We tested how respiration rate and its thermal acclimation would be influenced by AMF colonization with four possible scenarios (Fig. 2), where we hypothesized that AMF colonization would increase whole‐plant respiration. In scenario A, if respiration rates do not acclimate to growth temperature, we would see no difference in respiration rate between the temperature treatments and the AMF‐respiration response curves would overlap (Fig. 2). If acclimation is independent of mycorrhizal status, we would expect a parallel downward shift of the relationship for warm‐acclimated plants compared to ambient grown plants, but no difference in slope of these two lines (Scenario B, Fig. 2). If AMF colonization stimulates, or impedes acclimation then we would, respectively, see a decrease (Scenario C, ‘AMF‐stimulated acclimation’) or an increase (Scenario D, ‘AMF‐suppressed acclimation’) in slope of the warmed lines relative to those of control plants at ambient temperature (Fig. 2).