Kasvukauden alku lehtimetsissä /Start of vegetation period in deciduous vegetation

The data set consists of yearly maps of the start of the vegetation active period in deciduous vegetation(Day of Year), which is defined as the day when deciduous trees unfold new leaves in spring. It is also often referred to as the green-up or greening day. The data set was derived from time series of the Normalized Difference Water Index (NDWI)calculated from Moderate Resolution Imaging Spetroradiometer (MODIS) satellite observation.