Fig. 1

Climatic data characteristics in the period of 1999–2011 and in 2009 when study was conducted. Average monthly temperatures in ± SD (A), average yearly temperature (B), average monthly precipitation ± SD (C), and total year precipitation (D). Source: Syców Forest District (51° 15′ 48.6000″ N; 17° 40′ 27.8400″ E; 189 m a.s.l)