Aimée Classen is an American

ecologist Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

who studies the impact of global changes on a diverse array of terrestrial ecosystems. Her work is notable for its span across ecological scales and concepts, and the diversity of terrestrial ecosystems that it encompasses, including

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

meadow A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non- woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or artif ...

bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...

s, and

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred ...

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

and

boreal Boreal may refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch *Boreal climate, a climate characterized by long winters and short, cool to mild ...

climates. She is currently the director of the University of Michigan's Biological Station (UMBS), a student and faculty research organization at the university devoted to studying various types of environmental change. Classen is editor-in-chief of the

Ecological Society of America The Ecological Society of America (ESA) is a professional organization of ecological scientists. Based in the United States and founded in 1915, ESA publications include peer-reviewed journals, newsletters, fact sheets, and teaching resources. I ...

(ESA) journal ''Ecological Monographs''.

Education

Classen attended

Smith College Smith College is a private liberal arts women's college in Northampton, Massachusetts. It was chartered in 1871 by Sophia Smith and opened in 1875. It is the largest member of the historic Seven Sisters colleges, a group of elite women's c ...

, in Massachusetts, where she completed her bachelor's degree in

biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditar ...

in 1995. She then went on to graduate studies at

Northern Arizona University Northern Arizona University (NAU) is a public research university based in Flagstaff, Arizona. It was founded in 1899 as the final public university established in the Arizona Territory, 13 years before Arizona was admitted as the 48th state. ...

, where she obtained her PhD in biology in 2004. Afterwards, in 2005 she completed her postdoctorate fellowship at the Oak Ridge National Laboratory in Tennessee and continued there as a staff scientist until 2008.

Career

Classen began her first teaching position as an assistant professor in the Department of Ecology and Evolutionary Biology at the University of Tennessee-Knoxville. In 2015, she became an adjunct associate professor at the university. During this period, she began to hold multiple positions at a time. From 2014 to 2018, she served as an associated professor at the

Natural History Museum of Denmark The Natural History Museum of Denmark ( da, Statens Naturhistoriske Museum) is a natural history museum located in Copenhagen, Denmark. It was created as a 1 January 2004 merger of Copenhagen's Zoological Museum This is a list of natural his ...

in Copenhagen. During that same time, she became a faculty member in the Center of Macroecology at the

University of Copenhagen The University of Copenhagen ( da, Københavns Universitet, KU) is a prestigious public university, public research university in Copenhagen, Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in ...

in 2014 and an adjunct professor at the

Victoria University of Wellington Victoria University of Wellington ( mi, Te Herenga Waka) is a university in Wellington, Wellington, New Zealand. It was established in 1897 by Act of New Zealand Parliament, Parliament, and was a constituent college of the University of New Z ...

in New Zealand in 2016, positions which she continues to hold today. Finally, from 2018 to 2020, Classen served four simultaneous roles at the

University of Vermont The University of Vermont (UVM), officially the University of Vermont and State Agricultural College, is a public land-grant research university in Burlington, Vermont. It was founded in 1791 and is among the oldest universities in the United ...

: professor for the Rubenstein School at the

, director for the George D. Aiken Forestry Sciences Laboratory, fellow of the Gund Institute for Environment, and adjunct professor for the Department of Biology. Classen's most recent appointments are as professor of ecology and evolutionary biology at the

University of Michigan , mottoeng = "Arts, Knowledge, Truth" , former_names = Catholepistemiad, or University of Michigania (1817–1821) , budget = $10.3 billion (2021) , endowment = $17 billion (2021)As o ...

and director of the University of Michigan Biological Station. She was appointed to the directorship in the summer of 2020.

Research

Classen studies diverse ecosystems worldwide to predict how

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

will alter ecosystems including

forests A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

meadows A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non-woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or artifici ...

, and

bogs A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...

in the tropical zone and

and

temperate climates In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

. She also studies organisms in soil and the effects of biodiversity underground on ecosystems. Her research on soil microbes is important to understanding mechanisms such as carbon storage and the impact of climate change. Classen participated in a second phase of the "Warming Meadows" project. Warming Meadows was started by John Harte. From 1991-2019, Harte heated target plots of soil at the Rocky Mountain Biological Laboratory to simulate the effects of increased temperature due to global warming. Heated and unheated plots were matched to control for differences other than temperature. Heat dried the surface soil, nearly reversing the populations of woody shrubs like sagebrush and forbs (broad-leafed herbaceous plants) by year 27 of the project. This also changed the

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

of the area: with woody shrubs absorbing almost double the energy of wildflowers, In a second phrase of the project, scientists including Classen gathered samples from the plants and soil, to examine the effects of those decades of rising temperatures on species below ground. By monitoring 60 different sites in the

Tibetan Plateau The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia covering most of the T ...

she has been able to study biodiversity in

alpine grassland Montane grasslands and shrublands is a biome defined by the World Wildlife Fund. The biome includes high elevation grasslands and shrublands around the world. The term "montane" in the name of the biome refers to "high elevation", rather than th ...

under varying climate conditions involving temperature, rainfall, and soil acidity. This is enabling scientists to better understand ecosystems in terms of multiple functions which they provide, how those functions are controlled and how they may be effected by climate change. Classen was a principal investigator (PI) for WaRM, a project measuring the impact of direct and indirect effects of warming on mountain landscapes in 10 nations and 5 continents. In research reported in ''Nature'' (2017) she and her colleagues used changes in elevation as a surrogate for changes in temperature. Examining nutrient cycles at different elevations, they were able to predict that changes in temperature are likely to cause imbalances between nitrogen and phosphorus cycles at high elevation treelines and disrupt montane ecosystems. In 2020, Classen and Appala Raju Badireddy received a Gund Institute Catalyst Award to develop low-cost, flexible sensors to better study biogeochemical responses such as changes in soil nutrients like nitrogen in extreme environments. In addition to soil, Classen has studied the relationships between large animals, parasites and ecosystems. A study focused on the relationship between infectious diseases in ruminants and methane release, reporting that sick animals produced more methane. Classen described the interaction between climate's effects on disease and disease's impact on climate as a "vicious cycle". As part of an interdisciplinary partnership between The Living Earth Collaborative at

Washington University in St. Louis Washington University in St. Louis (WashU or WUSTL) is a private research university with its main campus in St. Louis County, and Clayton, Missouri. Founded in 1853, the university is named after George Washington. Washington University i ...

, the

Missouri Botanical Garden The Missouri Botanical Garden is a botanical garden located at 4344 Shaw Boulevard in St. Louis, Missouri. It is also known informally as Shaw's Garden for founder and philanthropist Henry Shaw. Its herbarium, with more than 6.6 million ...

and the

Saint Louis Zoo The Saint Louis Zoo, officially known as the Saint Louis Zoological Park, is a zoo in Forest Park, St. Louis, Missouri. It is recognized as a leading zoo in animal management, research, conservation, and education. The zoo is accredited by the ...

, Classen has helped to model the impact of herbivore parasites on the broader ecosystems of which they are a part. Researchers found that non-lethal parasites reduced the feeding rates of caribou, reindeer, and other herbivores, which in turn decreased their impact on plants and lichens and available biomass. The research is an example of how frequently overlooked factors in an ecosystem can have significant ecological consequences. In 2020, Classen was recognized by the

(ESA) for: “creative leadership and vision for international research collaborations using mountain ecosystems as models for climate change research… and for stellar research contributions to the ecology of global environmental change, including how soil microbial diversity shapes ecosystems, and environmental controls on soil nutrient cycling and carbon storage.”

Honors and awards

* 1991–1993. NCAA All-American in

swimming Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...

* 1995. Sigma Xi * 1995. Smith College Brown Botany Prize * 2002. Best paper, Soil Science Society of America S-7 * 2002–2003. Merriam-Powell Center for Environmental Research Graduate Fellow * 2006. US Department of Energy Outstanding Mentor Award * 2007. Promising young scholar, The US National Academy of Sciences Frontiers in Science * 2007. Kavli Foundation Science Fellow * 2007. Best paper, Soil Science Society of America S-7 * 2012. UT College of Arts and Sciences Research and Creative Achievement Award * 2012.

Pi Beta Phi Pi Beta Phi (), often known simply as Pi Phi, is an international women's fraternity founded at Monmouth College, in Monmouth, Illinois on April 28, 1867 as I. C. Sorosis, the first national secret college society of women to be modeled after ...

teaching award * 2014. Promising young scholar, The US National Academy of Sciences, Frontiers in Science * 2015. Association for Women Soil Scientists Mentoring Award - to recognize individuals (male or female) who have made significant contributions to the education, professional growth, & achievement of females in soil science * 2020, Fellow,

(ESA) * 2020, Gund Institute Catalyst Award

References

{{DEFAULTSORT:Classen, Aimée Living people Year of birth missing (living people) Smith College alumni Northern Arizona University alumni University of Michigan people University of Tennessee faculty American ecologists Ecology journal editors Women ecologists Climatologists Soil scientists Biodiversity Climate change and the environment Climate change and agriculture