As the name implies, they are haunting—long stretches of standing, dead trees with exposed roots. These “ghost forests” are an unsettling scene in unsettling times for the environment. While coastal erosion is a fact of life—incoming waves, hurricanes, longshore drift of beach sand—the rate of its occurrence is startling lately.
Global rises in sea level due to increased atmospheric carbon levels mean more saltwater is moving into flat, coastal habitats that once served as a buffer from the open water. Salt is an exceedingly difficult compound for plants to handle, and only a few species have evolved mechanisms for tolerating it. Low-growing salt marshes and thick mangrove stands have always served as “first line of defense” buffers to take in wave action and absorb saltwater. If shorelines have too much wave action for marshes to form, wide stretches of sandy beach and dunes serve the same function, protecting the inland species of shrubs and trees. Many coastal areas are flat and stay at or just above sea level for thousands of yards, or even miles. This means that even a small increase in sea level can send saltwater deep into previously freshwater systems, drowning the marsh and flooding stands of oak and pine. The salt and sulfate in seawater will kill a tree quickly, although it may remain standing, dead, for months or years. Hurricanes and tropical storms exacerbate that damage, scouring out chunks of shoreline and knocking down already-unstable trees.
A slow increase in sea level could be tolerated and adapted to as salt marshes move inland and replace non-salt tolerant species. But this process of ecological succession can be interrupted if erosion and increased water levels occur too quickly. And if there is hard infrastructure inland of the marshes (like roads or buildings), the system experiences “coastal squeeze,” winnowing the marsh to a thin, eventually nonexistent ribbon, with no natural protection for that expensive infrastructure.
Ghost forests are popping up everywhere. Last year, Popular Mechanics magazine reported on a recently published study that used satellite imagery to document how 11% of a previously healthy forest was converted to standing dead trees along the coast of North Carolina. The trees died within a span of just 35 years (1984-2019). During that time frame, this stretch of coastline also experienced an extended drought and Category 3 Hurricane Irene. These impacts sped up the habitat loss, with over 19,000 hectares converted from forest to marsh and 1100 hectares of marsh vegetation gone, becoming open water.
Due to increased coastal flooding and saltwater standing in forested areas, U.S. Fish and Wildlife Service employees are concerned that the historic Harriett Tubman Byway in Maryland—part of the famed underground railroad of the Civil War era—will soon be gone. Over 5,000 acres of tidal marsh have converted to open water in the area and large stands of trees have died. Even locally, trees along Escambia and Blackwater Bay are dying due to salt damage and heavy erosion. Hurricane Sally delivered a knockout punch to many remaining trees along the scenic bluffs of the bay.
Sea level has risen over 10” in the past 100 years in the Pensacola Bay area, and even mid-range Army Corps of Engineers estimates expect 0.6 to 1.4 feet of rise in the area by 2045. There are some actions we can take to mitigate future damage. Building a “living shoreline” of vegetation along a piece of waterfront property instead of using a seawall can help, especially if the vegetation growth outpaces sea level rise. You can also visit the City of Pensacola’s Climate Task Force report to learn more about climate action recommended (and being taken) locally, such as increasing the use of renewable energy and dedicating staff to sustainability measures.
The land of the wet and muddy – that’s what lot of folks call the salt marsh. If you have ever experienced walking through one you know why they call it that. Salt marshes are wetlands that are dominated by grasses and are partially flooded with salt water during high tide; some portions of the marsh are still flooded at low tide. The grasses that grow there are halophytes (salt tolerant). Their diversity is low, but abundance is high.
Salt marshes grow on the protected side of the island – the bay side – and even there they do better in protective coves and inlets off of the main shoreline. They are not big fans of high wave energy. The grasses that live there are spaced in zones. Smooth cordgrass (Spartina) is more water and salt tolerant than black needlerush (Juncus) and is found along the marsh edge close to the shore of the bay itself. Black needlerush dominates the upper marsh closer to the maritime forest and tertiary dunes.
If you approach the marsh from the dune/forest side, you will encounter a dense field of needlerush. As you step into it you will experience soupy layers of black mud and detritus. Your feet sink and, if you do not have on secured shoes, you will lose them. You will get the odor of rotten eggs as you walk. This is hydrogen sulfide released by bacteria who are decomposing the leaf litter, and other organic matter, that is trapped and collected with the rising and falling tide. There is not a lot of wildlife in this area. The mud is deep, and the food sources are few. You will notice small white snails on the needlerush blades. These are marsh periwinkles. During high tide they move up the grass blades to avoid predators, at low tide they come down to feed on the organic material on the exposed mud.
Eventually you find small creeks heading towards the bay. Here the water is murky and the bottom still very muddy. Scattered amongst the needlerush are mounds of high dry ground covered in salt bush (Baccharis) where some animals can move around much better. Raccoons frequently these small “islands” seeking the numerous fish and shellfish that can be found in the creeks. Ribbed mussels can be found attached the base of the needlerush and are a particular favorite of the raccoons. Juvenile blue crabs can be found scavenging food sources in the creeks, juvenile mullet is common, as are small killifish and mollies. These can provide food for wading birds like the great blue heron who has widespread feet that resist sinking in the mud and allow them to hunt. Sometimes oysters and crown conchs are found in the creeks. Oysters do not move and cement to each other forming clumps. They filter feed in the water column collecting organic material and improving the water clarity – unless you walk through and sir up the mud and silt.
These small creeks become wider and deeper as you approach the bay. In places the bottom becomes sandier, and all of this allows other species to forage. The above mentioned are still present. Oyster clumps become more numerous because they are not covered by the silt of the upper marsh. In the sandier areas flounder can be found feeding on the small fish and shrimp that reside here. This part of the marsh can be an important nursery for many open estuarine species. A variety of shrimp are found here, crabs, and juvenile fish as well. With more sand it is easier for herons to walk and hunt.
There are also a few reptiles found here. The American alligator can be found at times, but are more common in the open lagoons. The Gulf salt marsh snake (Nerodia) resides here. They are nocturnal and rarely seen. But in the spring when breeding is going on, they can be encountered during daylight hours. These are none venomous snakes.
Interestingly the venomous cottonmouth can be found here. This is an interesting story. The cottonmouth is associated with freshwater. It is not surprising, or uncommon, to find them near the freshwater ponds we have discussed already. By they do not have the lachrymal glands found in sea turtles and terrapins that allow them to swallow seawater, excrete the salt through glands in their eyes, and use this as a freshwater source. It appears that the cottonmouth needs freshwater for drinking. Despite this they are being encountered more often in more saline areas. One barrier island near Cedar Key, Seahorse Key, supports a large population of cottonmouths. It has been stated there may be more per square meter there than anywhere in Florida – and there is no source of freshwater. Researchers from the University of Florida have found they drink from pools of freshwater that form after heavy rains and are very opportunistic when it comes to selecting prey – including other cottonmouths. The species found on Seahorse Key is Agkistrodon conanti (Florida Cottonmouth). The eastern cottonmouth (A. piscivorous) is the one most common in and around our freshwater systems. It would be interesting to determine which species is living on our barrier islands, and how they use the landscape. Though I have never seen them swimming in the larger creeks of the marsh, I have seen them basking along its edges many times. I am sure they use this saline environment.
Another unique marsh reptile is the turtle known as the diamondback terrapin. This is the only resident estuarine turtle in the United States. They are related to the freshwater pond turtles people frequently see but prefer the more saline marshes of these islands. They feed primarily on shellfish and have a preference for the marsh periwinkle snails that climb the grass blades.
River otters have been found swimming in these large creeks searching for food. They seem to like both fish and shellfish. Redfish can be found in the wider deeper creeks. The mullet and flounder found here are larger.
Hermit crabs are abundant here. These are crabs whose abdomens are not covered by shell. So, they must seek abandoned mollusk snails to “hide their rears”. They will select any shell but seem to prefer oyster drill and moon snail shells – possibly because they are more abundant. Oyster drills are snails who use their serrated tooth (a radula) for “drilling” into oyster and consuming them. Crown conchs and ribbed mussels are abundant here.
These larger creeks sometimes feed directly into the bay, but sometimes they feed into a large open lagoon. These lagoons are full of fish. Mullet, redfish, flounder, stingrays, pinfish, and – if deep enough – even small sharks can be found here. Wading birds, like herons and egrets, and common along the shorelines and diving birds, like osprey and pelicans, are found here. The shoreline near the grasses still has small juvenile fish. The sandy beaches can support the hunting of raccoons and armadillo tracks are common. The alligator encounters I have had are more common here and we often see the heads of terrapins. The river otters I have seen here are usually along the edges.
Another unique marsh critter is the fiddler crab. Though found throughout the marsh, they seem to be more abundant where there is more sand. Related to the ghost crab of the Gulf side, these small crabs dig burrows down to the water table. When the tide is high, they plug their burrows with mud and sand, then wait. When low tide arrives they emerge in the thousands to scavenge the shoreline for organic material in the sand – forming these round balls of sand as they are cleaning it that I call “coco-puffs”.
All large creeks and lagoons are connected to the open bays of the northern Gulf of Mexico where seagrass meadows form. As you walk the north shores of panhandle barrier islands you find sandy beaches often loosely covered by a variety of grasses. Walking inland you again return to either the tertiary dunes or maritime forest and may be another salt marsh. You have now experienced the primary habitats, and wildlife found within, on our barrier islands. But there are new concerns that could alter the ecology of these systems. One of those are invasive species. We will discuss this one in Part 8.
For some the forest is a scary place; for some it is a magical one; and for others it is spiritual. For wildlife it is a popular place. There are many places to shelter and plenty of food. Though the forest of our barrier islands is not as dense and dark as those of the west coast of the United States or the mountains of Appalachia, it is very wooded provides the same needs. Much of the wildlife on our islands call this part home. Even if they forge in the dunes, or on the beach, it is the forest where they reside.
I have hiked through many of these maritime forests. The northern terminus of the Florida Trail ends at the edge of a maritime forest on Santa Rosa Island. They are populated by many of the same species of trees you would find in inland forest. Pine, Oak, and Magnolia are all common. In some locations they short and twist their branches in all sorts of patterns to avoid direct exposure to the salt spray from the Gulf. Those more protected from the spray by large dune fields grow quite tall. Small rolling dunes of quartz sand can still be found on the forest floor, as can palms and palmettos, holly trees, and species of shrubs found in the dune fields themselves. All of these provide good shelter, and some provide food. And, as with the American southwest, these xeric conditions support cactus – there are plenty of cactus in the tertiary dunes and maritime forest of our islands. Covered toed shows are recommended when hiking here.
Though not common, within these forest there are small ponds of freshwater. Back in the 1950s there was an attempt to build a pompano hatchery within the forest of Santa Rosa Island. It failed because the water they chose to use (groundwater) was fresher than they thought it would be. Visiting the site today you will find the grow out ponds the farmers dug, full of freshwater. Near Ft. Pickens, on the west end of Santa Rosa Island, there are moats the soldiers dug to protect the fort from attack. These too are filled with freshwater. Between these and the naturally occurring ones, there is habitat for fish. The few samples I have collected over the years have yielded live bearers, like mosquitofish and mollies, and as well members of the killifish family. There could be others, but I have not explored this enough.
It is also good habitat to support frogs. I have seen southern leopard frogs and southern toads, and have heard spring peepers on the islands, but I have not conducted formal surveys to determine what other species might exist. There are inland species that do well in dry sandy soils, and you would think would do well on barrier islands if they could reach them. Maybe some have, again – we need to conduct a good survey. I am not aware of any salamanders on these islands, but again I have not looked for them.
This is the realm of the reptile. As with the deserts of the American southwest, reptiles do very well in dry xeric conditions. Snakes and lizards seem to be the most abundant. Six lined racerunners are quite common, as are other species of skinks (if you look for them in hiding places). The horned toad was once common in all sandy environments in Pensacola, but then were only found on the barrier islands, and now are hard to find there. They are reported to still be found on Santa Rosa Island though I have not seen one in years. One of my colleagues recently saw one on Perdido Key – so, they are still around.
With snakes, the southern black racers and their close cousins the eastern coachwhip are very common here. I have found garter and ribbon snakes. I have seen the rough green snake in the maritime forest, usually in the branches. I have found both the cottonmouth and the banded water snake near the freshwater ponds. The denser forested areas have a lot of leaf litter on the floor that could support the eastern coral snake. Though I have never seen one on the islands, they could be – they are very secretive. One of the more common snakes – found in all habitats of the barrier island – is the eastern rattlesnake. Encounters with impressive creature is rare. Most of mine have been near the campgrounds and after hurricanes when the National Seashore was closed. When FIRST opened to the public, you see them, then they just disappear.
Alligators are known to haunt the freshwater ponds; I have seen them near the old pompano hatchery. I have seen photographs of them crossing the island, swimming across the intracoastal waterway, and even swimming in the Gulf! But sightings and encounters on our end of the panhandle are rare.
Birds have no problem reaching barrier islands and they love forested areas. There are numerous species of songbirds (passerines). I have seen cardinals, blue jays, mockingbirds, and more. Many of the ones you find just across the intracoastal can be found here. Mourning doves are quite common in all habitats. The forested areas are where you encounter the raptors. I have seen osprey, bald eagles, and great horned owls all nesting here. Within the pines of the forest, you often see the great blue herons nesting. There are other occasional aquatic birds visiting the ponds, including ducks. Duck hunting still happens in the winter on some islands. These barrier islands are popular places to conduct the Audubon Christmas Bird Counts.
And there are plenty of mammals. Though more crepuscular or nocturnal, you often find their tracks in the sand in the morning, and occasional see them. Raccoons and armadillos are abundant, not only in the forested areas, but all island habitats. Skunks were once very common in the maritime forest. I remember days camping at Ft. Pickens when they would approach you eating lunch knowing you were going to leave you food and move away! We encountered them frequently while hiking and saw them inside some of the fortifications. Then… in 2004… Hurricane Ivan rolled over Santa Rosa Island. A study conducted by LSU suggested the entire west end of the island may have rolled over 300 feet north that night. Since then, I have not seen a skunk. They may still be out there, but I have not seen one.
In recent years there have been more encounters with river otters. They may have always been there but recently more tracks, and more encounters with live animals have occurred. There are squirrels and mice, out there. I have seen deer, fox, and coyotes on the islands. I have heard there are black bears. I have never seen one, nor their tracks, but know they have been encountered a lot recently in coastal Santa Rosa County and also know they are good swimmers. So, these reports could be true. I have looked for bats at dusk and have not seen them, but I am sure they are around. Especially near the forts and old live oak trees.
Time in these maritime forest will yield a lot of wildlife encounters. This is most likely the most diverse location on these islands. I would encourage you to dawn some good hiking boots (waterproof if you can), long pants (the green briar and cactus can be bad), a pair of binoculars, sun protection and water, and explore these amazing forests. Many of them within our state and national parks provide trails for easier access.
We have once last habitat to explore – and that would be the salt marsh. This will be Part 7.
Since entering the U.S. from Eastern Asia in the 1920s and especially since its promotion as the ultimate wildlife tree in the last few decades, I doubt there has been a more widely planted tree by outdoor enthusiasts than Sawtooth Oak (Quercus acutissima). It is easy to see the tree’s appeal. Sawtooth Oak grows quickly relative to other oaks, rates of 3-4’ per year in youth are not uncommon. It bears fruit at a very young age, as soon as five-seven years from seed, and produces a heavy crop almost every year, unlike many native oak species. Mature specimens are also mostly pest/disease free and very attractive, reaching 40-60’ in height with sweeping, wide-spreading branches, and deep, furrowed bark.
While it seems that I just described the ideal wildlife tree, and Sawtooth Oak can indeed be a worthy inclusion to your property, it is not perfect. All too often I see landowners and hunting lease holders plant solely Sawtooths as a part of their mast-producing tree strategy. As in other areas of life, avoiding monocultures and adding a little diversity to your wildlife tree portfolio is beneficial. Keep that, and the following lessons I’ve learned the hard way, in mind when you consider adding these wildlife attracting trees to your property.
Acorns Drop Early – Sawtooth Oaks produce all their acorns very early in the season, beginning in September. Conversely, most of our native oaks drop their mast (a fancy word for tree fruit) during the winter months that comprise our main hunting season, November-January. So, while Sawtooth Oak is an excellent wildlife attractor and most any creature will readily gobble up their acorns, if you plant them to hunt around or provide a critical winter food source, you’ll likely be disappointed.
Invasive Potential – As Sawtooth Oak is non-native, very adapted to the Southeastern U.S. climate, and produces literal tons of acorns each year, the species has the potential to become a nuisance invasive. I’ve visited several sites over the last few years that had a couple of large Sawtooth Oaks planted in areas mostly excluded from wildlife pressure. I was surprised to see small Sawtooth saplings popping up everywhere. It was eerily reminiscent of other nuisance trees like Chinaberry and Camphor. Though I don’t think Sawtooth Oak will ever be a problem on the level of Chinese Tallow or Cogon Grass, it’s wise to use caution with plants that have invasive potential.
Less Nutritious Acorns – Sawtooth Oak acorns are heavily browsed, but it’s not necessarily because they’re extremely nutritious. A study from the 1960s compared the nutritional quality of Sawtooth Oak acorns to 8 common native oak species and found Sawtooth lagged the natives by a significant margin in all macronutrients measured: protein, fat, and carbohydrates. This finding suggests that, while Sawtooth Oak is an excellent wildlife attractor, if your goal is growing higher quality game animals and providing valuable nutrients to get them through the winter when wildlife forages are scarce, Sawtooth Oak should be a minor component of your strategy, not the endgame.
Longevity – The jury is still out on longevity. However, anecdotal evidence from around the Southeast suggests that Sawtooth may not be as long-lived as some of our native oaks. This could be due to several factors. First, as a rule, extremely fast-growing trees tend to be shorter lived due to weaker branching structure, less dense wood, and other factors. Think of the tortoise and the hare analogy. The quickest do not always win the race. Second, Sawtooth Oak did not hold up particularly well during Hurricane Michael and other strong storms. Their growth habit (heavy, wide spreading branches low to the ground) is not conducive to major wind resistance. This is to be expected as Sawtooth Oak is native to areas that do not experience tropical wind events and likely evolved accordingly.
I am by no means suggesting that you shouldn’t add Sawtooth Oak to your property in the hopes of encouraging wildlife. There are few trees available that do a better job of that. I am suggesting that Sawtooth Oak should be a small part of your larger overall planting strategy and you should keep in mind the potential drawbacks to the species. Plant mostly native oaks, allow Sawtooth Oak to be merely a supplement to them, and I think you’ll be pleased with the results! Putting all your acorns in one basket is rarely a good strategy.
For more information on Sawtooth Oak, other wildlife forage and attractant strategies, or any other natural resource, agronomic or horticultural topic, please reach out to your local UF/IFAS Extension Office!
There are a lot of cool and interesting creatures that live on the barrier islands of Northwest Florida. The conditions out there require they make changes and adaptations different from what they would do in a more upland or wetland environment. Some creatures are unique to these beach and dune systems and found nowhere else. But to begin this series lets first look at the islands themselves.
The name barrier island comes from the fact that they do serve as a barrier between the open Gulf of Mexico and the mainland of the Florida panhandle, protecting coastal communities from storm surge and waves of the all too frequent hurricanes and tropical storms. They are basically sandbars formed with sands from the Appalachian Mountains. There the wind, rain, and temperature erode the granite rock into its mineral components and wash them downstream. First in the fast-moving mountain streams, then into creeks, into rivers which eventually discharge into the Gulf. The different minerals settle out based on their size, type, and densities. Quartz is one of the less dense and is the dominant mineral forming the coastal barrier islands, making them some of the whitest beaches on the planet.
When these quartz sands reach the Gulf, they encounter longshore currents that are formed from the winds blowing across the open water. In this part of the Gulf of Mexico these currents tend to move from the east to the west in most cases. As the rivers reach the passes that connect the estuaries to the open Gulf and the longshore currents move the sand into long thin spits at the mouth of the bays running parallel to the coastline. In some cases, the sand bars form perpendicular to the coastline, and we call them capes. Initially still connecting to land, many creatures can venture out on these sand spits searching for food. Some of the sand spits are very small and seem to come and go as the winds and waves move them. At times these smaller spits may actually close off the opening into the bay as they once did on Perdido Bay and still do with the Walton County dune lakes. In other cases, the spits accumulate more sand, become long and can eventually break contact with the mainland forming an island.
At first these islands can be nothing more than sand bars. Barely above sea level, moving and changing very quickly, sometimes disappearing and reappearing in slightly different locations after storms, such as Sand Island off Dauphin Island Alabama. In others they are larger, harder to move quickly and may be vegetated so that movement is slower and the island more established, such as Santa Rosa Island near Pensacola. The creatures on any of these islands will need to be able to adapt to the new conditions. Some will be able to leave and return the mainland when they need or want to. Birds are very common on all forms of barrier islands due to the fact they can fly. In some cases, the distance from the mainland is not a far swim for those who can, such at Indian Pass near St. Vincent Island. In some cases, the distance may not be as close and the currents between very swift during tide changes making crossing more difficult. In these cases, the creatures who find themselves on these islands must adapt to the new conditions or risk losing their populations entirely.
Island conditions can be tough. There is a lot of wind, and this wind carries salt spray. There is little cover from the intense sun during the summer months. Needed freshwater can be hard to find. Some islands will develop freshwater systems, but others will not. And then there is the fact that it is an island. Thus, a finite amount of resources and space for each species, and, at times, fierce competition for those.
In Part 2 we will explore the different habitats that developed on these islands that available for the different wildlife that exploit them.
October has been designated as Coastal Dune Lake Appreciation month by Walton County government. Walton County is home to 15 named coastal dune lakes along 26 miles of coastline. These lakes are a unique geographical feature and are only found in a few places in the world including Madagascar, Australia, New Zealand, Oregon, and here in Walton County.
A coastal dune lake is defined as a shallow, irregularly shaped or elliptic depressions occurring in coastal communities that share an intermittent connection with the Gulf of Mexico through which freshwater and saltwater is exchanged. They are generally permanent water bodies, although water levels may fluctuate substantially. Typically identified as lentic water bodies without significant surface inflows or outflows, the water in a dune lake is largely derived from lateral ground water seepage through the surrounding well-drained coastal sands. Storms occasionally provide large inputs of salt water and salinities vary dramatically over the long term.
Our coastal dune lakes are even more unique because they share an intermittent connection with the Gulf of Mexico, referred to as an “outfall”, which aides in natural flood control allowing the lake water to pour into the Gulf as needed. The lake water is fed by streams, groundwater seepage, rain, and storm surge. Each individual lake’s outfall and chemistry is different. Water conditions between lakes can vary greatly, from completely fresh to significantly saline.
A variety of different plant and animal species can be found among the lakes. Both freshwater and saltwater species can exist in this unique habitat. Some of the plant species include: rushes (Juncus spp.), sedges (Cyperus spp.), marshpennywort (Hydrocotyleumbellata), cattails (Typha spp.), sawgrass (Cladiumjamaicense), waterlilies (Nymphaea spp.), watershield (Braseniaschreberi), royal fern (Osmundaregalis var. spectabilis), rosy camphorweed (Pluchea spp.), marshelder (Ivafrutescens), groundsel tree (Baccharishalimifolia), and black willow (Salixnigra).
Some of the animal species that can be found include: western mosquitofish (Gambusiaaffinis), sailfin molly (Poecilialatipinna), American alligator (Alligatormississippiensis), eastern mud turtle (Kinosternonsubrubrum), saltmarsh snake (Nerodiaclarkii ssp.), little blue heron (Egrettacaerulea), American coot (Fulicaamericana), and North American river otter (Lutracanadensis). Many marine species co-exist with freshwater species due to the change in salinity within the column of water.
The University of Florida/IFAS Extension faculty are reintroducing their acclaimed “Panhandle Outdoors LIVE!” series. Come celebrate Coastal Dune Lake Appreciation month as our team provides a guided walking tour of the nature trail surrounding Western Lake in Grayton Beach State Park. Join local County Extension Agents to learn more about our globally rare coastal dune lakes, their history, surrounding ecosystems, and local protections. Walk the nature trail through coastal habitats including maritime hammocks, coastal scrub, salt marsh wetlands, and coastal forest. A tour is available October 19th.
The tour is $10.00 (plus tax) and you can register on Eventbrite (see link below). Admission into the park is an additional $5.00 per vehicle, so carpooling is encouraged. We will meet at the beach pavilion (restroom facilities available) at 8:45 am with a lecture and tour start time of 9:00 am sharp. The nature trail is approximately one mile long, through some sandy dunes (can be challenging to walk in), on hard-packed trails, and sometimes soggy forests. Wear appropriate footwear and bring water. Hat, sunscreen, camera, binoculars are optional. Tour is approximately 2 hours. Tour may be cancelled in the event of bad weather.