An Ecological Profile of Lanark County

In this one hour talk given to the Ottawa Field-Naturalists’ Club in 2014 Paul will take you on a tour of some natural highlights of Lanark County.

Read more about the talk

Lanark County is like a piece of Algonquin Park attached to the limestone plains of the Ottawa Valley. This is perfectly illustrated by geology.  Lanark County has Precambrian rock in the west, as you find in the upper Ottawa Valley (including Algonquin Provincial Park) as well as limestone in the east, as you find in the lower Ottawa Valley (including the city of Ottawa).  There are also extensive areas of marble.

Lanark County also has an old ocean shoreline. About ten thousand years ago, the eastern side of Lanark County was flooded by the Champlain Sea. If you drive from Carleton Place to Perth along Highway 7, you climb past this old shoreline near Lanark Cedar. There is a large wetland on the south side of the highway near this location.

 When the first Europeans arrived, the area was mainly deciduous forest, but there were also fire barrens and pine ridges, as well as lakes and beaver ponds and extensive swamps.  The history is also typical: indigenous peoples were replaced by Europeans, predominantly Scottish and Irish settlers, who logged the forests and cleared for farms.  On deeper soils there are now prosperous communities, while on shallow and rocky soils, farming collapsed and the forests are recovering.

In spite of two centuries of human settlement, there are still important natural areas left.  These include alvars, rock barrens, and wetlands.  There are also distinctive southern species including five-lined skinks, black rat snakes and southern flying squirrels. Shagbark hickories have crept as far north as some rocky south-facing hillsides, while a stand of hackberry trees clings to the limestone cliffs along the rapids in Carleton Place.

Additional links

A Guide to the Natural Environment of Lanark County

Web page for Lanark County Ecology

Plants of Lanark County by David White.