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Graeme P. Berlyn 
(1933 – 2024)

Graeme P. Berlyn, a world-renowned expert on the anatomy and physiology of plants and trees who taught at the Yale School of the Environment (YSE) for more than 60 years, died February 16 in Hamden, Connecticut. He was 90.

Berlyn’s breadth of research included wood anatomy, plant embryology, tissue culture, biotechnology, and the morphology and physiology of trees and forests in relation to environmental stress. He published more than 166 journal articles and his book “Botanical Microtechnique and Cytochemistry” has more than 2,200 citations. He was an expert on histology and electron microscopy and served as the only plant scientist on the Biological Stain Commission, the international organization that sets the guidelines for the acceptable biotechnique of staining.

After working for the U.S. Forest Service in Oregon and Washington, Berlyn came to YSE in July 1960, at the age of 26. While at YSE, Berlyn broadened his research focus on wood cellular structure, examining the nuclear effects of radiation on plants; the adaptation of spruce fir to acid rain across elevation gradients; and leaf morphology and physiology responses to light. In the 1990s, he pioneered the development of nonhormonal plant biostiumulants and created a line of plant food called Roots that helped fund his subsequent research.

Through the decades, Berlyn, E.H. Harriman Professor of Forest Management and Physiology of Trees, became a beloved presence at Greeley Memorial Lab, where he would host weekend lunches in the kitchen with his research students, serving meals he cooked and nutrition drinks he had created, often with his dogs by his side. He enjoyed working out with weights in the basement in what fondly became known as the “Heavy Metals Uptake Lab” to the tunes of Texas swing. Berlyn liked to jog, even before it became popular, was an avid hiker, and also pursued martial arts.

Berlyn was involved in the formation of the Tropical Resources Institute (TRI) and worked in the mountains of British Columbia and the Northeastern U.S., collecting plant samples at different gradients.

At the heart of all his work was his commitment to his students, says Mark Ashton, senior associate dean of The Forest School at YSE and Morris K. Jesup Professor of Silviculture and Forest Ecology. Ashton first met Berlyn in the 1980s while he was working toward his master’s and doctorate at YSE and Berlyn became his mentor.

Berlyn, who liked to dress in black, could seem intimidating and gruff at first, but he was the opposite, Ashton says.

“He was an absolute softy. If you were a serious student and he saw you working hard, he offered lifetime mentorship. He was an extremely giving person,” Ashton said. “His students were devoted to him because he was devoted to them.”

Over the years, Berlyn took great pride in the accomplishments of his former students.

“That’s probably the greatest part of the job — the students we’ve had here,” Berlyn said. “I’ve mentored a number of PhD students … a number of them went on to become professors at various universities and so that’s a very satisfying part of being a professor, that your students make a mark for themselves. And all of them have in one way or another.”

Dean Indy Burke noted Berlyn’s enthusiastic mentoring of alumni.

“Our alumni feel a deep sense of connection to Graeme, who came to every reunion to catch up with his students and friends, and they have remained in touch through the years and decades. Graeme graced us all with his sharp intellect, wry grin, and sense of humor. He remained deeply committed to diversity, equity, and inclusion throughout his entire career, helping us advance our efforts in this important area, especially over the last decade. We will miss him deeply,” she said.

Berlyn is survived by his wife Mary Berlyn ’66 PhD and two children, Dina and John. YSE will host a memorial gathering to honor the life and work of Berlyn on Sunday, October 6, 2024, beginning at 12:00 pm EDT, in conjunction with YSE Reunion Weekend events. The memorial will be held in person at Marsh Hall and will be streamed for those who cannot attend in person. This event will be open to alumni, the YSE community, and all who knew Berlyn. 

Jared Leigh “Jerry” Cohon
(1947 – 2024)

Jared Cohon portrait

Jared Leigh Cohon, who served as the dean of the Yale School of the Environment (then F&ES) from 1992-1997, died March 16 in Ligonier, Pennsylvania. He was 76.

“Jerry Cohon was a wonderful person, an outstanding Dean, and an important leader in the emergence of the Sustainability Imperative that has become a foundation of life in the 21st century. Under his tenure at Yale, the forestry school began the process of becoming a global school of the environment with wider focus and broader reach. All of us at YSE today owe him a great debt of thanks,” said Daniel Esty, Hillhouse Professor of Environmental Law and Policy.

The appointment of Cohon, an engineer, to head the School of Forestry and Environmental Studies marked a fundamental shift for the school. He was the first nonforester to hold the position. Cohon helped to create the foundation of the school YSE is today. He diversified the school’s non-forest interests, expanding into the area of industrial ecology with the hiring of Professor Emeritus Thomas Graedel, and into law and policy with the appointment of Esty. He also significantly increased focus areas around water resources.

“When I think of Jerry I think of an exceedingly good human being. He got to YSE in the 1990s with something new — credentials from MIT as a civil and environmental engineer who spoke in the language of quantitative analysis,” Marian Chertow, director of the Center for Industrial Ecology, said. “The 1990s saw the beginnings of industrial ecology, and Jerry was the one who recruited Tom Graedel from Bell Labs to Yale. He left as classes were formed along with the Center for Industrial Ecology.”

“Shortly after my arrival, Jerry and his wife, Bunny, invited my wife and myself (and several other F&ES faculty and spouses) to an informal dinner at their home,” said Graedel. “This event was emblematic of his efforts to not only enhance F&ES scope and community but also its internal cohesiveness. He was strategist, team builder, and friend to all.” 

Cohon received his undergraduate degree from the University of Pennsylvania and his doctoral degree from the Massachusetts Institute of Technology, both in civil engineering. He served as science advisor to U.S. Sen. Daniel Patrick Moynihan before joining the Johns Hopkins University faculty. While there, he became the vice provost for research, which began his career in administration. It was his extraordinary generosity as a mentor, combined with his intellect and knack for bringing people together, that those who knew him most remember.

“When Jerry became dean, I was a young first-year assistant professor,” said Mark Ashton, Morris K. Jesup Professor of Silviculture and and senior associate dean of The Forest School. “As dean, he was enormously helpful in mentoring me and helping me with both my teaching and research. I have such fond memories of his dinners with all the faculty and staff at his house and his schoolwide picnics. Even after 25 years, we remained in contact with our annual holiday cards. I will really miss him.” 

After leaving YSE, Cohon served as the eighth president of Carnegie Mellon University (CMU) from 1997 to 2013. He was later a professor of civil and environmental engineering and public policy and the director of the Wilton E. Scott Institute for Energy Innovation at CMU. He also served on the Atomic Energy Commission, the Homeland Security Council, the Carnegie Foundation board, and the American Association of Universities board (ultimately serving as chair of the board), as well as on several other national and international corporate boards. 

“He was an excellent leader, recognizing the importance of crossing disciplinary boundaries to solve environmental problems,” says Robert O. Mendelsohn, Edwin Weyerhaeuser Davis Professor of Forest Policy. “He began the push to broaden the school towards more environmental concerns than just forestry. For the first time, the school began to attract students interested in environmental management, not just forest management.” 

He is survived by his daughter Hallie Donner (Joshua); grandsons Nathan and Solomon; sisters Cindy Lowenkamp and Shelia Nathanson; and an extended family. 

Darius M. Adams ’68 MFS (1944 – 2023) passed away on December 7, 2023. Darius loved thinking and caring about forests, what they give us, and the people who depend on them. Darius was born in Los Angeles and grew up in San Bernardino, California. He discovered a love for forests as a Boy Scout, and eventually an Eagle Scout. He studied forestry at Humboldt State University, supporting himself by fighting forest wildfires for the California Department of Forestry. He loved analyzing problems and, therefore pursued graduate studies in forest economics at YSE and the University of California, Berkeley and served on the forestry faculties at the universities of Wisconsin, Washington, Montana, and Oregon State.

He taught innumerable forestry students and mentored young forest economists all over the world as they grew in their careers, many of them becoming lifelong friends. These included his wife, Claire, for whom he relinquished tenure briefly so that she could start her academic career and they could work together as a team. The week he received his cancer diagnosis, he also received notice that his lifetime of research would be honored with the Marcus Wallenberg Prize, informally known as the "Nobel Prize for Forestry."

George Robinson “Bob” Barker ’58 MF (1929-2023) passed away on September 28, 2023. Bob grew up in Connecticut and attended the Choate School for Boys and Middlebury College. A U.S. veteran, Bob enlisted in the Navy in 1950, where he worked on a hurricane hunting team stationed out of Jacksonville, Florida. In 1953 he married his longtime friend and sweetheart, Joyce Edwards. After studying silviculture at YSE, he went on to work for the St. Regis Paper Company, first as a forester, then as an early expert in satellite imaging and GIS mapping, a skill he took to his next job with French company SPOT Imaging. He later became an adjunct professor at the University of Georgia’s Warnell School of Forestry and served for over a decade on the Athens-Clarke County Community Tree Council. A friend to anyone he met, Bob was known for his jokes and funny sayings. He often said his day was complete if he could make someone laugh or smile.

Phillip “Flip” Dibner ’70, ’75 MFS (1948 – 2023) passed away on May 11, 2023, in Los Altos, California. Born in Cleveland, Ohio, Flip spent his childhood summers helping to run Camp Tall Timbers and Camp Truda with his family in Maine. While at Yale, Flip met his wife and lifelong partner, Diane Renshaw ’75 MFS. 

After many years working in the technology industry in Silicon Valley, Flip returned to his environmental interests in the early 2000s as a consultant working with the Open Geospatial Consortium and others to make ecological data available and interoperable across many different platforms, including the Darwin Core standard for sharing and re-use of biodiversity data.

Flip had many diverse interests. He loved learning languages, was a dedicated Zen practitioner, and in his early 60s, he took up running again. Inspired by his daughter, he ran marathons, ultramarathons, and triathlons, including three Ironman events. Flip was also a talented musician and hauled his 8-inch telescope around to peruse the night skies. He was also a docent at Stanford University’s Jasper Ridge Biological Preserve, with interests that included basic research, botany, and slime molds.

Rolf W. Benseler ’58 MF (1932 – 2022) passed away on February 18, 2022, in Walnut Creek, California.

Rolf earned a bachelor’s degree at the University of California, Berkeley before attending Yale and returned to Berkeley for doctoral studies, earning a PhD in 1968. After serving as a junior specialist in forestry at the School of Forestry at Berkeley, he went on to become a professor of biological science at California State University, where he was well respected for his expertise in California native plants and ecological restoration. Rolf was widely acknowledged as a supportive and effective academic advisor. He served on the Regional Parks Botanic Garden Advisory Council and wrote and edited for numerous botanical publications. 

Eric L. Ellwood ’54 PhD (1933 – 2022) passed away on May 27, 2020, in Raleigh, North Carolina. Born in Melbourne, Australia, Eric graduated from the Victoria School of Forestry in 1942, going on to earn his BSc and MSc from the University of Melbourne before coming to Yale for his PhD in forestry, where he was president of his class. 

His early career was spent as a research forester studying fire protection in Australia before returning to the U.S. to work with the U.S. Forest Products Laboratory at the University of California, Berkeley. In the latter part of his career, he focused on advancing program development and enhancing research and management practices concerning forests and natural resources. He also had an interest in shaping strategic policies on state, national, and international scales.

Eric enjoyed a long and happy retirement. His zest for life was tremendous, as exemplified by his first sky diving jump at the young age of 92. He was a true Renaissance man, always interested in new ideas in the world and the people around him.

L. Keville Larson ’61 MF (1937 – 2023) passed away on October 27, 2023, in Mobile, Alabama. Born in New York City,  Keville attended Stanford University for his bachelor’s  in geography before coming to Yale for his Master of Forestry. After graduating, he moved to Mobile, Alabama, to work with his uncle at the forestry consulting firm Pameroy & McGowin, later forming Larson & McGowin, Inc. — where he was president — creating a successful and widely respected company that exists to this day. 

Keville was a lifelong learner who loved to acquire and share knowledge. He returned to YSE to teach courses in forestry as the K.F. Weyerhaeuser Fellow in 2000. Keville was deeply involved in many forestry organizations, including the Society of American Foresters, the Alabama Forestry Association, the Forest History Society, and the Yale Forest Forum, and was a career-long Registered Forester.

His many passions included sailing, playing the guitar, riding horses, and soccer. He helped establish a soccer program for young people and adults in Mobile and played soccer into his 60s. His philosophy in life was always to keep things in perspective, build for the long run, and, most importantly, "accentuate the positive."

Douglas A. MacKinnon ’58 BS, '64 MF (1936 – 2023) passed away on February 26, 2023, in North Carolina. Born in in Queens, New York, Doug attended Yale College, graduating with a bachelor of science degree in industrial administration. He then served as a lieutenant on a destroyer in the U.S. Navy Pacific Fleet in the role of chief engineer on the USS Rupertus. 

His wide-reaching career included professorships in forestry management at the University of Michigan and Duke University, consulting with the World Bank on sustainable forestry management alternatives for tropical forests, and more. 

In his retirement, Doug loved volunteering with the North Carolina chapter of the Nature Conservancy, where he helped the organization protect forests and preserve species, including longleaf pine and Atlantic white cedar. 

Martin L. Mador ’71 BA, ’02 MEM (1949 – 2023) passed away on June 21, 2023, in Hamden, Connecticut. A longtime environmental activist, Martin moved to Connecticut to attend Yale College, and stayed, becoming a clean water activist and president of Quinnipiac River Watershed Association and River Advocates of South Central Connecticut. He served on the Hamden Conservation Commission, where he lobbied for the Connecticut Chapter of the Sierra Club and created the Sierra questionnaire for deciding candidate endorsements. He started his career as an organizer for the ACLU and created the early computer system for the Yale School of Medicine. Martin was highly regarded within the environmental and conservation community, earning the respect and admiration of his peers and colleagues. His knowledge and expertise were sought after, and he became a trusted advisor and mentor to many.

Earl L. Marcellus ’68 MF (1944 – 2021) passed away on March 15, 2021 — his 77th birthday — in Plain, Washington. Born in Schaghticoke, New York, in the Adirondacks, Earl was a third-generation lumberjack and followed the family tradition of competing in logging sports. He won his first championship at the age of 13 and went on to win many more, including the World’s Underhand Chopping Championship and the World Axe Throwing Championship. Earl and his brother set a new world double bucking record, sawing a 30-inch log in 34.8 seconds. 

He began performing in lumberjack shows in 1971 and took his talent to many notable locations such as the 1974 World’s Fair in Spokane, three trips to Japan, and multiple contracts with Disneyland. He also held the title of 1975 World’s Top Logger.

In addition to his passion for the woods, Earl served his community as Chelan county commissioner. 

David P. Miller ’59, ’72 MFS (1936 – 2023) passed away on September 1, 2023. Born in New Haven, Connecticut, David grew up in Washington, Connecticut, living on the campus of The Frederick Gunn School, where his father was the head of school. His childhood was full of camping and exploring the Connecticut woodlands. He graduated from Yale College with a degree in history in May 1959 and joined the U.S. Army in October of that year, serving as a lieutenant with the 18th Airborne Corps 1959-1961.

David then went on to earn a master’s degree from Columbia University and taught Latin and history for several years before he was inspired to change his career trajectory and earn his master’s degree.

David and his wife, Trudy, moved to Maryland, where he worked for the Chesapeake Bay Center for Environmental Studies before being named executive director of the Maryland Environmental Trust, one of the oldest and most successful land trusts in the country. In this role, David oversaw the purchase of 1,500 acres along the upper Youghiogheny River, which later became a designated wild river. Back in Connecticut in 1991, he helped found the Hartford Land Trust.

Nils Parr ’64 MF (1936 – 2023) passed away on April 26, 2023. Nils taught college economics for 20 years before retiring for the first time. He later became a health inspector and an elected township supervisor before returning to school for a PhD in forestry economics from SUNY College of Environmental Science and Forestry. He also taught in the Emergency Health Services Program at the University of Maryland Baltimore County, served on various health-related boards and commissions, and was a volunteer EMT. Nils was a firm believer that the YSE Class of 1964 is “the best class EVER, and that’s the truth.”

Earl W. Raymond ’53 MF (1929 – 2024), passed away on February 2, 2024. Born in Lowell, Massachusetts, in 1929, he was proud of his family’s lineage, tracing back to a Revolutionary War ancestor. After an early graduation from high school, Earl served as a corporal at the Marine Air Station at Cherry Point, North Carolina. He received a bachelor’s in forestry from the University of Massachusetts, Amherst in 1952 and hitchhiked across the country to spend college summers working as a smokejumper with the U.S. Forest Service in Montana. Raymond spent his entire working life with the James W. Sewall Company in Old Town, Maine, retiring as COO. He was integral to the formation and leadership of the Maine Society of Land Surveyors.

Earl was a lifelong outdoorsman, a skier, kayaker, and hiker. He was a Maine Guide and a founding member of the Maine Chapter of the International Appalachian Trail, to which he devoted much time. He spent much of his retirement researching and writing about the history of surveying and mapping in the state of Maine, writing more than a dozen papers, which he later donated to the Maine Historical Society. He was an amateur astronomer who shared his knowledge and love of the stars while working for many years as a volunteer for the National Park Service. 

In his retirement, Earl traveled the world, staying in elder hostels and adventuring in Europe, India, New Zealand, China, Mongolia, Peru, Argentina, and Antarctica. While traveling in Africa, he climbed near the summit of Mt. Kilimanjaro. Into his last few months, he enjoyed kayaking local lakes and ponds, and across Falmouth Harbor to Clapboard Island. He was never happier than when he was out of doors or reading a good book.

George H. Sisterhenm ’57 MF (1929 – 2023) passed away on July 18, 2023. Born in Durham, North Carolina, George lived most of his younger days in Danbury, Connecticut. He attended the University of Massachusetts at Amherst, earning his bachelor’s in forestry in 1956 before coming to YSE. George served in the Korean War as a medic and certified jumper. He spent five years in the Army Reserves and assisted in the treatment of over 4,000 soldiers injured by frostbite during the war. After his service, George met and married his wife, Beverly, and they moved to Redding, California, where he began a long successful career in the lumber industry at U.S. Plywood. He was an active member in the Rotary Club of Redding East and was an avid golfer. 

Keith D. Tait ’81 MFS/MPH (1956 – 2023) passed away on February 9, 2023. For more than 25 years, Keith traveled globally, promoting occupational hygiene while working at Pfizer. He was an active member of the American Industrial Hygiene Association Exposure Assessment and International Affairs Committees, and he championed the control banding approach. He served as a faculty member at AIHA’s first “Fundamentals of Industrial Hygiene” program in India. Keith was also instrumental in supporting India’s first master’s program in industrial hygiene. Keith cared deeply for the people who crossed his path and will be remembered by his many friends and colleagues for his generous spirit, fiery intellect, and passion for public health and the environment. 

Rebecca (Glass) Woodell ’55 MS (1931 – 2022) passed away on October 7, 2023, her 91st birthday. Rebecca was a student in the nascent Yale Conservation Program, started by Paul Sears. Earning her YSE degree well over a decade before women were officially admitted to the Forest School, Rebecca and the other women in the Yale Conservation Program laid the groundwork for women in conservation and environmental work at Yale. Rebecca stayed abreast of happenings at YSE over the years and is fondly remembered by her surviving classmates.

John G. Worrall ’64 MF ’69 PhD (1938 – 2023) passed away on August 8, 2023. John arrived in North America on a whaling ship on which he was working as a chemist in 1965. He received a bachelor’s degree in forestry from the University of British Columbia. After graduating from YSE, John returned to the University of British Columbia, where he developed and taught the first-year dendrology course. For the next 35 years, John dedicated himself to teaching and to his students’ well-being. He made a point of learning (and never forgetting) the name of every new forestry student at UBC. He retired in 2003. John was so well loved by the community at UBC that his name remained on his office door even 20 years after his retirement.