Transcript Sandhill Ecosystems

Sandhill Ecosystems
Sandhill Ecosystems
• Sandhill is a forest of widely spaced pine trees
with a sparse midstory of deciduous oaks and
a moderate to dense groundcover of grasses,
herbs and low shrubs on a xeric environment
• Sandhills, like scrub, are found in dry, upland
areas with sandy soils and sloping terrain
Sandhills
• They occur on the rolling topography and
deep sands of the Southeastern U.S. Coastal
Plain
• These sands are well developed and relatively
infertile
• Due to the poor water retention properties of
the soils and open canopy, temperature and
humidity fluctuate rapidly compared to
closed-canopy forests.
Sandhills
• Only a few large tracts of sandhills still exist in
Florida today; Most are in north and central
Florida (about 754,000 acres state-wide)
• Although sandhill systems have nutrient-poor
soils the open canopy allows plenty of sunlight
to reach the forest floor so a diverse variety of
grasses and other herbaceous plants grow
well in these habitats
Sandhill Ecosystems
• Typical associations of plant species are longleaf
pine, turkey oak, and wiregrass
• In some areas, slash pine may replace longleaf
pine
• The midstory trees and low shrubs can be sparse
to dense, depending on the history of fire in the
area
• Species include turkey oak, bluejack oak, sand
live oak, sand post oak, saw palmetto,
sparkleberry, pricklypear, and gopher apple
• A common vine is the Smilax auriculata
Sandhill Ecosystems
• Greatest plant diversity is in the herbacious
groundcover
• Dominant grasses besides wiregrass are
several species of grasses; in particular,
broomsedge
• Bracken fern is very common as is blazing star,
and goldenrod (Solidago)
Sandhill Ecosystems
• Sandhill is important for recharging the
aquifer because the porous sands allow water
to percolate rapidly with little runoff and
minimal evaporation
• The deep, sandy soils and a lack of near
surface hardpan or water table result in a xeric
environment
• Gopher tortoises often dig burrows that are
10 or 15 feet below the surface of the sandhill
Sandhill Ecosystems
• Sandhill dominated by longleaf pine was once
widespread on well-drained sands throughout
the Southeastern U.S. Coastal plane
• This longleaf pine ecosystem has declined by 98
percent across its range and is considered
critically endangered
• From 1936 to 1995, Florida experienced a 90
percent decline in longleaf pines because those
lands were converted to slash pine development,
as well as agriculture, primarily citrus
Sandhill Ecosystems
• Sandhill provides important habitat for many
rare plants and animals
• Animals include the gopher frog, gopher
tortoise, eastern indigo snake, Florida pine
snake, Eastern Diamondback, red cockaded
woodpecker, American kestrel, Florida mouse,
and Sherman’s fox squirrel
The importance of Fire
• Fire plays a major role in maintaining sandhill
ecosystems
• This habitat requires frequent, low-intensity
fires about every two to five years to minimize
competition and stimulate flowering and seed
germination of many sandhill plants
• Species of both plants and animals increase in
diversity with application of prescribed fires in
areas where fire has long been excluded
The importance of Fire
• Frequent low-intensity ground fires in the
growing season reduce hardwood competition
and perpetuate pines and grasses
– This results in fewer woody shrubs and thickets of
undergrowth
• Wiregrass, one of the most common
groundcover species in sandhills needs the
heat of a summer fire in order to bloom and
reproduce
Community variation
• In the absence of regular fire, the abundance
and density of sandhill shrubs and small trees
such as turkey oak increases, and sand live
oak, laural oak, or sand pine can invade
• Lack of fire may ultimately lead to the
development of a xeric hammock, turkey oak
barrens, or sand pine-dominated sandhill