Dynamic Forest: Man Versus Nature in the Boreal Forest by Malcolm F. Squires

Author:Malcolm F. Squires [Squires, Malcolm F.]
Language: eng
Format: epub
Tags: Technology & Engineering, Public Policy, Agriculture, Forestry, Trees, Political Science, Plants, Nature, Environmental Policy
ISBN: 9781459739345
Google: ISFDDQAAQBAJ
Goodreads: 32608475
Publisher: Dundurn
Published: 2017-08-26T00:00:00+00:00

Eastern White Pine — Not a Boreal Species but Present

Eastern white pine (Pinus strobus) is found from the southeastern corner of Manitoba to Newfoundland and well down into the eastern United States.14 This magnificent tree has limited range within the NWO boreal forest, existing mostly along its southern fringe where the boreal and Great Lakes–St. Lawrence forests merge. There are, however, small stands and scattered trees well north in isolated micro-climates, giving the impression that it is a boreal species.

An examination of the tree’s needles will reveal that they are clustered in bundles of five on the twigs. This distinguishes it from the other native pines in our region, jack and red pines, which have only two needles per bundle. Its hanging, ten- to twenty-centimetres-long, flexible seed cones, which require two years to mature, begin appearing at about age twenty years. Seeds are “disbursed by wind and seed-eatinganimals” upon maturity in late summer.15

“Rapid-growing; thrives in full sunlight; seedlings moderately shade-tolerant; can survive under an open canopy and attain full vigor if the shade is removed within 20 years.”16Indeed, partial shade has been shown to offer the tree some protection from the white pine weevil and white pine blister rust, its two most dangerous pests in NWO.

The larva (worm) of the weevil burrows up through last year’s main-stemgrowth leader. Some authorities suggest that, under shade, that leader is too thin to accommodate the worm’s diameter, thus limiting its development.

Blister rust requires additional hosts, the gooseberry and currant genus members (Ribes), from which it releases heavy spores that must find a receptive pine needle. Dew on needles is considered an enabler because it helps by initially attaching the spores to the needles. Dew formation is less likely under a partial tree canopy. Also shaded young pines shed the needles from their lower branches earlier than do more open-growntrees and are thus less likely to collect heavy spores on higher needles and thus become infected.

The disease spreads from the needles through the twigs and branches into the main stem, causing large sores that may kill the bark and eventually girdle the tree’s main trunk. That portion of the tree above the girdle then dies. An internet search will reveal most of what we know about the disease today.

Beginning in the 1990s Abitibi-Price(after 1997 Abitibi-Consolidated) planted white pine mixed with red pine and black spruce on its privately held Grand Trunk Pacific blocks in Ontario around Athelstane and Muskeg Lakes and the Dog River, until the firm sold the land in 2005. It was similarly introduced to the Spruce River FMA north of Thunder Bay and as far north as the TransCanada pipeline.

Semi-matureand mature white pines were already components of some stands on the company’s private lands and in the Wolf River watershed of the Spruce River FMA. On both land tenures the company reserved (i.e., did not cut) the white pines, but harvested other tree species (shelterwood harvesting), and treated (site prepared) the ground to encourage natural regeneration of the pines. On the

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