Clear-cutting experiment far too risky

Clearcutting

White pines, probably the most evocative symbol of the wild in Ontario, are almost commercially extinct in the province. They already have become commercially extinct in Michigan, Minnesota and, except for the Menominee Forest, they’re commercially extinct in Wisconsin.

In addition, Ontario’s red spruce and yellow birch are now commercially extinct, and hemlock has been decimated.

We have not managed our forests well, and now the provincial government is proposing a radical change in logging guidelines that will allow clearcutting over vast areas that can be unlimited in size.

In an earlier draft of its proposal, the province had called for a cap of 10,000 hectares (100 square kilometres) on the size of clearcuts — far in excess of the 150-hectare maximum allowed in Quebec, the 100-hectare maximum allowed in Manitoba, and the average 20 to 40 hectares cut in British Columbia. Now Ontario, in its second draft of the proposal, has removed the cap and there’s no limit at all proposed.

Last week, I said that this column would finish the series on Electromagnetic interference. However, since the province is prepared to receive comments on its clearcutting proposal only until the end of October, I’ve interrupted the electromagnetic series to deal with clearcutting.

The central idea behind the proposal is to regulate clearcutting in such a way that the province hopes it will mimic wildfires — which, in theory, is not a bad idea.

Forests have existed for about 30 million years, and throughout their evolution wildfires have been key to their renewal and restoration.

With this in mind, the province wants all clearcuts, even the smallest, those of only few hectares, to mimic the effect of fires. And since a few fires range over huge areas, it is suggesting that a few clearcuts do so too.

The problem is that wildfires are part of a complex ecological process that clearcutting cannot possibly duplicate in its entirety. So the big question is: How can you manage clearcuts to gain some of the benefits that wildfires deliver and, at the same time, avoid disrupting ecological systems in ways that do serious harm to both the forests and the wildlife that depend upon them?

The conundrum is exquisitely well laid out in a study that will be published later this year in The Journal of Environmental Reviews, but which is available now at  www.nrc.ca/cgi-bin/cisti/journals/rp/rp2_jour_e. Choose « Environmental Reviews’’ and then the contents menu. Next, go to the table of contents and click on Vol. 9, No. 4, Dec. 2001.

The study is written by D. J. McRae, L. C. Duchesne, and T.J. Lynham, all with the Canadian Forest Service, Natural Resources Canada, S. Woodley, with Parks Canada, and B. Freedman, a biologist at Dalhousie University in Halifax.

The province’s draft guidelines can be found at www.mnr.on.ca/mnr/forests/forestdoc/ebr/guide/disturbance.html.

The study concludes that there will need to be « a careful experimental approach’’ to determine how clearcuts can be used to duplicate the benefits of fire.

So, do we want to experiment with vast tracts of land? After reading the report, I think we’d be mad to experiment on that scale — regardless of how advantageous it might be to forestry companies.

To give only one example, genetic inbreeding of trees happens if clearcutting knocks down too many parent trees. When the remaining parents cast their seeds, it results in too many saplings that are related. When they cast seeds, inbreeding begins. The results are trees that are shorter, thinner, slower growing, and more frail.

Inbreeding doesn’t happen after fires because lots of trees survive in pockets here and there — enough to ensure that genetic diversity continues. That’s what 30 million years of evolution have contributed.

Duchesne, who has a doctorate in botany, emphasizes that science is still at the starting point point with this idea. Read his and his colleagues’ study. I think you’ll agree the province should be urged to slow down and get it right.

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