Restoring an Ancient Scrub

Naples Botanical Garden and Conservation Collier team up to restore a disappearing ecosystem

In the midst of industrial development in North Naples lies an oasis of sorts: a 135-acre preserve containing some of the region’s last remnants of Florida scrub habitat.

The county purchased Railhead Scrub Preserve in the 2000s through Conservation Collier, a land acquisition and management program. The preserve contains several ecosystems, including pine upland and freshwater marsh, but the prize is the 49 acres of xeric oak scrub. This type of habitat once spanned more than 2,200 acres throughout Collier County and today has diminished to a mere 200 acres, mostly in Rookery Bay National Estuarine Research Reserve, according to county records. Real estate development accounts for most of Florida’s scrub habitat decline, though that’s not the only stressor. Climate change, invasive species, and fire suppression (many scrub plants depend on fire for survival) have also taken a toll.

Having Railhead Scrub Preserve under county protection is an important conservation measure. But the preserve isn’t a pristine ecosystem and needs significant human intervention to undo human-induced damage. For decades, all-terrain vehicle riders have accessed the site, trampling plant communities and carving road-like paths throughout much of the preserve. ATV use became illegal once Conservation Collier purchased the land using taxpayer dollars under a voter-approved referendum, but riders continue to trespass despite the County’s efforts to secure the property.

Now, Conservation Collier has teamed up with Naples Botanical Garden to revegetate those ATV trails using plants grown from seeds and cuttings collected within the preserve.

The partners hope to not only heal this land but also to increase conservation collections and protect native plant genetics before they disappear.

“This entire ecosystem is under threat of being lost,” says Chad Washburn, the Garden’s Vice President of Conservation.

The project promises to break new ground in restoration science. Little is known about Southwest Florida’s scrub plants and how to put them to use in repopulating an area such as this preserve.

“We’re still in the stage of even beginning to figure out the scale of this project,” says Molly DuVall, Senior Environmental Specialist for Conservation Collier. The County and Garden experts, quite literally, are writing a playbook.

Railhead Scrub is extraordinary for its ability to shelter wildlife amid industrial and residential development.

“There’s a huge diversity of wildlife that uses this preserve, even though it’s urban and surrounded by development on all four sides,” DuVall says.

Camera traps have documented large mammals, including black bear and deer. Nearly 40 species of birds are believed to breed there. Endangered gopher tortoises abound. Close to 400 plant species have been chronicled, including 14 categorized as state and/or federal threatened species.

But the ATV trails disrupt the habitat’s functioning. If you were to combine them into one area, you would have eight acres worth of barren land, DuVall says. They cut into vegetation, interrupt wildlife habitat, and invite the growth of invasive plants, which thrive on the margins of disturbed areas.

“It’s called the edge effect,” says Washburn. “(Roads) not only impact that spot, but the spot next to it. You’re opening up light gaps. You’re creating barriers.” A gopher tortoise may be able to cross a road from one plant “island” to the next, but a small pollinating insect may not, he explains.

This restoration project, among other things, seeks to fill in those paths with native plants to reconnect the ecosystem.

That’s not as simple as it may sound. The preserve’s restoration will take years — not only for its scale but because a litany of questions must be answered first:

• What native species grow there now?
• Are any species missing from the ecosystem?
• Should they be re-introduced?
• How do these native species behave?
• What conditions encourage their growth?
• In what sequence should species be planted?
• Should seeds be started in a nursery or planted directly on site?
• How does water move across the site?
• What are the soil conditions?
• The elevation?

Much of the native plant research falls to Jessica DeYoung, the Garden’s Conservation Horticulture Manager. For the past three years, she’s been studying native plants on the Garden’s nine-acre scrub habitat, researching seed germination, optimal growing conditions, and best practices for long-term seed storage. That work is crucial for this project, as plants used in Railhead’s restoration will be grown from seeds collected on site rather than imported from other regions.

The partners are excited to delve into the project, DeYoung says. “There are just so many unknowns we want to figure out.”

What the County and Garden experts learn at Railhead Scrub will be applicable to future restoration projects elsewhere in the region.

DeYoung started with a deep dive of the property’s 384 plants, relying largely on a 2017 floristic inventory. She has chronicled the habitats in which they grow, their bloom cycles, whether they provide food for gopher tortoises, and their potential roles in future restoration efforts.

From that inventory, DeYoung developed a priority list for collecting. She’s going after seeds from plants that will be used to restore this preserve — species such as the sprawling gopher apple plant (Licania michauxii) that can stabilize vehicle-churned soil — as well as species that are underrepresented in botanical collections.

The latter point requires explanation. Botanical gardens are genetic repositories for plants. That’s why conservationists collect both rare and common plants, lest the ones that are abundant now decline in the future. On the Railhead Scrub plant list, 176 species — 45% of the preserve’s flora — lack sufficient protection in botanical collections.

“It’s very important that we protect all of this incredible biodiversity that is missing from conservation collections,” Washburn says.

The need for seed collections is both long term and immediate. On a tour of the property, DuVall points out Florida rosemary (Ceratiola ericoides) withering in the sand. Further investigation later on will suggest the scrub needs fire to rejuvenate plants like rosemary. She climbs over a small fence and points out a popular off-roading spot where once vegetated land has been denuded.

“This is the best example of how, over time, if you don’t protect it from impact, this is what it turns into,” DuVall says, looking over vast patches of sugar-white sand. “This is what we’re trying to prevent.”

The restoration will include additional barriers to deter riders, as well as public education to explain the importance of the scrub ecosystem and why the county seeks to protect it.

The land’s potential is evident in other portions of the preserve.

“I love this marsh,” DuVall says. This habitat is located in the minimally traversed northern section. Ten years ago, the marsh was a monoculture of melaleuca, an invasive tree introduced to Florida to drain wetlands for development and agriculture. Today, following Conservation Collier’s restoration efforts, the marsh is a grassy expanse that will fill with water during the rainy season. Nearby, a few young pines offer evidence of renewed growth and expanding biodiversity. 

DuVall says the Garden and County restoration work will start on the northern end of the property because it is inaccessible to unauthorized vehicles and less impacted than the southern portion. She, DeYoung, and Washburn intend to start with trial plantings, study the outcomes, and then design larger projects.

More changes are coming to the area surrounding Railhead. The newest Collier County high school is underway, and Veterans Memorial Boulevard will be expanded to reach it, with further extensions to come. Those developments amplify the imperative for restoration. With ever-shrinking habitat, plants and wildlife depend on preserved land set amid urban development. 

“We’re trying to restore this area to the highest quality possible,” DuVall says.

This article originally appeared in the 2022 issue of Conserve.