The presented thermal parameters obtained between 1987 (1986) and 2008 at the meteorological station in Zielonka included: mean annual, half-year, monthly and daily air temperature; number of days of different temperature categories; duration of the meteorological growing season; beginning and finish of the meteorological growing season, and period without slight frost. The study results indicated the occurrence of changes in the values of the above-specified parameters. From 1987 to 2008 the mean annual and monthly air temperature and mean temperature of the winter and summer half-years shows a rising tendency. In recent years, the number of days with the average temperature between –5.0 and 15.0°C has decreased while the number of days with temperature above 15.0°C has increased. The mean length of the meteorological growing season was 200 days. However, earlier start and later completion of the growing season trends are noted. The average annual frost-free duration was 153 days and was characterised by a distinct positive trend. The average annual amount of sunshine was 1378 h and showed in the last decade a clear tendency to decrease. Among the analysed characteristics statistically significant linear trend was shown for the following characteristics (p = 0.05): annual, half-years and monthly (February, May, June, July, August, October) sums of sunshine; annual, summer half-years and monthly (April, May, June, July, August) average air temperatures; number of days with daily mean temperature > 15.0°C; dates of the beginning of growing season; terms of early and late slight frosts; and the duration of the period without slight frost.
| MLA | Grajewski, Sylwester. "Warunki termiczne w Puszczy Zielonce w latach 1987-2008." Nauka Przyr. Technol. 7.1 (2013): #9. |
| APA | Sylwester Grajewski (2013). Warunki termiczne w Puszczy Zielonce w latach 1987-2008. Nauka Przyr. Technol. 7 (1), #9 |
| ISO 690 | GRAJEWSKI, Sylwester. Warunki termiczne w Puszczy Zielonce w latach 1987-2008. Nauka Przyr. Technol., 2013, 7.1: #9. |
Sylwester Grajewski
Katedra Inżynierii Leśnej
Uniwersytet Przyrodniczy w Poznaniu
ul. Mazowiecka 41
60-623 Poznań
Poland
e-mail: sylgraj@up.poznan.pl