An Alvar Ecosystem: A Hidden Meadow Treasure

Juniper and sumac shrubs in a snow-dusted alvar meadow, ON (photo by Nina Munteanu)

It was two years ago, on a crisp April morning—as I walked the naturalized trail through Peterborough—that magic found me.

I was heading north and unsure where the Rotary Trail would take me. My muse had brought me here to explore my new environment; I’d recently moved from the bustle of Toronto and felt the restlessness of discovery. The trail wound mostly through backyards and cleared parkland, lined with mixed woodland of locust, black walnut, maple and oak and clearings bordered by thickets of sumac and buckthorn. I caught glimpses of houses and backyards as I walked the trail, surrounded by a chorus of lively birdsong. Robins and cardinals. Goldfinches. Red-winged blackbirds brought fond memories of childhood with their signature conk-la-ree! Chickadees flitted across the trail and sang their chickadee-dee-dee. A group of grackles took over a lilac-buckhorn thicket, their chatter sounding like an overused squeaky clothes line.

The trail crossed a main road then a minor one and the backyards became harder to see as the shrubs and trees that lined the trail grew dense.

Rotary Trail in Peterborough after a light snow in spring, ON (photo and rendition by Nina Munteanu)

Then, at a set of rocks on the east side of the trail, the thicket opened to a grassy rise and I glimpsed a small path, leading up the rise. The path was more like a depression in the grass where repetitive footfalls had created a trail of sorts. Several mature buckthorns and willows dotted the crest of the rise. And beyond the crest … well, that was my question. What lay beyond it? From my current position I could only make out the possibility of forest in the distance. The main trail up to this point had been through forest scrub of sumac, dogwood, black locust and other shrubs dense enough to obscure what lay beyond them.

Drawn to what lay beyond the rise, I turned onto the path, boots crunching on a brittle layer of frost that had settled on the grass and leaf litter. It was a steep climb through slippery wet grass. When I crested the hill, I stopped and inhaled with wonder at the unexpected view below me. It was as though I’d walked through a portal. Gone was any sign of Peterborough suburbia; below me, stretching in all directions lay a vast natural meadow, with a maple-beech woodland rising to the east; striking white limbs of birch and poplar trees marked the leading edge of the monochrome forest.

View of alvar meadow from the rise of the rotary trail, ON (photo by Nina Munteanu)

The meadow that stretched before me was a gently rolling landscape of pale gold grasses and a chaos of strewn limestone rocks and gravel dotted by russet junipers and the gray-brown umber of dwarf hawthorn, buckthorn and sumac shrubs. In a lower depression in the centre of the meadow, a grove of young cedar trees added splashes of green to the gold-copper mosaic.  

I made my way down into the rock-strewn meadow and was immediately struck by the silence. As though a hush had settled there, a kind of sacred humility stayed me. I felt unexpectedly blessed. I walked with silent steps as if in a church, toward a grove of stunted sumacs and came suddenly face to face with two white-tailed deer. We were both startled. In that protracted moment when our gazes met, time paused and the world stopped. Then one deer sprang away, followed by the other, their shocking white behinds bobbing as they fled through the sumacs toward the forest.

As if by design, at that exact moment, it began to snow. Huge flakes fell lazily like confetti in a mild breeze. Then it came down in a thick passion.

I felt the presence of magic.

Rolling alvar rocky meadow strewn with sumac, cedars, and birch trees, ON (photo by Nina Munteanu)
Rock-strewn path through alvar in spring, ON (photo by Nina Munteanu)
Staghorn sumac bobs from previous year in alvar meadow, ON (photo by Nina Munteanu)

Alvar Ecosystem

In the next two years, I returned many times to this magic place of barren beauty. My good friend and naturalist Merridy suggested that this meadow was likely an alvar, a distinct ecosystem that establishes on a limestone or dolostone plain with thin or no soil, and characterized by sparse grassland vegetation. This made sense to me, given the habitats I’d observed. Also called a pavement barren or limestone pavement and a calcareous grassland, alvars are often flooded in the spring and affected by drought in midsummer. Because of this, alvars support a distinct prairie-like community of grass, lichen and mosses, as well as stunted trees and shrubs.

Grassland area dotted with buckthorn and hawthorn, ON (photo by Nina Munteanu)

The term ‘alvar’ originated in Sweden to describe the unique ecosystem of the Swedish island of Öland, with its unique exposed limestone slabs. Alvars are a rare ecosystem; they are found in a handful of places, including the eastern European Baltic region, the United Kingdom and Ireland. In North America, close to 75% of alvars are located in Ontario. Ecologists describe seven habitat types for alvar ecosystems in Ontario. These include: tall grassy meadows, tall forb-rich meadows, low grassy meadows, low forb-rich meadows, dry grassland, rock margin grassland, and bare rock flats. In my various wanderings through this alvar meadow over the seasons, I recognized several of these habitats, from wet marshy lowland grass-forb meadow to dry tall grasslands and rock-strewn stretches of dry flatland.

View east along rock-strewn path of alvar toward forested drumlin, ON (photo by Nina Munteanu)

Given the role of disturbance in the formation of alvars, I studied the lower ‘bowl’ of the meadow more closely for signs. An old structure may have once stood where semi-structured rock piles were arranged to form a square.  A patch of young cedars and birches—both flood-tolerant—surrounded it. I’d seen this same successional phenomenon in the Trent Nature Sanctuary, where it had been previously farmed. At the southern rising edge of the alvar stood a farmhouse, accessed by the little minor road I’d crossed earlier on the trail. I considered that this alvar was dominated by early sere plants, often the first to colonize a disturbed environment—lilac, hawthorn, buckthorn, staghorn sumac, juniper, wild strawberry. Had there been a fire through here? Had someone tried to cultivate this site? It was surrounded by rural and residential development with a dedicated parkland (Trent Nature Sanctuary) of a drumlin covered in maple-beech forest bordering it to the east. Attempts to cultivate parts of the nature sanctuary at one time are also evident.

Path through alvar in late spring, ON (photo by Nina Munteanu)

I walked over the rolling grassy hills dotted with trees and shrubs, through hummocked grasslands and wet soggy marsh. As I walked over the shallow soils of strewn limestone and granite rocks, many covered in lichen and some with moss, my boots crunched.

Alvar meadow and environs in A) 1959 and B) 2019

I found an aerial photograph of this place from 1959 (A) and was able to compare it to a photo taken in 2019 (B). The 1959 photo suggests attempts to parcel out land and farm it. Much of the cleared land has since gone to forest, but the alvar remains a natural meadow. This place remains a bit of a mystery and I am intrigued to solve it. Stay tuned…

View of alvar from south drumlin forest in early spring after a light snowfall, ON (photo by Nina Munteanu)
Alvar in April through birch, poplar, ironwood forest edge, ON (photo and rendition by Nina Munteanu)

Nina Munteanu is a Canadian ecologist / limnologist and novelist. She is co-editor of Europa SF and currently teaches writing courses at George Brown College and the University of Toronto. Visit www.ninamunteanu.ca for the latest on her books. Nina’s bilingual “La natura dell’acqua / The Way of Water” was published by Mincione Edizioni in Rome. Her non-fiction book “Water Is…” by Pixl Press(Vancouver) was selected by Margaret Atwood in the New York Times ‘Year in Reading’ and was chosen as the 2017 Summer Read by Water Canada. Her novel “A Diary in the Age of Water” was released by Inanna Publications (Toronto) in June 2020.

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