Canada's old-growth forests
published May 2000
by Willard Carmean, Lakehead University
Ontario is one of the largest provinces of Canada, 1,000 miles from north to south and 850 miles wide east to west, covering an area larger than the combined areas of Minnesota, Wisconsin, Michigan, Ohio, Pennsylvania and New York ö more than 400,000 square miles.
Within this vast area we find the rich mixed hardwood forests in the south (Carolinian region), mixed hardwoods and pines (Great Lakes-St. Lawrence region) as we move north, then mixed conifers (jack pine, spruces, balsam fir) and hardwoods (aspen and birch) that grade into an open boreal conifer woodland (Hudson Bay lowlands), and finally a thin strip of tundra bordering Hudson Bay.
This article will briefly describe the major old-growth forests of this vast and varied landscape. We will consider the original old-growth forests that greeted the first Europeans to see the region, then we will outline what remains of our old-growth heritage. Finally we will discuss steps that could be followed to ensure that old-growth forests remain as part of our forested landscape.
Climate, geologic and soil differences vary greatly from south to north, with many deep and fertile soils in the south, shallow stony moraines (glacial deposit structures) further north covering the granites of the Canadian Shield, then poorly drained peatlands in the Hudson Bay Lowlands, and finally muskeg overlying permafrost in the thin tundra strip bordering Hudson Bay.
Varied geologic and soil conditions were further complicated by the passage of at least four continental glaciers. The Wisconsin glacial period covered Ontario as recently as 9,000 to 12,000 years ago. This glacier left a complex pattern of moraines, glaciofluvial outwash, glacially deposited clays and silts, and large areas of lakes and peatlands, all having complex patterns of forest conditions.
Forest complexity was further increased by repeated wildfire, particularly in the boreal region, where pioneer forest species have evolved under the pervading influence of repeated natural fires. More recently forest area has been reduced by land clearing for agricultural and urban development, particularly for the rich Carolinian hardwood forest region of southern Ontario. Lumbering has greatly affected most of the mixed hardwood and pine forests of central Ontario. First to be cut were the tall white and red pines, followed by highgrading ("cut the best and leave the rest") of the hardwood forests. In the boreal region large areas of conifers and hardwoods have been clearcut to provide fiber for pulp, fibreboard, and lumber industries.
An appreciation of old growth, or the lack of old growth, in the various forest regions of Ontario requires a closer look at each region. Such a look provides a general view of what might have been the original presettlement forest. Such a look also can provide an appreciation of the role of climate, soil, fire, and humans in shaping the present forest conditions of Ontario.
In the following sections, we will consider the original and present old-growth and mature forests for each forest region of Ontario. Then we will discuss how certain forest areas might be managed to achieve a "sustained yield" of old-growth forests for the future.
Carolinian forest region
This southernmost region of Ontario has mild climates tempered by the influence of Lakes Ontario and Erie. Here we find large areas of rich soils derived from glacially deposited silts and clays derived from underlying limestone bedrock or calcium-containing moraines. These favourable climate and soil conditions produced rich hardwood forests that resembled rich hardwood forests further south in the United States. Sugar maple and beech were most common, together with basswood, yellow birch, elm, red maple, black cherry, white ash, and red oak. A host of other tree species close to the northern limits of their range were also found, including tulip poplar, cucumber magnolia, Kentucky coffee-tree, sassafras, black gum, black walnut, sycamore, and many species of oak and hickory.
Most of these rich mixed hardwood forests disappeared long ago, because most of the productive soils were converted to agricultural fields and to ever-spreading urban , industrial, and highway developments. The few remaining forest fragments usually are found on soils less desirable for agricultural such as dry ridges and cliffs, shallow bedrock outcrops, swamps or peatlands, and dry sandy deposits along lake shores.
Most of the remaining hardwood forests are young, reflecting a history of repeated harvesting. Fortunately, conservation organizations have been active in identifying and preserving many of these forests. Reserved forests include relatively undisturbed old-growth hardwood forests such as Backus Woods, Walpole Island First Nation lands, and John E. Pearce, Rondeau and Credit Provincial Parks. Conservation groups have also helped reserve several areas of mature hardwood forests, including Shunkâs Misery, Grand River Forests, Six Nations Indian Reserve, and the Strathroy, Springwater, Albion Hills, and Hilton Falls Conservation Areas. Drier areas of interest include prairies and oak savannahs such as found in the Ojibway Prairie Complex and in Pinery Provincial Park.
Great Lakes ö St. Lawrence forest region
Moving northward we find a transition region between the rich Carolinean hardwoods and the boreal conifer forests. Here majestic white and red pine towered over mixed sugar maple and beech forests. The shallow stony morainal soils over granites of the Canadian Shield usually had mostly hardwoods with scattered pine; sandy glacial outwash soils often had mostly pine forests. Natural fires favoured the white and red pines as well as red oak. The tall pines were first to be logged and used for constructing Canadian and American towns and cities. Many squared timbers were exported to Europe, and many of the largest pines were used as masts for sailing ships. Hardwood forests also were heavily cut by removing the most commercially valuable species such as yellow birch, black cherry and white ash.
A few scattered stands of old-growth white and red pine still remain in the Great Lakes-St. Lawrence region. These majestic forests have attracted much public attention (white pine is the provincial tree). Reserving additional old-growth pine forests has been the subject of much public controversy, and has been one of the major interests in a provincial old-growth initiative as well as in the recent "Lands for Life" provincial program.
Algonquin Provincial Park was established only in 1893, following the early era of tall pine exploitation, so only small areas of undisturbed old-growth pine and hardwood forests remain. But old-growth pine forest areas remain in Algonquin Park at the Big Crow White Pine and Dividing Lake Nature Reserves, and Dickson Lake has a stand of old-growth red pine and a stand of old-growth hemlock. East of the park we find old-growth white and red pine at Temagami whose lack of protection remains the subject of continuing controversy. Other old-growth pine areas are in the Algoma Highlands and in the Upper Spanish River.
Old-growth hardwoods also occur in Algonquin Park at Nadine Lake Hardwoods and at the Hardwood Hill Picnic Area. South of Algonquin Park are old-growth hardwoods together with pines and hemlock at the Pigeon River Headwaters Conservation Area, the Fleetwood Creek Natural Area, Shaw Woods, Kinghurst Forest, Gillies Grove, Peterâs Woods Provincial Nature Reserve, and at the Burnham Provincial Park.
There is a remarkable old-growth white cedar forest on the Niagara Escarpment that extends from the Niagara Peninsula northwest to the tip of the Bruce Peninsula. Here dwarfed cedar more than a thousand years old cling to dolomite cliffs and bluffs. A particularly impressive cedar forest is found at the Mono Cliffs Provincial Park.
The Great Lakes-St. Lawrence forest region also occurs in northwestern Ontario. Considerable old-growth pine remains in Quetico Provincial Park at McNiece Lake as well as at Shan Walshe Lake. There is a particularly impressive old-growth white pine forest at the Greenwood Lake Conservation Reserve, where 250- to 300-year-old trees are more than three feet in diameter and have heights of more than 130 feet. There are also impressive old-growth white pine forests at Sowden Lake and in the Turtle River-White Otter Lake Provincial Park. Old-growth red pine forests also occurs at Sowden Lake, at Clay Lake, and far to the north in the boreal forest at Miniss Lake.
Boreal forest region
Conifers of the boreal forest include jack pine and black and white spruce, and boreal hardwoods include trembling aspen and white birch. These species have evolved under a regime of repeated wildfire and are able to quickly regenerate after fire because of "serotinous" cones that contain viable seeds that remain on fire-killed trees (jack pine and black spruce) or because of shoots that sprout from roots of fire-killed trees (aspen and birch). These pioneer species usually regenerate in almost pure even-aged stands following fire, but these species are relatively short-lived when compared to long-lived hardwoods in southern Ontario such as sugar maple, or when compared to long-lived white and red pine. For example, jack pine and aspen slows in growth and stands begin to break up at about seventy to eighty years; black spruce stands live somewhat longer. Because of their short lives these old-growth boreal species do not have the impressive ages and sizes found with the old-growth forests of southern Ontario.
Older jack pine and black spruce stands growing on very shallow or very sandy gravelly soils grow slowly and have relatively little timber value. However, these stands do have much value as habitat for woodland caribou because of tree and understory lichens. Such undisturbed conifer stands in Woodland Caribou and Wabikimi Provincial Parks are noted for the presence of woodland caribou as well as for wilderness recreation values.
Further north we find the Hudson Bay lowlands. Here relatively flat lands have open woodlands of stunted black spruce and tamarack growing on peatlands underlain by calcareous marine clays.
Old-growth forests of the future
Conservationists as well as forest land managers of Ontario have an increased awareness and interest in the multiple values associated with old-growth forest ecosystems. Old-growth forests are often sought by the forest industry because they contain large trees having considerable wood product value. However, these forests have many additional values that often exceed their material values for wood products. These additional values include:
Recognition of the additional values of old-growth forests have resulted in the establishment of many provincial and national parks in Ontario. Also many conservation reserves have been established to protect areas having unique biological and geologic values. The recent provincial "Lands for Life" process resulted in a doubling of land areas reserved for protection of these many additional values.
We must face the challenge÷"How do we sustain old-growth ecosystems in our forested landscape?"
Many hardwood forest ecosystems, such as sugar maple and beech forests, are self-sustaining because seedlings regenerate in the shade and eventually become dominant when old trees die. But many old-growth forest ecosystems, including white pine, red pine and oak forests, are "successional" ecosystems that usually became established following wildlife or other natural and human disturbances. These species are long-lived but are following a path of constant successional change. We cannot preserve such successional old-growth forests forever even though they may survive for many centuries. We can protect such old-growth forests, can enjoy their beauty, and can study and learn much while they remain. But eventually these magnificent old trees will die and a new forest will evolve composed of more tolerant species such as balsam fir and spruce that may be less attractive than the present old-growth pine forests. Thus management for old-growth pine requires a recognition of the entire lifecycle of pines÷regeneration of new forests, development of mid-aged forests, and the development and eventual decline of the old-growth pine forests.
Sustained management for future old-growth white and red pine forests established following fire and other disturbances may depend on silvicultural methods designed for establishing and developing young pine forests that can become old-growth forests of the future. Foresters now use sustained yield plans for establishing and managing younger timber production forests because foresters recognize that these industrial forests will be harvested at a rotation age when growth rates decline. But for managing old-growth pine forests a longer rotation is involved where old forest trees eventually are naturally harvested by insects, disease, and perhaps fire and wind.
Accordingly, sustained-yield old-growth forest management involves more than the commendable policy of reserving the few remaining, scattered old-growth pine stands. For white and red pine we also must be concerned with regenerating areas of new pine forests, and with identifying and protecting mid-age pine forests.
These newly regenerated areas and mid-age forests thus can become the old-growth forests of the future that will replace the present magnificent old-growth forests that inevitably will be naturally harvested by insects, disease, and fire. Development of a successful old-growth pine management program thus could provide significant areas of old-growth pine forests of the future that can provide values for recreation, ecotourism, aesthetics, and habitat for rare and endangered plant, animal, and bird species.
Dr. Carmean is professor emeritus in the Faculty of Forestry and the Forest Environment at Lakehead University, Thunder Bay, Ontario. Information for southern Ontario is from A Nature Guide to Ontario, edited by Winifred Cairns Wake, Anne Champagne, and John Cartwright, 1997.
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