Douglas-fir water "take up"
How much ground water does a full-grown Douglas-fir (Pseudotsuga
menziesii) "take up" per day? If there is no information on
the Douglas-fir, any large conifer will do.
In Irwin P. Ting's "Plant Physiology" of a
47-ft. maple tree with 177,000 leaves and total leaf surface area of
675 sq. meters. This tree lost about 220 kg of water per hour in the summer sun.
Assuming negligible water loss at night and 12 hours of daylight and a
conversion factor of 354 ml in 12 fluid ounces
(which I picked up off of my Diet Pepsi can),
220 kg/hr should be equivalent to 699 gallons in a 12-hr day.
Clearly, a maple is not a Douglas fir, but
I doubt that the difference is two orders of magnitude.
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Update: June 2012