For ecologists around the world, Cedar Creek Ecosystem Science Reserve, a College of Biological Sciences field station, is synonymous with major discoveries rooted in long-term research. It’s where David Tilman first demonstrated the importance of biodiversity for ecosystem resilience, and many other researchers documented the unexpected long-term ecosystem effects arising from biodiversity loss, nutrient shifts, and climate change. In 2024 alone, Cedar Creek supported the work of 32 lead scientists whose projects included over 40 postdoctoral researchers and graduate students and 80 undergraduate researchers.
The findings generated by long-term experiments at Cedar Creek are so influential that an average of 95 publications cite Cedar Creek research each day. Work at Cedar Creek has also been central to putting the UMN at the top of the global rankings in ecology research. Cedar Creek’s reach extends across UMN, with faculty from nine UMN colleges working at or visiting the field station. From a global perspective, Cedar Creek (CDR) LTER maintains hundreds of freely available data sets that were used by scientists in 44 countries in 2024 alone.
The experiments that have given Cedar Creek its global reputation have been made possible in part by sustained support from the National Science Foundation (NSF). Cedar Creek is part of NSF’s Long-Term Ecological Research (LTER) network, which includes 28 sites around the globe with a common goal of uncovering the principles underlying ecosystem health. Cedar Creek joined the network in 1982, establishing some of the most famous long-term ecological experiments in the world over the ensuing four decades. NSF recently renewed funding for the eighth time, which means six more years of support.
“The LTER is the research grant that pays for some of our highest profile experiments,” says Eric Seabloom, the interim director of Cedar Creek. “It keeps the really basic experiments going. But you can think of these experiments as research platforms or experimental infrastructure that researchers can leverage to get additional funding to ask their own unique questions within the context of the broader experiments."
Seabloom estimates that the reserve leverages $3 of funding from alternative sources for every dollar they get from NSF in support of long-term research. Often, these grants support research that is nested within the LTER-supported experiments, but could be focused on specific topics, from pollinators to lichens.
A new framework to increase impact
Plant biodiversity is a key theme of all experiments connected with the CDR LTER. But after nearly 40 years of long-term data collection, CDR LTER leadership is using this new funding to create a new, integrated framework that links the most important long-term projects, providing a deeper understanding of how ecosystems respond to and recover from disturbances like fire, loss of biodiversity, nutrient pollution, and climate change.
These projects include studies that track the natural recovery of ecosystems following agricultural abandonment and also experimental studies where researchers alter fire, soil tilling, nutrients, pollution, climate, and many other factors. On one end of the spectrum is an “old field” succession study, wherein abandoned pastureland acquired by the reserve is studied for gradual changes in biodiversity, soil health, and nutrient cycling.
On the opposite end of the spectrum is a highly manipulated experiment called BioCON. In combination with an added experimental treatment (known as TerraCON), it simulates global change in a native prairie ecosystem. Each plot contains varying numbers of prairie plants that are subjected to treatments that simulate a range of possible future conditions, including increased drought, temperature, carbon dioxide levels, and nutrient pollution.
According to the CDR LTER team, integrating these many studies will provide new insights from these long-term studies.
“We've always had a bunch of really long-term research platforms examining diversity and global change in grasslands and forests. However, these were often studied independently. These studies have a lot of potential to complement each other to provide new insights,” says Seabloom. “Our focus over the next six years is to weave these together and make them work more complementary.”
Setting the standard
With that in mind, Cedar Creek leaders plan to more firmly establish standardized sampling protocols that will allow scientists to examine data across a broader scope of their experimental platforms.
“One of the new directions being pursued in this LTER renewal is intentionally doing identical measurements across the different experiments,” says Peter Kennedy, a professor in the College of Biological Sciences Department of Plant and Microbial Biology, one of the CDR LTER co-leaders.
“By measuring the same variable, be it the amount of carbon in the soil or water in the air, across different experiments in grasslands, savannas, and forests, we have the chance to uniquely integrate an ecological understanding of the Cedar Creek landscape and determine how much the ecological findings in one ecosystem type are shared more broadly.”
Simplifying and standardizing efforts across these categories will allow interested scientists to more deeply compare long-term dynamics of altered and non-altered environments, nutrient-enriched and non-nutrient-rich environments, and more.
The kinds of long-term studies that make Cedar Creek and other LTER sites unique are rare and get more valuable each year. However, keeping these projects running across decades is challenging and rests on the work of multiple generations of dedicated scientists.
“Long-term research is like a time machine,” said Elizabeth Borer, a Regents Professor in the College of Biological Sciences’ Department of Ecology, Evolution, and Behavior, and incoming CDR LTER co-lead with Kennedy. “Each year adds another layer of insight, and only by looking across decades can we see how ecosystems respond to naturally and experimentally changing environmental conditions. We gain new insights with each decade of observation, spanning multiple careers.”
A source of unexpected insights
The U.S. LTER program, and Cedar Creek, in particular, demonstrate how long-term ecological research offers a unique window into how ecosystems change. Long-term studies don’t just track trends — they reveal unexpected shifts and surprises that reshape scientific understanding. And because the studies and data sets span decades, they can answer questions that weren’t even imaginable when the work began. Comparing results across Cedar Creek’s many observational and experimental platforms will amplify this power, opening new frontiers of discovery and potentially revealing patterns no single study could detect on its own.
“The value of long-term research compounds over time,” says Borer. “These records don’t just confirm what we expect — they reveal surprises, sometimes after decades, that help us answer questions we couldn’t have imagined at the start. As we begin to compare long-term responses across Cedar Creek’s platforms, we expect new insights that will help us understand how ecosystems will function under accelerating environmental changes.” –Adara Taylor