Estimated values, standard error and p-value of the diurnal and vertical effect on the Fv/Fm parameter in the nonlinear mixed model.

a = amplitude of the Fv/Fm values; b = indicator of the width of the seasonal dip (expressed in DOY2); c = minimum Fv/Fm value; d = day of the year where the minimum Fv/Fm value was reached. NN = node number and TOD = time of the day, with TODam = morning, TODnoon = midday and TODpm = afternoon, SE = Standard error.
Values followed by the same letter within a column are not significantly different from each other at p<0.05. NS = not significant.