Geographical variation in reproductive capacity of sugar maple (Acer saccharum Marshall) northern peripheral populations
Article first published online: 3 AUG 2013
© 2013 John Wiley & Sons Ltd
Journal of Biogeography
Volume 41, Issue 1, pages 145–157, January 2014
How to Cite
Graignic, N., Tremblay, F., Bergeron, Y. (2014), Geographical variation in reproductive capacity of sugar maple (Acer saccharum Marshall) northern peripheral populations. Journal of Biogeography, 41: 145–157. doi: 10.1111/jbi.12187
- Issue published online: 16 DEC 2013
- Article first published online: 3 AUG 2013
- NSERC (Natural Sciences and Engineering Research Council of Canada). Grant Number: STPGP 336871
- Climate change;
- discontinuous populations;
- north-eastern North America;
- northern distribution limit;
- sugar maple;
- tree regeneration
Several models have predicted that, with climate change, Northern Hemisphere species will migrate northwards from their present distribution ranges. Sugar maple (Acer saccharum Marshall) reaches its northern continuous distributional limit in north-eastern North America at the transition between boreal mixed-wood and temperate deciduous forest. Our objective was to determine whether lower sugar maple recruitment potential accounts for this gradual transition between the continuous and discontinuous zones of the distribution.
The northern limit of sugar maple in eastern Canada.
We analysed the reproductive capacity of sugar maple populations along three latitudinal transects (located in the west, centre and east of Québec) in 24 sites located between 45°51′–48°59′ N and 70°21′–79°27′ W. The study area was divided into two zones, continuous and discontinuous, based on sugar maple stand abundance. We examined stand structure, sugar maple seed abundance and germination, and sugar maple seedling density and age structure.
Sugar maple regeneration was uneven-aged and similar between continuous (south) and discontinuous (north) zones. For the western transect, more filled seeds and more seedlings were recorded in the continuous zone than in the discontinuous zone. Sugar maple seedling density was positively influenced by (1) basal area of mature sugar maple and saplings of all species, and (2) July mean temperature and precipitation. Four mast seed years were identified that were well synchronized across all sites; mast seeding covaried significantly with July mean temperature and July mean precipitation of the previous year.
Our study clearly demonstrated an effect of climatic variables and stand characteristics on sugar maple regeneration. However, these factors did not explain the transition from a continuous to a discontinuous distribution for this species. Most of our northern sites exhibited constant sugar maple recruitment over time. These results highlight the importance of including non-climatic factors in models predicting species change in abundance.