Percent reduction (−) or increase (+) in Fv/Fm after 72 hours following heat stress (44 °C, 20 minutes) in foliar tissue of 8 Acer species. Species are ranked in order of tolerance based on percent increases in Fv/Fm as a measure of recovery from damage to the leaf photosynthetic system.
| Species | Fv/Fm |
|---|---|
| A. platanoides ‘Royal Red’ | +8.42b |
| A. pseudoplatanus ‘Spaethii’ | +7.21ab |
| A. campestre | +6.36ab |
| A. platanoides ‘Princeton Gold’ | +4.79ab |
| A. pseudoplatanus ‘Negenia’ | +2.59ab |
| A. platanoides ‘Drummondii’ | −1.17ab |
| A. campestre ‘Louisa Red Shine’ | −1.76ab |
| A. platanoides ‘Emerald Queen’ | −22.80a |
Numbers within a column followed by a common letter (taken from regression equations [Figure 3]) are not significantly different according to Tukey’s honest significance test (P = 0.05).