Tomczyk, ArkadiuszSzyga-Pluta, Katarzyna2018-08-062018-08-062017Badania Fizjograficzne, Seria A, Tom 68, 2017, s. 223-2322081-6014http://hdl.handle.net/10593/23662The objective of the study consisted in determining the changeability of the dates of commencement and termination of the period of intense vegetation growth and the period of maturing of plants in north-western Poland, and also the respective durations thereof. Use was made of data concerning average monthly air temperatures for the years 1966–2015, which were obtained from the collections of the Institute of Meteorology and Water Management – National Research Institute. The period of intense vegetation growth has been defined as a period with average daily air temperature of ≥ 10oC, whereas the period of maturing of plants as one with an average daily air temperature of ≥ 15oC. The dates of commencement and termination of the aforementioned periods were determined using mathematical formulae proposed by Gumiński. On average, the period of intense vegetation growth commenced 3 days/10 years earlier and terminated 1 day/10 years later. In turn, the period of maturing of plants commenced on average 2 days/10 years earlier and terminated on average 2 days/10 years later. Research also revealed an increase in the duration of both the period of intense vegetation growth, and the period of maturing of plants in north-western Poland.enginfo:eu-repo/semantics/openAccessperiod of intense vegetation growthperiod of maturing of plantsnorth-western PolandArtykułhttps://doi.org/10.14746/bfg.2017.8.16