Effects of harvesting intensity, vegetation control and fertilization on 5–20 year post-harvest N availability in boreal jack pine and black spruce forest soils in northern Ontario, Canada

•Profile mineralizable N pools were higher in operational clearcut treatments than in uncut reference forest.•Profile mineralizable N pools and microbial biomass C and N were lower in full-tree compared to stem-only harvesting.•Full-tree harvesting with blading significantly reduced profile mineralizable N pools compared to operational harvesting.•Fertilization and vegetation control treatments had few effects on N mineralization.•Soil N indices were useful predictors of dominant height growth for jack pine to a greater degree than black spruce.