Research for Impact: Someone Has to Understand Beech Leaf Disease in the Tri-State Area

The Impact Series spotlights urgent questions and real-world issues that need fresh thinking—and real research. Each post breaks down a problem, explores why it matters, and reveals where curiosity can turn into action. If you’re looking for something that sparks your interest and pushes you to do more than just learn—this is where you start.

The Environmental Issue We Can't Ignore

Beech Leaf Disease is Disseminating Trees in the Tri-State Area.

Beech trees are one of the most common species of trees in the tri-state area. They are also dying at an alarming rate — primarily on account of Beech Leaf Disease (BLD).

First discovered in Ohio in 2012, Beech Leaf Disease has since spread to 15 states. It was first observed in New York in 2018. Then, in 2019, BLD spread to Connecticut, and by 2020, it had spread to New Jersey, threatening the entire tri-state area. Even as we speak, this disease continues to spread — both in terms of its territory and its intensity.

Beech Leaf Disease affects both native and ornamental beech tree species and kills young and mature trees alike. Currently, Beech Leaf Disease is categorized as chronic, meaning that infected trees steadily decline, with young trees dying in 2-3 years and mature trees dying in 6-10 years.

Unfortunately, very little is known about Beech Leaf Disease. The disease occurs in the presence of a nematode (Litylenchus crenatae ssp. mcannii), accidentally imported from Japan, but we do not know if the disease is caused directly by the nematode or rather, its association with another pathogen. We also don’t know how to treat affected trees or prevent the disease from spreading.

Why This Issue Is So Pressing

American beech trees can live up to 250 years and can grow as tall as 160 feet. Their lush canopies and smooth gray bark (often likened to elephant skin) makes them a favorite among many. They also play a vital role in our ecosystems, providing important nesting sites and nutrient-dense nuts for a wide variety of wildlife, including black bears, deer, squirrels, and many species of birds. Since BLD is so new, and so rampant, we cannot anticipate how far-reaching its effects may be…how will the forests and wildlife be affected? At this point, no one knows.

What We Actually Don’t Know Yet

As previously mentioned, researchers still don’t fully understand the role of the nematode in the spread of BLD…How does it disrupt leaf and bud production? Does it play a primary role? Or does the nematode serve as a host for a more deadly fungi or bacteria?

Some beech trees can host the nematode without showing severe symptoms, while others deteriorate quickly. This suggests that genetic differences and/or environmental stressors may play a large role in the spread of BLD as well. Of course, this leads to even more questions: How does climate affect the spread of this disease? How will climate change affect the trajectory of this disease?

We also don’t know how to treat affected trees or stop the spread of this disease. There are some treatments and forest management strategies being studied, but a lot of more research needs to be done. And quickly!

Why This Hasn't Been Solved (Yet)

While scientists are trying their best, there are a lot of unknown factors at play, which makes it difficult to limit the scope of research being done. To state it plainly, there are lots of questions that need to be asked and not a lot of time to ask them.

The Questions That Are Still Sitting There

Scientists have barely begun to scratch the surface when it comes to Beech Leaf Disease. We still don’t know what exactly causes the disease, how it spreads, or what its long-term effects may be. In other words, there are lots of questions on the forefront of scientists minds, including:

• Is Litylenchus crenatae mccannii the sole cause of BLD, or does it require other pathogens (fungi, bacteria) to produce disease?

• Why do some trees show nematodes without symptoms, while others become severely diseased?

• Are there genetic differences in beech trees that influence susceptibility or resistance?

• What triggers the shift from early infection to tree mortality?

• Does BLD alter soil chemistry or nutrient cycling?

• Are certain habitats (wet vs. dry forests) more susceptible?

• Will warming climates allow the disease to expand northward?

• Are there any viable treatments for this disease?

The Questions That Are Still Sitting There

It’s easy to feel overwhelmed by the state of the world. After all, there are lots of problems that need to be addressed and only so many hours in the day. But what if you could focus on one worthwhile, easily definable problem? Maybe researching Beech Leaf Disease could be the way that you can contribute.

This is What Acting Could Look Like

Watching a species steadily decline is heart-breaking. Especially if it’s happening right in your back yard. But what if there was something you could do to help? 

Believe it or not, there’s a lot of good you can do when it comes to preventing the spread of Beech Leaf Disease. For one, you can help scientists by photographing sick (and healthy!) beech trees and uploading your findings on free apps, like iMapInvasives, iNaturalist, and TreeSnap. This will help scientists map the spread and concentration of BLD. 

You can also help by spreading awareness about firewood regulations: In order to limit the spread of various forest diseases and pests, do not move firewood further than 50 miles from where it was harvested. And if there are known cases of BLD in an area, restrict the movement of firewood even more. 

You can also jump in and join the research! After all, as the saying goes, many hands make light work. Reach out to local organizations, such as the New York State Department of Environmental Conservation or the New Jersey Department of Environmental Protection to see how you can help. You could also kick off your own research project under the guidance of an expert mentor.

Beech Leaf Disease is a tragedy. One that is quickly spreading. And unfortunately, time is not on our side. But increased awareness may cause progress. And right now, it’s important for as many people as possible to research this disease to help preserve beech trees and their vital role in our ecosystems.