Hi, evolution system is a big piece with several aspects, i'm working on it and i'll try to release a first iteration soon even if it's partial and not the final system yet.
Indeed, i forgot to explain that only root extremity collects water. I know it's not so obvious despite the visual hint (blue pulsing circles). I'll add it in the doc.
The top right chart is the climat of the region. It shows the evolution of humidity and luminosity range over one cycle (a year). You can see seasonality and periods of rain and drought. The actual value for a particular day will be in the range defined by the line thickness. In game, you can see a little white dot around the humidity and luminosity charts (top right) which indicates where you are in the cycle. (yeah I have to document this too somewhere).