand pines weakened by age, insects, and pathogens typically fall over and release seed from heat sensitive cones. This provides a seed source for sand pine germination under conditions conducive for regeneration. This practice involves selective removal of pines via mechanical methods, usually for the purpose of improving residual stand conditions. These techniques can promote restoration of stand structure and composition to more uneven-aged conditions, and promote natural regeneration of longleaf pine where seed source is available. In the current model, this treatment does not include “high grading” of pine stands, which is a type of selective logging targeting only the most merchantable trees. This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. This driver includes wildland fire such as fires ignited by arson, accidents, or lightning. These fires tend to be infrequent (greater than 20 year return interval) and intense due to high fuels accumulation. These are conditions which accelerate wildlife fire ignition and spread and induce stand-replacing fires. Also included in this category are planned prescribed fires designed to mimic high intensity wildland fires. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Pathway 5.2B
Community 5.2 to 5.3

Late Successional Pine - Oak Scrub WOODLAND: mature sand pine overstory

Xeric Hammock FOREST: sand live oak canopy, dense midstory

In the continued absence of fire (greater than100 years); Phase 5.2 scrub will succeed to Phase 5.3 (Xeric Hammock). This occurs when the larger statured sand live oaks overtop the other scrub oaks creating a closed canopy, coupled with the eventual mortality of canopy sand pines and lack of sand pine regeneration. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from greater than 20 years to many decades.

Pathway 5.3A
Community 5.3 to 5.1

Xeric Hammock FOREST: sand live oak canopy, dense midstory

Early Successional Oak Scrub SHRUBLAND: no overstory, dense oak groundcover

A single catastrophic fire or a series of hot fires could convert Phase 5.3 to early successional scrub (Phase 5.1) if the fire is hot enough to kill the oak overstory. Similarly, other natural disturbances which remove the sand live oak canopy will affect transition to Phase 5.1. These include strong winds associated with hurricanes and storms. Mechanical treatments can affect transition of Phase 5.3 to early successional scrub (Phase 5.1) via canopy reduction. These include clearing of canopy sand live oaks and mechanical chopping to reduce oak cover. This driver includes wildland fire such as fires ignited by arson, accidents, or lightning. These fires tend to be infrequent (greater than 20 year return interval) and intense due to high fuels accumulation. These are conditions which accelerate wildlife fire ignition and spread and induce stand-replacing fires. Also included in this category are planned prescribed fires designed to mimic high intensity wildland fires. This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. Strong winds are often associated with hurricanes, and occasionally affect large scale landscape disturbance in the Central Florida peninsula. Storm winds of this magnitude occur on the order of several times a century. Sand pine (P. clausa) is particularly susceptible to wind generated damage and mortality. Storm related sand pine mortality on a large scale can convert late successional sand pine scrub and xeric hammock to early successional oak scrub. Strong winds may affect other pine woodlands similarly, although longleaf pine sandhill communities are generally invulnerable to severe hurricane damage, in light of widely spaced and uneven aged longleaf pine stands.

State 6
Pine WOODLANDS / GRASSLANDS: restored ecological function / structure

See Community Phase Narratives

Community 6.1
GRASSLAND: SEEDED native ground cover OR mixture native / non-native

Figure 25. Phase 6.1: GRASSLAND: SEEDED native ground cover OR mixture native / non-native

Figure 26. Phase 6.1: GRASSLAND: SEEDED native ground cover OR mixture native / non-native

Phase 6.1 describes a grassland of seeded native gound cover species, OR a mixture of native and non-native herbaceous species. Notably, this phase describes conditions where native propagules have been extirpated following long term fire suppression and/or extensive soil disturbance associated with commodity land uses. In this phase, native ground cover plant populations are purposefully re-established on site. There is no canopy or midstory in this phase, as these have typically been removed to create a grassland. Low growing sprouts of clonal oaks and other hardwoods may persist in the understory, depending on conditions prior to site clearing. Re-introduction of native plant populations, coupled with natural colonization of various weedy native and non-native species, creates herbaceous ground cover in Phase 6.1 which superficially resembles that of reference site conditions. However, the full complement of ground cover composition typical of Phase 1.1 remains incomplete. Perennial grasses and forbs with seed dispersal mechanisms not conducive to colonization of distant and disturbed sites are notably absent (i.e. big seeded species which rely on animal and gravity dispersal, and long lived clonal species). To date, there are no examples of whole scale reintroduction of Phase 1.1 native ground cover on Yellow Sands of Central Florida (S. Carr, pers. obs.). However, there are examples of restored ground cover containing common bunch grasses such as wiregrass and Indiangrass, either seeded or planted, mixed with a partial compliment of predominantly wind-dispersed native and non-native herbaceous species. The current STM does not include pathways from State 6 to State 1 at this time, until techniques are developed for restoration of the whole compliment of reference site native ground cover populations. Phase 6.1 is a grassland community with restored ecological function and restored habitat for some wildlife species. Specifically, restoration of native bunchgrasses provides fine fuels for frequent ground fires and is necessary for restoration of ecological site dynamics. Once established, the bunch grass matrix provides habitat suitable for establishment of other native plant populations, either from artificial seeding or natural recruitment. Phase 6.1 grasslands may provide suitable habitat for ground nesting birds and small mammals (see Wildlife interpretations). Furthermore, the open nature of Phase 6.1 coupled with the availability of native forage provides habitat for the gopher tortoise (Gopherus polyphemus), a terrestrial turtle listed as a threatened species in Florida. Gopher tortoise burrows provide habitat for over 350 commensal species (FWC 2014). Following the establishment of grasslands, fine fuels can carry low intensity ground fires. Fire frequencies of two to three decades (or more frequent) are necessary to discourage woody plant encroachment and maintain herbaceous native populations.

Community 6.2
Planted Pine Uneven - Age WOODLAND with SEEDED native ground cover

Phase 6.2 describes longleaf pine woodlands with “restored ecological structure and function”. Specifically, this phase describes a woodland community that is restored following extirpation of native ground cover via either long term fire suppression and/or ground disturbance. Phase 6.2 is distinguished by the presence of native ground cover which was established via seeding and/or planting. Accordingly, Phase 6.2 woodlands approximate reference site conditions in stand structure and wildlife habitat suitability (i.e. for native songbirds, fossorial animals, game species, etc.). Similar to Phase 1.1, pine woodland structure of Phase 6.2 is uneven-aged, with patches of regenerating pine seedlings and saplings. Depending on precursor conditions, fire frequency and propagule availability, oaks species may be present in the mid- and understory. Oaks may be present in the midstory and/or understory, depending on precursor community conditions and availability of propagule sources. Despite the resemblance of stand structure, Phase 6.2 woodlands do not fully resemble reference site conditions (Phase 1.1) in species composition, relative species abundance or diversity. At the time of this report, there is no known example of restored ground cover vegetation that is specific to Astatula and Candler soils, which approximates the full complement of native species presence and relative abundance. In particular, restored sandhill woodland would need to resemble the small scale diversity of reference site conditions. Although there are examples of ground cover restoration following soil disturbance and fire suppression on Entisols, these examples are in regions other than MLRA 154/155 (i.e. the Florida Panhandle). Dominant ground cover species can be reintroduced to the Site, as is part of Phase 6.2 conditions. In this manner, fine fuels necessary for frequent fires are established, which further promotes the re-colonization of native plant species. Furthermore, reintroduced native ground cover and fire regime maintains open aspect and ground cover necessary for suitable habitat for many rare and endemic animals such as the gopher tortoise, indigo snake, gopher frog, red-cockaded woodpecker, and numerous ground nesting birds. The practice of planting native wiregrass plugs is common on xeric sands of MLRA 154, particularly on public and private lands managed for conservation and endangered species habitat (A. Barkdoll, pers. comm.). Wiregrass planting is often preceded by mechanical and/or chemical site preparation to reduce dominance of non-native and weedy ground cover vegetation. After a single growing season, ground cover of mainly planted wiregrass is sufficient to carry a ground fire (D. Printiss, pers. comm.). In addition to wiregrass, other native ground cover species may be introduced via seeding (D. Gordon and D. Printiss, pers. comm.). It is possible that populations of most plant species typical of Phase 1.1 could be established over time with repeated seeding and consistent burning. However, as stated above, there is currently no example of this specific to Yellow Sands of Central Florida.

Community 6.3
Planted Pine Uneven – Age WOODLAND with weedy and / or non-native ground cover

Figure 27. Phase 6.3: Planted Pine Uneven – Age WOODLAND with weedy and / or non-native ground cover

Similar to Phase 6.2, this phase describes restored pine stand structure with ground cover suitable for spread of frequent fires. This difference in this phase is the composition of the ground cover. Phase 6.3 ground cover can be a mixture of non-native grasses and weedy native/non-native species. This condition particularly describes old pastures or fallow fields that have been managed for uneven age pine structure for wildlife habitat. Ground fires are possible in these conditions, but do not mimic the fire behavior and intensity of native ground cover fuels. Phase 6.3 longleaf pine woodlands approximate the uneven-aged structure and density of State 1 sandhill conditions, with longleaf pine regeneration present to some degree. Midstory oaks may be present depending on previous site conditions and propagule availability. Phase 6.3 ground cover consists of non-native and/or weedy native plant species. Often, non-native pasture grasses dominate the ground cover, including bermudagrass (Cynodon dactylon), and bahiagrass (Paspalum notatum). In addition, weedy native and non-native species are typical of disturbed sites, such as bluestems (Andropogon spp.), dog fennel (Eupatorium capillifolium), Natal grass (Melinis repens), torpedograss (Panicum repens), etc.

Pathway 6.1A
Community 6.1 to 6.2

The transition from Phase 6.1 to Phase 6.2 requires pine planting and continued application of prescribed fire. In this transition, pines are planted and managed to eventually resemble Phase 1.1 woodland stand structure: an uneven aged mixture of pines. Although any native pine species (except sand pine) can be managed for this reason, longleaf pines are best suited for uneven aged stand structure on these excessively drained yellow sand soils. Frequent prescribed fire is necessary to perpetuate the ground cover established in Phase 6.1. This includes hand and mechanical planting of pine seedlings, as well as some methods which allow the natural reseeding from remnant mature pine trees. Typically, slash (P. elliottii) and sand (P. clausa) pine seedlings are densely planted in even aged stands for the purpose of pulpwood and saw timber production. Loblolly pine (P. taeda) may be planted for commodity production but is infrequent on Central Florida yellow sands. This includes hand and mechanical planting of longleaf pine seedlings, as well as methods which promote natural reseeding from remnant mature longleaf pine trees. Prescribed burning for site preparation and post-planting management is generally linked to this practice. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season.

Pathway 6.2A
Community 6.2 to 6.1

Transition to Phase 6.1 can occur if canopy pines are removed, either from clear-cut logging or natural disturbances including catastrophic fire, extremely strong winds, and pine mortality due to insects. This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Strong winds are often associated with hurricanes, and occasionally affect large scale landscape disturbance in the Central Florida peninsula. Storm winds of this magnitude occur on the order of several times a century. Sand pine (P. clausa) is particularly susceptible to wind generated damage and mortality. Storm related sand pine mortality on a large scale can convert late successional sand pine scrub and xeric hammock to early successional oak scrub. Strong winds may affect other pine woodlands similarly, although longleaf pine sandhill communities are generally invulnerable to severe hurricane damage, in light of widely spaced and uneven aged longleaf pine stands.

Pathway 6.2B
Community 6.2 to 6.3

Phase 6.2 can transition to Phase 6.3 under conditions that encourage the replacement of native ground cover with weedy and/or non-native species. Land management practices include over-grazing, seeding of pasture grasses, invasion of non-native species (not including invasion by noxious plant species such as Cogongrass as described by transition to State 6). Similarly, reduction of fire frequency (or fire suppression) may encourage colonization of non-native or weedy plant species. This condition describes grazing in excess of biomass and compositional recovery capacity of plant species or the plant community. Heavy grazing may affect large shifts in plant composition through loss of populations of palatable plants. Heavy grazing by cattle leads to the decline in palatable grasses such as lopsided indiangrass (Sorghastrum secundum), and causes increases in less palatable forage species (e.g. wiregrass, Aristida stricta var. beyrichiana). The over-utilization of forage species through heavy grazing can be caused under either continuous or rotational grazing systems. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. Invasive plant species will colonize natural xeric sandhill and scrub, as well as successional and cultural states, including abandoned crop and grove lands, clearings and old fields. In particular, there are four species common to Central Florida Yellow sands which are recognized by the Florida Exotic Pest Plant Council as “Category 1” species: lantana (Lantana camara), natal-grass (Melinis repens), ceasar’s weed (Urena lobata) and cogongrass (Imperata cylindrica). These invasive species displace native populations and change plant community dynamics and ecological functions. Cogongrass is a highly clonal species which forms dense naturalized populations that extirpate local native plant populations. Furthermore, cogongrass is rapidly expanding in geographic and environmental range in the southeastern Coastal Plain, and is difficult and expensive to eradicate.

Context dependence. Heavy Intensive Grazing, Site Prep (ground penetration), Fire Suppression (or very infrequent non-catastrophic fire [more than 20 yr. return interval]), Invasion of Noxious Non-Native Plant Species

Pathway 6.3A
Community 6.3 to 6.1

Planted Pine Uneven – Age WOODLAND with weedy and / or non-native ground cover

GRASSLAND: SEEDED native ground cover OR mixture native / non-native

The transition from Phase 6.3 to 6.1 occurs when pine canopy is removed, either via mechanical means (clear-cut logging) or natural disturbance (catastrophic fire, wind, pine mortality from insect attack). In addition, transition to Phase 6.1 may involve planting of native ground cover species and increased fire frequency. Non-native and undesirable vegetation may need to be controlled in preparation for native ground cover planting. Site preparation may involve chemical treatments targeting undesirable herbaceous or woody plants. Mechanical treatments such as disking or tilling may be applied to prepare a seed bed for planting native species. This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Strong winds are often associated with hurricanes, and occasionally affect large scale landscape disturbance in the Central Florida peninsula. Storm winds of this magnitude occur on the order of several times a century. Sand pine (P. clausa) is particularly susceptible to wind generated damage and mortality. Storm related sand pine mortality on a large scale can convert late successional sand pine scrub and xeric hammock to early successional oak scrub. Strong winds may affect other pine woodlands similarly, although longleaf pine sandhill communities are generally invulnerable to severe hurricane damage, in light of widely spaced and uneven aged longleaf pine stands. Large scale pine mortality is caused by periodic epidemics of insect infestation. The southern pine beetle is the most common insect responsible for large scale mortality of southern pine species.

Pathway 6.3B
Community 6.3 to 6.2

Transition from Phase. 6.3 to 6.2 involves treatments for native ground cover establishment, without removal of overstory pines. This category includes practices for native ground cover restoration which involve re-introduction of native plant seed or other propagules. Mechanical and chemical applications may be required for site preparation and seedling establishment. In cases where the ground cover is dominated by exotic grasses, frequent herbicide or fire treatment may be necessary. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. This includes all treatments which target invasive plant populations for the purpose of eradication or containment. Invasive plant control is often a part of natural area restoration, but can also be applied to improve wildlife habitat, rangeland, forestry and croplands. Mechanical treatments such as hand clearing, disking, and raking are generally applied to smaller infestations ( 0.25 acre). Chemical treatments include direct and indirect herbicide applications on small and larger areas. Fire may also control spread of invasive plant populations but is not included in this category.

State 7
Invasive Non-Native Community

See Community Phase Narratives

Community 7.1
Cogongrass; severe infestation of non-native FDACS Category 1 species

Figure 28. Phase 7.1: Cogongrass; severe infestation of non-native FDACS Category 1 species

Phase 7.1 describes a condition where a single noxious non-native species has invaded and dominated the site. In the excessively drained Yellow sands of MLRA 154, by far the most common noxious invasive plant species is cogongrass (Imperata cylindrica; (MacDonald 2004)). This highly clonal grass spreads rapidly by underground rhizomes and windblown seeds, forming dense circular patches which can become very large (on the order of 100’s of acres). Cogongrass grows vigorously in full sunlight and thrives on acidic, nutrient-poor soils and droughty conditions such as those of Astatula and Candler soils (MacDonald 2004). Furthermore, cogongrass is a prolific seed producer, and readily invades following soil disturbances. (Yager, Miller, and Jones 2010). Once clones are established, rapid cogongrass growth will extirpate native ground cover plant populations. In addition to its competitive advantage over native vegetation for space and resources, cogongrass may be allelopathic in some situations (Brook 1989, Bryson and Carter 1993). A cogongrass invested pine stand may have mature pines present, with stand structure resembling that of State 1 or State 6 longleaf pine woodlands. Similarly, cogongrass can occur as pure grasslands or mixed with a few remnant hardwood trees or shrubs. Cogongrass infestations of commodity lands can damage crops directly by yield reduction and suppressed growth from competition for nutrients and moisture, and cause (Seth 1970). Cogongrass is very poor forage (Coile and Shilling 1993, Colvin et al. 1993), and cogongrass invasion lowers the forage quality of pasture lands. Cogongrass is a fire adapted species which burns readily and intensely. Furthermore, it thrives in post-fire conditions where it colonizes rapidly clonally and from seed. Cogongrass fueled fires are up to 20% hotter than natural ground fires of native pinelands (MacDonald 2004). These hot fires may deter any pine or hardwood regeneration. In the Southeastern U.S., cogongrass does not have any natural herbivore enemies, nor any known pathogens.

State 8
Active commodity production or fallow / barren areas: no native plant populations

All Phases of State 8 (except Phase 8.1) describe commodity land uses of the Yellow Sands Xeric Uplands site. Commodity crops common on the xeric sands of this site include a variety of annual and perennial crops, the most notable of which is citrus. Other crops common on excessively drained yellow sands include horticultural ornamentals, vineyards, and some row crops. In the southern portion of MLRA 154 sod farms are occasionally present on these soils. Pine plantations which are managed for community production of pulpwood or saw timber are included in State 8. Longleaf and slash pine are typically grown commercially on these soils. Additionally, improved pastures of bahiagrass (or other sod forming grass species) are included in State 8. All Phases of State 8 describe conditions following ground penetrating soil disturbance, to the degree that native ground cover is mostly absent. Generally these phases are characterized by the complete extirpation of native ground cover populations, including seed banks and dormant propagules, although native weedy species may persist (mostly annual species). Depending on the severity and frequency of ground disturbance, soil profile characteristics in the upper part of the soil may be altered.

Community 8.1
Fallow: post – plowing / tilling, “old field”

Figure 29. Phase 8.1: Fallow abandoned citrus grove

Figure 30. Phase 8.1: Fallow field

Phase 8.1 describes a non-production condition of “fallow fields”, generally following land conversion, or crop or pasture abandonment. Ground cover of this phase includes weedy native and non-native plants. If soils were recently tilled, most plants will be annual, predominantly wind dispersed weeds. If the previous land use was improved pasture or plantation with sod grass, bahia or centipede grass may predominate.

Community 8.2
Planted Pine Plantations: dense even aged, no or weedy ground cover

Figure 31. Phase 8.2 Tree Plantation

Phase 8.2 describes commercial pine plantations. Tree species grown for commodity production on Astatula and Candler sands in Central Florida include slash and longleaf pines. Sand pine is generally not grown for commercial harvest. Pine plantations are usually very densely planted and even aged stands. Mechanical and chemical site preparation generally precedes mechanical planting of pine seedlings. Herbicides are often applied before and after planting to control competing vegetation. Ground cover and midstory vegetation of pine plantations is usually sparse or absent, depending largely on the age of the plantation. The ground is typically covered with needle fall following canopy closure.

Community 8.3
Crop Production: annual and perennial crops

Figure 32. Phase 8.3: Citrus grove

Phase 8.3 describes croplands. Included in this category are annual and perennial croplands (i.e. fruit and ornamental orchards, sod farms, etc). Citrus is the most common perennial community crop of Astatula and Candler soils, mostly confined to the Southern LRU. Other commercial crops of this region include corn, truck crops, ornamental (trees and ferns). Management for agricultural crops includes mechanical and chemical treatments for soil tilling and vegetation manipulations.

Community 8.4
Seeded Pasture: nonnative grasses

Phase 8.4 describes pastures with established non-native turf grasses, which support livestock production, or horse farms. Sod grasses almost completely replace native perennial sandhill species. Some hardwood oak species may persist in the under- and mid-story, depending on the degree of land clearing.

Pathway 8.1A
Community 8.1 to 8.2

Fallow: post – plowing / tilling, “old field”

Planted Pine Plantations: dense even aged, no or weedy ground cover

This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. This includes hand and mechanical planting of pine seedlings. Typically, slash (P. elliottii) and sand (P. clausa) pine seedlings are densely planted in even aged stands for the purpose of pulpwood and saw timber production. Loblolly pine (P. taeda) may be planted for commodity production but is infrequent on Central Florida yellow sands. This includes hand and mechanical planting of longleaf pine seedlings, as well as methods which promote natural reseeding from remnant mature longleaf pine trees. Prescribed burning for site preparation and post-planting management is generally linked to this practice.

Pathway 8.1B
Community 8.1 to 8.3

Fallow: post – plowing / tilling, “old field”

Crop Production: annual and perennial crops

This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Pathway 8.1C
Community 8.1 to 8.4

This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. Prescribed grazing is the controlled harvest of vegetation with grazing or browsing animals, that are managed with the intent to balance forage production and animal demand to ensure proper utilization of forage species. Management may be continuous or rotational grazing systems, with proper forage/animal balance, composition of forage species will remain stable over extended periods. Regardless of the type of grazing management, deferment of areas or fields for 30 to 90 days during the growing season to allow for seed production, plant recruitment, and mitigation of grazing following other management practices (i.e. prescribed burning, brush management, etc.) is recommended for ground cover restoration.

Pathway 8.2A
Community 8.2 to 8.1

Planted Pine Plantations: dense even aged, no or weedy ground cover

Fallow: post – plowing / tilling, “old field”

This phase may occur immediately following land conversion such as plowing or tilling, where the land is left absent form active crop production. Fallow fields may be made fallow following the abandonment of the field / crop. Depending on the previous land use, plants may consist of annual or perennial crops interspersed with weedy species.

Pathway 8.3A
Community 8.3 to 8.1

Crop Production: annual and perennial crops

Fallow: post – plowing / tilling, “old field”

This phase may occur immediately following land conversion such as plowing or tilling, where the land is left absent form active crop production. Fallow fields may be made fallow following the abandonment of the field / crop. Depending on the previous land use, plants may consist of annual or perennial crops interspersed with weedy species.

Pathway 8.4A
Community 8.4 to 8.1

This phase may occur immediately following land conversion such as plowing or tilling, where the land is left absent form active crop production. Fallow fields may be made fallow following the abandonment of the field / crop. Depending on the previous land use, plants may consist of annual or perennial crops interspersed with weedy species.

Transition T1A
State 1 to 2

Removal of native longleaf pine canopy via clear-cut or heavy selective logging will convert State 1 to Phase 2.1 (cutover pineland with native ground cover grassland). As the transition to Phase 2.1 only involves stand alteration, the presence of continuous native ground cover continues to support frequent ground fires. Transition to Phase 2.1 followed by fire suppression accelerates the transition to hardwood dominated shrubland and forest (Phases 5.1, 3.1). Canopy removal under these condition may result in a recovery of ground cover populations as light and nutrients are suddenly available. The following contributes to this Transition: This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season. Infrequent fire regimes are generally applied for land management objectives other than natural area conservation and restoration. These include, but not limited to, fuels reduction, forage management, tree plantation management, and site preparation (for crops and plantations). Included here are fire regimes with longer return intervals (> 3 years but < 15 years for LRU 154-1, and > 10 years and < 20 years for LRU 154-2). These prescribed fires generally occur in the dormant season in the Southeastern Coastal Plain, although this category of infrequent fire regimes includes dormant and growing season prescribed fires.

Transition T1B
State 1 to 3

Continued fire suppression will eventually cause Phase 1.3 to succeed State 3. State 3 represents the site condition after more than 20 years of fire suppression (the length of fire suppression depends on geography, local environmental conditions, and availability of colonizing oak species). This transition is complete when these oaks dominate the mid-story and herbaceous ground cover is not visible (see description for Phase 3.1). Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades.

Transition T1C
State 1 to 7

Cogongrass may invade State 1 depending on seed/propagule availability and the presence of local disturbances. However, the shady conditions of Phase 1.3 may deter cogongrass establishment (MacDonald 2004, Yager et al. 2010). Invasive plant species will colonize natural xeric sandhill and scrub, as well as successional and cultural states, including abandoned crop and grove lands, clearings, and old fields. In particular, there are four species common to Central Florida which are recognized by the Florida Exotic Pest Plant Council as “Category 1” species: lantana (Lantana camara), natal-grass (Melinis repens), ceasar’s weed (Urena lobata) and cogongrass (Imperata cylindrica). These invasive species displace native populations and change plant community dynamics and ecological functions. Cogongrass is a highly clonal species which forms dense naturalized populations that extirpate local native plant populations. Furthermore, cogongrass is rapidly expanding in geographic and environmental range in the southeastern Coastal Plain and is difficult and expensive to eradicate.

Transition T1D
State 1 to 8

Conversion of State 1 to commodity land uses (State 8) generally involves removal of native ground cover via ground penetrating treatments. A number of treatments can be used for this, including disking, racking, plowing and herbicide application. Following conversion, other treatments may include: mowing, site prep, tree, or crop planting, seeding of non-native pasture grasses. Many land conversion activities may contribute to this transition: This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Restoration pathway R2A
State 2 to 1

Phase 2.2 can transition to Phase 1.1 or 1.2 through the restitution of uneven-aged structure of longleaf pine stands and native regimes of frequent low intensity fire. Silvicultural treatments used to manipulate stand structure include selective logging of canopy pines, which creates regeneration space for longleaf pine seedlings. Eventually this practice can produce a mosaic of uneven-aged “cohorts”. If longleaf pine is not present in Phase 2.2, it would need to be reintroduced via logging of existing stand followed by longleaf planting (i.e. via Phase 2.1). This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. Large scale pine mortality is caused by periodic epidemics of insect infestation. The southern pine beetle is the most common insect responsible for large scale mortality of southern pine species. Strong winds are often associated with hurricanes, and occasionally affect large scale landscape disturbance in the Central Florida peninsula. Storm winds of this magnitude occur on the order of several times a century. Sand pine (P. clausa) is particularly susceptible to wind generated damage and mortality. Storm related sand pine mortality on a large scale can convert late successional sand pine scrub and xeric hammock to early successional oak scrub. Strong winds may affect other pine woodlands similarly, although longleaf pine sandhill communities are generally invulnerable to severe hurricane damage, in light of widely spaced and uneven aged longleaf pine stands. This includes hand and mechanical planting of longleaf pine seedlings, as well as methods which promote natural reseeding from remnant mature longleaf pine trees. Prescribed burning for site preparation and post-planting management is generally linked to this practice. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season.

Transition T2A
State 2 to 3

Depending on propagule availability, sand pine and scrub oaks may colonize heavily shaded planted pine woodlands. Fire suppression would encourage the transition to State 3.1 (Pine-oak Forest). Herbaceous ground cover attenuates with continued fire suppression. Eventually, ground cover populations are extirpated and replaced by woody vegetation. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from > 20 years to many decades.

Transition T2B
State 2 to 7

Cogongrass may invade State 2 depending on seed/propagule availability and the presence of local disturbances. Invasive plant species will colonize natural xeric sandhill and scrub, as well as successional and cultural states, including abandoned crop and grove lands, clearings, and old fields. In particular, there are four species common to Central Florida which are recognized by the Florida Exotic Pest Plant Council as “Category 1” species: lantana (Lantana camara), natal-grass (Melinis repens), ceasar’s weed (Urena lobata) and cogongrass (Imperata cylindrica). These invasive species displace native populations and change plant community dynamics and ecological functions. Cogongrass is a highly clonal species which forms dense naturalized populations that extirpate local native plant populations. Furthermore, cogongrass is rapidly expanding in geographic and environmental range in the southeastern Coastal Plain and is difficult and expensive to eradicate.

Transition T2C
State 2 to 8

Conversion of State 2 to commodity land uses (State 8) generally involves removal of native ground cover via ground penetrating treatments. A number of treatments can be used for this, including disking, racking, plowing and herbicide application. Following conversion, other treatments may include: mowing, site prep, tree, or crop planting, seeding of non-native pasture grasses. Many land conversion activities may contribute to this transition: Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Restoration pathway R3A
State 3 to 1

A combination of hardwood reduction and reintroduction of fire can affect succession to Phase 3.1, as long as dormant propagules and off-site seed sources exist and are able to recolonize the site. This sort of “passive” ground cover restoration is thought to be possible only if prior land use precluded ground disturbance such as plowing or disking. Transition from Phase 3.1 to Phase 1.3 may occur with selective logging and hardwood control (mechanical or chemical), especially if pine canopy is retained in an effort to restore stand structure. Reinstitution of frequent fire regimes will facilitate ground cover recovery, and eventually may encourage restoration of Phase 1.1 conditions. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1-3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season. This driver includes wildland fire such as fires ignited by arson, accidents, or lightning. These fires tend to be infrequent (more than 20 year return interval) and intense due to high fuels accumulation. These are conditions which accelerate wildlife fire ignition and spread and induce stand-replacing fires. Also included in this category are planned prescribed fires designed to mimic high intensity wildland fires. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. This practice involves selective removal of pines via mechanical methods, usually for the purpose of improving residual stand conditions. These techniques can promote restoration of stand structure and composition to more uneven-aged conditions, and promote natural regeneration of longleaf pine where seed source is available. In the current model, this treatment does not include “high grading” of pine stands, which is a type of selective logging targeting only the most merchantable trees.

Transition T3A
State 3 to 2

A combination of hardwood reduction and reintroduction of fire can affect succession to Phase 2.1, as long as dormant propagules and off-site seed sources exist and are able to recolonize the Site. This sort of “passive” ground cover restoration is thought to be possible only if prior land use precluded ground disturbance such as plowing or disking. Transition to 2.1 involves total removal of canopy, either by clear-cutting and hardwood reduction, or catastrophic wildfire. Following canopy removal, frequent low intensity fire is necessary to encourage ground cover recovery. Reinstitution of frequent fire regimes will facilitate ground cover recovery, and eventually may encourage restoration of Phase 1.1 conditions. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season. This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. This driver includes wildland fire such as fires ignited by arson, accidents, or lightning. These fires tend to be infrequent (more than 20 year return interval) and intense due to high fuels accumulation. These are conditions which accelerate wildlife fire ignition and spread and induce stand-replacing fires. Also included in this category are planned prescribed fires designed to mimic high intensity wildland fires.

Transition T3B
State 3 to 4

In the continued absence of fire, and the absence of colonizing scrub oaks, a closed canopy forest of laurel oak (Q. laurifolia) and sand live oak can prevail. These forests are more common in the northern LRU (154.1) following decades of fire suppression. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This “driver” (absence of scrub oaks) represents situations where scrub oaks (and other typical scrub plant species) are not available to colonize the site, thus succession in the absence of fire follows an alternative path. The Yellow Sands considered in this site are geographically widespread throughout Central Florida, and occur in regions without scrub oaks (Carr, pers. obs). Other oaks may eventually colonize the site, including water oaks (Quercus nigra), laurel oak (Q. laurifolia) and live oak (Q. virginiana).

Transition T3C
State 3 to 5

In the absence of hardwood reduction and frequent fire, Phase 3.1 will transition either to a scrub shrubland or a closed canopy forest, depending on the influence of infrequent fire and colonization of oak species. The latter also depends on geography. Transition to Phase 5.1 (early successional oak scrub) can follow a high intensity fire which severely reduces pine-oak canopy. In the presence of colonizing scrub oak (myrtle, Chapman’s and sand live oak), low oak scrub will develop. If complete fire suppression continues and scrub oaks are present, late successional scrub may dominate as scrub oaks dominate the midstory suppressing growth of other hardwood and pine species. Shade tolerant sand pine can germinate under these conditions if seed source is present. This driver includes wildland fire such as fires ignited by arson, accidents, or lightning. These fires tend to be infrequent (more than 20 year return interval) and intense due to high fuels accumulation. These are conditions which accelerate wildlife fire ignition and spread and induce stand-replacing fires. Also included in this category are planned prescribed fires designed to mimic high intensity wildland fires. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades.

Transition T3D
State 3 to 8

Conversion of State 3 to commodity land uses (State 8) generally involves removal of native ground cover via ground penetrating treatments. A number of treatments can be used for this, including disking, racking, plowing and herbicide application. Following conversion, other treatments may include: mowing, site prep, tree, or crop planting, seeding of non-native pasture grasses. Many land conversion activities may contribute to this transition: This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Transition T4A
State 4 to 6

The forest canopy of State 4 can be removed via clearcutting and other mechanical and chemical hardwood reduction techniques. If left fallow, weedy herbaceous plants will colonize (Phase 6.1), followed by advantageous hardwoods. Frequent burning may retard reforestation of the site; however, in the absence of fine fuels of native ground cover, reintroduction of ground fires is difficult. Restoration of some elements of native ground cover may be accomplished to transition from Phase 4.1 to Phase 6.1 (with native ground cover). Treatments to affect this transition include canopy removal, mechanical and/or chemical hardwood control, and site preparation in the form of light mechanical chopping and/or burning. Following this, native grasses can be reintroduced to the site via seeding or planting of plugs. Successful establishment of native bunchgrasses (wiregrass, Indian grass) has been observed on Entisols similar to Astatula and Candler, specifically in the Florida Panhandle (TNC, unpublished data). Similarly, other native herbaceous species have been restored via seeding on similar soils in other regions. However, we currently do not know the full potential of ground cover composition restoration using these techniques. Furthermore, we do not have any example of such restoration (from seeding and plantings) specific to these soil types in this MLRA. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season. This category includes practices for native ground cover restoration which involve re-introduction of native plant seed or other propagules. Mechanical and chemical applications may be required for site preparation and seedling establishment. In cases where the ground cover is dominated by exotic grasses, frequent herbicide or fire treatment may be necessary.

Transition T4B
State 4 to 8

Conversion of State 4 to commodity land uses (State 8) generally involves removal of native ground cover via ground penetrating treatments. A number of treatments can be used for this, including disking, racking, plowing and herbicide application. Following conversion, other treatments may include: mowing, site prep, tree or crop planting, seeding of non-native pasture grasses. Many land conversion activities may contribute to this transition: This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Transition T5A
State 5 to 6

State 5 can be converted to Phase 6.1 (grassland of seeded native or mixture native/non-native species). For this, the dense growths of clonal scrub oaks would have to be eradicated through mechanical and chemical means. Clonal oaks are exceptionally difficult to remove, requiring more than just repeated burning (J. Hinchee, pers comm.). Repeated chemical treatments may be necessary to deter re-sprouting. Herbaceous ground cover may be established via seeding or planting, although success of these treatments is unknown (see discussion in previous section). This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season. This category includes practices for native ground cover restoration which involve re-introduction of native plant seed or other propagules. Mechanical and chemical applications may be required for site preparation and seedling establishment. In cases where the ground cover is dominated by exotic grasses, frequent herbicide or fire treatment may be necessary. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category.

Transition T5B
State 5 to 7

Invasion of State 5 by cogongrass (transition to State 7) is possible, particularly following ground disturbance from logging or site preparation. Invasive plant species will colonize natural xeric sandhill and scrub, as well as successional and cultural states, including abandoned crop and grove lands, clearings, and old fields. In particular, there are four species common to Central Florida which are recognized by the Florida Exotic Pest Plant Council as “Category 1” species: lantana (Lantana camara), natal-grass (Melinis repens), ceasar’s weed (Urena lobata) and cogongrass (Imperata cylindrica). These invasive species displace native populations and change plant community dynamics and ecological functions. Cogongrass is a highly clonal species which forms dense naturalized populations that extirpate local native plant populations. Furthermore, cogongrass is rapidly expanding in geographic and environmental range in the southeastern Coastal Plain and is difficult and expensive to eradicate.

Transition T5C
State 5 to 8

Conversion of State 5 to commodity land uses (State 8) generally involves removal of native ground cover via ground penetrating treatments. A number of treatments can be used for this, including disking, racking, plowing and herbicide application. Following conversion, other treatments may include: mowing, site prep, tree or crop planting, seeding of non-native pasture grasses. Many land conversion activities may contribute to this transition: This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Hardwood reduction includes mechanical and chemical treatments designed to reduce hardwood biomass and stem densities. The flush of available resources following hardwood reduction treatments generally favors growth of pines and herbaceous ground cover. Mechanical hardwood reduction treatments include chopping, felling, shearing, “anchor chaining”, and disking. Selective and non-selective herbicides are often used for reduction of hardwoods in the understory and midstory strata. Fire and weather events also affect hardwood reduction, but these are not explicitly included in this category. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Transition T6A
State 6 to 4

State 6 can transition to Phase 4.1 (Oak dominated forest) in the absence of fire and clonal oaks. This state transition is regionally specific to the Northern parts of MLRA 154. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This “driver” (absence of colonizing scrub oaks) represents situations where scrub oaks (and other typical scrub plant species) are not available to colonize the site, thus succession in the absence of fire follows an alternative path. The Yellow Sands considered in this site are geographically widespread throughout Central Florida and occur in regions without proximate scrub oaks (Carr, pers. obs). Other oaks may eventually colonize the site, including water oaks (Quercus nigra), laurel oak (Q. laurifolia) and live oak (Q. virginiana).

Transition T6B
State 6 to 5

State 6 can may be converted to Phase 5.1 (early successional scrub) if scrubs oak species either colonize the site naturally (available propagule source) or are reintroduced via planting. The success of scrub restoration on yellow sands is uncertain (but see Schmalzer et al). If scrub oak clones become established, regime of infrequent fire would be required to maintain early successional habitat. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This refers to the deferment of livestock grazing for a period of greater than one full growing season. Deferment of cattle grazing predominantly benefits grass species. Deferment of goat grazing predominantly benefits “browse” species such as small shrubs and low statue trees, and deferment of sheep grazing predominantly benefits forbs and grass species. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. Reintroduction of scrub oak and other woody species populations typical of Central Florida scrub communities, for the purpose of scrub restoration. Scrub oaks include myrtle oak (Quercus mytifolia), sand live oak (Q. geminata), and Chapman’s oak (Q. chapmannii). Other species include saw palmetto (Serenoa repens), scrub palmetto (Sabal etonia), and fetterbush (Lyonia spp.).

Transition T6C
State 6 to 7

Depending on propagule availability, invasion of cogongrass can affect the transition to State 7. Invasive plant species will colonize natural xeric sandhill and scrub, as well as successional and cultural states, including abandoned crop and grove lands, clearings, and old fields. In particular, there are four species common to Central Florida which are recognized by the Florida Exotic Pest Plant Council as “Category 1” species: lantana (Lantana camara), natal-grass (Melinis repens), ceasar’s weed (Urena lobata) and cogongrass (Imperata cylindrica). These invasive species displace native populations and change plant community dynamics and ecological functions. Cogongrass is a highly clonal species which forms dense naturalized populations that extirpate local native plant populations. Furthermore, cogongrass is rapidly expanding in geographic and environmental range in the southeastern Coastal Plain and is difficult and expensive to eradicate.

Transition T6D
State 6 to 8

Conversion of State 6 to commodity land uses (State 8) generally involves removal of native ground cover via ground penetrating treatments. A number of treatments can be used for this, including disking, racking, plowing and herbicide application. Following conversion, other treatments may include: mowing, site prep, tree, or crop planting, seeding of non-native pasture grasses. Many land conversion activities may contribute to this transition: This includes clear-cut logging natural or planted of pine stands. In MLRA 154, clear-cut logging generally involves mechanical means of cutting, stacking, and hauling logs. Heavy equipment such as feller-bunchers and skidders can affect soil conditions via compaction and ground disturbance. Clear-cutting directly affects plant community composition and function through soil disturbance, alteration of canopy conditions and available resources, such as light and available moisture. Other logging methods that result in significant canopy removal are included under this description, such as seed tree logging. These methods involve removal of the majority of mature canopy pines, with a few residual trees left to serve as seed sources. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Transition T7A
State 7 to 5

Transition from Phase 7.1 to any other State first requires control and reduction of cogongrass. Fire alone will not control spread of cogongrass. Rather, fire stimulates cogongrass growth and seed production. Repeated tillage throughout a growing season may be sufficient to contain cogongrass spread if the infestation is small (i.e. under 0.25 acres). However, this treatment is insufficient and cost ineffective for larger well-established infestations. In these situations, a combination of burning followed by repeated chemical applications has been found effective (Byrd 2007). Two active herbicide ingredients found to affect cogongrass growth are glyphosate and imazapyr (Byrd 2007). If cogongrass control is achieved, planting and site preparation followed by restitution of fire regimes may allow re-establishment of native ground cover and transition to Phase 5.1. This includes all treatments which target invasive plant populations for the purpose of eradication or containment. Invasive plant control is often a part of natural area restoration, but can also be applied to improve wildlife habitat, rangeland, forestry and croplands. Mechanical treatments such as hand clearing, disking, and raking are generally applied to smaller infestations ( 0.25 acre). Chemical treatments include direct and indirect herbicide applications on small and larger areas. Fire may also control spread of invasive plant populations, but is not included in this category. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management. Reintroduction of scrub oak and other woody species populations typical of Central Florida scrub communities, for the purpose of scrub restoration. Scrub oaks include myrtle oak (Quercus mytifolia), sand live oak (Q. geminata), and Chapman’s oak (Q. chapmannii). Other species include saw palmetto (Serenoa repens), scrub palmetto (Sabal etonia), and fetterbush (Lyonia spp.) Prescribed fire (Rx fire) is fire purposefully ignited to accomplish defined land management objectives such as woody fuel reduction and stimulation of herbaceous growth. Fire regimes denoted here are intended to mimic pre-settlement natural fire regimes of frequent, low intensity ground fires with return intervals between 1 to 3 years for the North LRU (154-1) and 1 to 10 years for LRU 154-2 (see Ecological Dynamics section). This driver includes frequent fires in the growing as well as dormant season.

Transition T7B
State 7 to 6

Transition from Phase 7.1 to any other State first requires control and reduction of cogongrass. Fire alone will not control spread of cogongrass. Rather, fire stimulates cogongrass growth and seed production. Repeated tillage throughout a growing season may be sufficient to contain cogongrass spread if the infestation is small (i.e. under 0.25 acres). However, this treatment is insufficient and cost ineffective for larger well-established infestations. In these situations, a combination of burning followed by repeated chemical applications has been found effective (Byrd 2007). Two active herbicide ingredients found to affect cogongrass growth are glyphosate and imazapyr (Byrd 2007). If cogongrass control is achieved, planting and site preparation followed by restitution of frequent fire regimes may allow re-establishment of native ground cover and transition to Phase 6.1. This category includes practices for native ground cover restoration which involve re-introduction of native plant seed or other propagules. Mechanical and chemical applications may be required for site preparation and seedling establishment. In cases where the ground cover is dominated by exotic grasses, frequent herbicide or fire treatment may be necessary. This includes all treatments which target invasive plant populations for the purpose of eradication or containment. Invasive plant control is often a part of natural area restoration, but can also be applied to improve wildlife habitat, rangeland, forestry and croplands. Mechanical treatments such as hand clearing, disking, and raking are generally applied to smaller infestations ( 0.25 acre). Chemical treatments include direct and indirect herbicide applications on small and larger areas. Fire may also control spread of invasive plant populations, but is not included in this category. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Transition T7C
State 7 to 8

Conversion of State 7 to commodity land uses (State 8) generally involves removal of native ground cover via ground penetrating treatments. A number of treatments can be used for this, including disking, racking, plowing and herbicide application. Following conversion, other treatments may include: mowing, site prep, tree, or crop planting, seeding of non-native pasture grasses. Cogongrass control is necessary for transition to commodity land uses. Many land conversion activities may contribute to this transition: This includes all treatments which target invasive plant populations for the purpose of eradication or containment. Invasive plant control is often a part of natural area restoration, but can also be applied to improve wildlife habitat, rangeland, forestry and croplands. Mechanical treatments such as hand clearing, disking, and raking are generally applied to smaller infestations ( 0.25 acre). Chemical treatments include direct and indirect herbicide applications on small and larger areas. Fire may also control spread of invasive plant populations but is not included in this category. Periods of 20 years or more without fire can affect significant changes in vegetation structure and composition. Fire suppression encourages increased growth of oaks and other hardwoods, as well as the attenuation of natural longleaf pine regeneration and native ground cover growth. This driver represents periods of fire suppression from more than 20 years to many decades. This land use practice, as practiced in commodity plantation management, generally proceeds mechanical or hand planting of seedlings. However, site prep treatments may precede planting for natural community restoration, field crop production, and wildlife management. Specific treatments may involve ground penetration and soil disturbance, such as disking, roller chopping, shearing, raking, etc. In general, ground penetration of site preparation for forest management is not as severe as tilling and plowing for crop management.

Transition T8A
State 8 to 5

Transitions among the Phases of State 8 are affected by land use and land conversion practices (i.e. land clearing, raking, disking, planting, chemical treatments). Although not specified in the STM diagram (Figure 5), transitions are possible between all phases. Some transitions involved conversion to the “Phase 8.1” fallow field phase as an intermediary step. Depending on the severity of site and soil disturbances, State 8 phases may be restored to natural or semi-natural conditions, including early successional scrub (Phase 5.1). Transition from State 8 to early successional scrub (Phase 5.1) may involve clearing, site preparation, and chemical control of undesirable non-native vegetation. Of key importance is the establishment of scrub oaks and palmetto, the dominant scrub plant species.

Transition T8B
State 8 to 6

Transitions among the Phases of State 8 are affected by land use and land conversion practices (i.e. land clearing, raking, disking, planting, chemical treatments). Although not specified in the STM diagram (Figure 5), transitions are possible between all phases. Some transitions involved conversion to the “Phase 8.1” fallow field phase as an intermediary step. The transition from State 8 to Phase 6.3 can be achieved by clearing non-native woody vegetation and planting pine. Depending on initial conditions, the midstory and understory would be vegetated with residual pasture or crop species, and/or weedy plants. Chemical and mechanical treatments may be needed to maintain conditions needed for successful pine establishment, coupled with the institution of periodic fire. Transition to Phase 6.2 would involve the additional step of native ground cover vegetation restoration and re-introduction of native fire regimes.

Transition T7C
State 8 to 7

Transitions among the Phases of State 8 are affected by land use and land conversion practices (i.e. land clearing, raking, disking, planting, chemical treatments). Although not specified in the STM diagram (Figure 5), transitions are possible between all phases. Some transitions involved conversion to the “Phase 8.1” fallow field phase as an intermediary step. All phases can transition to State 7 if noxious non-native plants (i.e. cogongrass) colonize the site. Particularly susceptible are State 8 Phases with little or no overstory and ground disturbance.