Kasvukauden alku havumetsissä / Start of vegetation period in coniferous forest

The data set consists of yearly maps of the start of the vegetation active period (VAP) in coniferous forest (Day of Year), which is defined as the day when coniferous trees start to photosynthesize in spring. The data set was derived from Moderate Resolution Imaging Spetroradiometer (MODIS) satellite observation of Fractional Snow Cover. The day when snow cover decreases during spring melt was used as a proxy indicator for the beginning of the start of the vegetation active period.