Table 1.

The three first rows show chlorophyll a fluorescence lifetime data for normal conditions, UV-stressed conditions (2 h under full UV-B, UV-A and PAR) and post UV-stressed conditions

Condition	${\mathit{\tau }}_1(\mathrm{ps})$	${\mathit{\tau }}_2(\mathrm{ps})$	$a_1(\%)$
Normal	262 ± 31	728  ±  133	87  ±  5
UV stressed 2 h	389  ±  40	984  ±  145	85  ±  6
Post UV stressed 24 h	280  ±  42	886  ±  142	80  ±  5
UV stressed (reduced UV-B) 2 h	256  ±  23	750  ±  120	84  ±  5
UV stressed (reduced UV-B) 4 h	246  ±  25	823  ±  134	80  ±  7
DCMU inhibited	425  ±  46	1186  ±  321	82  ±  7

The fourth and fifth rows show chlorophyll a fluorescence lifetime data for half-dose UV-stressed conditions (2 and 4 h under 50 % UV-B in addition to full UV-A and PAR, respectively). The bottom row shows chlorophyll a fluorescence lifetime data for cells inhibited by DCMU. ${\mathit{\tau }}_1$ is the short lifetime component, ${\mathit{\tau }}_2$ is the long lifetime component, and $a_1$ is the relative amplitude of the short lifetime component. Uncertainties are calculated as one standard deviation