Forest Ecosystem Topics

Reforestation

Today, all Crown lands are replanted after commercial harvest. This was not always the case, as the rapid rise in harvest through this century rapidly outpaced natural regeneration. By the 1970s a huge backlog of Not Sufficiently Restocked (NSR) land threatened future forestry. A federal-provincial Forest Renewal Development Agreement (FRDA) from 1981 to 1986 resulted in planting of millions of trees, and was renewed from 1986-91 (FRDA II). By then, improved reforestation regulations for commercial harvest and a greatly expanded seedling production infrastructure had largely eliminated the "NSR backlog" and reached a steady state of replanting approximately equaling harvest area. A small gap between harvest area and reforestation area is accounted for by the amount of time between harvest and planting, including delays caused by reforestation failures that must be replanted. Compare the proportions of trees replanted in the region (graph, above) with those that represent natural tree diversity in the region.

One of the issues in forest biodiversity is the diversity of tree species in the recovering forest after harvest. Biodiversity guidelines now specify a diversity of tree species in reforestation appropriate for the ecosystem. Nevertheless, the heavy reliance on lodgepole pine in reforestation is of concern because of the low biodiversity in lodgepole pine stands. This species has commercial advantages because it grows well in many environments and reaches harvest age (60 years) more quickly than other species (80 years). In the graph, some cottonwood planted experimentally rounds off to 0%, and hardly any yellow cedar were planted, also approximating 0%. Hemlock is not planted because it self-seeds so readily and is not as highly valued commercially as other species that do well on the same sites (e.g., western red cedar, Douglas-fir and western white pine). Pacific yew is not planted because it is difficult to propagate, grows too slowly to reach maturity at the same age as other species, and is not valued commercially. Since western white pine regenerates well naturally in the Interior Cedar-Hemlock biogeoclimatic zone, the small amount replanted is appropriate.

Less than one percent of the trees planted were Ponderosa Pine, despite the large area of Ponderosa Pine biogeoclimatic zone in the East Kootenay, and substantial stands in the southern parts of the West Kootenay. Ponderosa Pine is a fire-maintained ecosystem: frequent, natural wildfires normally clear out the underbrush and seedlings of other tree species, leaving the fire-resistant pines to grow big and old, widely spaced with grasses and wildflowers in between. This, of course, make good grazing for wild ungulates and livestock (see Grasslands). But fire suppression allows encroachment of other trees, especially Douglas-fir, and infilling of underbrush, that greatly alters this ecosystem. For this ecosystem to be restored, more planting will be required and fire will have to be re-introduced on a larger scale. This is an active area of investigation for wildlife and forest agencies as well as livestock ranchers' associations and environmental groups.

It is important to recognize that terms such as "reforestation" and "forest renewal" do not equate to restoration of natural forest, with all of their structural and biological attributes. Replanting selected species and harvesting at rotations of 60 (lodgepole pine) and 80 (other coniferous forest) years can not allow the renewal of habitats required by old-growth dependent species, nor is it enough time for more slowly dispersing species, such as some plants, fungi and insects, to recolonize the harvested area. Once timber has been harvested by clear cutting, the land replanted, and harvested again in currently planned rotations, the natural forest and some of its non-timber values are lost forever. For this reason, modern industrial forestry can not be considered "sustainable" in the sense of maintaining all options for future generations, even though timber harvest, per se, is sustainable.

References

Ministry of Forests, 1998. Annual Report 1996/97.
Harding, Lee, 1994. Threats to diversity of forest ecosystems in British Columbia. In L.E. Harding and Emily McCullum (eds.), Biodiversity in British Columbia: our changing environment. Environment Canada.

More Information

http://www.gov.bc.ca/for/
Follow links to Forest Practices Code summaries and document lists, Biodiversity and other Guidebooks; or go to http://www.for.gov.bc.ca/hfd/ and Search for these documents.

Follow links from luco.gov.bc.ca to find this site containing Resource Inventory Committee standards for collection of biological data in B.C.

Treebook - classifying the natural world is downloadable.

The Ministry of Forests, Forestry Division, Services Branch page allows you to search for specific documents. Enter the exact title or author of the forest tree genetic references listed above. You can read the abstract on-line and download the full documents to read offline. They are in *.PDF format, and you need Adobe Acrobat Reader to read them, which you can also download by linking from the same site.

 Forest Ecosystem Topics