http://cfs.nrcan.gc.ca/authors/read/17877 Publications by M. Betts en-ca 2005-04-29 00:00:00 MST 2005-04-29 00:00:00 MST webmaster@nofc.cfs.nrcan.gc.ca http://cfs.nrcan.gc.ca/publications?id=25393 The importance of biodiversity has become widely recognized but the best methods for conserving forest biodiversity are still being debated. Central to this debate is the influence of plantaitons and managed stands on local and landscape-scale biodiversity. A recent paper by Erdle and Pollard in the Forestry Chronicle (2002), which concluded that few plantations are strict monocultures in terms of the total number of tree species, could be interpreted as making the case that plantations have relatively minor consequences for biodiversity. We argue that: (1) it is not only the number of species, but also the identities and relative abundances of species that are of ecological importance, and (2) defining biodiversity in terms of tree species alone is of limited applicability. Existing research in New Brunswick on the impact of plantations on biodiversity at the stand scale reveals potentially significant biodiversity losses, at least in certain taxa. The proposal that incorporating more structural elements (e.g., snags, coarse woody debris, vertical structure) and retaining greater tree species diversity to ameliorate negative consequences of plantations remains a hypothesis to be tested in this region. Scientific information gathered in the following areas will allow better decision making: (1) to what degree are older plantations used by native species? (2) are productivity and survivorship of vertebrates in intensively managed stands similar to those in unmanaged stands? (3) are intensively managed stands suitable habitat for non-vertebrates? (4) are there thresholds in the response of some species to landscape-scale habitat lloss caused by intensive forest mangement? Fri, 29 Apr 2005 http://cfs.nrcan.gc.ca/publications?id=25393 http://cfs.nrcan.gc.ca/publications?id=20217 The characterization of "natural" or "presettlement" forest has become a relatively common practice in Canada as forest managers strive to put into practice concepts of sustainable forest management. Various methods have been developed to undertake such characterizations, leading to confusion about how to define "presettlement forest" and uncertainty over the approach that will best serve as a basis for management. We report on two methods of presettlement forest characterization: the "Witness Tree" and the "Potential Forests" approaches. We compare results from these approaches to the existing forest composition in the Fundy Model Forest, New Brunswick. Both approaches indicate a decline in the predominance of tolerant hardwood and eastern cedar since presettlement. However, the Potential Forests approach consistently suggests much higher presettlement frequencies of spruce (Picea spp.) and, in most cases, pine (Pinus spp.) than the Witness Tree method. Differences between frequencies of tree speceis estimated by the two methods probably result from biases associated with both methods and the different scales of reporting. If used critically, the combined use of both sets of presettlement forest information will allow managers to determine the historical frequency of individual tree species and forest communities. Such information will provide some guidance in maintaining the diversity of native species and community types. Wed, 10 Jul 2002 http://cfs.nrcan.gc.ca/publications?id=20217 http://cfs.nrcan.gc.ca/publications?id=20304 Fri, 19 Jul 2002 http://cfs.nrcan.gc.ca/publications?id=20304