Exploring Roots of the Dairy Bush

U of G botany prof compiles history of
living laboratory on campus

Botanist Doug Larson in U of G's Dairy Bush.

Is that sound the whispering of wind in the branches or something else? To hear Prof. Doug Larson, Botany, relate the history of the U of G Dairy Bush, you might think he's hearing the voices of the woodlot's founders echoing down through more than a century.

  As he hikes through the nine-hectare forest marking the western boundary of the campus, it's obvious that Larson sees himself as treading in the footsteps of two of the University's earliest faculty, who, around the turn of the century, were instrumental in establishing the second-oldest plantation forest at a North American university.

  One was William Brown. An arboriculturist from Scotland, he served as the first professor of agriculture when the Ontario School of Agriculture and Experimental Farm - the forerunner of the Ontario Agricultural College - opened in 1874. A smaller plot he planted in 1887 was named Brown's Woods in his memory four years ago by the University.

  Brown was an ecological restorationist long before the term became fashionable, says Larson. In numerous writings, Brown stressed the role of forests in alleviating the effects of climate change, erosion and other problems. His arguments resonate today in discussions about conservation of woodlands, including the impact of development on the Dairy Bush, Larson says.

  Many of those writings, as well as numerous photos, annual reports and other documents about woodlots on campus, are collected in a heavy black binder in Larson's laboratory in the Axelrod Building. His paper chase began a few years ago, after encountering a schematic diagram from the last century that left him stumped. Dated 1877, the cryptic diagram was a geometric grid of numbered plots without an explanatory legend. What did it represent?

  His first clue, says Larson, came from a public transit map of today's campus. Overlaying the schematic with an aerial photograph of the western portion of the University, he shows how much of today's Dairy Bush was planted on the agricultural field plots laid out more than a century ago.

  Only the most westerly section represented natural growth, depicted on Larson's schematic as a grove of trees. That portion, adjacent to Edinburgh Road, had regenerated on its own after most of its trees had been stripped for firewood and the area left bare as a cattle and sheep run.

  He says the land now called the Dairy Bush was first mentioned in OAC's 18th annual report, written in 1892. That was two years after head gardener James Forsythe had planted a variety of species on the hilltop directly eastward of that natural stand, including larch, Norway spruce, Austrian pine, walnut, butternut, birch, ash, Norway and hard maple, elm, sycamore, linden, hickory, catalpa and sweet chestnut.

  Many of those specimens had died by the time Jacob Zavitz, Ontario's first forester, arrived to head Guelph's forestry program. Around 1906, Zavitz planted a stand of white pine whose arrow-straight rows show up clearly in Larson's photos.

  Thanks to all of these original plantings, the Dairy Bush contains the second-oldest plantation forest on any university campus in North America and has been identified as a natural heritage area. For several years, Larson has used the Dairy Bush as a kind of field laboratory for students who have, among other things, drawn tree cores for aging studies, mapped trails, studied animal life, assessed replacement rates and studied the impact of the family housing complex on the area. Along the way, they've uncovered a few surprises.

  "At one time, we thought it was all secondary growth," says Larson, but a study of core samples drilled by research associate Peter Kelly proved otherwise. "Probably a couple of dozen trees date to the beginning of the 19th century, which means this is a really special place."

  A related surprise came when Kelly cored several trees to test the apparently self-evident theory that the larger trees in the Dairy Bush are the oldest. His analysis showed that the mature trees that now make up the forest canopy have grown relatively rapidly. Another group - what Larson calls the grandparent generation - consists of older, slower-growing specimens. "We didn't know there were two populations out there."

  Even the recent discussions over the University's proposal for commercial development and an office/research park on U of G land south of the Dairy Bush at Stone and Edinburgh have proven useful to students as a test case of how to reconcile conflicting stakeholder values. Larson says he was relieved to learn that planners had dropped a residential component from their proposal, which he says would have increased pedestrian traffic - and the associated environmental impact - in the forest.

  Studying ecological restoration without the Dairy Bush on campus "would be like teaching music without any musical instruments," says fourth-year ecology student Margy Degruchy, who took Larson's course in ecological methodology. "It's small, but big enough and homogeneous enough to serve for ecological studies. It's our lab."

  Such studies are precisely the kinds of projects that the founders of the Dairy Bush and nearby Brown's Woods had in mind a century ago, says Larson. "They're as much experimental tools as buildings, centrifuges and growth chambers are. It gives students the sense of being connected to the birth of the place."

  Larson says he likes to think he's speaking for Brown and Zavitz. "I think they would like me to say that experiments started in the 1800s should be allowed to continue indefinitely."

"Old Growth" Forest

The Dairy Bush includes the second-oldest plantation forest on a university campus in North America - the portion first planted in 1890. The oldest? That honour belongs to a one-hectare stand at College Avenue and Smith Lane next to OVC that was christened Brown's Woods four years ago.

  Labelled by Prof. Doug Larson, Botany, in a research paper as an "early forest restoration project," Brown's Woods was planted in 1887 on the site of a newly abandoned gravel pit.

  "For its time, the restoration of this completely denuded site was exceptionally modern," Larson wrote in 1996. "Evidence suggests that it was to be an example of how rapidly and efficiently complex forest cover could be returned to denuded land. To Brown's credit, in the winter of 1993, the City of Guelph mistakenly listed this site as an important natural forest fragment within the city's municipal boundary."

  Besides these two plots, former professor William Brown planted a walnut grove that stood until about 1960 near today's Cutten Club, as well as a stand of Austrian pine and European larch, a sliver of which remains near today's veterinary buildings.