Ongoing Research and Conservation of the Bald Head Woods
Ongoing Research and Conservation of the Bald Head Woods
Conservation Technician Lauren CollverThe 191 acres of the Bald Head Woods Reserve and the patches of preserved forest throughout Bald Head Island make up the unique maritime forest ecosystem that anchors our barrier island. As part of our mission to discover and conserve the natural wonders of BHI, the Conservancy has focused efforts on monitoring the health of our unique maritime forest.
Over the past fifty years, forestry experts have been increasingly focused on the ecological mystery of oak regeneration failure, which refers to the slowing rate of recruitment and growth of young oak trees in forests across the continent. Historically, across North America, mature oak trees that die have been replaced by young oak saplings that have been lying in wait in the midstory of the forest. These young saplings grow slowly in their “teenage years” in the shady midstory until a disturbance causes a mature tree to die. In the space where a mature tree has fallen, a gap forms in the canopy where sunlight can reach the next generation of saplings, allowing them to take off and grow quickly into the canopy. This natural cycle relies on a healthy population of 3-4 foot tall saplings ready to take over following a disturbance.
Similar to mainland forests, research conducted by Bald Head Island Conservancy scientists and collaborators has revealed that our new generation of oak trees may not be strong enough to replace our mature trees. Initial surveys began in 2011 by collaborators John Taggart and Zachary Long of UNCW and have been continued by Jodi Forrester of NCSU. These surveys have found a very low abundance of oak seedlings and almost no young trees in the 3-4 foot height range, meaning that there may not be many viable candidates to replace our mature live oaks.
Young oak trees face a wide array of challenges that make reaching the teenage years difficult. The oaks that call Bald Head home are well adapted to the natural challenges of living on a barrier island, like salinity in the wind and groundwater, high heat and humidity, and frequent storms, which should allow for occasional clearings in the canopy to provide sufficient sunlight. While these environmental challenges are likely contributing to this concerning pattern, the main culprit could be a member of our island fauna. Unfortunately for our oaks, millions of years of evolution have not prepared them for the challenge of being a tasty snack for an island population of white-tailed deer that is largely unsuppressed by top predators or hunting practices.
We closely monitor our deer population through spotlight surveys and camera traps, and alongside our collaborators’ ongoing vegetation surveys, we have been able to recommend an island capacity of about 120-200 deer. This capacity represents the largest population that BHI is able to support without detrimental effects to our forest and the spread of disease and malnutrition expected with overpopulation. BHIC Director of Science Dr. Beth Darrow recently spoke to the Coastal Review about ongoing talks related to deer management.
This summer, we completed a re-survey of the forest vegetation with the help of Dr. Jodi Forrester and Thomas Hatling. This survey will culminate in a report on how the vegetation of the island has changed over time and how the deer population has been affecting the forest. We found that our young oaks are still struggling to grow above about six inches, both in areas that deer have been able to access and in plots where deer access has been intentionally restricted by fencing. Data analysis will focus on determining if the deer are changing the density of oak seedlings and how they are impacting the growth and composition of the rest of our forest floor and shrub species.
Our ongoing research suggests that the answer to this ecological mystery does not have a single cause. Our dynamic and unique maritime forest needs to be studied with equally dynamic research methods, and island development, strengthening tropical storms, warming temperatures, and rising sea levels are all contributing to an increasingly unpredictable ecosystem. BHIC is continuously grateful for the support of our collaborators, sponsors, members, and the Village that allows us to adapt to the challenges of BHI’s unique ecosystems and work together toward complex and effective conservation solutions to protect our beloved island.
If you would like to learn more about the unique ecosystem of our maritime forest, please reach out to Lauren and attend her BHI Club talk, “Mysteries of the Maritime Forest,” on July 15.
