A survey of tree species of concern in Canada: the role for genetic conservation

Abstract

A survey was conducted in 2003 to identify Canadian native tree species (woody perennials ≥10 m tall) that may be in need of genetic conservation. Thirty expert respondents from various agencies in provinces and territories graded the tree species in their respective geographical regions based on nine criteria that describe potential reasons for conservation (e.g., rarity, decreasing range or frequency, preferred habitat in high demand, uncertain viable seed source) and then provided a rating that identifies the type of conservation that may be required (species is in good shape, insufficient knowledge for a designation, in situ or ex situ conservation measures are required). Either in situ or ex situ conservation was recommended for 52% of Canada's native tree species, and 8% required more information before a rating could be made. The results of the survey will be used to identify genetic conservation priorities for tree species in Canada.Key words: Canadian tree species of concern, genetic conservation, genetic diversity, species rarity RÉSUMÉ En 2003, on a procédé à une enquête dans le but d'identifier les espèces d'arbres indigènes canadiennes (vivaces ligneuses atteignant 10 m et plus) qui pourraient faire l'objet de conservation génétique. Trente répondants experts de divers agences dans les provinces et territoires ont classé les espèces d'arbre présentes dans leur propre région géographique selon neuf critères qui décrivent des raisons possibles pour la conservation (par ex., rareté de l'espèce, réduction de l'étendue ou de l'occurrence, habitat préféré en grande demande, source de semences viables incertaine), et ont ensuite déterminé, par l'attribution d'une cote, les actions de conservation appropriées (maintenir l'espèce en bon état, accroître les connaissances pour attribuer une désignation, appliquer des mesure de conservation in situ ou ex situ). La conservation in situ ou ex situ a été recommandée pour 52 % des espèces d'arbre indigènes du Canada, et pour 8 % des espèces, il y aurait lieu d'accroître les connaissances avant de les classer dans une désignation. Les résultats de cette enquête serviront dans la détermination des actions à privilégier en matière de conservation des espèces d'arbres indigènes au Canada.Mots clés : espèces d'arbre en situation préoccupante au Canada, conservation génétique, diversité génétique, rareté d'espèce

Pinus albicaulis Engelm. (Whitebark Pine) in Mixed-Species Stands throughout Its US Range: Broad-Scale Indicators of Extent and Recent Decline

“…This level of mortality is dramatic and rare in other tree species with such broad geographic distribution and ecological importance, except among species susceptible to broad-scale fungal or insect infestations, such as chestnut blight, Dutch elm disease, and emerald ash borer, all of which have caused greater than 50% mortality in their host populations in eastern Canada [29]. However, this shift covers less than 30 years and thus represents the recent tail end of the long-term effects of white pine blister rust, which began spreading throughout western North America in the 1940s [13], combined with more recent mortality caused by synergistic stressors such as the mountain pine beetle and climatic factors [2][3][4][5][6][7][8].…”

From Urban Forests to Neighbourhood Treescapes: An Examination of Power, Actors and Processes in Champlain Park, Ottawa

“…Ottawa is located near the northern edge of the bur oak's growing zone (see Appendix A). Experts in Canada have considered the bur oak as a conservation priority in the northern growing region due to a decrease in its abundance (Beardmore et al, 2006;Gucker, 2011).The presence of the bur oak in this area bordering the Ottawa River is partially related to the area's unique natural history dating back to pre-settlement . There are currently 82 mature bur oaks mapped in Champlain Park.…”