Scientists Replicate 70-Year-Old Landmark Lichen Survey to Reveal Impact of Changing Forest Conditions

A new study co-authored by New York State Museum Curator of Botany Dr. James Lendemer highlights how seven decades of changing forest cover have impacted local biodiversity. More than 70 years after renowned lichenologist Mason Hale first surveyed the lichens of Aton Forest in northwestern Connecticut, researchers returned to the same site to conduct a rare direct comparison between historical and modern ecological conditions.

Dr. James Lendemer, Curator of Botany at the New York State Museum, said, "Studies like this show the extraordinary value of preserving scientific specimens and returning to sites that previous generations so meticulously documented. These studies help us better understand the relationships between species and their environments, and why documenting biodiversity today matters for future research."

Researchers have found that the lichen community has changed dramatically over the last 70 years. As forest cover increased, conditions became shadier, favoring lichen species adapted to lower light levels. Meanwhile, species associated with open habitats that receive full or nearly full sunlight declined. Although the researchers identified changes in the forest cover as a likely explanation, they noted additional research is needed to establish the precise cause of changes to individual species.

Similar resurveys have yet to be conducted in New York because the lichens of few comparable sites have been studied in such detail as Aton Forest. Lendemer believes the findings likely reflect trends throughout the Northeast, including in the Hudson Valley where previously farmed land has been reforested. By collaborating with partners in neighboring states, State Museum researchers can better understand not only what is happening in New York but also how it relates to the region on a larger scale.

Hale began his scientific career as an undergraduate at Yale University in 1949. His early work at Aton Forest documented more than 150 lichens and included detailed observations of their ecology. He also collected specimens and established permanent research plots, creating a valuable historical record that researchers could revisit decades later.

Billy Gridley, President of Aton Forest, said, "Our founder Dr. Frank Egler pursued 'long-term, low-cost, low-impact' interpretive ecological studies here for 70 years and would be thrilled by this important follow-on study."

The study, "Resurvey after 70 years reveals significant changes to the lichens of Aton Forest, Connecticut," was published in October 2026. In addition to Lendemer, it was co-authored by Christopher R. Mangels, Steven N. Messier, and Nels E. Barrett.

About the New York State Museum

Established in 1836, the New York State Museum is the oldest and largest public museum in the United States. Home to leading scientists, historians, archaeologists, and anthropologists, its collections represent the State's rich cultural and natural heritage from the past and present, including a staggering 20+ million artifacts spanning 1.1 billion years ago to today. Located at 222 Madison Avenue in Albany, the Museum is open Tuesday through Sunday from 9:30 a.m. to 5 p.m. It is closed on all state-observed holidays, including the Fourth of July, Thanksgiving, Christmas, and New Year's Day. Admission is free. For additional information, visit the New York State Museum website and subscribe to our newsletter.

About Aton Forest

Aton Forest is a 501c3 Ecosystem Field Station and Natural Area organization. It stewards 2,500 protected and forested acres in Norfolk, Connecticut. It focuses on long-term scientific study of vegetation succession and ecosystem health. In 2026, it celebrated its centennial year. For more information, visit the Aton Forest website.