Wpływ warunków siedliskowych na zróżnicowanie wysokości dębu na gniazdach

The paper presents the study on the height of 10−12−year−old pedunculate oak regeneration in clear−cut gaps in three fertility variants: mezotrophic of poorer productivity (fresh mixed coniferous forest – BMśw), mezotrophic of higher productivity (fresh mixed deciduous forest – LMśw) and eutrophic (fresh deciduous forest – Lśw). BMśw and LMśw were represented by two locations: Gostynin (G) and Parczew (P), while Lśw – by one: Czarna Białostocka (CzB). We analysed the variation of oak height in the patches along the north−south (N−S) and east−west (E−W) gap axes. In each location 3−5 gaps were selected and measurements taken on three transects along the N−S axis located in the western (W), central (C) and eastern (E) part. Significant differences in oak height were found along the N−S axis. Oaks in the BMśw and LMśw habitats in the south−central part, and those in the Lśw habitat in the centre−northern part of the patch were the highest. The height growth of oaks on sandy soils (BMśw, LMśw) was found to be limited by moisture deficit, while on loamy soils (Lśw) – by light deficiency. The differences in oak height along the E−W axis were smaller and less apparent, indicating a tendency towards the reduction of their height growth in the central part of the gap.