- - Habitat Connectivity (A2A)



A number of large landscape-scale initiatives to maintain or restore habitat connectivity are being carried out in North America. They are based on the premise that isolated protected areas are unable to maintain their full complement of species over time, and must remain interconnected to permit wildlife to move across the landscape between them.

A broad vision for habitat connectivity in eastern North America has been put forward by the Wildlands Network (http://www.wildlandsnetwork.org/). Examples of individual initiatives include the Yellowstone to Yukon Initiative (http://y2y.net/) in the Rocky, Columbia and Mackenzie Mountains, the Two Countries One Forest Initiative (http://www.2c1forest.org/) in the northern Appalachian and Adirondack Mountains and the Algonquin to Adirondacks Initiative between the southern Canadian Shield and the Adirondack Mountains.

Here we highlight the Algonquin to Adirondacks (A2A) Initiative which forms a critical link in eastern North America.


The Algonquin to Adirondacks region forms a critical ecological link in eastern North America, allowing the movement of wildlife across the Great Lakes-St. Lawrence River waterway. The waterway bisects the eastern portion of the continent. Although the Great Lakes and the river below Quebec City are too wide to permit most species to cross, historically, wildlife were able to migrate between the lakes or across the St. Lawrence River above Quebec City. However, intense urban and industrial development has largely blocked passage between lakes Huron and Erie and lakes Erie and Ontario, as well as along portions of the St. Lawrence, especially in the vicinity of Montreal and Quebec City.

The most important remaining connection across the waterway is located between the eastern end of Lake Ontario and Montreal. This region is the focus of the A2A initiative that began more than two decades ago to maintain and restore the web of ecological connections between the Algonquin Highlands of Ontario and the Adirondack Mountains of New York State. A2A is a key link in a much broader set of connections through eastern North America.

A2A Region

The A2A region encompasses the two large parks, Algonquin Provincial Park and Adirondack State Park, which form its northwestern and southeastern anchors respectively, as well as the broad area between. It extends from the eastern basin of Lake Ontario to the western outskirts of Montreal. Between the two large parks there are a number of small protected areas, the largest being Gatineau and Kawartha Highlands parks. About two million people live within the region. Its largest urban centre is Ottawa-Gatineau, although there are a number of smaller cities such as Kingston, Plattsburgh, Watertown and Cornwall, as well as many towns and villages. There are several First Nation communities, and a large portion of the A2A region is currently the subject of a land claim negotiation between the Algonquins of Ontario and provincial and federal governments. Much of the land between Algonquin and Adirondack parks is privately owned. Tens of millions of people live within a few hours drive of the region in centre such as Montreal, the Greater Toronto Area, Buffalo, Albany, Boston, New York and Philadelphia.


A2A Geology

The geology of the A2A region is critical to understanding its importance as an ecological link. Much of the region lies on the rugged Canadian Shield, a vast area of Precambrian igneous and metamorphic rocks that extends over much of eastern and central Canada. Both Algonquin and Adirondack parks are on the Canadian Shield and are connected by a narrow band of Precambrian rocks known as the Frontenac Arch. The southeastern portion of the Canadian Shield, including the A2A region, was once a lofty mountain range, known as the Grenville Mountains, created during a period of continental collision more than a billion years ago. Over hundreds of millions of years the Grenville Mountains were eroded to a depth of several tens of kilometres. Shallow seas invaded the region in the Paleozoic. Flat-lying sedimentary rocks, laid down in these shallow seas, overlie Precambrian rocks on either side of the Frontenac Arch. It is on these sedimentary rocks that most of the region's agricultural lands are found. Over the past few million years a dome-shaped uplift has produced the mountainous topography of the Adirondacks.  

Drainage in the A2A region is governed largely by geology. The largest river in the region is the St. Lawrence which cuts across the area, draining the Great Lakes. The Ottawa River flows through the northeastern portion of the region to join the St. Lawrence at Montreal. Rivers and streams in the Algonquin and Madawaska Highlands radiate off the highlands to the Ottawa River and Georgian Bay. Those in the Adirondack Mountains radiated off the dome to the St. Lawrence, Lake Ontario, the Albany River or Lake Champlain. Along the Frontenac Arch the rivers flow either northeast to the Ottawa or southwest to Lake Ontario.

Forest Cover

In general the Canadian Shield is the most heavily forested portion of the A2A region. Although attempts were made to settle and farm on the Frontenac Arch in the 19th century, few farms survived into the 20th century. As a result, much of the land that was cleared in the 19th century has reverted to forest.

Off the Shield, forests have not fared as well. Much of the land has been cleared for agriculture. Some areas however, do retain a significant portion of forest cover, including those between the St. Lawrence River and Adirondack Park and the area north of Cornwall. A few areas that proved unsuitable for agriculture, such as the area of the LaRose Forest, were reforested during the mid-20th century. Unfortunately, however, in the past several years there has been an increase in clearing of lands to expand the area available for agricultural production. 


Wetlands are important as habitat for a wide variety of wildlife including many species at risk, in regulating flow of water during time of flood or drought, and in filtering and purifying our water. Unfortunately, many of the wetlands in the portion of the A2A region underlain by Paleozoic sedimentary rocks have been destroyed to accommodate agriculture and urban development. Typically losses exceed 50% in most counties. In some cases losses are over 85%. Many wetlands that have survived have been severely compromised by nearby development or pollution.

Rivers and Watersheds

Historically the rivers of the region acted as routes for the movement of fish and other aquatic species. However, most have been severely impacted by hydro-electric and other dams, pollution and invasive species. Dams fragment habitat and prevent fish migration to the extent that several once-prolific species such as the American Eel and Lake Sturgeon have been designated as species at risk. With few exceptions, dams have been constructed and continue to be constructed without fish ladders. The St. Lawrence Seaway is the most heavily-used inland waterway on the continent, and the source of on-going concerns related to pollution and habitat loss.  

Islands and Island Chains

In some areas islands form critical pathways for the movement of wildlife. The Thousand Islands act as stepping stones that assist small mammals in crossing the St. Lawrence River and Seaway. The eastern basin of Lake Ontario is part of a critical spring and fall migration route for millions of birds. The islands and points that ring the eastern end of the lake, as well as the Main Duck chain of islands that extends across the lake farther west are considered and as a result have been designated as Important Bird Areas. Currently most of these Important Bird Areas are at risk from proposed large scale industrial wind turbine developments.

Superhighways and Other Roads 

There is a dense network of highways and roads especially in the central portion of the A2A region. Roads and highways fragment wildlife habitat and result in very high road-kill numbers because they have not been designed with the needs of wildlife in mind. The growing number of superhighways in the A2A region is of particular concern because of their high traffic volume and speed. Currently there is a effort to re-think the design of roadway in the region to better accommodate wildlife.

Figure: Superhighways of the A2A region and adjacent areas

A2A Program Outline

Our A2A program involves several important components, which are aimed at: (1) maintaining and restoring ecological links between protected areas, (2) ensuring the ecologically based management of parks and other protected areas, (3) expanding the protected areas network, (4) protecting species at risk and their habitat, (5) maintaining links to other natural regions in eastern North America.

Links to Other Organizations and Initiatives in the A2A Region

A2A Collaborative (formerly A2A Conservation Association): The A2A Collaborative has assumed a leadership role in bringing together the various Canadian and U.S organizations that are working within the A2A region, to help increase collaboration, share resources and avoid duplication.

Frontenac Arch Biosphere: The Canadian portion of the Frontenac Arch, in the heart of the A2A region, is a designated UNESCO World Biosphere Reserve. The mandate of the Frontenac Arch Biosphere is to protect the reserve's globally significant natural and cultural heritage through the promotion of sustainable development.

Save the River (Upper St. Lawrence Riverkeeper): Save the River is based in Clayton, New York and works on both sides of the U.S.-Canada border to protect the ecological integrity of the Upper St. Lawrence River.

The Land Between: The Land Between is an initiative focused on protection in the transition zone along the southern edge of the Canadian Shield and adjacent Paleozoic sedimentary cover which stretches from the St. Lawrence River to Georgian Bay. This zone is ecologically of great importance because of its abundant granite barrens and alvars, numerous lakes and wetlands, and high level of biological diversity.