Treasure Hunt

Guarding the entrance to Thickson’s Woods is one of the oldest hop hornbeams in southern Ontario, its spreading branches indicating that it sprouted in a clearing. Its other name, ironwood, comes from the dense, extremely heavy wood of this slow-growing deciduous tree. Migrating sapsuckers drilling holes in its bark in late April reveal the other reason it is called “ironwood” – the oozing sap turns rusty orange.

The loop trail west of the entrance, past a few surviving butternut trees, leads to “warbler corner,” a favourite spot to view migrating songbirds busily feeding on midges at nearly eye level when winds are from the south in spring.

Along the north ridge to the east is a tall, slim tree with reddish bark, standing ten feet off the trail among some black cherries. Because of its height, shape and forest location, few visitors would at first glance recognize this foot-thick “mystery tree” – a wild apple that produces lovely white flowers in late May, tiny yellow-green fruit in September.

A grove of large-toothed aspen along the ridge adds to the diverse mix of trees in Thickson’s Woods. Look for their round, jagged-edged leaves on the ground in winter.

To preserve the pine component in the woods, baby white pines were planted in sunny clearings left by loggers. The grove at the top of the hill sprouted on its own, shooting up from tiny green, inch-wide bottle brushes into the healthy young pines reaching for the sky today.

The only American beech in the woods died of stress not long after the woods were gutted in 1983. But underground runners from its roots sent up new shoots, resulting in young trees around the carcass of the parent. Like some ironwood and oak, beeches retain their warm brown leaves throughout winter.

Corbett Creek Marsh supports a host of native wetland plants.  At water’s edge in early May marsh-marigolds blossom in a blaze of golden yellow. Unfortunately, invasive phragmites is rapidly taking over this provincially significant wetland.

 Meticulous hand pulling every spring and fall keeps garlic mustard, another insidious alien, from choking native wildflowers in the woods.  Starflowers are a woodland species rare this far south. Trilliums throughout the woods were rescued from an Oshawa woodlot slated for development.

Peek under the knee-high umbrellas of May-apples to see their large white flowers in spring, their yellow fruit in summer.

Path rush, a short grass-like plant growing in dim light in forest clearings, lines the north trail in summer. More than 375 species of vascular plants have been identified in this botanically rich reserve, including 17 grasses and 18 sedges.

Six species of maples grow in Thickson’s Woods. Can you find them?

One hemlock, a climax species, joins the fringe of tall white pines left around the woods by the loggers in 1983. Two hemlock saplings planted in a nearby clearing may grow up to replace it one day.

Black cherry is a common hardwood throughout, distinguished by its curling black bark. Many tops snapped off in the great ice storm of 2008, which took down four big pines.  But several resilient black cherry trees survived and grew new leading branches, one of the miracles of life. Great flocks of robins and Hermit Thrushes gather in early September some years to gorge on their ripening berries. 

Be sure to visit the Valley of the Giants in the southwest corner, where the oldest white pines, once earmarked for masts of sailing ships for the British Royal Navy, still tower. Several grow in backyards of local residents, who work with TWLT to protect forest habitat. Listen for the hooting of Great Horned Owls in February at dusk, the staccato trill of Pine Warblers high in the branches in early spring, the tick-tick-tick of Blackpoll Warblers late in migration.

Roadways to the lakeshore, owned by Thickson’s Woods Land Trust, are accessible to pedestrians. Please respect private property.

A rare slippery elm, a Carolinian species whose inner bark was used by native people and pioneers to prevent scurvy, grows along the west roadway, near its junction with the trail. Like basswood, it has multiple trunks.

Dying trees are as full of life as living ones. Dead stubs make apartment houses for Downy Woodpeckers, Chickadees, Great Crested Flycatchers and Flickers. In 1996 a pair of Red-headed Woodpeckers nested in the dead top of a sugar maple.

Fallen limbs and branches are slowly broken down by fungi and various microorganisms, enriching the soil for the next generation of trees. Brush piles provide hiding places for cottontail rabbits, chipmunks and winter wrens.