Impacts of organic matter removal and vegetation control on nutrition and growth of Douglas-fir at three Pacific Northwestern Long-Term Soil Productivity sites

•Annual vegetation control (AVC) resulted in losses of soil N and base cations.•AVC treatments improved stand volume growth for most sites.•Soil and volume growth responses to whole tree removal were variable at each site.•Additional organic matter removal decreased Ca availability over whole tree removal.•Plant root simulator probe adsorption improved the understanding of treatment effects.