“It’s just a beautiful place,” says Professor of Earth and Climate Sciences Beverly Johnson, offering a simple but apt description of a coastal marsh where she and 乐播传媒 students have done research for more than two decades.

In recent years, Johnson’s summer research, done alongside 乐播传媒 students, has been studying blue carbon sinks at four Maine sites, including 乐播传媒 Morse-Mountain Conservation Area, the aforementioned “beautiful place,” which 乐播传媒 oversees as a place for conservation, preservation, research, and education.

Theophil Syslo/乐播传媒 College

Johnson’s research recently contributed to a groundbreaking report from the Environmental Protection Agency on blue carbon 鈥� the carbon sequestered in vegetated coastal areas.

The EPA report that Johnson co-authored was the first-ever regional assessment of blue carbon sinks from Long Island, N.Y., to Maine. The Maine data comprised 25 percent of the overall assessed habitat in the report, and 80 percent of that data came from Johnson鈥檚 lab. 

“I’ve been studying in BMMCA for 22 years, and it’s always quite different when I go in. I learn something new every time.”

Beverly Johnson

This summer, Johnson鈥檚 team measured greenhouse gas fluxes in salt marshes, looking at carbon dioxide going into plants and soils in healthy marshland 鈥� as well as methane, a greenhouse gas released from degraded coastal systems.   

鈥淲e’re trying to understand these degraded parts of salt marshes, if there’s an opportunity to restore them,鈥� Johnson said. 鈥�If we restore a salt marsh that is degraded right now, can we turn it back into a carbon sink? Because healthy salt marshes are very valuable.鈥�

Engaging students as research colleagues reflects a guiding philosophy for many 乐播传媒 professors. “Hands-on activities, hands-on research with students up through senior theses prepares students very well for a world and life beyond 乐播传媒.”

And it never gets old. “I’ve been studying in BMMCA for 22 years, and it’s always quite different when I go in. I learn something new every time.”

This article was prepared by 乐播传媒 College using Federal funds under award NA22OAR4170121 from the University of Maine System/Maine SeaGrant, U.S. Department of Commerce.  The statements, findings, conclusions, and recommendations are those of the author(s) and do not necessarily reflect the views of the University of Maine System/Maine SeaGrant or the U.S. Department of Commerce.

Five 乐播传媒 students jumped out of a pair of Subarus at Sprague Marsh in the midcoast Maine town of Phippsburg on what promised to be a hot day in mid-July. Expecting to be swarmed by biting black flies and mosquitos, they came prepared.

In an instant they pulled on pants, shirts and hoods 鈥� all made from bug netting 鈥� and  grabbed equipment. As her classmates recorded notes in yellow field journals, Fiona Wilson 鈥�25 of Barnstead, N.H., stood in the marsh and struck a pose, hands on hips, like the lead explorer on an expedition.

This summer, these intrepid students are working with Professor of Earth and Climate Sciences Beverly Johnson to gather sediment cores from four Maine salt marshes to help inform the U.S. Environmental Protection Agency鈥檚 ongoing study of blue carbon 鈥� carbon dioxide from the atmosphere that is sequestered in vegetated coastal areas, including salt marshes and seagrass meadows.

The students are among the first in the state to use a state-of-the-art greenhouse gas analyzer that will tell a more complete story of blue carbon 鈥渟inks鈥� in Maine salt marshes. That, in turn, will provide further evidence to show whether marsh restoration could significantly help mitigate the effects of climate change by increasing carbon sequestration in salt marshes. 

It鈥檚 work Johnson has done for the past decade to help scientists, stakeholders and policy makers, including the EPA, better understand the potential of blue carbon in the Northeast.

Blue carbon is an especially 鈥渉ot topic now that seems to capture the imagination of the general public,鈥� said Phil Colarusso, a biologist at the EPA鈥檚 Boston office. That鈥檚 because scientists only discovered recently that blue carbon sinks are far more efficient than forestland (called green carbon) at sequestering carbon from the atmosphere. 

鈥淚f you compare the same area of forest to salt marshes and other blue carbon systems in terms of how much carbon is going into the ground, blue carbon systems are moving four to 10 times more carbon into the ground than forests. So they are very effective at photosynthesis and then sequestering and storing that carbon for a long period of time,鈥� said Johnson, who is at the forefront of this research in Maine and one of the region鈥檚 top salt marsh experts. 

Johnson is a founding member of the Maine Blue Carbon Network, which provides a forum to discuss Maine鈥檚 blue carbon resources, as well as a member of Gov. Janet Mills鈥� Maine Climate Council. 

This summer, Johnson鈥檚 five 乐播传媒 student researchers worked in marshes between Wells and Phippsburg looking at historic features that restrict carbon sequestration in salt marshes, like century-old dikes with roads built across them. They also looked at the amount of carbon being stored in the marshes in real time, using 乐播传媒鈥� powerful new greenhouse gas analyzing tool, the LI-COR device. 

Specifically, the 乐播传媒 team is looking at how unhealthy marshes, or those where the tides are restricted due to development, not only function less effectively as carbon sinks, but also produce methane, a greenhouse gas, in the rotting, decomposing areas of the restricted marshland.

鈥淚f we open up the tidal restrictions and get the tides back to where they need to be, you could conceivably reduce the amount of methane coming out of (restricted salt marshes). That鈥檚 the prevailing thinking,鈥� Johnson said as she scanned Sprague Marsh.

Restoring coastal marshland in Maine also could allow more of it to serve as carbon sinks, she said. Other benefits of restoration include improving habitat for fish and birds, providing nutrients for nearshore fisheries, and offering protection from storm surges and coastal erosion. 

This summer, Johnson鈥檚 research interns used her new portable greenhouse gas analyzing system to measure the fluctuation in greenhouse gasses in designated areas in the four marshes 鈥� both in areas where the marshes are restricted and where there are no restrictions. It鈥檚 work that used to take six hours to attain a single measurement back in her lab but now, thanks to the LI-COR device, takes minutes. 

Johnson鈥檚 lab is among the first in Maine to use the state-of-the-art greenhouse gas analyzing system, producing this kind of blue-carbon data.

鈥淲ith the LI-COR, you’re getting the CO2 and methane and greenhouse gas flux readings in real time. It is brand-new technology. We are the first to use it in Maine salt marshes. That is so exciting,鈥� said Anna Sarrazin 鈥�24 of Berlin, Conn. 鈥淚 feel at 乐播传媒 we have a unique opportunity as undergrads to be a part of something that at larger institutions would be available only to graduate students.鈥� 

On that hot mid-July day at the 乐播传媒鈥揗orse Mountain Conservation Area, Kate Dickson 鈥�24 of Princeton, Mass., hiked into the marsh with some of that technology on her back: a 40-pound case containing part of the LI-COR device which is operated from an app on her phone.

When Dickson reached the first flagged sample area, a cylinder 10 inches in diameter was placed in the marsh and the LI-COR device placed on top of it. Soon air was cycled through it and the device started reading the amount of carbon dioxide and methane in the cylinder. After a few minutes, the readings were used to determine the amount of greenhouse gasses either taken up by the plants or released from the soils into the atmosphere at that location.

The data, at first, was slow in coming. It was supposed to appear on Dickson鈥檚 cell phone, but a momentary technological hiccup prevented the data from loading. Together Dickson and Johnson worked to sync the apps on their phones with the LI-COR system on Dickson鈥檚 back. They worked as a team, literally with their heads together, as Johnson addressed the problem with aplomb.

Dickson sought a summer research position in Johnson鈥檚 lab to provide fodder for her senior thesis. But the All-American rower said learning about the threat posed by restricted marshland gave her summer work at 乐播传媒 new meaning.

鈥淭idal restrictions and human involvement in marshes not only stops (the marsh) from being a carbon sink, but it actually releases a ton of methane, which is a greenhouse gas that is about 25 times worse than carbon dioxide. So unhealthy marshes are a double-edged sword,鈥� Dickson said. 鈥淚t鈥檚 a real privilege to be out there walking around in the marsh and doing some good work.鈥�

Right back at you, Johnson indicated, with a nod to her student. 鈥淭his is the most productive summer I have ever had with students. It is one of my best teams,鈥� she said.

The students started that day with Johnson taking these readings in the healthier part of the marsh, on the side closest to the ocean. In the afternoon, they took readings on the inland side of the marsh, where an 80-year-old gravel road built during World War II restricted the tides. 

As she knelt in the Sprague Marsh in mid-July collecting water samples, Sarrazin was all-in on helping Johnson pursue different lines of inquiry into blue carbon sinks. When told that the data she gathered might contribute to a future EPA blue-carbon report, the rising senior was delighted, but not surprised. 

鈥淚 think this work is really groundbreaking and I鈥檓 really excited to turn that into a senior thesis that is going to have meaning outside of an undergraduate thesis at 乐播传媒,鈥� said Sarrazin. 鈥淚t鈥檚 extremely relevant.鈥�

The student research team was funded by grants totalling around $330,000 from the Maine Sea Grant and Maine Community Foundation, as well as from smaller grants from the Maine Climate Science Information Exchange and Maine Coast Heritage Trust. 

Johnson said time is of the essence when it comes to restoring and preserving Maine salt marshes that serve as blue carbon sinks because of the threat of sea-level rise. While salt marshes can adapt to smaller increments of sea level rise, too much too quickly can literally drown them. 

鈥淭he predictions for sea level rise due to continued warming over the next 20 years will result in the loss of salt marshes unless something is done,鈥� Johnson said. 鈥淓nhancing blue carbon habitats and employing other natural climate solutions, while decreasing our dependence on carbon-based fuels, will slow the warming of our planet and reduce the amount of sea level rise. But time is short and we need to act now.鈥�

This article was prepared by 乐播传媒 College using Federal funds under award NA22OAR4170121 from the University of Maine System/Maine SeaGrant, U.S. Department of Commerce.聽 The statements, findings, conclusions, and recommendations are those of the author(s) and do not necessarily reflect the views of the University of Maine System/Maine SeaGrant or the U.S. Department of Commerce.

To do research at the extreme north or south of the planet, you need a good enough project to get funding from the National Science Foundation or another government agency. You also have to be organized, independent, and technically excellent.

鈥淵ou have to be able to work alone, be flexible, have a plan and be willing to change it,鈥� says Professor of Biology Will Ambrose, who studies life on the Arctic Ocean floor. 鈥淭hat鈥檚 what I tell my students.鈥�

And they listen.

Before they attached video cameras to whales, drilled through 15 feet of ice to lakes below, or tracked ancient glaciers, the 乐播传媒 alumni who conducted Antarctic research in recent months benefited from the same education available to all 乐播传媒 biology and geology majors 鈥� one that involves plenty of fieldwork and close collaboration with professors who involve students in their own research.

乐播传媒 Professor of Biology Will Ambrose (center) and Kelton McMahon ’05 (right) ride with Gro Harlaug Olsen of the University of Tromso through Kongsfjorden in Svalbard, Norway. (Courtesy of Kelton McMahon)

鈥淚 had the opportunity to conduct some really amazing cutting-edge research with world-class researchers,鈥� says Kelton McMahon 鈥�05, an assistant professor of oceanography at the University of Rhode Island who traveled to Antarctica in 2016 and plans to return next year. 鈥淭hat is not common in a lot of universities for undergraduates.鈥�

McMahon, who鈥檚 developed chemical tools to answer biological questions, started studying at the intersection of biology and geochemistry at 乐播传媒. For a marine ecology course taught by Ambrose, he was assigned an independent research project.

Several of Ambrose鈥檚 former students, including Ari Friedlaender 鈥�96, Doug Krause 鈥�99, and Carolynn Harris 鈥�11, have gone on to conduct research in Antarctica. For Ambrose, gaining the skills to work independently is critical to success as a scientist. 聽

Professors Michael Retelle (left) and William Ambrose on the island of Ing酶ya, Norway. (Randall Hyman)

鈥淢y philosophy has always been that by the time students get to be seniors, they have to be functioning like a first-year grad student, or close,鈥� he says. 鈥溊植ゴ� students are bright, and that鈥檚 how I treat them.鈥�

McMahon鈥檚 interest in aspects of geochemistry also led him to take a course with Professor of Geology Beverly Johnson. He worked with both Ambrose and Johnson for his marine ecology project, which concerned the diets and movements of a killifish species in a Maine salt marsh. That turned into McMahon鈥檚 first published scientific paper.

Johnson, who also co-advised Carolynn Harris, is used to working closely with students.

Professor of Geology Beverly Johnson (right) joins her environmental geochemistry students to study the water quality of Lake Andrews. (Phyllis Graber Jensen/乐播传媒 College)

鈥淭hey drive the research that I do,鈥� she says. 鈥淭hey come in and often have their own questions, and are eager to get involved in some of the questions I鈥檓 pursuing for my own research.鈥�

Working closely with her students benefits both her and them, Johnson says. The students鈥� work turns up geochemical data that both student and professor can use 鈥� and because the data must be carefully collected in a specific way, students learn technical skills that can serve them well in graduate school and beyond.

Students also help Johnson think about her own research in new ways.

鈥淪tudents bring so much to a project, they really do,鈥� Johnson says. 鈥淭hey have different ways of thinking about things. They have different experiences at 乐播传媒 than I had as an undergraduate, so they鈥檒l bring in what they learned from other classes. I consider them more collaborators and colleagues.鈥�

“It’s training the next generation of scientists, if not polar scientists.”

Both Ambrose and Johnson again advised McMahon for his senior thesis, on ice algae and phytoplankton in the Arctic Ocean. He did fieldwork in Svalbard, a Norwegian archipelago above the Arctic Circle. It鈥檚 an area where scientists can see up close the rapid effects of climate change on the polar regions, and it鈥檚 a popular destination for 乐播传媒 students and faculty interested in polar science.

One of them is Professor of Geology Mike Retelle, who studies the movements of glaciers on the islands and usually brings students with him on his trips. While 乐播传媒 undergraduates work within the scope of Retelle鈥檚 ongoing research, they design and execute their own projects.

鈥淭hey help with the preparation before they go into the field, and they see the project right through the end,鈥� Retelle says. 鈥淚t鈥檚 how field science is done. It鈥檚 not a canned experiment.鈥�

The opportunity to work directly with students was what drew Retelle to 乐播传媒 in the first place, he says.

鈥淚t鈥檚 fun seeing them experience something you鈥檙e so passionate about,鈥� he says. 鈥淚mportantly, it鈥檚 training the next generation of scientists, if not polar scientists.鈥�

Professor of Geology Mike Retelle poses with Allie Balter ’14 and Greg de Wet ’11 at a field site in Svalbard, Norway, in 2013. Balter, now a graduate student at the University of Maine, conducted research in Antarctica in recent months. (Courtesy of Greg de Wet)

One of Retelle鈥檚 first students to catch what he calls the 鈥淎rctic bug鈥� was Brenda Hall 鈥�90. Now a professor in the School of Earth and Climate Sciences at the University of Maine, she studies glacial history and paleoclimatology. She鈥檚 made more than two dozen research trips to Antarctica.

As an undergraduate, Hall traveled with Retelle to Canada鈥檚 Resolute Island to research lakes.

鈥淗e鈥檚 really good at explaining things in the field especially,鈥� she says. 鈥淥ne of the things I like about fieldwork is that it鈥檚 fun, and Mike really managed to make the work interesting. That鈥檚 something that I鈥檝e kept with me.鈥�

Retelle later mentored Hall during her graduate school search and connected her with faculty at UMaine, where she earned a doctorate. Now herself a teacher and adviser to students 鈥� including Allie Balter 鈥�14, who traveled to Svalbard with Retelle as a 乐播传媒 student and went to Antarctica with Hall this year 鈥� she brings both undergraduate and graduate students into her research, early and often.

Brenda Hall 鈥�90 and UMaine undergraduates Laura Mattas and Tyler Pollock take notes about an Antarctic boulder they鈥檙e about to sample. (Courtesy of Allie Balter)

鈥淕etting students involved in research early is really critical,鈥� she says. 鈥淢ike did that with me, and I do that with my own students.鈥� 聽

After his own Arctic research experience, Kelton McMahon wrote a senior thesis that was also published as a scientific paper. He鈥檚 since collaborated with both Ambrose and Johnson on several projects as he moved through graduate school at the MIT-WHOI Joint Program in Oceanography, postdoctoral positions at the University of California, Santa Cruz, and now in his faculty role at the University of Rhode Island.

Working with his advisers was 鈥渁 phenomenal opportunity to think transformatively, to learn how to think like a scientist,鈥� McMahon says.

鈥淚t gave me an incredible leg up as I got to graduate school 鈥� I had done oceanographic cruises, I鈥檇 published multiple papers, I鈥檇 presented at conferences, all because I had been able to work with these professors.鈥�

Professor Emeritus of Geology John Creasy, whose appointment to the 乐播传媒 faculty in 1975 ushered in the thriving modern era for geology studies at 乐播传媒, died June 21. He was 71 years old.

Creasy earned a B.S. with high distinction in geology from Colorado State University in 1967 and completed a Ph.D. at Harvard University in 1974. He taught briefly at Middlebury College before joining the 乐播传媒 faculty. He retired in 2014.

John Creasy marches in the academic procession at Commencement in 2012. (Phyllis Graber Jensen/乐播传媒 College)

Creasy鈥檚 arrival at 乐播传媒 coincided with seismic shifts both at the college and in the discipline of geology. At 乐播传媒, he was part of a major expansion of the faculty and an invigoration of the curriculum under President Hedley Reynolds. At the same time, Creasy’s coming of age as a geologist coincided with the field鈥檚 embrace of the revolutionary theory of plate tectonics, the idea that the earth鈥檚 crust is made of massive plates that can move around.

Against that backdrop, Creasy used the resources at hand, including 乐播传媒鈥� relatively new Short Term option and the senior thesis program, to expand and deepen the geology major into today鈥檚 highly rigorous program, one emphasizing extensive fieldwork (a tradition fostered by his predecessor, Roy Farnsworth), intensive lab work, and a required two-semester thesis.

David Bailey 鈥�81, professor of geosciences and chair of the department at Hamilton College, was one of Creasy鈥檚 early students, and he recalls how the 1973 oil crisis also contributed to making geology 鈥渁n up-and-coming field of study.鈥� The hiring of Creasy and another young geologist, Patricia Cashman (who would go on to a long career at the University of Nevada in Reno), added to the sense that suddenly, geology at 乐播传媒 was hip.

鈥淢y freshman year, I took a geo course on a whim,鈥� recalls Professor of Geology Dykstra Eusden 鈥�80. 鈥淗ere was this young guy who was so into plate tectonics, which was brand-new. He just captivated me and a whole bunch of other kids.鈥�

Eusden, who was hired by Creasy in 1988, recalls Creasy leading a special-topics course on plate tectonics that involved 鈥渞eading the brand new peer reviewed papers.鈥� It was more than a thrill, Eusden says, 鈥渢rying to get our heads around this new global paradigm 鈥� it was awesome!鈥�

Near Flagstaff, Arizona, in 2011, on his final Short Term trip to the U.S. Southwest, John Creasy poses next to examples of “volcaniclastic” rock, which has been moved or affected by wind, water, or similar action. (Photograph by Dykstra Eusden ’80)

For many geology students, the excitement of that youth movement 鈥� and Creasy鈥檚 high expectations as a professor 鈥� was felt during excursions far from 乐播传媒 that created, in some cases, lifelong bonds.

Bailey, for example, was a first-year when he took what would become Creasy鈥檚 signature course, a five-week Short Term trek to map the geology of the U.S. Southwest. Bailey thought the course would be a lark. Then he got into the van for the trip West.

鈥淏ut it was so good for me, and I am where I am because of him.鈥�

Driving upwards of 15 hours a day, the 20 students riding in two vans were expected to observe the passing terrain, all the way from Maine to Arizona, and make field notes. 鈥淎t the end of every day, after dinner and doing dishes, we would have a quiz on the geology of the states we drove through,” Bailey says. “John ran the course like a boot camp in geology.鈥�

And his students loved it. Tall and reserved in manner 鈥� the actor James Cromwell could be his doppelg盲nger 鈥� Creasy looked the part of the taskmaster. 鈥淲e were in awe of him, but his intensity was contagious,鈥� Bailey said. 鈥淭here was so much respect for him: I wanted to work my butt off to impress John, to achieve for John.鈥�

By 1981, Bailey鈥檚 senior year, Creasy had ramped up the department鈥檚 thesis program. 鈥淢y thesis defense at 乐播传媒 was the hardest of my career,鈥� he says. 鈥淛ohn brought in a big-name Ph.D. as part of the examining committee, and they put me in my place. My master鈥檚 and Ph.D. defenses were love fests in comparison.

鈥淏ut it was so good for me, and I am where I am because of him.鈥�

A few years ago, several geo majors from that Short Term, joined by Creasy, enjoyed a mini-reunion at an alum鈥檚 camp on Sebago Lake. 鈥淭he geology department was our home at 乐播传媒, academically and socially,鈥� Bailey says. 鈥淲hen you spend so much time in the lab and in the field together, you bond. That speaks to the power of the 乐播传媒 geology department.鈥�

“His philosophy was to teach to your strength; he didn鈥檛 shoehorn us into one area. Thirty years later, I so appreciate that gift.鈥�

Equally powerful was Creasy鈥檚 support of the junior faculty members in his department, and he helped them build teaching and research careers by giving them the freedom to follow their interests.

John Creasy poses with geology majors Saebyul Choe ’14 and Sula Watermulder ’14 during a mapping project in the Gilead Quad in western Maine. The two majors had given Creasy the matching blue bandana for the trip. (Photograph by Dykstra Eusden ’80)

鈥淛ohn gave us direction when we needed it, but also allowed us to explore and follow our passions,鈥� Eusden said. 鈥淗is philosophy was to teach to your strength; he didn鈥檛 shoehorn us into one area. Thirty years later, I so appreciate that gift.鈥�

That open-minded approach extends to the department鈥檚 hiring practices, says his colleague Professor of Geology Beverly Johnson. When Johnson, whose expertise is in biogeochemistry and paleoclimatology, was hired, 乐播传媒 at the time was actually seeking a hydrogeologist. 鈥淏ut John had the openness to consider candidates like me with other abilities,鈥� she says.

“He was a mentor and friend, almost like an older brother 鈥� a calming influence.”

As a young graduate student in the 1980s, Professor of Geology Mike Retelle had a one-year appointment to the geology faculty. His youth and energy showed; as a teacher and researcher, 鈥淚 was all over the map,鈥� he recalls.

Still, Creasy hired Retelle to a tenure-track position in 1987. 鈥淗e must鈥檝e known that I could direct that energy,鈥� Retelle says with a shake of his head. 鈥淛ohn hired people and let them do what they were best at. He let us rock and roll.鈥�

John Creasy in 2004.

Importantly, adds Retelle, Creasy chose to serve as department chair for long stints in the 1990s, shouldering loads of administrative work as Retelle and Eusden were establishing themselves. 鈥淗e protected us,鈥� Retelle says. 鈥淔or me, he was a mentor and friend, almost like an older brother 鈥� a calming influence. Every morning, we鈥檇 check in with each other. We鈥檇 run together. We鈥檇 talk about everything under the sun.鈥�

As a researcher, Creasy’s work added to the knowledge of the geologic history of the White Mountains. As a doctoral student at Harvard under the legendary Marland Billings, he studied ancient volcano craters, known as calderas, within the White Mountains. Through field mapping and laboratory analyses, he identified two major periods of volcanic activity 100 to 200 million years ago, associated with the opening of the North Atlantic Ocean.

In 2014, Johnson delivered the traditional retirement tribute at the final faculty meeting of the year. In it, she praised Creasy for 鈥減romoting experiential learning and inquiry-based approaches to teaching way before it became popular. His de-emphasis of traditional lectures and emphasis on field-based, hands-on data collection, coupled with subsequent laboratory analysis and interpretation of the data, has influenced the way all of us teach in geology.鈥�

In practice, Retelle recalls how Creasy 鈥済ently鈥� taught him how to teach in the field, especially during Short Term. He recalls Creasy marching his group of Short Term students to the rim of a canyon, giving them a brief overview of the wide-open space before sending them down to map the features.

鈥淲e sat on the rim watching them move around,鈥� Retelle recalls. 鈥淓ven from a mile away, by how they moved around you could see the light bulbs go on when they figured something out.鈥�

In 1901, Buffalo played host to fairgoers, stunts, and a presidential assassination 鈥� Christian Science Monitor

During the 1901 Pan-American Exhibition in Buffalo, anarchist assasinated President McKinley.

Professor of History Margaret Creighton grew up in Buffalo, yet “knew little about the exposition next door,” writes Christian Science Monitor staff writer Randy Dotinga. “No wonder. Almost all of the fair鈥檚 buildings have vanished, replaced by streets and elegant homes.”

Creighton fills the gap with her new book The Electrifying Fall of Rainbow City: Spectacle and Assassination at the 1901 World’s Fair.

She came up with the book idea after her students read Devil in the White City, about the 1893 Chicago World鈥檚 Fair, and asked her about other such fairs.

“Creighton鈥檚 curiosity about Buffalo鈥檚 past inspired her to dig into the fair and the epic tragedy that defined it,” Dotinga writes.

Creighton says that she soon learned “that an entire world surrounded this assassination, very rich and compelling and full of eccentric characters.鈥�

Students and professors dig in deep for lessons on climate change 鈥� Portland Press Herald

The primary function of the 乐播传媒鈥揗orse Mountain Conversation Area, writes Portland Press Herald staff writer Mary Pols, is “to serve as a research and educational laboratory for both 乐播传媒 students and professors.”

Case in point is Cailene Gunn ’16, whose research experiences at BMMCA with Professor of Geology Beverly Johnson led to Gunn’s job at the Pacific Northwest National Laboratory, one of the U.S. Department of Energy鈥檚 national labs.

Cailene Gunn ’16 of Granby, Conn., poses for a portrait in a marsh near 乐播传媒鈥揗orse Mountain in August 2015. (Josh Kuckens/乐播传媒 College)

Pols explains that Johnson is an expert on how coastal ecosystems capture carbon emissions. These so-called blue carbon ecosystems “sequester roughly 15 times more carbon per unit area than the upland forests.”

Johnson is part of the international policy and scientific experts who come from universities, governments, and NGOs worldwide.

Our magnetic 5-year-old is not a threat to anyone 鈥� Washington Post

Over the summer, Vanessa Kalter-Long Ford ’02 and her husband Ron Ford shared their experiences, including a first-person , as parents of a young transgender child.

They did so after a May 2016 federal directive to public schools about accommodations for transgender students sparked backlash in some states.

“The national conversation about transgender people 鈥� about our daughter, Ellie 鈥� isn鈥檛 truly about bathrooms,” Vanessa and Ron write. “It is about discrimination.”

They write:

Our daughter, like thousands of transgender and gender non-conforming children, does not want special treatment. She wants to make friends, to learn, to participate in sports, to go trick-or-treating on Halloween and wear pretty dresses on her birthday.

聽And, yes, she wants use the bathroom that matches her gender identity when she needs to pee. Not because that鈥檚 special treatment, but because that鈥檚 the same treatment everyone else receives. Our daughter wants to be included, just like everyone else.

10 questions with Val Smith, president of Swarthmore College 鈥� NBC10 Philadelphia

In a Q&A with NBC10 of Philadelphia,聽Val Smith ’75, now into her second year as president of Swarthmore College, was asked about the qualities of a good listener.

Good listening, she said, furthers the goal of making “every effort to respect the opinions and ideas of our interlocutors, even if we think we have nothing in common with them.”

There are time, she said candidly, “when I think I don鈥檛 want to listen to what other people have to say.” That’s the exact moment to “remind myself that however right I may think I am about a particular issue, there was usually always something I can learn if I let myself listen to what other people have to say.”

The result? “One鈥檚 deeply held opinion might change or be modified or gain nuance if one is able to enter into conversation with other people.”

Her poetry is much like the author herself: passionate and purposeful 鈥� Take Magazine

In a Q&A with Take Magazine, Crystal Williams talks about her work as the college’s chief diversity officer and associate vice president for strategic initiatives, then deftly switches to the meaning of a line of her poetry (she’s also a widely published poet and professor of English).

Crystal Williams is a professor of English, chief diversity officer, and associate vice president for strategic initiatives at 乐播传媒. (Photograph by Brian Fitzgerald)

The line is, “The heart is a beautiful monster; it nearly always survives its fate.”

Williams tells writer Alexa Harrison that “our hearts, or spirits, are our most robust qualities. They are from whence emerge our kindnesses and our travesties. So they can be both monstrous and beautiful and are often both 鈥� at once. This duality is what makes human beings, at least to me, so very interesting and compelling.”

In 2016, most students don’t have memories of 9/11 鈥� Portland Press Herald

A Press Herald story published on the 15th anniversary of the Sept. 11 attacks quotes Associate Professor of English Eden Osucha, who has taught the course 鈥淣arrating 9/11 in Literature and Film.鈥�

Associate Professor of English Eden Osucha. (Phyllis Graber Jensen/乐播传媒 College)

The youngest 乐播传媒 students, barely 3 years old when 9/11 took place, “don鈥檛 have personal baggage” associated with the attacks, she tells reporter Edward Murphy.

But they do carry 鈥渃ultural baggage”: the burden of comprehending all the stories of what happened that day.

At the same time, Murphy writes, “many don鈥檛 have a full understanding of the cultural landscape of America prior to the attacks because, understandably, the events of that day overshadowed the years that immediately preceded them.”

As geology students did faculty-guided fieldwork in and around the 乐播传媒鈥揗orse Mountain Conservation Area on Aug. 13, 乐播传媒 photographer Josh Kuckens followed along.

And after a long day looking down at sand, marsh, and water, the young researchers, whose work will inform and guide their senior theses, got a chance to look in a different direction 鈥� like up, into the night sky.

9:52 a.m. 鈥� Measuring up

At Popham Beach State Park, Nicole Cueli ’16 of Fort Lauderdale, Fla., sets up an a transit, or autolevel, a device used by scientists, builders, and surveyors to measure distances and elevation changes. In the distance at right is Ian Hillenbrand ’17 of Terrace Park, Ohio.

9:53 a.m. 鈥� Staff support

Hillenbrand ’17 holds a stadia rod, which is used in tandem with an autolevel to measure the elevation change between two points on the beach.

Geology majors Cueli and Hillenbrand have joined 乐播传媒 geologist Mike Retelle’s long-term work to monitor and evaluate how the area’s sandy beach systems respond to changes brought about by storms, seasonal wave climate, and rising sea level.

9:54 a.m. 鈥� Level best at Popham

Cueli uses the autolevel. In her left hand is the geologist鈥檚 trusty companion, a yellow field notebook.

10:20 a.m. 鈥� Sooner or ladder

As Dana Cohen-Kaplan ’16, of Newton Mass., steadies the ladder, Retelle downloads weather data and time-lapse images from a unit mounted on the west bath house at Popham Beach.

11:28 a.m. 鈥� Break time

Back at the 乐播传媒 College Coastal Center at Shortridge, adjacent to 乐播传媒-Morse Mountain and Popham Beach State Park, the 乐播传媒 researchers break for lunch.

Here, Cueli jokes with Retelle, who is reviewing time-lapse images from the beach, and with聽 Laura Sewall, who is director of the 乐播传媒-Morse Mountain Conservation Area and Shortridge.

1:24 p.m. 鈥� You can get there from here, but it’ll take awhile

Geology majors Cailene Gunn ’16 (left) of Granby, Conn., and Dana Cohen-Kaplan ’16 of Newton, Mass., secure benches to the top of Gunn’s car before heading out to do fieldwork at Long Marsh in Harpswell.

The distance from Shortridge to Long Marsh is just 10 miles as the crow flies, but it’s 30 miles (and a 45-minute drive) on roads that follow Maine’s infamously zig-zaggy shoreline.

2:22 p.m. 鈥� Waist deep in big muddy

Gunn suddenly finds herself waist deep in Long Marsh. “It happens, but it’s not usually this bad,” she says.

Gunn and Cohen-Kaplan have been working with geology professor Bev Johnson to measure the carbon budget of Maine’s salt marshes.

Specifically, they are measuring the amount of methane released by two different salt marshes, the Sprague River Marsh, part of 乐播传媒-Morse Mountain, and Long Marsh, in Harpswell.

Long Marsh, occupying a long, narrow glacially carved valley at sea level, has experienced restricted tidal flow for decades. As a result, its health has suffered.

3:21 p.m. 鈥� Gassing up

In early 2014 a new and wider culvert was installed beneath a road that crosses the marsh.聽 The wider culvert allows sea water to flood the marsh regularly.

The tactic is working, says Gunn, seen here taking a gas sample from the marsh. 鈥淲e can actually see the ecosystem beginning to restore itself.鈥�

Taking gas samples is necessary to measure the amount of methane being released from the marsh. Among other things, better tidal flow throughout Long Marsh should help the marsh retain more methane.

While carbon dioxide is the more prevalent greenhouse gas, methane is much more potent as a heat-trapping gas.

3:37 p.m. 鈥� Wetlands at work

Tidal marshes are paramount to the overall health of coastal ecosystems. They provide nursery habitat for important fisheries, protect against storm surges, filter out pollutants, and serve as carbon sinks.

Unfortunately, most of Maine’s salt marshes have been anthropogenically altered in some way, and many are in need of restoration to function properly.

7:25 p.m. 鈥� Setting the scene

Gunn and Cohen-Kaplan join Adam Auerbach ’16 of Silver Spring, Md., and Nathan Stephansky ’17 of Whitman, Mass., on Hermit Island., about three miles from Shortridge, where they watch the sunset from a spot called the Bath Tub.

The four students, each of whom did fieldwork or related coastal work over the summer, used Shortridge as their home base.

7:43 p.m. 鈥� Getting rooted on the rocks

Gunn does some sunset-inspired yoga.

9:16 p.m. 鈥� Back to Shortridge

Cohen-Kaplan and Cueli finish off their late supper at Shortridge.

Shortridge was donated to 乐播传媒 in the mid-1990s by John and Linda Shortridge, who had built a retirement home on the land. It has facilities for field research while also supporting other 乐播传媒 activities. Each year, some 25 student groups, representing up to 400 students, use the center.

The center sits on 79 acres of woodlands, wetlands, granite escarpments, and a glacially-scoured pond.

10:03 p.m. 鈥� Starry starry night

At night, “the Rock,” an outcropping behind Shortridge that looks out over Meetinghouse Pond, is a dark and spectacular place 鈥� a perfect spot to watch the night sky.

How will future changes in sea level affect salt marshes?

Hold on. Before tackling that question, we need to measure the changes.

On April 22, faculty and geology students traveled to the Sprague Marsh, part of the 乐播传媒鈥揗orse Mountain Conservation Area, to place rods deep in the marsh as benchmarks to measure future changes in sea level.

The students are part of the Short Term course Coastal Hazards.

taught by Professor of Geology Beverly Johnson, who was joined by estuarine ecologist David Burdick of the University of New Hampshire.

Afterward, they all adjourned for lunch hosted by Laura Sewall, director of the 乐播传媒-Morse Mountain Conservation Area.

Photographer Sarah Crosby followed along and prepared this audio slide show.

乐播传媒 environmental economist Lynne Lewis. Photograph by Phyllis Graber Jensen/乐播传媒 College.

“Desperate Alewives,” a featuring 乐播传媒 environmental economist Lynne Lewis among others, has been nominated for a New England Emmy in the category of Outstanding Environmental Program. The program is part of the MPBN series Sustainable Maine.

The 35th Annual Boston/New England Emmy Awards, sponsored by the National Academy of Television Arts & Sciences Boston/New England chapter, will be presented June 2 in Boston.

A river herring called the alewife 鈥� aka sawbelly, mooneye, gaspereau and big-eyed or spring herring 鈥� is an essential component in the fresh- and saltwater food chain along much of the Eastern Seaboard. In Maine, alewife populations have plummeted, prompting research by a group whose members include scholars from 乐播传媒, Bowdoin College and the University of Southern Maine, many of whom are featured in the MPBN segment.

.

“I think if we don’t care, it’ll be too late,” Lewis says. “Policymakers always want to know the costs and benefits — and the costs of these decisions always tend to be very localized, the politics very intense, about taking out a dam or putting in a fish ladder.

“But the benefits accrue to so many different people: to the anglers, to the property owners, to the codfishery, to the lobster fishery.”

Associate Professor of Geology Beverly Johnson.

Lewis and her 乐播传媒 colleague Beverly Johnson, a geology professor depicted in the documentary, are collaborating with faculty from Bowdoin and USM on the project 鈥淢aine Rivers, Estuaries and Coastal Fisheries,鈥� funded by the National Science Foundation鈥檚 Office of Experimental Programs to Stimulate Competitive Research (ESPCoR) through a grant to the University of Maine鈥檚 Sustainability Solutions Initiative.

That initiative is designed to connect research with concrete action that promotes the economy, vibrant communities and healthy ecosystems in and beyond Maine.

Funded by the National Science Foundation, the collaboration will weigh the costs and benefits of river rehabilitation in Maine and the effects of rehabilitation efforts on fisheries and economies.

Chair of 乐播传媒’ economics department, Lewis鈥� own research explores the potential benefits and costs of river rehabilitation and, specifically, dam removal.

Johnson鈥檚 research seeks to reconstruct the Gulf of Maine鈥檚 ancient nearshore ecosystem in order to help scientists predict current responses to natural and human influences. Funded by a $393,000 NSF grant, that interdisciplinary project also includes biologist Will Ambrose and archeologist Bruce Bourque of 乐播传媒 and Robert Steneck of UMaine鈥檚 School of Marine Sciences.

In Kongsfjorden on the west side of Svalbard, Will Ambrose (facing) and Kelton McMahon 鈥�05 haul a dredge to collect Serripes groenlandicus and other clam species for McMahon鈥檚 thesis in 2004. Photograph by Glenn Lopez, SUNY鈥揝tony Brook.

Professor Will Ambrose, a bearded biologist specializing in Arctic sea-floor ecology, is a pioneer in the science of deciphering the past 鈥� including past climates 鈥� by studying the annual hard-tissue accretions of organisms such as mollusks.

As an expert in sclerochronology, Ambrose has discovered a link between Arctic clam growth and regular shifts in the region鈥檚 climate. In short, Arctic clams grow more rapidly during regimes of warm and wet weather and less during cold and dry regimes. This sensitivity to climate change, says Ambrose, makes the humble bivalve a 鈥渟entinel of climate change.鈥�

While Ambrose is collaborating on no fewer than five clamshell research projects at the moment, the scientific paper that detailed the initial findings of a correlation between climate change and Arctic clamshells appeared in Global Change Biology in September 2006.

Seen here is the cross section of a small portion of aSerripes groenlandicus shell, near the umbo, or hinge. The lines indicate annual growth: dark lines for slow winter growth; light areas indicate fast summer growth. For an image showing the complete shell, click the image above. Will Ambrose has discovered a correlation between growth and climate shifts. This image is a composite of 18 images produced by the College鈥檚 new Imaging and Computing Center using a Nikon SMZ 1500 stereo microscope. Collected in 1926, the shell鈥檚 actual length is 2.5 inches.

The paper emerged from work done three years earlier, when Ambrose dispatched divers to the bottom of a high Arctic fjord in the Svalbard archipelago, a popular Arctic research site about halfway between the Norwegian mainland and the North Pole. From the ocean bottom, the divers returned with four Greenland cockles (Serripes groenlandicus).

After encasing the shells in epoxy and slicing them apart, Ambrose and a team of scientists, including Kelton McMahon 鈥�05, analyzed the growth bands. First, the team found that growth bands were indeed deposited annually. Then the team was able to correlate annual differences in shell growth with a measurement of Arctic weather oscillations known as the Arctic Climate Regime Index.

鈥淲hat makes the work exciting,鈥� says Ambrose, interviewed in his cluttered office on Carnegie鈥檚 third floor, 鈥渋s that this is the first time in the Arctic that we鈥檝e been able to track a large-scale climatic oscillation and see that large-scale regional event reflected in animals living on the bottom.鈥�

While scientists have for decades analyzed growth lines in shells (Ambrose and others call them 鈥渢rees of the sea鈥�) in order to reconstruct past environments, the intensity around climate-change research has 鈥渞eally made the field of sclerochronology take off,鈥� he says.

In this hot field, Ambrose鈥檚 research is distinctive for its location, on the Arctic continental shelf. 鈥淎 lot of the work has been done at lower latitudes, mostly because it鈥檚 harder to get clams in the Arctic and there are simply fewer people available to help,鈥� he says. 鈥淭hat鈥檚 why we鈥檙e ahead of the ball.鈥�

If it鈥檚 true that Arctic clams grow faster in warmer weather (and grow faster when there鈥檚 less of a seasonal ice pack, another signal that Ambrose saw hints of), a simplistic response might be, 鈥淕reat 鈥� fatter clams for walruses to munch on.鈥� But, explains Ambrose, fat clams won鈥檛 offset the problems walruses are having due to less pack ice to rest on. And less ice will also affect tiny creatures inside the ice that are the first link in a food chain for polar cod, seabirds, and seals. And so on, throughout the Arctic food web.

These Serripes groenlandicus clams were collected in Storfjord at a site last visited by 19th-century Russian explorers. Photograph by Greg Henkes '08.

In the end, changes in water temperature and salinity (due to runoff from melting glaciers) and increased sea levels, leading to erosion and turbidity, will all take their toll on the Arctic ecology. 鈥淓cosystems operate at the interface of physics, chemistry, and biology, with both complementary and contradictory interactions,鈥� Ambrose writes in a forthcoming article predicting that 鈥渞egional, and perhaps global, biodiversity will suffer.鈥�

Until recently, Ambrose researched other organisms of the benthic community, such as bloodworms along Maine鈥檚 coast. A simple matter of funding helped bring bivalves into focus, as a 乐播传媒 grant (from the Philip J. Otis Endowment) and an external one (from the Howard Hughes Medical Institute) helped purchase a pricey Isomet low-speed saw for preparing shell cross-sections. 鈥淰ery expensive,鈥� Ambrose says.

In researching the biological response of Arctic bivalves to climate change, Ambrose has depended on the interests and expertise of colleagues and students at 乐播传媒 and abroad.

Geology professor Beverly Johnson, for example, has been invaluable in co-advising biology students so they can learn to use the College鈥檚 stable isotope ratio mass spectrometer, a tool to help identify the age and origins of molecules in various materials. Johnson herself has used the instrument to look at amino acids in dinosaur eggs, and it can likewise be used to tease out the chemical components of clamshells.

鈥淚 work with Will to understand how modern systems work,鈥� says Johnson, 鈥渁nd then go back to old shells, using the geochemistry of shells from 125,000 years ago to reconstruct the environment.鈥�

Ambrose also depends on Matt Duvall, who directs 乐播传媒鈥� new Imaging Center, to create elegant microscopic images of his clamshell sections that Ambrose calls 鈥渏ust incredible.鈥�

Geology professor Mike Retelle, another Svalbard regular who specializes in reconstructing climates from lake sediments, has collaborated with Ambrose on researching climate-change information from fossilized Ice Age clams.

Beyond the sciences, Ambrose, Johnson, and Retelle belong to an informal North Atlantic Study Group on campus that also includes archeologists Gerald Bigelow and Bruce Bourque, historian Michael Jones, and political scientist 脕slaug 脕sgeirsd贸ttir. What started informal 鈥� an interdisciplinary coffee klatsch 鈥� has given rise to 鈥淣orth Atlantic Studies,鈥� a thematic grouping of 乐播传媒 courses, known as a concentration, under the College鈥檚 new general education requirements. 鈥淲e represent an area of study, rather than just a bunch of us sitting around having coffee,鈥� Ambrose says.

鈥淚t鈥檚 a truly special group,鈥� Retelle adds. 鈥淭he richness of discussion is such that the boundaries between disciplines disappear. The walls of the box dissolve. Will is a big part of that. As a model for an undergraduate institution, Will has really raised the bar.鈥�

Ambrose himself is quick to point out that 鈥渟tudents here are the ones driving the bus in terms of getting the work done.鈥� As he speaks, Greg Henkes 鈥�08 of Chapel Hill, N.C., is downstairs in the environmental geochemistry lab cutting shells and extracting organic material. Henkes鈥� senior thesis involves a study of 130 years of climate change in the Barents Sea and Svalbard using a historic Russian collection of Serripes groenlandicus. He will present his findings to an American Geophysical Union conference in San Francisco.

Greg Henkes 鈥�08, one of Will Ambrose鈥檚 thesis students, took this photograph at 3 a.m. on June 3, 2007, as the research shipLance heads through sea ice in Storfjord in the Svalbard archipelago, about halfway between the North Pole and Norway.

鈥淚t鈥檚 pretty incredible to be able to do this at 乐播传媒,鈥� says Henkes. 鈥淚t鈥檚 the way science is going,鈥� says Ambrose of the collaborative nature of scientific enquiry, noting his international partnerships with colleagues at the Norwegian Polar Institute and the research firm Akvaplan-niva. 鈥淧eople aren鈥檛 doing their own little thing anymore.鈥�

鈥淭hat鈥檚 the way science should be done,鈥� emphasizes Kelton McMahon, co-author of the Serripes groenlandicus paper. 鈥淚n certain circles, it is. But a lot of people come from departments that don鈥檛 share data because they feel funding is in direct competition. 乐播传媒 takes a very progressive approach to interdisciplinary research.鈥�

McMahon is now working on his Ph.D. in a program co-sponsored by MIT and the Woods Hole Oceanographic Institution. His contribution to the clamshell research has been to use two gizmos 鈥� a New Wave Research UP213 laser ablation system coupled to a Thermo Finnigan Element 2 single collector field inductively coupled plasma mass spectrometer 鈥� to measure the chemical components of shell samples. Ambrose et al. used changes in the ratio of strontium to calcium to establish that the external lines of the Greenland cockleshells were, in fact, annual growth lines. 鈥淚f it wasn鈥檛 for Kelton getting us access to those machines,鈥� says Ambrose, 鈥渢he paper wouldn鈥檛 have been anywhere near as good.鈥�

As he sits in his Carnegie office discussing his work 鈥� Ambrose also hopes to extend his sclerochronology research to coral in part because 鈥渢hey live much longer than clams鈥� 鈥� he is eagerly awaiting a new shipment of Svalbard shells that he hopes will solve a quirk in his findings. Until recent years, Ambrose found that annual clam growth was high in years when the extent of Arctic ice pack, as measured each March, was low. But over the last several years, 鈥済rowth didn鈥檛 track ice cover the way it did before. Something happened, but we鈥檙e not sure what,鈥� he says. 鈥淎re the last four years unnatural? That鈥檚 why I want those new clams. It鈥檚 another four years of data that will help establish some baselines.鈥� And baselines will help provide more answers, which will probably just beget more questions. It鈥檚 the wayscientific inquiry works. 鈥淧eople like simple answers,鈥� Ambrose says. 鈥淣ature doesn鈥檛.鈥�

By Edgar Allen Beem

Freelance writer Edgar Allen Beem wrote about the in the Fall 2007 issue of 乐播传媒 Magazine.

For many thousands of years, two species of large flightless birds shared the same habitats in Australia.

One was the emu, still thriving in Australia today.

The other was a bigger, heavier bird, known to scientists as Genyornis newtoni, that became extinct around 50,000 years ago 鈥� around the same time humans arrived on the island continent.

Why did one species disappear while the other survived? The simple answer is diet. Genyornis couldn’t adapt to radical changes in the available food supply, while the emu could, according to a geological study published in the July 8 issue of Science magazine and co-authored by 乐播传媒 geochemist Beverly Johnson.

But the tale of Genyornis and the emu is the key to a much greater story, one that suggests the human capacity for affecting the environment. Today, much of interior Australia is arid, hosting only sparse, scrubby desert plants. Prior to the arrival of Australia’s first human inhabitants, though, that landscape supported trees, shrubs and nutritious grasses watered by summer rains.

It was that ecological change that doomed Genyornis and it was the human presence that caused the change, say the study’s authors. They theorize that those early inhabitants altered the ecosystem drastically enough, probably through large-scale burning, to cause the extinction not only of Genyornis, but of the continent’s large land mammals as well.

Moreover, the rapid transformation of prevailing flora apparently also affected the climate by reducing “biosphere-atmosphere interactions that promote penetration of monsoon moisture into the interior,” as an abstract of the study states.

This much-publicized research is based on the analysis of fossil eggshells from the two species, including shells collected in core samples and analyzed by Johnson. “You are what you eat, basically,” she explains: Different types of food leave discernible chemical traces in our tissues and, as in this case, in the eggs that birds lay.

Through the analysis of carbon isotopes in the eggshells, “you can determine the proportion of grasses consumed by the birds, relative to trees and shrubs. For an non-discriminating herbivore, such as the emu, the eggshell chemistry reflects the diversity of the ambient vegetation,” Johnson says.

In other words, the eggshell record indicates that “between 140,000 and 50,000 years ago, a wide variety of plants existed to support both the emu and the more picky eater, Genyornis,” she continues. “But shortly after humans arrived in Australia, beginning 50,000 years ago, the vegetation shifted to scrub. Emus could adapt, but Genyornis newtoni and most of the other large browse-dependent animals went extinct.”

So how do humans figure in the story? “Prior to 50,000 years ago, large climate shifts occurred, yet Genyornis was able to adapt to changing conditions,” Johnson says. “The critical part to all this is that the vegetation change and the extinctions occurred simultaneously at three different sites in Central Australia and at a time when climate was relatively stable.

“So there has to be another mechanism for the ecological changes that occurred at approximately 50,000 years ago,” she says. “The timing of these changes is nearly coincidental with human arrival into Australia, and therefore human activity is inferred.”

The researchers surmise that the repeated use of fire by those first human immigrants reduced certain types of vegetation critical to the diets of Genyornis and other plant-browsing fauna. More opportunistic feeders, such as emus, survived.

“We don’t present direct evidence for fire in this paper 鈥� it’s very difficult to get, though not impossible,” Johnson explains. “But we do show an ecosystem shift roughly coinciding with the arrival of humans.”

In addition, hunting and the introduction of diseases may have also contributed to the extinction of species, if not the change in plant life.

Led by Professor Gifford Miller, a geologist at the University of Colorado at Boulder, the research team that produced the study also included scientists from the Carnegie Institution in Washington, D.C., the Australian National University and Wollongong University, also in Australia.

Johnson, an assistant professor of geology, has been involved with this ongoing effort since the mid-1990s and, she says, “it’s going to be several more years, probably, before we get to the bottom of it.”

Using the same basic approach, the analysis of stable isotopes in organic matter, Johnson has shifted the current focus of her research to the study of vegetal matter found in sediment cores from northern Australia. She and 乐播传媒 students also have ongoing paleoenvironmental research projects in northeast Siberia and in Maine salt marshes. Her overarching interest, as well as the techniques involved, is the same for all these studies: using geological evidence to try to understand changes in climate and the environment, especially changes influenced by humankind.

“If humans were capable of completely altering an ecosystem on a continental scale 50,000 years ago using fire, a relatively unsophisticated technology,” she says, “imagine the extent of our impact today.”

At first it may be, as Johnson puts it, “mind-numbing” to consider the human potential for impacting our surroundings. But the real value in this examination of prehistoric events lies in the lessons we can apply today. “If you can understand how the system responds to past human activity,” Johnson says, “you can potentially predict how it will respond to current human activity.”