Fig 2. The chlorophyll fluorescence (ChlF) transients from dark-adapted leaves of expansive grass Brachypodium pinnatum from young (30–50 years), intermediate age (ca. 100 years) and old (>300 years) calcareous grasslands.
The results were plotted on logarithmic scale from FO(50 μs) to 1 s. A. The fluorescence curves for all 12 populations under study divided into age classes. The time points important for the calculation of JIP test were marked: O–fluorescence intensity recorded at FO (50 μs), L–at 150 μs, K–at 300 μs J–2 ms, I–at 30 ms, P–maximum fluorescence intensity (FM) at ca. 1 s. B. The curves of average ChlF values for each age classes.