Susan Cohen’s entire face lights up when she talks about trees. Her passion for preserving forests — from the mountains to the coast — is unmistakable.

“Trees are amazing,” Cohen says with a smile. “Just think about the products we get from forests: building supplies, food, textiles. We can manipulate them to get what we need but still maintain their ecological integrity.”

With master’s and PhD degrees in forestry, Cohen has spent most of her career exploring how to conserve and sustainably manage our nation’s forests. Before joining the UNC Institute for the Environment in 2018, she worked with the U.S. Department of Defense (DoD) at Camp Lejeune, studying the resilience of coastal, estuarine, and forest ecosystems surrounding the military base.

“The DoD manages almost 30 million acres of natural resources, which often surprises people,” Cohen says. “The military uses those land and water resources for training, and that is very compatible with managing habitat and ecosystem services.”

Her deep-rooted love for forests hasn’t changed — but her toolkit has. Today, Cohen is just as enthusiastic about drones as she is about trees.

“Drones are a game-changer,” she says. “They allow us to collect data faster, safer, and often more accurately than traditional methods.”

When Cohen arrived at Carolina, she quickly realized that while many researchers were using drones, there was no centralized hub for training, equipment, or collaboration. So in 2021, she helped launch the Carolina Drone Lab (CARDNL) to harness aerial technology for tackling environmental challenges.  

Now, CARDNL supports researchers across UNC-Chapel Hill and beyond, offering technical expertise and data solutions that elevate environmental research.  

Cohen will be one of 26 participants at this year’s Research and Discovery Fair, part of University Research Week, on Wednesday, October 22 from 11 a.m. to 2 p.m. at the FPG Student Union. The event showcases active research spaces across campus — all offering opportunities for students to get involved.

UNC Research Stories sat down with Cohen to learn more about her work and why hands-on research experiences are so important for students.

What’s the main goal of your research?

Our mission is to provide tools and actionable information to the people managing and stewarding our natural resources. The pitch is simple: Come and do important field work and collect data, fly drones, and help solve problems.

What projects are you working on now?

We have many projects, but I have a few favorites. One is studying how the moisture content in the understory plants longleaf pine forests changes over time. This is a major factor for determining if and how a prescribed fire is set and then how it behaves. You’d be surprised by how that moisture changes hourly. This project uses remote sensing — when aerial sensors obtain data — but is really based on traditional on-the-ground field work. Fire managers and modelers want that information.

The other project is working in the marshes and sea grass beds of Currituck Sound to understand their resilience and track changes over time from restoration efforts. These ecosystems have incredible social and economic benefits. We are using drones, machine learning, and remote sensing to help our partners manage those marshes. This work has applications across North Carolina and beyond.

What are the biggest challenges in your research?

Funding is always the biggest challenge, but once we acquire that, it’s logistics and planning. Sometimes, we work in challenging conditions and do intensive fieldwork like wading through marsh muck or working in severe heat. And the drones have lots of rules and regulations, which can be difficult to navigate. For example, you have to be able to see the drone at all times, which is super hard in a forest. And batteries definitely don’t last long enough.

What’s the most surprising discovery your team has made recently?

We’re seeing some early data showing a clear difference in how certain sections of bunch grasses — plants that benefit from fire, which removes dead vegetation and stimulates new growth — hold moisture. Specifically, the leaves near the ground and the flowering parts higher up dry out at different rates and have noticeably different moisture levels. It might sound like a small detail, but it can have a big impact when it comes to how fire behaves.

If your research could solve one big problem, what would it be?

A big interest of mine is getting rid of invasive species in forest habitats. They destroy biodiversity and ecosystem function and cost a shocking amount of money to control.

What’s the coolest tool you use in the lab?

It is hard to deny that our big drones are pretty cool. Folks are familiar with the smaller ones that tend to be more widely owned, but our biggest, heavy lift drone makes an impression with its size and the noise it makes when flying. It sounds like a helicopter.

Can undergraduate students get involved in your lab?

Some projects have funding built in to support student involvement, and we try to create those opportunities. Unfortunately, our field schedule for data collection often doesn’t jive with students’ class and semester schedules. But there is so much work to do in addition to field work and data collection like literature reviews, data entry, processing imagery, and analyzing data. It isn’t very glamorous, but these are critical parts of research.

What do students gain from working with you?

Students are immediately exposed to teams collaborating on research projects and independent work addressing parts of a project. We talk about natural resource challenges and management a lot, so there is broad exposure to that world, from attending meetings with collaborators to organizing projects to translating data. And while we might not be able to take a student to the field, we always make sure there is plenty of drone flying, map making, and a chance to take their FAA Part 107 test to become a certified drone pilot.

Share a specific anecdote of how a former student on your team took what they learned and applied it in the real world.

One is working with the Mojave Desert Land Trust to help identify conservation priorities and strategies to prioritize lands. Another is a graduate student who does remote sensing of surface water and ice. We’d like to think his love of technology for environmental work comes from his time with us!