Abstract: It is important to understand the effects of extreme weather events and climate oscillations on forested ecosystems to enable quantification of their sensitivity to these events. This study highlights the response of a young planation forest to low frequency climate oscillations. Half hourly fluxes of net ecosystem productivity (NEP) in a twelve-year-old white pine plantation were used to evaluate the impacts of El Niño Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) events from 2008 to 2013. In general, spring NEP values were higher than those of summer. The highest NEP values were recorded in spring 2012 at 1.8 g C m-2 day-1 when the winter of 2012 experienced a moderate La Niña episode and a strong positive NAO phase at the same time. The effect of ENSO on NEP was most pronounced during springs following winters with warm ENSO phases. However, in winter 2010 the effects of a moderate El Niño event were offset by a concurrent strong negative phase of NAO. Warm winter temperatures brought by positive NAO, and wet conditions by both La Niña and positive NAO contributed to high NEP spring values.