A Humble Naturalist With a
Flair for the Offbeat Retires

By Alan Bisbort

Tom Siccama has some sage and simple advice for students agonizing over whether to pursue botany or zoology.

“Plants stand still, which means they are easier to catch,” he deadpans.

Homespun wisdom like this, imbued with a wry—if offbeat—sense of humor, had long endeared F&ES students to Siccama, who after 41 years on the faculty officially retired last fall. He is also something of a character for his unpretentious wardrobe of baggy Dockers held up by suspenders, scuffed leather shoes and outmoded aviator-style glasses, as well as his legendary lunches of Wonder Bread (two slices between two slices, really) chased by a Pepsi, chocolate chip cookie dough and Oreos. On overnight field trips, he would sleep in his truck.

Such eccentricities have never obscured the fact that Siccama is, in the words of John Battles, his former student and now an associate professor of forest community ecology at the University of California, Berkeley, “one of the foremost ecologists of the Northeastern forests.” Mary Arthur ’83, a former student and current professor of forest ecology at the University of Kentucky, calls him “an unbelievably good naturalist who can read any landscape at a glance.” According to his long-time teaching partner, Herb Bormann, “Tom is a genuine scientist who has made a big contribution to F&ES and who is almost too important to lose to retirement. He is a reservoir of information and sponsor of so many students’ projects.”

Siccama’s shirt pocket always holds a stack of IBM punch cards, a holdover from the days when he was the sole faculty member who could operate the old computers. “These are my Blackberry,” he says, turning over one of the IBM punch cards to show where he’d penciled a note about a recent appointment.

One gets the impression that Siccama never stops testing people, things or ideas. “Tom doesn’t believe in truisms,” says Ruth Yanai, Ph.D. ’90, a professor of forest ecology at Syracuse University and SUNY. “I’ve been doing research for five years, based on something he tried, analyzing sequential extractions from wetter and drier spots in the forest floor, which was incredibly time-consuming work. He did it just because nobody had ever tried it before. It led to a major finding, the basis for years of follow-up study by many other people, myself included.”

Their shared work, “New Insights Into Calcium Depletion in Northeastern Forests,” published in the January/February 2005 issue of the Journal of Forestry, contradicted the popular notion that forest regeneration in the Northeast had been slowed because acid rain depleted calcium in the soils. Five other authors, besides Siccama’s, are cited, including former students Yanai, Arthur and Steve Hamburg ’77, Ph.D. ’84.

“It never mattered to him whether you or he made the discovery,” says Battles, who recalls how he met Siccama as an undergraduate biology major. Battles volunteered to work with him at Hubbard Brook Experimental Forest, a 3,160-hectare reserve inside New Hampshire’s White Mountain National Forest.

“I came in after the Watershed 5 Experiment, a clear-cut harvest in 1983. The idea was to get a closer look at the soil,” said Battles. “At night, after all the hard grunt work, we would hear how science was really done. It was invaluable, and Tom always included the undergraduates as equals with the master’s students and the postdocs. It was totally empowering. He made us all feel that we could make contributions as future scientists. I was just one of hundreds of students who’ve served an ‘apprenticeship’ like this under Tom. They would all tell you the same thing, I’m sure.”

Arthur also worked with Siccama at Hubbard Brook. (She was, in fact, Battles’ “crew boss.”) She says, “It was a formative experience to spend a tremendous amount of time in the field with Tom. We traveled all over New England coring trees in Vermont and New Hampshire. He always thought outside the box and encouraged us to do so too. He also treated us like peers and made us feel like we really could be scientists. It is rare to get that kind of access to your professors.”

Though his knowledge of forest soils and trees is encyclopedic, Siccama was not one to wave credentials in faces or flaunt his experience. “I’m 72 and still a postdoc,” he says, smiling like the cat that ate the canary. “I beat the system.”

Of his career, he says, “I wouldn’t know a prairie from tundra, but I know some stuff about forests east of the Hudson River pretty well.”

Indeed, there are few people who can match the data Siccama has amassed on trees and soils at Hubbard Brook, focusing on spruce and sugar maple decline. His archive of soil samples taken from forests across the Northeast helped establish baseline data on the accumulation of trace metals in the forest floor that will be invaluable for future forest researchers.

“He is a great field scientist with a respect for the value of long-term data and is always willing to share his data,” says Battles, who has taken over Siccama’s duties at the reserve as a senior scientist in charge of vegetation sampling. “Only now, as I try to pick up from what he did at Hubbard Brook, do I realize how he had his fingers in everything up there. And he was so selfless about it.”

Bormann, Oastler Professor Emeritus of Forest Ecology at F&ES, echoed that sentiment. “Tom was always excellent at making observations and then calling them to the attention of those who would most profit from them.”

To celebrate Siccama’s career, Yale hosted a “TomFest” in 2003. A group of his former students, including Yanai, Arthur and John Aber ’73, Ph.D. ’76, organized a symposium, and generations of admirers contributed to a scrapbook titled “Let’s Blow This Popsicle Stand: Documenting the Continuing Saga of Tom Siccama’s Living Legacy at the Yale School of Forestry & Environmental Studies,” composed of photographs and fond remembrances—mostly comical—of Siccama.

In addition to his Hubbard Brook research, Siccama introduced new students to local flora as part of their basic training during summer modules. During a mods session on plant identification in 2003, Siccama carried a large sprig of poison ivy into Bowers Auditorium and laid it down before a roomful of puzzled students. “Anyone know what this is?” he said, to dead silence. Then daring the sandal- clad to go near, he added, “You better learn it pretty fast.” He also led them through the mud and muck of the Atlantic White Cedar Swamp in Madison, Conn., and a salt marsh in nearby Branford, among other places, on his field trips and as part of courses on Terrestrial Ecosystems (Terr Eco, to the faithful), field soils and protected areas.

On a field trip in southern Connecticut, Elizabeth Swain recalled standing on a bridge over a small river. Gazing into the water, she and her classmates noticed an accumulation of pebbles in one spot, and Siccama asked them how they had been deposited there. A number of unconvincing theories were advanced until someone, after prodding from Siccama, suggested simply enough that the pebbles had been tossed into the river by people over decades. “It was so many lessons wrapped up in one—how to see the obvious through the fog of scientific theories, how to approach every challenge with fresh eyes and how never to discount the human element in the landscape,” she said.

Siccama grew up in northern New Jersey but spent almost as much time in the Pine Barrens in the southern part of the state, where his grandparents lived. His grandmother was “an outdoorsy type” who kept a garden. Even now, Siccama insists that his favorite trees are a relic stand of pitch pines in Wallingford, Conn., because they remind him of his childhood in the Pine Barrens. 

After obtaining a Ph.D. from the University of Vermont, Siccama took a postdoctoral position at Hubbard Brook, which began a four-decade association with that experimental forest. He collaborated on important research with Bormann and Gene Likens, an ecologist and pioneer in the study of acid rain.

“Herb and I hit it off because we both like plants and the woods, critters and trees,” says Siccama. “I got interested in collecting data about trees on the IBM punch cards. They made a special position for me at Yale, because I like computers and nobody else could program those old machines. I was also useful in the woods, too. I’ve been a part of the grant for Hubbard Brook ever since.”

Hubbard Brook sits atop impenetrably solid bedrock, making it an ideal natural laboratory. Research there has produced some of the most extensive databases on the hydrology, biology, geology and chemistry of a forest and its associated aquatic ecosystems.

“We wanted to determine how fast vegetation grew, so we took 30 acres of land and broke it down into 25-meter-by-25-meter plots,” says Siccama. “We measured every tree bigger than 10 centimeters. I’ve been involved with maintaining and redoing these measurements every five years.”

One of his areas of concentrated study is trace metal accumulation in the forest floor. For example, he found that rain was depositing lead in the forest soils at Hubbard Brook. “We then did lead measurements all over New England and found that they were heaviest in the I-95 corridor,” says Siccama. The findings eventually led the federal government to remove lead from gasoline.

“Tom was an inspiration to all of us,” said Alyn (Greene) Caulk ’75. “More than any other, he brought alive our surrounding physical and biological world. I often think of Tom when I recognize my deep appreciation, love and awe of nature. I was in awe of Tom and his genius. I remember too his silly expressions, his humility, his quiet praise, his enthusiasm and his smile. Oh how I wish I could have continued learning from him.”