I was going to make it all up, but then I decided I would look it up. I did, and now I'm back to making it up. OMG! Nobody has done anything on this! I found that one guy did a total speculation without physics, and then others followed with mathematical simulations of this process. This is exactly like Climate Science. The computer models prove the assumption.
So, we are back at square one. We know that this is a closed system, since the sap can run up and down all March. We also know that this gave the Maple tree an evolutionary advantage, or else it wouldn't have happened. They didn't do it to give us maple sugar. We also know that it is temperature driven -- you need warm days and freezing nights. No other tree operates like this.
As with chaotic systems, we can draw boxes around the process, drawing tighter and tighter. We can put forward testable hypotheses. Not 'Instant Theories', like 'Social Physics'. Things must resolve down to known physics at some scale. For instance, we know a lot about photosynthesis, but not the final quantum transfer of a key atom.
-whoops, people coming.
ps. I'm stopping here. This whole thing is worse than climate physics. Nobody has done anything. Blah.
pps. unless, of course, somebody sends me bitcoins in a plain brown envelope.