Wow, that's quite a question! So, each cell in a given tree undergoes respiration. That uses energy. So too, the photosynthesis so major a part of any tree's livelihood is exothermic, even though newer and more complex molecules are being built in the process. Man, I'd have to think long and hard to even attempt to come up with a good answer on this. Any idea what the agenda is in asking? Seems such an odd angle to take.

........thinking just a bit more........I wonder if the person posing the original question is aware of the situation with "our own" bodies. Simply put, "in" your body, there are more cells that aren't "you" than that are "you". Bacteria in the gut and elsewhere far outnumber the actual millions of "human" cells that make up our bodies. So....given this little item, does the questioner know where he or she wishes to cleave the line between what is "the tree" and what isn't? Trees, we now know, work with symbiotic fungi to extract nutrients from the soil. It is reasonable to assume we're just at the beginning stages of understanding this process. But what is clear, is that in most natural systems, "a tree" does not exist in and of itself, just as "a human body" does not exist without the myriad microscopic helpers we have on and in us. Maybe more than he/she wants to get into but that's no small line of questioning!

What the question reminds me of is comparisons between the efficiency of man-made solar cells and plant photosynthesis. Then there are sub-debates over leaf surface area in a tree, but at least it is a line of research to try.

Oh, I was purely thinking photosynthesis, forgot about dealing with what it takes up from the roots.

Amazingly I don't have much of an "angle" on it. Just wondering.

It is easy enough to figure I take in ~ 3000 calories a day. My newest kid has 8 or 9 bottles @ 4 ounces a piece a day. Just wondering about the big oak out there.

I know wood releases a lot of energy when I burn it in the stove.

Perhaps it could be measured by how much heat it releases.

Mike

Toronado, if you can wait just a few years for me to retire, I'll get right on that, lol!