God Mode Trees vs. Mayor Rating / Environment

[Barker]

Before I go into my question, a little background....Over the past year, I have been building class specific tiles in SC4, and I've always had problems with cycling abandonment in my R$$ cities at about 200k.  For some reason the buildings grow like mad, then the traffic gets bad and commute times through the roof (700+ in my current city).  As a result, I get abandonment, population drops, traffic eases, and the cycle begins again.  I have plenty of jobs in neighboring cities, so there are no no job zots and Res Demand is maxed, Com and Indu minimal. I can see that they are trying to commute, it's just taking too long.  I use the NAM with Simulator A Easy, and it does ease the problem.  Now the strange part:

I can see that my desirability is low in a lot of areas and my environment bar is pinned at 0, probably due to air pollution. I recently tried to clean this up with parks, but that didn't make much of a difference.  I was getting frustrated and ready to just start destroying my buildings when I figured I would just pepper the area with the god mode trees.  Shortly after doing this, my environment shot up, as well as the desirability, and new growth happened almost immediately.  My mayor rating bar jumped from 50 to 100, and the city is going strong now.

My question is does this really make a big difference, or was this just a fluke?  I can barely see the trees I planted, as I just randomly plopped them over existing buildings in really dense areas (no empty tiles, large buildings).  On some street corners I see 1 or 2 trees, but it doesn't seem like that would be enough to turn the whole city around...I'm baffled why this would work.  Anyone ever seen this?