Thermal growing season in Poland calculated by two different methods

Abstract

Methods of identifying dates of passing determined threshold value are of significant importance in the study of thermal growing seasons. The difficulty to determine dates of beginning and end of growing season in a given year stems from the fact that daily mean air temperature changes irregularly on a day-to-day basis often crossing the threshold value (i.e. 5°C) multiple times. The most frequently used method to identify dates of threshold value crossing is the mathematical or graphical method proposed by Gumiński in 1950 which based on monthly mean air temperature values. In the 1970s, Huculak and Makowiec presented a method using daily mean values of air temperature. It is assumed that both methods give comparative results although calculations of daily mean air temperature render more accurate results. This paper presents the comparison of these two methods. Air temperatures measurements from 1966–2005 taken at 38 weather stations located in various physiographic conditions in Poland were used.

Variability of thermal and precipitation conditions in the growing season in Poland in the years 1966–2015

“…The obtained date is the beginning or end of the separated period. The above method is commonly adopted in determining growing seasons and thermal seasons (Skowera and Kopeć 2008;Szyga-Pluta 2011;Kępińska-Kasprzak and Mager 2015;Czernecki and Miętus 2017). It was also used for the variability of seasons in individual years by Kossowska-Cezak (2005).…”

Modelling Wetland Growing Season Rainfall Interception Losses Based on Maximum Canopy Storage Measurements

“…Because the ecological factor which affects the rate of plant life processes is thermal conditions, the duration of the growing period is approximately equal to the thermal growing season [50]. Results for perennial trends are showed in Figure 5.…”

Anomalies in the length of the growing season in Poland in the period 1966–2015

“…The obtained date is the beginning of the separated period in time of the temperature increase and the end of the separated period in time of the decreasing temperature. The above-mentioned method is widely adopted in determining the growing and thermal seasons for both the multi-year period and individual years (Skowera and Kopeć, 2008;Szyga-Pluta, 2011;Kępińska-Kasprzak and Mager, 2015;Czernecki and Miętus 2017;Tomczyk and Szyga-Pluta, 2019). Kępińska-Kasprzak and Mager (2015) compared the thermal vegetation period determined by the method of Gumiński with those determined by the method of Huculak and Makowiec (the latter consists in calculating the accumulated series of deviations of average daily air temperature values from appropriate threshold values) for the period 1966-2005, and stated that in long-term datasets, both methods lead to similar results.…”