Mast seeding is the synchronous production of large seed crops by a plant population and is believed to be triggered by climate. Climate influences seed production, and species are believed to be more sensitive to climate change near their range limits. We studied cone production by white spruce in 2012 at six sites within each of two regions, Huron (northern MI) and Kemp (northern WI); the southernmost distribution of white spruce is in Wisconsin. We marked 727 individual trees, determined tree and forest characteristics, and quantified cone production. There was a significant difference in average cone production both between regions, with a mast occurring at Huron but not Kemp, and between sites within regions. Competition for resources (e.g., light, moisture) may contribute to within-site differences. The closer proximity of Kemp to the southern range limit and differences in precipitation between the two study regions in 2012 may explain the patterns of cone production observed.
"Variation in Cone Production of White Spruce at Two Sites near its Southern Range Limit,"
1, Article 7.
Available at: http://via.library.depaul.edu/depaul-disc/vol2/iss1/7