Graignic, Noemie , Tremblay, Francine , Bergeron, Yves .
Geographical variation in sexual reproduction of sugar maple (Acer saccharum (Marsh.)) peripheral populations.
The reconstruction of postglacial vegetation in North America shows a maximum expansion of several forest tree species distribution range during the middle Holocene followed by a contraction that would have been caused by a climate cooling. With anticipated climate changes, we can envisage a range expansion of many species, which will be particularly marked for populations located at the northern limit of their distribution range. Therefore, it's important to understand the current potential of regeneration in marginal populations and its relationship to climate conditions. Sugar maple (Acer saccharum) is a widespread and abundant tree in North-Eastern America that reaches its northern continuous distribution range at the transition between the boreal mixedwood and the temperate deciduous forests. This limit is characterized by a progressive decrease of population size and increase distance between populations. Our objective was to determine whether sugar maple recruitment is different between the continuous and the discontinuous zone of its northern distribution range. We analyzed the reproductive capacity of 24 sugar maple populations along a latitudinal gradient in QuÃ©bec. Our results clearly demonstrated that sugar maple regeneration is globally similar in the discontinuous and continuous part of its distribution range. Seedlings age structures showed a similar pattern with high recruitment, a higher mortality rate at early stage and mortality rate decreasing over time in the majority of sampled sites. Seedling's density was not explained by transects (west-east) and bioclimatic domains (zone) interaction. The variation in sugar maple regeneration is explained by stand characteristics (basal area) and weather conditions (average temperature and precipitation in July). Despite northern climatic conditions, there is good sugar maple reproduction in northern populations. All these findings suggest that sugar maple northern populations will be able to migrate under the influence of global warming.
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1 - uqat, Institut de recherche sur les forêts, 445 boul. de l'université, Rouyn-Noranda, Québec, J9X5E4, Canada
2 - Université du Québec en Abitibi-Temiscamingue, Institut de recherche sur les forêts, 445 boul. de l'université, Rouyn-Noranda, Québec, J9X5E4, Canada
3 - UQAT, Chaire AFD, 445 Boul. De L'Université, Rouyn-Noranda, QC, J9X 5E4, Canada
species distribution modeling
Presentation Type: Poster:Posters for Topics
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM