“…In contrast, results on upland forests have been less consistent. For example, individual wood ash amendment studies of coniferous species on mineral soils have reported positive (Hallenbarter, Landolt, Bucher, & Schutz, ; Omil, Piñeiro, & Merino, ; Saarsalmi, Smolander, Kukkola, & Arola, ; Saarsalmi, Smolander, Moilanen, & Kukkola, ; SollaâGullĂłn, Santalla, PĂ©rezâCruzado, Merino, & RodrĂguezâSoalleiro, ; SollaâGullĂłn, Santalla, RodrĂguezâSoalleiro, & Merino, ), negative (Bieser & Thomas, ; Brais, BĂ©langer, & Guillemette, ; Prescott & Brown, ; Shepard, ; Staples & Van Rees, ), and neutral (Jacobson, Lundström, Nordlund, Sikström, & Pettersson, ; Mandre, PĂ€rn, & Ots, ; Saarsalmi, Derome, & Levula, ; Saarsalmi, MĂ€lkönen, & Kukkola, ; Wang, Olsson, & Lundkvist, ) tree growth response. Although wood ash is typically enriched in calcium (Ca), magnesium (Mg), potassium (K), and phosphorus (P; Demeyer, Voundi Nkana, & Verloo, ), inconsistencies in tree growth responses to wood ash amendment have been attributed to the lack of nitrogen (N) in wood ash at sites with N limitations (e.g., Jacobson et al, ).…”