The impacts of different methods of mechanical site preparation (MSP) treatments on foliar nutrients of planted plug+ 1 white spruce seedlings were examined at two mixed-wood boreal forest sites (Judy Creek, Fox Creek in Alberta, Canada). The treatments included three types ofMSP: disc trench, ripper plough, and bladed which included 'thin' and 'thick' microsites; as well as a harvested-control (no MSP) and an adjacent unharvested area. Seedlings were planted four months after MSP and foliar element contents (N, P, K, Ca, Mg, S, Mn, Fe, AI) were assessed 17,27,29, and 32 months after MSP. MSP treatments resulted in initially higher foliar nutrient content (N, S, Mg; July 1992, 17 months after MSP). Foliar Fe and AI were dramatically increased and levels indicated potential toxic effects. The elevation offoliar nutrient content in site-prepared areas was still evident 27 months after treatment (N, P, K, S, Ca, Mg, Mn; May 1993). Foliar AI was still elevated in seedlings at Fox Creek at this time. By 29 months following MSP the effect of the treatments had diminished and, in some cases, seedlings in MSP-areas had lower foliar nutrient content (K, Mn) than those in harvested-control. By 32 months (October 1993) seedlings in the MSP treated areas showed significantly lower foliar content for several nutrients (Mn, P, Mg) while still showing elevated Fe. There were few clear differences among the different MSP treatments. In general, however, blading (particularly the 'thin' microsite) resulted in the largest initial increases in foliar element content and, subsequently, the greatest reductions in these elements.