Special issue in honour of Prof. Reto J. StrasserSeasonal variation and trade-off between frost resistance and photosynthetic performance in woody species
We tested the seasonal variability of frost resistance and photosynthesis characteristics, namely net photosynthetic rate at saturating irradiance and ambient atmospheric CO2 concentrations, maximum carboxylation rate, and measurements based on the JIP-test, namely maximum quantum yield of PSII and the performance index. Additionally, we measured leaf functional traits, namely specific leaf area, leaf dry matter content, stomatal pore area index, and chlorophyll content. We assessed all traits
... ssessed all traits weekly on two evergreen species Berberis vulgaris and Quercus × hispanica as well as the two summer green species Betula pendula and Quercus pubescens. We found that there was a high seasonal variability in all traits except stomatal pore area index. In a multivariate analysis, we could show trade-offs between growth rates and leaf thickness on the first axis, as well as resistance and performance on the second axis. The findings help understand ecophysiological processes and fine-tune biosphere models. Abbreviations: Chl -chlorophyll content; Fv/Fm -maximum quantum yield of PSII; PIabs -absorption based performance index; LDMCleaf dry matter content; PELeff -effective percentage of electrolyte leakage; PNsat -net photosynthetic rate at saturating irradiance and ambient atmospheric CO2 concentrations; SLA -specific leaf area; SPI -stomatal pore area index; Vcmax -maximum carboxylation rate. Acknowledgements: The authors would like to thank the staff of the Botanical Garden of the Friedrich Schiller University, Jena. We would also like to thank Christin Weilandt, Josephine Ulrich, and Amy Milligan for support and conducting measurements and Benjamin Curtis for language editing of the manuscript. We also thank the University of Jena for financial support (DRM/2018-05). We would most of all like to thank Prof. Dr. Reto Strasser for developing the technology of chlorophyll fluorescence measurements for the quick and easy analysis of photosynthesis.