Hole-in-the-Donut

Restoration

National Park Service

U.S. Department of the Interior

South Florida Natural Resources Center

Everglades National Park 

The Hole-in-the-Donut (HID) is a 6,600-acre wetland in the Everglades so named for the patch of farmland surrounded 

by native landscape that once characterized the region. When farming ceased in 1975, the patch was quickly invaded by 

Brazilian pepper (Schinus terebinthifolius), a non-native shrub from South America. Now, under management of Everglades 

National Park (ENP), the “donut hole” is being restored. The project was initiated twelve years ago and the efforts to restore 

and maintain the landscape are still underway.

Farmed for over 50 years before it was acquired by ENP, the 

HID, with its aerated and fertilized soil, was far more suitable 

for the growth of non-native Brazilian pepper than the waterlogged, 

nutrient-poor environment of the untouched Everglades. The plant 

was first introduced to Florida in 1926 and before long, fruit-eating 

animals had spread the weedy tree throughout south Florida. Typical 

of invasive plants, Brazilian pepper thrived in disturbed areas. It was 

this trait that allowed the plant to invade the HID. Once a few of the 

shrubs became established, the aggressive weed rapidly dominated 

the abandoned farmland. The dense thicket that eventually formed 

monopolized the nutrients, water, and sunlight, thereby inhibiting 

the growth of native plants.

Restoration

In 1997, ENP initiated a large-scale effort to restore the infested 

former farmland to its natural state. But getting rid of 6,600 acres of 

Brazilian pepper is no easy task. Using bulldozers and backhoes, the 

park set out to conquer the exotic invader. They leveled nearly half 

of the vast pepper forest and removed the debris. Yet, the battle was 

far from won. The persistent plant recovered as new shoots cropped 

up from underground root systems and from viable seeds remaining 

in the soil. In a final, ambitious effort, the soil was scraped away 

down to the bedrock. 

A drastic measure, scraping the soil down to bedrock turned out 

to be the key to restoring the HID. With the aerated and nutrientrich agricultural soils removed, the treated areas were successfully 

restored to wetland. Many native plants have reestablished in these 

areas on their own and wading birds and other animals have become 

regular visitors. But while basic ecosystem function has been largely 

restored, the full suite of native organisms has not yet returned. With 

time, a more representative community of native plants is expected 

to develop. 

By 2009, 4,100 acres will have been restored in the HID. Efforts to 

monitor native communities and introduce missing native plant 

species are ongoing in the restoration area. In addition, the question 

of what to do with the seven million tons of removed soil remains. 

Currently stored on-site in large mounds, carrying the soil out of the 

park would be very disruptive to park visitors and damaging to park 

roads since such a project would require transporting 250,000 dump 

truck loads of soil out of the park. Therefore, park managers are 

looking for alternative uses for the soil, including its potential as fill 

for several borrow pits located throughout ENP.

Brazilian pepper (Schinus terebinthifolius) prior to restoration on the 

left and restored marl prairie on the right. Photo by Joy Brunk, ENP 

Printed on 30% post-consumer waste paper with vegetable-based inks. Fiber sourced from responsibly 

managed forests.
May 2009 • South Florida Natural Resources Center • 950 N Krome Avenue • Homestead, FL 33030 • (305) 224 - 4200

Photos by Lauren Serra, ENP, and Rodney Cammauf, ENP Volunteer Restoring a Wetland

Restoring thousands of acres of Brazilian pepper to native marshland is an challenging task. First, the towering weeds are cut down 

and mulched. Next, the debris is bulldozed into long windrows, scooped up with front end loaders, and then hauled to soil disposal 

mounds via trucks. Finally, a grader is used to scrape the remaining soil from the bedrock. Scientists actively monitor the progress of 

the restoration. Wading birds and other wildlife have been quick to return. 

Wetland Mitigation Program

Restoration of the HID is an expensive undertaking with a current price tag of approximately $90-120 million — far in excess of 

what the park’s operating budget can support. Outside funding for HID restoration comes from selling wetland mitigation credits 

to developers who build on wetlands within Miami-Dade County. As part of former President George H. W. Bush’s “no net loss” 

of wetlands initiative, mitigation banking allows developers to fill in small, isolated wetlands if they pay for restoration of equivalent 

acres of wetlands in areas that are protected, like Everglades National Park. The HID wetland restoration project is a partnership 

project involving Miami-Dade County, the National Park Foundation, the National Park Service, and the private sector. A trust fund 

established with mitigation funds will allow for long-term management of the HID area by the National Park Service, preserving 

and protecting the area unimpaired for the enjoyment of future generations. 

Scientists from universities and research groups outside of 

ENP have taken advantage of the HID project as an opportunity to study aspects of ecological restoration. Researchers 

from the University of Florida are 

examining the ability to restore 

pine rockland habitat, which 

is known to have once 

occurred naturally in 

portions of the HID. 

Another University 

of Florida project is 

tracking soil nutrient 

dynamics in restored 

sites to determine 

what conditions favor 

the growth of different 

plants. A third project is 

being conducted by Florida 

International University. This 

group is developing a microbial 

biocontrol agent that targets Brazilian 

pepper. 

The park has contracted the consulting firm, Everglades 

Research Group (ERG), to monitor the return of native 

vegetation and wildlife in the HID. In addition to documenting 

the presence of all native species in restored sites, ERG has 

conducted several smaller scale studies. In one study, they 

examined the growth and survival of south Florida slash 

pine seedlings (Pinus elliottii var. densa) on a 31-acre 

section of the HID after Brazilian pepper had been 

removed. Published in the journal Ecological Restoration (O’Hare and Dalrymple 2006), the project 

revealed that, through natural recruitment, 3,013 

pine seedlings taller than 4 inches had become 

established in the area after four years. Most of 

these seedlings were found within 82 feet of pine 

rockland habitat and at elevations of at least 3.5 feet. 

The ERG authors concluded by emphasizing the importance of expanding the pine rockland habitat, now 

classified as globally imperiled. They suggest that such 

restoration projects could benefit from planting or seeding 

native understory species and implementing a prescribed 

burning program. 

Photo by Joy Brunk, ENP

Applied Science and Monitoring