What is Sustainable Forestry

One of the best ways to understand the definition of sustainability is to begin by recognizing that nothing is sustainable forever. Change is the only constant as ice-ages come and go, fires ravage areas of boreal forest the size of European countries, and even the Sun gets closer to its demise five billion years from now. When we use the term sustainability we are talking about 100-200 years, certainly longer than the usual five-year forecast from the accounting department, but not exactly geological.

In a general sense, sustainability means keeping the Earth in a state that can support the next generations of species, including humans, in a healthy condition. Clearly we are not there yet for the 2 billion or so people who live in conditions we would not consider suitable for a dignified life. Then again, some people think the sustainability of beetles in tropical forests is more important than the people who are clearing the forests for sustenance. Sustainability is very much about what it is we want to sustain rather than some absolute or ideal state of being.

Most of the resources used today are non-renewable, such as steel, cement, plastic and fossil fuels. When compared with these industries, it is clear that forestry is the most sustainable of all the primary industries that provide civilization with materials and energy. Forests are innately renewable and they grow with solar energy, air, water, and minerals from rocks as their only requirements.

The real change that has occurred in the past 20 years is the transition from thinking of sustainable as having to do with wood supply to thinking of it in terms of sustaining all the species in the forest. We are now talking about sustaining biological diversity in its fullest sense; genetics, species, and ecosystems. This requires a dramatic shift from a mentality of timber production alone to one of timber production combined with the maintenance of biodiversity across the landscape. Fortunately, this would appear to be entirely possible.

The real change that has occurred in the past 20 years is the transition from thinking of sustainable as having to do with wood supply to thinking of it in terms of sustaining all the species in the forest. We are now talking about sustaining biological diversity in its fullest sense; genetics, species, and ecosystems. This requires a dramatic shift from a mentality of timber production alone to one of timber production combined with the maintenance of biodiversity across the landscape. Fortunately, this would appear to be entirely possible.

At both the stand level and the landscape level loss of biodiversity can be prevented through three basic approaches:

The protection of reserves, streamside zones, steep areas, and ecologically sensitive areas in general.

The prevention of severe erosion to soils by adopting high standards for road building and maintenance.

The retention of key structural elements such as standing and fallen dead trees, shrubs, and woody debris.

The main challenge for professionals is to avoid either focusing totally on timber production or on biodiversity protection and to learn to do both simultaneously. Of course we can not maintain all values at all places at all times. The trick is to plan the landscape so there is always somewhere capable of providing habitat for all species at any given time. Sometimes this means creating permanent reserves, such as the 12% parks and wilderness we have adopted in BC. This is an insurance policy against unforeseen loss of biodiversity in managed areas. For most, if not all species, it is possible to retain them in the context of managed forests so long as their needs are taken into account in planning.

I believe the best document produced to date on harmonizing timber production with biodiversity protection is the work of the Centre for Applied Conservation Biology in the Faculty of Forestry at UBC. Led by Fred Bunnell, the Centre was commissioned by MacMillan Bloedel to apply the work done by the Scientific Panel for Sustainable Forest Practices in Clayoquot Sound to their forest tenures in coastal BC. The resulting document, “An Ecological Rationale for Changing Forest Management on MacMillan Bloedel’s Forest Tenure”, is a brilliant treatise on how to combine industrial-scale timber harvest with biodiversity protection.

Professor Bunnell begins with the reasonable assumption that vertebrate biodiversity is a suitable surrogate for biodiversity in general. He then describes the biological needs of all 215 vertebrate species known to exist in MacMillan Bloedel’s tenures and designs a harvesting regime to accommodate those needs. As it turns out there are species that have evolved to occupy all stages of ecological succession, from recent clearing to old growth. Bunnell’s first rule is “Don’t do the same thing everywhere”, the opposite to a rigid prescriptive approach but still very disciplined in its provision of all necessary habitats. There is no reason why the rationale in this paper cannot be applied to any forest in the world.