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