Linking phenocam derived phenology with field observations in the boreal forest

Bud phenology is a sensitive indicator of climate change. Therefore, it’s important to understand the direct relationship of canopy greenness and bud phenological events at higher spatial and temporal resolutions. Recently, phenocam based near surface remote sensing methods has been extensively used for time series analysis of canopy greenness to measure leaf and canopy phenological transition dates. Thus, this study compared the spring and autumnal bud phenological phases of black spruce[Picea mariana(Mill.) B.S.P] derived from field observations and greenness time-series data derived from phenocam. Results indicated that the 72th and 92th percentage of the GCC amplitude corresponded to the start and end of bud burst, respectively, and considered as the essential reference points for start of the canopy growing season. Whereas, end of bud set was represented by the 94th percentage of the GCC and may be considered as an option for the end of vegetation development. Overall, results enabled new dimensions to process time series phenocam-derived indices and to establish their relationship with field based observations.