Figure 3.

Changes in parameters characterising the state and efficiency of the photosynthetic apparatus of birch trees under the influence of environmental factors at investigated sites. The data presented are means (n = 10). Means followed by single asterisks are significantly different from the reference, whereas those with double asterisks differ from both the reference and the other population, based on the Tukey HSD test (p ≤ 0.05). Abbreviations: T—reference population from Tychy; K—birch population from post-coal mine spoil heap; P—birch population from post-smelter spoil heap; φP₀—maximum quantum yield of the primary PSII photochemistry; ψE₀—probability (at time 0) that a trapped exciton moves an electron into the electron transport chain beyond Q_A^–; φE₀—quantum yield for electron transport from Q_A⁻ to plastoquinone; δR₀—probability with which an electron from the intersystem electron carriers will move to reduce the end acceptors at the PSI acceptor side; φR₀—quantum yield for the reduction in the end electron acceptors at the PSI acceptor side; φD₀—quantum yield (at t = 0) of energy dissipation; NPQ_T and φNPQ—non-photochemical quenching; LEF—linear electron flow; φNO—non-regulatory energy dissipation; φ_II—quantum yield of photosystem II; PSI AC—active centres of photosystem I.