Does canopy diffusive conductance refer to canopy stomatal conductance, canopy transpiration, or canopy evapotranspriation? Or is it something else entirely?
It seems to be defined in the second paragraph of this intro:
http://onlinelibrary.wiley.com/doi/10.1111/nph.13354/full
Not sure if context matters.
It is obtained by canopy micromets with canopy temperature and weather station and includes boundary layer limitations on stomatal conductance. In still air vapor pressure difference from leaf to air is minimal and stomata open for CO2 and humidity. http://www.sciencedirect.com/science/article/pii/S0168192309001646
Diffusive through stomat higher thanother epidermal cells by 300 to 3000 times, Lentical can be considered as previous stomata gate, since they replace stomata by ttimes
The article John links to presents the equation:
G = T / VPD
Yet the units for canopy diffusive conductance (G) are given in mmols m-2 s-1. If following the equation above, the units should be mmols m-2 s-1 kPa-1 as transpirtaion (T) is expressed in mmols m-2 s-1 and VPD is expressed in kPa. Can someone please clarify?
I sent an email to the author in Utah asking him. Maybe Dr. Santiago would know.
Maybe it has something to do with what Dr. Guido said about VPD?
edit:
author stated via email:
"VPD is expressed as mole fraction and so is dimensionless"
Louis is probably a good person to ask. Maybe I can catch him today. Let me know what you hear back from Sperry! Thanks John.
Prof. Erik H. Murchie has a lot of papers regarding canopy photosynthesis. You can search of it!
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