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+====== [PLANTMODEL] Section ======
+===== Purpose =====
+To calculate the transpiration of plants, it is necessary to know the actual stomata resistance.\\
+The stomata are active components of the plant system and react on environmental impacts such as solar input, air temperature and water availability in the soil.
+ENVI-met provides two methods for calculating the stomata resistance: A simple approach based on the work of Deardorff (1978) and a very sophisticated approach called A-gs model following the work of Jacobs (1994) (for exact references please refer to the papers available on the UNCONVERTED WINHELP MACRO:! ''ExecFile("www.envi-met.com")ENVI-met webpage'')
+The Deardorff approach scales an explicitly given maximum value of the stomata resistance with respect to the solar input and the water availability whereas the A-gs model calculates the photosynthesis rate of the plant and concludes from that to the C02 demand and finally to the state of the stomata.
+**We recommend the use of the A-gs model as it is more plant physiologically based than the Deardorff model.**
+To choose the model, use the [PLANTMODEL] section:
+<file>
+: [PLANTMODEL] _____________Settings for plant model
+: Stomata res. approach (1=Deardorff, 2=A-gs)  =2
+: Background CO2 concentration [ppm]           =350
+</file>
+===== What do the lines mean? =====
+=== 01: Stomata res. approach (Default 2, A-gs) ===
+Select the stomata resistance model to be used in the simulation.
+=== 02: Background CO2 concentration [ppm] (Default 350 ppm) ===
+Sets the background CO2 concentration. Only needed for the A-gs model.\\
+Remark: If other sources in the model are of the CO2 type, they will add up to the CO2 concentration.