Jan 31, 2011

Free to grow or free to fail? Emerging science raises questions about health of our future forests


As tree-planting company representatives from across British Columbia gather in Kelowna for a conference this week, a lot of attention will focus on the question of just how significant a reforestation challenge we have on our hands in the province.

Even those of us who know comparatively little about our forests understand that some astonishing things have occurred in recent years that raise questions about the health of one of our most important publicly owned resources.

Two of the more evident of those things are the epic mountain pine beetle attack that has left in its wake one billion or so dead older pine trees, and a spate of terrifically intense fires that have burned forests across huge swaths of land.

But as it turns out, these are far from the only events that are giving rise to a burgeoning reforestation crisis in the province. While the beetle attack and fires have predictably captured  media attention, another event with significant implications for the health of future forests has quietly unfolded.

That event is the widespread die-off of large numbers of planted trees in allegedly healthy tree plantations – our so-called future forests.

How significant a problem this is and what it means for the province’s already considerable reforestation challenge is not yet fully understood. But as the results of early field studies come in, it appears that the province has a lot more forestland in need of rehabilitating than previously thought.

Last year, Forests Minister Pat Bell claimed that the amount of forestland that was “not sufficiently restocked” and in need of replanting was in the vicinity of 240,000 hectares or 600 Stanley Parks in size. But this week Anthony Britneff, a former public servant who was in his 40th year of service in Bell’s ministry when he retired last year, will vigorously challenge his former boss’s number at the Kelowna conference, suggesting it may be off by a factor of 10 or more.

Part of the reason why, has to do with the growing number of once healthy tree plantations that now show significant signs of stress.

In the tree-panting world, areas of logged land that have been replanted are only considered to be successfully rehabilitated when their trees are deemed “free-to-grow”.

Free-to-grow means that the planted trees have reached a height where they can no longer be outcompeted by undesired plants. At this point, it is assumed that the unimpeded trees will simply continue growing until a point decades down the road when they are logged.

A few years ago, however, some forest scientists began to question whether this assumption was correct. They worried that if the provincial ministry of forests relied on such an assumption to guide it in setting logging rates, and the assumption later proved incorrect, sustainable management of publicly owned forests was in doubt.

It turned out they were right to raise the question and that a lot of free-to-grow tree plantations were in trouble. Among those to initially focus on the health of such plantations was Alex Woods, a forest pathologist formerly with Bell’s ministry and now with the new Ministry of Natural Resource Operations.

Woods’ preliminary results, presented to an international gathering of forest disease experts in Valemount last October, indicated that fully one third of free-to-grow plantations in the Okanagan region had fewer than the minimum number of trees needed to meet provincial reforestation requirements. Other areas of the province are being similarly surveyed.

The bad news with such findings is that future forests may deliver far less by way of important natural services (cycling water) and economic benefits (wood for forest industry jobs). The good news is that with proper resources our public servants can continue the critically important fieldwork that may lead to productive changes in how we reforest public lands for maximum public benefit. Whether those resources will continue to be there, however, is a big question. The provincial forest service has lost 1,006 positions – one quarter of its workforce – in less than a decade, and its budget fell by 23% between the 2008/09 and 2010/11 fiscal years.

Woods’ findings come as no surprise to others who have conducted surveys in once seemingly healthy tree plantations. They believe that an underlying problem with the plantations is rooted in the free-to-grow requirement itself. Forest companies are legally required to establish a new crop of trees on lands that they log. That requirement is only met when the trees that are planted reach free-to-grow status. Since the quickest and easiest way to do that is to plant trees that favor open, light environments – which is precisely what recently logged lands are – one tree species has been overwhelmingly favored over all others. That tree is lodgepole pine.

Scientists such as University of British Columbia forest ecologist Suzanne Simard, are among those to suggest that the free-to-grow requirement itself has spurred the over-planting of lodgepole pine (fully 55% of all trees planted in B.C.) and that such over-planting has resulted in pines being placed in large numbers where they shouldn’t be, for example on wetter sites. The homogeneous plantations then see their trees die in large numbers when things like the mountain pine beetle come around.

Add climate change to the mix, and we have a major reforestation challenge on our hands. Not only has climate change contributed to the severity of the mountain pine beetle outbreak, but it has fueled other problems, including blights such as Dothistroma that have wiped out planted pines by the drove over large areas – a phenomenon described by Alex Woods and other public servants.

Dealing with this triple whammy will not be easy. We must build on our proven success in planting trees, but in new and creative ways. Public funds will need to be invested in the hundreds of millions of dollars to plant new generations of trees (a significant increase over current funding levels). But before such trees are planted, far more care will be needed to determine which trees are planted where. Then, once the trees are planted, we’ll need public servants out there on our public lands, systematically tracking what is happening so that our planting plans can be changed as circumstances require.

If we want forests for tomorrow, we’ll have to put forest scientists where they’re needed most — in our forests.

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