Method for Field Measurements of CO2-Exchange. The Diurnal Changes in Net Photosynthesis and Photosynthetic Capacity of Lichens under Mediterranean Climatic Conditions
The determination and interpretation of patterns in photosynthetic primary production which are characteristic of different lichen species within their respective habitats may lead to a better understanding of habitat preferences and species distributions. However, the necessary photosynthetic CO2 exchange measurements are difficult to accomplish in the field. Thus, only a few examples of diurnal courses of photosynthetic CO2 uptake by poikilohydric organisms may be found in the ecophysiological literature. Recently mathematical models have been developed which have been used to simulate the net photosynthetic performance of lichens under natural conditions. Because such models are usually based upon physiological parameters obtained from laboratory experiments, their validity can only be established by comparing simulated rates of photosynthesis with rates actually measured in the field. Thus, the development of instrumentation and methods which allow accurate determination of CO2 exchange of lichens under natural conditions is essential.
KeywordsDioxide Hydration Convection Depression Foam
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- Kappen, L., Lange, O.L., Schulze, E.-D., Evenari, M., and Buschbom,U., 1979, Ecophysiological investigations on lichens of the Negev Desert. VI. Annual course of the photosynthetic production of Ramalina maciformis(Del.) Bory, Flora, 168: 85–108.Google Scholar
- Kappen, L., Lange, O.L., Schulze, E.-D., Buschbom, U., and Evenari, M., 1980, Ecophysiological investigations on lichens of the Negev Desert. VII. The influence of the habitat exposure on dew inhibition and photosynthetic productivity, Flora, 169: 216– 229.Google Scholar
- Lange, O.L., 1984, “CO2/H2O-Porometer zur Messung von CO2-Gaswechsel und Transpiration an Pflanzen unter natürlichen Bedingungen,” Heinz Walz Mess- und Regeltechnik, Effeltrich.Google Scholar
- Lange, O.L, Beyschlag W., Meyer, A., and Tenhunen, J.D., 1984a, Determination of photosynthetic capacity of lichens in the field — a method for measurement of light response curves at saturating CO2 concentration, Flora, 175: 283–293.Google Scholar
- Lange, O.L., Geiger, I.L., and Schulze, E.-D., 1977, Ecophysiological investigations on lichens of the Negev Desert. V. A model to simulate net photosynthesis and respiration of Ramalina maciformis, Oecologia, 28: 247–259.Google Scholar
- Lange, O.L., Koch, W., and Schulze, E.-D., 1969, CO2-Gaswechsel und Wasserhaushalt von Pflanzen in der Negev-Wüste am Ende der Trockenzeit, Berichte der Deutschen Botanischen Gesellschaft, 82: 39–61.Google Scholar
- Lange, O.L., Schulze, E.-D., and Koch, W., 1970, Experimentell-ükologische Untersuchungen an Flechten der Negev-Wüste. II. CO2- Gaswechsel und Wasserhaushalt von Ramalina maciformis(Del.) Bory am natürlichen Standort während der sommerlichen Trocken-periode, Flora, 159: 38–62.Google Scholar
- Lange, O.L., and Tenhunen, J.D., 1984, “A minicuvette system for measurement of CO2 exchange and transpiration of plants under controlled conditions in field and laboratory,” Heinz Walz Mess- und Regeltechnik, Effeltrich, F.R.G.Google Scholar