White pine in the Lake Abitibi and Lake Temagami ecoregions of Ontario

Eastern white pine (Pinus strobus L.) can be a challenging tree species to manage. Past exploitation, a disease introduced from Europe to North America, and fire suppression have reduced the quantity and quality of this valuable resource province wide. This is especially true where white pine grows at the northern limit of its range. A cooler climate, small populations that produce few seeds, and a higher risk of disease may limit the establishment and growth of this tree species more here than in areas further to the south.

This report provides information about the ecology and the state of white pine in the Lake Abitibi (3E) and Lake Temagami (4E) ecoregions of northeastern Ontario (Figure 1), the factors influencing this resource, and how it is being managed.

Provincial overviews of the status of Ontario’s forests are available through the Forest Resources of Ontario Report and Ontario’s State of the Forest Reports (2001 and 2006).

The Lake Abitibi and the Lake Temagami Ecoregions

The Province of Ontario is divided into large ecozones and smaller ecoregions that have specific geological histories and climates. The Lake Abitibi and Lake Temagami ecoregions cover 14 per cent (13.8 million hectares) and four per cent (4 million hectares) of Ontario, respectively. The Lake Temagami Ecoregion is warmer and has more hills, ridges, and valleys than the Lake Abitibi Ecoregion. Both ecoregions are part of the larger Boreal Shield Ecozone that covers most of Ontario.

Forests of the Lake Abitibi Ecoregion are dominated by black spruce, trembling aspen, jack pine, white birch, balsam fir, and white spruce. White pine is uncommon and most frequently found growing in small, isolated populations, often with red pine. The northernmost populations of white pine are thought to be remnants of forests that covered this area 3,000 to 7,000 years ago when the climate was warmer and drier than it is today. During this period, white pine trees were possibly found as far north as James Bay.

The same tree species are present in the Lake Temagami Ecoregion, but white pine, red pine, and other species such as maples and yellow birch also form a significant portion of the forests. Here, the climate and natural fire regime are more favourable to white pine, and its distribution is therefore less restricted.

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