PARENT SESSION
Contributed Oral Session 134: Forest Ecology: Reproduction and Recruitment
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 516 D, Level 5, Palais des congrès de Montréal

Local-scale spatial variation in temporal patterns of white spruce cone production and potential effects on a seed predator population.

LaMontagne, Jalene^*,1, Boutin, Stan¹, ¹ University of Alberta, Edmonton, Alberta, Canada

ABSTRACT- Temporal patterns of mast seeding, the intermittent synchronous production of large seed crops by trees across large spatial scales (up to 1000 km), have been well documented. Much less is known about seed production at local scales. Here we will present research on the spatial and temporal synchrony in cone production among individual trees, and factors explaining spatial variation in cone production. From 1990 to 2004, visual cone counts were conducted annually for >200 individual white spruce (Picea glauca) trees located within three study areas (30 ha each) in the Yukon, Canada; as well as studies on red squirrel (Tamiasciurus hudsonicus) population dynamics. Red squirrels are the major predator of white spruce seeds in our study areas. Spatial synchrony in cone production patterns of individual trees separated by up to 2.5 km was determined based on correlations and bootstrap resampling. Preliminary results suggest that within each of the study areas the mean (± standard error) correlation coefficient was 0.60 ± 0.03, significantly less than both 1.0 (perfect synchrony), and 0.7 (a typical acceptable correlation value). Annual cone production by individual trees was modelled based on local factors including location, basal area, slope, aspect, and local tree density. Location, basal area, and local tree characteristics explained up to 50% of the deviance in cone production within a year. In addition, there appear to be 'hot spots' of cone production, areas with continually higher than average cone production. Spatial variation in cone production had effects at the population level for red squirrels, whereby red squirrel population dynamics do not necessarily follow the regional cone masting pattern but were also influenced by local cone conditions. Consequences for local cone production patterns include the theories of the occurrence of seed masting, and seed predator population persistence.

Key words: Picea glauca, seed mast, spatial synchrony, Tamiasciurus hudsonicus