What can seeds and tiny lake insects tell us about the environment and how it has changed over time?

That’s what a multi-university research team — including students and faculty from ASU, Rutgers and Purdue — wanted to find out.

They traveled to the Edmund Niles Huyck Preserve in upstate New York to do just that — and what they discovered could help us better understand the relationship between human activity, local ecosystems and long-term climate change.

The team included principal investigator Love Eriksson, Fulbright visiting student researcher from Sweden at ASU; Michael Monzón, PhD student at Purdue University; Lauren Adamo, associate professor of geology at Rutgers University; Lauren Weidner, assistant professor in the School of Interdisciplinary Forensics at ASU; Krystal Hans, assistant professor and lab director at Purdue University; Matthew San Miguel, geology student from Rutgers; and Christopher Morales, ASU student from Weidner’s lab.

By conducting a preliminary paleoecological survey of Lake Myosotis, a lake that was created in the 1800s by building a dam, the team was able to study how the natural landscape and local ecosystem have changed over the past two centuries.

What lake mud can tell us about ecological change

By collecting sediment cores — long tubes of sediment from the lake bed — the team was able to examine preserved seed, plant and insect remains that have accumulated over the past 200 years in a neat stratigraphical sequence.

“These often very small fossils give us clues about what the lake and surrounding landscape looked like in the past,” Eriksson said. “Photos can help, but the best way to identify ancient seeds or insect remains is by comparing them to their modern counterparts at a reference collection. Many species haven’t changed much in thousands of years, so even when we’re looking at material that’s 200 or even 8,000 years old, we can still match the species with those still present today.”

Sediment cores provide insight into the earliest stages of the lake’s formation. Initially, the presence of pondweed (Potamogeton pusillus), which grows in shallow water, indicates a young, shallow lake. Over time, this species was replaced by large amounts of submerged plants like common naiad (Najas flexilis) and green algae (from the Characeae family), which prefer deeper water. This brief window of ecological change reflects the lake’s transition from a shallow basin to the deeper lake we see today.

As the lake deepened over time, shoreline and wetland plants — such as knotweed (Polygonum) and sedges (Carex) — became increasingly abundant, reflecting the formation of a wetter, more established environment. In the upper, more recent sediment layers, grasses and shrubs appear more frequently, suggesting the surrounding forests were beginning to thin. This shift aligns with historical maps, which show the northern half of the lake being cleared to make way for a road and research cabins.

Insect fossils reveal a thriving ecosystem

Equally fascinating were the insect remains, or sub-fossil insects, preserved in the lake sediment — creatures like water fleas, mites and various beetles that thrive in wet, plant-rich environments.

“Insects are particularly helpful in tracking environmental change,” Eriksson explained. “Because their life cycles are so closely tied to specific plants and water conditions, their presence or absence can tell us a lot about how the ecosystem was functioning at different times.”

Together, the insect and plant data show that the lake has supported a diverse and resilient community of organisms over time. Researchers also observed evidence of a past erosion event in the sediment, suggesting a possible change in the surrounding landscape, such as increased rainfall or human activity.

A living lab for the future — and why it matters

The most recent layers of sediment aligned closely with a plant survey conducted by the preserve in 2022, confirming the accuracy of the core data. Today, Lake Myosotis remains a vibrant freshwater ecosystem with a variety of native flora and fauna — a living record of the changes it has weathered over time.

And this report is just a preliminary step; the research will continue, with further analysis planned on geological samples and nonbiting midges (Chironomidae). The full findings will be shared with the Huyck Preserve later this year.

But why is this research important in the first place?

“Even when we preserve natural spaces, we’re often still altering them in subtle ways,” Eriksson said. “This project shows how damming a lake, building roads or maintaining forests can have long-lasting effects on ecosystems.”

While the study couldn’t provide a clear picture of how climate specifically changed over the past century, it laid critical groundwork for future research. Analyzing other organisms found in the lake, like nonbiting midges, could offer more clues about past climate conditions.

By peering into the past, these researchers are helping scientists, land managers and the public better understand how today’s actions shape the landscapes of tomorrow.