Effects of Beech Leaf Disease on Falmouth Trees Revealed in MBL Student’s Publication

Much like the human body recycles vital nutrients to stay healthy, trees reabsorb nitrogen from their leaves before they fall, storing it for the next growing season. But beech leaf disease (BLD) disrupts this natural process in infected beech trees, posing a threat to forest ecosystems throughout the northeastern United States and Canada.

In a recent study of beech trees around Falmouth, Mass., MBL Ecosystems Center scientists found that BLD prevents trees from reclaiming as much nitrogen from infected leaves as from healthy leaves. This disruption in nitrogen storage could have “potentially drastic negative consequences for tree health,” the authors write. More nitrogen in the leaf litter might also disrupt nutrient cycling on the forest floor, which needs further investigation.

Beech leaf disease is new in the United States, arriving in Ohio in 2012 and spreading rapidly eastward since.

“The beech forests on Cape Cod and Naushon Island have been hit particularly hard,” says MBL Senior Scientist Zoe Cardon, senior author on the paper. “It's something people ask about all the time — Why do the beeches look so sick? Why are the trees dying?” The disease is caused by an invasive nematode, Litylenchus crenatae, that feeds on the tree’s leaves and buds, eventually killing the tree.

This publication began as a student project in the MBL’s Semester in Environmental Science (SES) program. Lead author Aaron MacDonald was an SES student, mentored by Cardon.

“Aaron’s project turned out so well, we realized he nearly had enough data for a publishable paper,” Cardon said. “We had to shore up a bit of the data after Aaron left for the semester, so Quincy Dowling, an MBL research assistant in my lab and former teaching assistant for SES, made some follow-up measurements in consultation with Aaron.”

This study was funded by the Semester in Environmental Science program and by an anonymous donor.

Citation:

Aaron A. MacDonald, Quincy S. Dowling and Zoe G. Cardon (2025) Beech leaf disease reduces nitrogen translocation at leaf fall, altering litter chemistry. Oecologia, DOI: 10.1007/s00442-025-05790-5