Summary
A digital registration system used with temperature- and humidity-controlled cuvettes for net photosynthesis and transpiration measurements in the field is described. The associated errors of the measured parameters and calculated data are estimated. The digitalization is based on an analogue registration which is of primary importance in the control of experimental conditions in the cuvettes. The digital system is connected to the analogue registration in series. The error associated with digitalization is 0.1% across 70% of the scale. This error increases to 0.2% between 3 and 30% on the scale due to a minor lack of linearity. The reproducibility of the digitalization is ±0.024%.
The error associated with data transfer in the digitalization and the errors of the analogue registration are estimated for temperature and humidity measurements (error of air and leaf temperature is ±0.1° C; error of the dew point temperature is ±1.1° C dew point). The effect of these errors on the calculation of relative humidity and the water vapour difference between the leaf and the air is determined using the progressive error law. At 30° C and 50% relative humidity, the error in relative humidity is ±7.4%, the error for the water vapour difference is ±6.6%. The dependence of these errors on temperature and humidity is shown.
The instrument error of the net photosynthesis measurement is calculated to be ±4.2%. Transpiration measurements have an average inaccuracy of ±8.3%. The total diffusion resistance which is calculated from values of transpiration and the water vapour difference has an average error of ±10.9%. The sizeable influence of errors in humidity and temperature measurements on the calculated diffusion resistance is demonstrated. The additional influence of biological errors associated with field measurements is discussed.
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References
Baumgartner, A.: Meteorological approach to the exchange of CO2 between the atmosphere and vegetation, particularly forest stands. Photosynthetica 3, 127–149 (1969).
Cernusca, A.: Der Einsatz automatischer Datenerfassungssysteme für klimaökologische Untersuchungen im Rahmen der Produktivitätsforschung. Photosynthetica 2, 238–244 (1968).
Cernusca, A., Moser, W.: Die automatische Registrierung produktionsanalytischer Meßdaten bei Freilandversuchen auf Lochstreifen. Photosynthetica 3, 21–27 (1969).
Diem, K., Lentger, C.: Wissenschaftliche Tabellen, 7. Aufl. Basel: Documenta Geigy 1968.
Eckardt, F. E.: Le principe de la soufflerie climatisée, appliqué a l'étude des éxchanges gazeux de la couverture végétale. Oecol. Plant. 1, 369–400 (1966).
Janáč, J., Čatský, J., Jarvis, P. G.: Infra-red gas analysers and other physical analysers. In: Šesták, Z., Čatský, J., Jarvis, P. G. (ed.), Plant photosynthetic production, manual of methods, p. 111–193. The Hague: Dr. W. Junk N. V. Publishers 1971.
Kiese, O., Surkow, R.: Zeitgemäße Meßwerterfassungsanlagen für bestandsmeteorologische Untersuchungen im Rahmen des Sollingprojektes. Meteorol. Rdsch. 24, 50–53 (1971).
Koch, W., Lange, O. L., Schulze, E.-D.: Ecophysiological investigations on wild and cultivated plants in the Negev desert. I. Methods: A mobile laboratory for measuring carbon dioxide and water vapour exchange. Oecologia (Berl.) 8, 296–309 (1971).
Lange, O. L.: Leaf temperatures and methods of measurement. In: Eckardt, F. E. (ed.), Methodology of eco-physiology, p. 203–209. Paris: Unesco 1965.
Lange, O. L., Koch, W., Schulze, E.-D.: CO2-Gaswechsel und Wasserhaushalt von Pflanzen in der Negev-Wüste am Ende der Trockenzeit. Ber. dtsch. bot. Ges. 82, 39–61 (1969).
Lange, O. L., Schulze, E.-D.: Measurement of CO2 gas-exchange and transpiration in the beech (Fagus silvatica L.). In: Ellenberg, H. (ed.), Ecological studies. Analysis and synthesis, vol. 2, p. 16–28. Berlin-Heidelberg-New York: Springer 1971.
Lück, W.: Feuchtigkeit: Grundlage, Messen, Regeln. München-Wien: Oldenbourg 1964.
Morrow, P. A., Slatyer, R. O.: Leaf temperature effects on measurements of diffusive resistance to water vapor transfer. Plant Physiol. 47, 559–561 (1971).
Perrier, A.: Leaf temperature measurement. In: Šesták, J., Čatský, J., Jarvis, P. G. (ed.), Plant photosynthetic production, manual of methods, p. 632–669. The Hague: Dr. W. Junk N. V. Publishers 1971.
Schmidt, E.: Thermodynamische Eigenschaften von Wasser und Wasserdampf. In: Landolt-Börnstein: Zahlenwerte und Funktionen, 6. Aufl., Bd. IV: Technik, Teil 4a: Wärmetechnik, p. 426–427. Berlin-Heidelberg-New York: Springer 1967.
Schulze, E.-D.: Der CO2-Gaswechsel der Buche (Fagus silvatica L.) in Abhängigkeit von den Klimafaktoren im Freiland. Flora (Jena) 159, 177–232 (1970).
Šesták, J., Čatský, J., Jarvis, P. G.: Plant photosynthetic production, manual of methods. The Hague: Dr. W. Junk N. V. Publishers 1971.
Slatyer, R. O.: Effect of errors in measuring leaf temperature and ambient gas concentration on calculated resistance to CO2 and water vapor exchange in plant leaves. Plant Physiol. 47, 269–274 (1971).
Thompson, F. B., Leyton, L.: Method for measuring the leaf surface area of complex shoots. Nature (Lond.) 229, 572 only (1971).
Tranquillini, W., Caldwell, M. M.: Integrated calibrations of plant gas exchange systems. Ecology (in press, 1972).
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Schulze, E.D., Lange, O.L. & Lembke, G. A digital registration system for net photosynthesis and transpiration measurements in the field and an associated analysis of errors. Oecologia 10, 151–166 (1972). https://doi.org/10.1007/BF00347987
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DOI: https://doi.org/10.1007/BF00347987