Sustainable forestry the focus of keynote address
EXETER – Terry Schwan does not expect forest cover in the Ausable Bayfield watershed to increase from 13 per cent to the 30 per cent recommended by Environment Canada.
“There's too much good farm land,” he said in a speech near Exeter March 17. "They're not going to take that away, but there's a lot of other things that can happen."
Schwan, a district forester with the Ontario Ministry of Natural Resources (MNR), made the remarks in his keynote address at the Ausable Bayfield Conservation Authority (ABCA)'s annual Conservation Award and Partner Appreciation Evening.
The address focused on sustainable forestry in the Ausable Bayfield watershed, and Schwan said sustainable forestry is a balance between the demand for forest products and the preservation of forest health and diversity.
Citing the Canadian Council of Forest Ministers, he defined sustainable forest management as that which “maintains and enhances the long-term health of forest ecosystems for the benefit of all living things, while providing environmental,
economic, social, and cultural opportunities for present and future generations.”
He listed several criteria for sustainable forest management, including conserving biological diversity, ecosystem condition and productivity, and conserving soil and water resources.
Schwan also listed a series of indicators of sustainable forest management, including the percentage of forest cover, percentage of forest interior, number of known species at risk and water quality.
He noted the Ausable Bayfield watershed has 2.8 per cent forest interior – a term applied to forest that's 100 metres from the edge of a woodlot – compared to the suggested 10 per cent.
Schwan added 20 per cent of streams are vegetated, while 3.3 per cent of land area in the watershed is fully or partially protected by mechanisms like conservation areas and parks.
Later Schwan said there are forest conservation bylaws in all counties in the Ausable Bayfield watershed, saying in his mind those are the most important things protecting forests and their sustainability.
Schwan spoke about clearing forests for agriculture, saying it often involves “straightening up a field, cutting off this or that to make things more efficient.”
He said in the Maitland River watershed, clearing for agriculture is the single largest loss of natural area cover, “if you’re looking at aggregates in urban and other recreational use.
"Those little half-acre, acre here and there (clearings) are what reduces our natural areas,” he said.
Schwan spoke later about a Huron and Perth study that collected data from 1997-1999 and followed by a study covering 2006-2009.
The study showed the location of forest harvests, the size of woodlots in the area, the area harvested, species of trees harvested, and value for landowners, among other things.
The area harvested decreased significantly in Huron County in the second study period (2006-2009), but tree marking increased dramatically.
Schwan saw the increase in tree marking as a good thing, saying in an interview that tree markers are trained to “look at the whole forest, to remove trees that are poor quality as well as improve the woodlot – compared to not tree marking, where they only take the big trees.”
In his presentation Schwan noted the area harvested in the first study period was 2,570 hectares, which decreased to 1,644 hectares during the second study period.
The area marked during the first study was about 27 per cent, compared to 43 per cent in the second study period.
Schwan later spoke about maintaining biodiversity when doing forest harvest, saying the main thing one wants to maintain is habitat, even on two-acre woodlots.
Maintaining habitat includes downed woody debris, which he said is important for wildlife.
He said "snags" – standing dead trees – provide great habitat, especially when they have cavities.
Schwan added that living trees with cavities are important, along with mast trees – those that produce nuts and fruit.
Developing a harvest structure and seasonal harvesting are also important for forest sustainability, according to Schwan.
"Good forest practices lead to sustainability," Schwan said later in the presentation, listing a series of measures involved in good forest practices.
The list includes having a management plan and tree inventory; a prescription for tree marking (meaning how the forest will be marked, then cut, then operated); minimizing damage; worker safety; harvest scheduling; and tree felling and skidding practice.
Schwan then spoke about diameter-based tree cutting, in which trees are harvested solely on the basis of their diameter at stump or breast height, without regard for other values.
"That is acceptable from a regulation point of view, but not from a forestry point of view," Schwan said.
"We promote good forestry, not diameter limit, and people who mark (trees) are supposed to mark to good forestry practice.”
Schwan showed a presentation slide that sketched out the negative effect of diameter-based harvesting, noting dense young portions of tree stands are not thinned.
The slide also states areas supporting large trees are completely cut over, and there is no control over reproduction.
"Trees of the highest vigour tend to be cut first, while trees with defects (or) low vigour remain in the stand," the slide states.
Schwan later discussed strategies to manage woodlots, reiterating the idea of an inventory, along with an operating plan and evaluation.
He suggested landowners work with a forester or logger they've carefully selected, get involved with woodlot owners' groups, and say "no" to high-grading and diameter-limit cutting.
Schwan listed a series of ways in which the watershed is "losing" when it comes to forest sustainability, including clearing for agriculture, draining wetlands, invasive plants, the Emerald Ash Borer, and poor logging practices.
He then listed areas in which the watershed is gaining, including forest conservation bylaws, tree marker certification and training, the Planning Act and Natural Heritage Reference Manual and the Huron Natural Heritage System.
Schwan closed with a list of restoration priorities, the first of which was increasing forest interior.
"This is an agricultural watershed," he said. "(You're) not going to be planting five and 10 acre blocks of forest – well, maybe the odd one.
"But you can work around the edges and increase forest interior."
Schwan listed buffers for watercourses and wetland areas as another priority, along with protecting fragile lands, establishing corridors between isolated natural areas, and noted the importance of windbreaks.