Scrub

If you lived here, you'd be home now!  

A Unique Habitat with a Long History

source:  Map of Scrub Regions in Florida

The Florida central highlands, or Florida Ridge comprises some of the oldest land in the state.  It consists of dunes that managed to rise above the seas millions of years ago.  The sand that anchors the flora has always been freely porous, and therefore unable to accumulate a layer of nutrients that characterize lower elevations' more mesic habitats.  The plants that grow in the central ridge are among the most rare and endangered species in the country.  The fact that these isolated dune systems originated so long ago accounts for the surprising variety of plants, and therefore, animals that depend upon them.

Scrub Habitat  (medium gray) - Prices Scrub State Preserve

Source:  https://www.floridastateparks.org/sites/default/files/media/file/Prices%20Scrub%20Trail%20Map%202017_0.pdf

At first glance, a scrub habitat seems an unlikely place to take up residence.  But the scrub as an ecosystem has a distinct beauty only found in places that despite their sparse appearances have evolved to survive and support the unique plants and animals that coexist there.  If you are a reader of Marjorie Kinnan Rawlings, you may be familiar with her book,  “South Moon Under,” set in the central Florida highland scrub and her description of its characters, the people in the last century who learned to live in harmony with the scrub’s natural systems rather than obey the artificial laws of city culture. 

Types of Scrub Systems in the Central Florida Ridge:

Sand Pine Scrub

Plants and animals that live in the sand pine scrub are infrequently subjected to fire, but when fire occurs in this scrub the accumulation of understory plants, most of which are very flammable, will contribute to a raging inferno that ignites the pine crowns.  Plants that are adapted to these fires, such as saw palmettos, have deep rooted defenses that allow them to resprout from the underground after fire cycles. They may live for hundreds of years despite their stunted appearance.  Sand pines are relatively short-lived, but the fire is just what they need to open the many cones they have produced in anticipation of fire-triggered seed germination.

sand pine with cones after fire - photo John Battle

Animals in this scrub are well-adapted to intermittent catastrophic fires.  Rats and reptiles, such as the crowned snake, skinks and lizards exist in the scrub and survive primarily because the gopher tortoise excavates deep underground tunnels that provide other species protection from the fire.  Beetles, ants, crickets and other Insects often live underground but above ground.   Migratory songbirds will use the habitat for shelter from the sun’s heat and as a resting spot after a nocturnal flight.  During spring and fall these animals find seeds from some of the scrub grasses and berries from bushes like the blueberry.  The red cockaded woodpecker takes up residence in living pines.  

Oak Scrub

Sand Live Oak - photo John Battle

In scrub habitat that doesn’t experience the high- temperature fires needed by sand pines to germinate, several species of oak manage to exist:  Chapmans, myrtle, sand live, and scrub can form a mass of stunted trees.  Understory plants include saw palmetto, fetterbush, or sedges.  Some animals are unique to the oak scrub since they utilize the oak products.  The scrub jay makes its nests in the underbrush and eats acorns from the scrub oaks, as well as berries, seeds and small reptiles.  The Florida mouse also lives in scrub oak habitats, devouring the acorns and “subletting” portions of a gopher tortoise tunnel.  The Florida scrub millipede eats the oak leaves, and the Florida mole cricket eats the millipede.  

Sand Post Oak - Photo John Battle

 

Rosemary Scrub

This is the rarest type of scrub and it features unique and rare plants, such as the Florida rosemary scrub.  The rosemary grasshopper and the emerald moth caterpillar use the rosemary scrub as its only food source.  Grey puffy lichens are found in patches in the scrub.  The most telling aspect of this scrub, the large patches of open sand, distinguishes it from the “treed” scrub.  One reason for the open patches is that the rosemary contains chemicals that inhibit other rosemary plants from establishing themselves in the neighborhood.  Real estate is a prime asset in this type of environment, and the rosemary is equipped to defend its territory!

Florida Rosemary Scrub - photo by John Battle

Plant Strategies

Unique species of plants are found disbursed through the scrub habitat.  Some, like the Florida rosemary  have special chemicals that inhibit other plants from growing nearby.  The flowering scrub balm emits chemicals that repel would-be predatory insects.  The plant also has special adaptations to lure its pollinator to its flowers to collect pollen, but prevents the pollen from the same bee from fertilizing its flowers; this ensures the plant only cross-pollinates.  Many scrub plants have unique adaptations that allow them to conserve water despite the porous soil.  

Scrub soils are rich in fungal species.  Some decompose dead plants.  Others connect plant species to each other to share nutrients, or process nutrients into forms that can be taken up by the plants.  Although they are unseen, they are essential to the functioning of all scrub ecosystems.  Lastly, because of the harsh conditions in the scrub, plants have adapted unique survival strategies that are of importance to science, horticulture and medicine.

Lichen - Photo by John Battle

Mammals

There are only a few small mammals that make their home in the scrub.  Deer manage to inhabit these ecosystems by becoming night-grazers; they stay in shady shelters during the day.  Large carnivorous mammals such as the black bear, panther, and bobcat, may pass through but their hunting ranges are elsewhere.  The North Florida Land Trust has a plan to provide a contiguous wildlife corridor between Ocala and Osceola.  When this happens, this large predators will be able to thrive in a range that is adequate for their needs.

Last but not least

The gopher tortoise is a great survivor, and can make its home in any of these habitats.  Its presence in an ecosystem provides a necessary survival affordance to a wide range of animals, making it a priceless keystone species.

Because of the delicate nature of the scrub, ensuring as much of it as possible is protected in a continuous area is the best way to preserve the plants and animals that live there.  And the other animals that merely pass through these areas would not experience mortality associated with human occupation.  In short, the NFLT is planning for YOUR future!  If you are adapted to this habitat you should get in touch with us so that we can help NFLT build the home of your dreams!

Gopher Tortoise Browsing - Photo by Dianne Battle