Results/Conclusions
Over the study area, no consistent spatial autocorrelations were detected among trees of the same species, suggesting a generally individualistic manner of phenological behaviors intraspecifically. Among the few exceptions, Populus tremuloides (trembling aspen, late cohort) showed spatial continuity within a 75 m radius in 2007 data. In regard to environmental drivers of phenology, no coherent correlations have been found between phenology and spatial variations of growing degree hours (GDHs), topography (elevation and aspects) and soil types. In addition, no coherent correlations exist between phenology and DBH and LiDAR estimated tree heights for most species, except for aspen which showed that bigger trees have earlier budbursts. Averaged species phenology across the study area is highly sensitive to weather fluctuations (especially to GDHs averaged over the entire study area for the previous 2 days), showing a corporate response to the environment at the population scale. Using both high resolution satellite images and ground survey data, community and landscape level phenologies were also derived. This study tackles questions related to plant phenology within its intricate ecological context, and provides a detailed account of phenological behaviors across scales within a typical seasonal forest.