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Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Much of Canada's terrestrial biodiversity is supported by boreal forests. Natural resource development in boreal forests poses risks to this biodiversity. This paper reviews the scientific literature to assess the effects of natural resource development on terrestrial biodiversity in Canadian boreal forests. We address four questions: (1) To what extent have Canadian boreal forests changed due to natural resource development? (2) How has biodiversity responded to these changes? (3) Will the biodiversity of second-growth forests converge with that of primary boreal forests? (4) Are we losing species from boreal forests? We focus on trees, understory plants, insects, fungi, selected mammals, and songbirds because these groups have been most studied. We review more than 600 studies and found that changes in community composition are prevalent in response to large-scale conversion of forest types, changes in stand structures and age distributions, and altered landscape structure resulting from forest management and habitat loss associated with other developments such as oil and gas, hydroelectric, and mining. The southern boreal forest has been more highly impacted than the north due to more extensive forest management and the cumulative effects of multiple forms of development. There is abundant evidence that most species are not in danger of being extirpated from the boreal forest due to these anthropogenic changes. A few species, including woodland caribou ( Rangifer tarandus) and grizzly bear ( Ursus arctos), have, however, undergone long-term range contractions. Significant gaps in our ability to assess the effects of natural resource development on biodiversity in the boreal zone are the lack of long-term spatial and population data to monitor the impact of forest changes on ecosystems and species. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper examines the impact that climatic change over the last millennium has had on aggradation and degradation of permafrost peatlands and the associated change in organic matter accumulation. Permafrost reached its southernmost Holocene extent in boreal continental western Canada during the Little Ice Age with 28 800 km2 of permafrost peatland present within a sensitive zone demarcated by permafrost degradation. Subsequent degradation of permafrost has occurredin response to warming, with forested bogs changing to nonforested poor fens, associated with rising water levels. In conjunction with this ecosystem change, long-term net organic matter accumulation increases. As permafrost is in disequilibrium with climate, much of the permafrost that remains is in a relict state. Mapping of past and present permafrost distribution from peatland landforms indicates only 9% has degraded since the Little Ice Age, resulting in a 5% increase in long-term net organic matter accumulation. Of the permafrost that remains, 22% is in disequilibrium, located largely in the northern part of the sensitive zone. Additional loss of forested lands will occur inthe future in boreal continental western Canada under present-day climatic conditions as permafrost approaches equilibrium, with a further 11% increase in long-term net organic matter accumulation predicted. [ABSTRACT FROM AUTHOR]

We studied the short-term impact of cutting with the protection of regeneration (CPR) on ruffed grouse (Bonasa umbellus) and its habitat.Drumming males were surveyed in the boreal forest of western Quebec between 1990 and 1994 in 5 control stands and 10 stands that were cutin 1992. Cutting caused a 50% decline in total density and basal area of trees. In harvested stands, shrubs were less abundant than in control stands. Lateral cover between 1 and 2 m and canopy closure werealso lower in cut stands. In the harvested stands, the density varied between 14.1 and 22.6 drummers/km2 between 1990 and 1992before the CPR. In 1993, density declined to 10.1 but was reestablished at 21.5 in 1994. Densities did not differ significantly before orafter the CPR nor between cut and uncut stands (p > 0.05). After theCPR, the grouse generally established their drumming sites in the periphery of cut areas. There they found lateral cover and canopy closure similar to those measured in control stands by choosing sites where deciduous shrubs were more abundant than in the remainder of the stand. However, the characteristics of the tree stratum were not optimal; their overall density, that of Betulaceae, and that of Salicaceae were higher near drumming sites located in control stands than those in harvested stands. In harvested stands, drumming sites had a lower total basal area of trees, and namely that of deciduous trees, than in control sites. To maintain ruffed grouse populations immediately after cutting in mixed and deciduous stands of public lands, we suggestthat CPRs be in 15-ha blocks while maintaining a basal area of at least 7.5 m2/ha, half of which should be in trembling aspen (Populus tremuloides Michx.) and paper birch (Betula papyrifera Marsh.). [ABSTRACT FROM AUTHOR]