Comparison of Gumiński and Satellite Remote Sensing Methods in Terms of Determining the Dates of the Onset of the Growing Season in Poland

The aim of the paper is to compare the dates of the onset of the growing season in Poland in the period 2001–2010, which were determined on the basis of two independent methods. The dates determined by Gumiński method based on gridded monthly mean air temperature ​​over Poland area. In turn, satellite data extracted from NASA LP DAAC product, which were the result of measurements performed with multispectral scanner (MODIS) on the Terra and Aqua satellites. It was demonstrated that the average dates of the onset of the growing season in Poland determined by two methods did not differ significantly. It may suggest a significant impact of thermal factor on the increase in the photosynthetic activity of vegetation after the winter months. Both methods confirmed that the earliest average dates of the onset of the growing season occur in the southwestern part of the country, and the latest in northern Poland and in the mountain areas.