The posted coordinates will bring you to the trailhead of the
Morris Lake Nature Trail. Topsail Hill Preserve is located about 10
miles east of Destin just off US 98 on scenic Highway 30A. The
park map
will take you to the highway 30A entrance. There is a $3 per car
entry fee for the park. From the entrance, take the tram to
Campbell Lake and use the trail system to access the Morris Lake
trailhead. Help keep this fragile dune ecosystem intact by staying
on established trails, not walking on the dunes, and following
Florida State Park rules at all times. The trailhead sign has a box
for an excellent brochure about the walk ahead of you. Reading this
brochure is not necessary to complete the earthcache, but it sure
wouldn’t hurt! Terrain rating was suggested by the rating
system at clayjar.com. Be prepared for 2 ½ miles
through sandy terrain, and bring your sunscreen and water bottle!
Sand dunes are formed when sand settles and accumulates in a
spot which shelters it from the wind. The signature white sand of
the Emerald Coast has its origins in the Appalachian Mountains.
Starting around 25 million years ago, rivers such as the
Appalachicola have been washing the particles south. White sand
like you see here is almost 100% pure quartz. Comparatively, sand
grains are larger than particles of silt and smaller than gravel.
In numbers, “sand” measures from .06 to 2.0 mm,
although the sand here on the Gulf Coasts tends toward the finer
end of that range.
Now that we have the sand, how do we keep it in place to form
dunes? Some types of vegetation offer a sheltered spot for the sand
to collect. In general, dunes tend to grow around communities of
plants that have vast root systems to serve as anchors for the
accumulation of sand. As the plant life grows and the root systems
expand, more sand is deposited, and dunes are formed. As wind blows
more sand to them, the dunes grow larger, the plants thrive, and
new species move in. The sand dunes and the plants that live there
are interdependent. The plants anchor the dunes, and the dunes
provide a habitat for the plants.
Accretion and erosion move sand around to change the appearance
and distribution of sand on a beach. Accretion is a buildup
of sand in an area. Accretion is especially obvious where man-made
structures (like stairs, footbridges, or sign poles) become
partially covered with sand. Conversely, erosion is a loss
of sand in an area. Wind and waves cause gradual erosion, while a
storm may cause rapid erosion. As you walk the trail, you will see
places where the sand has eroded, leaving behind extensive systems
of plant roots where the sand used to be. **You will need to be
on the lookout for an example of erosion so you can take a photo
for the logging requirements below!** When you see something
like this:
you will be able to see the root systems of dune plants which
provide the anchor on which the dune is built. There's a lot of
root hidden under there!
Morris Lake is another interesting feature of the dune system.
Occasionally, the valleys in between sand dunes will form wetlands
or coastal dune lakes. The Florida Panhandle is home to the only
freshwater coastal dune lakes in the United States. Morris Lake is
one of these. When the freshwater lakes in Florida overflow their
basins, they flow to the Gulf of Mexico. When this happens, or when
storms wash large quantities of seawater into the lake, the
composition of the water is altered. The mix of freshwater and
saltwater is called brackish water. This cyclical nature of this
environment allows it to host many diverse species of plant and
animals.
LOGGING REQUIREMENTS: According to Earthcache rules, in
order to claim the find, you must perform an educational task. So,
I ask that you make some observations along the way.
1- Along the trail, you will notice signs that prohibit walking
on the dunes. What three reasons are listed for this rule? (One
such sign is located at N 30° 22.057 W 086° 18.411, but there are
several identical signs along the trail.)
2- As mentioned earlier, you have been looking for an example of
where sand erosion has taken place and left an exposed root system.
I found my example at N 30° 22.050 W 086° 18.549, but given the
dynamic nature of the dunes, you could find your example somewhere
else. Take a photo of you and / or your GPS at an exposed dune
anchor, then post the photo with your log.
3- At N 30° 22.026 W 086° 18.613 , you will see a big brown
sign. Whose habitat is being restored here? These endangered
animals live in burrows in the dunes and are very adapted to this
specialized environment. A flourishing population of these animals
is a general indicator of a healthy dune ecosystem.
Logs not accompanied by email and photo within a reasonable
amount of time will be deleted per earthcache rules. That would be
bad.
References:
Witherington, Blair & Dawn. 2007. Florida’s Living
Beaches Sarasota: Pineapple Press
Topsail Hill Preserve State Park – Morris Lake Nature Trail
Guide
Florida
DNR website (Thanks to Leda Suydan for allowing this
earthcache!)
Thanks also to bennet, who brought me here :)