Tallahassee is nestled in the heart of a treasure – a global biodiversity hotspot known as the North American Coastal Plain. This region is made up of beautiful longleaf pine savannas – park-like ecosystems with widely spaced longleaf pine trees over an open grassy groundcover. The hotspot is home to thousands of species, many of which are rare, threatened, or endangered. If you’ve traveled anywhere in the region outside of Tallahassee, chances are you are familiar with it. Places like the Munson Sandhills of the Apalachicola National Forest or the St. Marks National Wildlife Refuge have large expanses of this ecosystem, and we are lucky to be near them.
The longleaf pine ecosystem is globally endangered after being reduced to <3% of its range through deforestation. It is endemic to the southeastern United States, meaning it’s a unique system found nowhere else in the world. The ecosystem used to cover the landscape from Texas through Virginia and down into central Florida. Today, threats include continued deforestation due to the pressure that urban sprawl puts on the system as our population rapidly grows, as well as impacts to the ecosystem due to climate change.
One of the particularly unique threats that climate change will bring in this region include the potential for hurricanes of greater intensity and frequency to occur.
Hurricane Michael impacted the Florida panhandle on October 10, 2018. It made landfall near Mexico City beach as a Category 5 storm and maintained hurricane force winds well into Georgia before downgrading and passing through South Carolina, North Carolina, and Virginia. As the storm passed over the panhandle of Florida, tropical storm force winds extended outward from the center of the storm as far as Gainesville to the east and further than Pensacola to the west. For many of us, the devastation brought by the storm is still apparent in our homes and communities. For land managers, the devastation extends far beyond their own homes and communities and includes the vast expanses of forests and natural areas also devastated by the storm.
As part of my Ph.D. research, I surveyed longleaf pine habitats before and after Hurricane Michael. My goals were to assess baseline conditions in habitats that were considered to be in exemplary condition and the subsequent damage caused by the storm. This information should help land managers and policy-makers be better informed while making decisions about recovery plans. In total, 0.3-0.4 million acres of longleaf pine habitat within the Florida panhandle were impacted by hurricane force winds, while up to 2.6 million acres experienced tropical storm force winds. My detailed surveys at four sites showed that the site nearest to the storm center experienced catastrophic losses with an estimated tree mortality of 88.7%. At the other sites further away, mortality ranged from 1.3 – 8.4%.
Conservation and restoration of this important and endangered ecosystem is a major goal for land managers in this region. Extremely high rates of mortality and damage at these sites bring unique threats and challenges for managers. Prescribed fire is integral to the health and maintenance of these ecosystems and will be especially important after a disturbance such as this. However, due to the incredible amount of downed trees, the risk of high severity fires is extremely high. Safely applying prescribed fire under these circumstances is challenging and under dry conditions the risk of wildfire is high. In addition to the challenges brought to fire management, many of these forests had such severe damage to mature trees that natural regeneration may be impossible. Lastly, restoration goals that aim for an extent of forest coverage to be restored or conserved need to incorporate the expectation that we may continue to lose large expanses of these habitats due to future extreme storms.
Longleaf pine systems are found in a region that has always experienced hurricanes and have evolved under the pressures of frequent hurricanes. These systems have adaptations that allow them to withstand disturbance and are generally resilient to storm events. However, hurricanes of increasing frequency and strength are likely under a climate that is rapidly changing, and we must prepare for accelerated losses to this already declining and vulnerable system.
Nicole Zampieri is a PhD student in the Department of Geography. She studies biogeography and longleaf pine ecology.