Table 4.

Percent increase (+) in leaf chlorophyll content (SPAD values) 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 leaf chlorophyll content (SPAD values) as a measure of recovery from damage to the leaf chloroplast membrane.

A. platanoides ‘Drummondii’+22.8a
A. platanoides ‘Princeton Gold’+17.9a
A. platanoides ‘Emerald Queen’+11.7a
A. platanoides ‘Royal Red’+9.80a
A. campestre ‘Louisa Red Shine’+7.26a
A. campestre+4.92a
A. pseudoplatanus ‘Negenia’+2.86a
A. pseudoplatanus ‘Spaethii’+2.28a
  • Numbers within a column followed by a common letter (taken from regression equations [Figure 4]) are not significantly different according to Tukey’s honest significance test (P = 0.05).