Confining the "invasive" varieties of bamboo is a subject worthy of it's own thread I suppose? Regarding the fastest biomass producing types...I am choosing to think of multiple use as part of my own equation. Garden stakes, edibles and as I am into primitive archery...even material for arrows (in the case of Arrow Bamboo). From what I have read so far, timber type bamboo will probably end up being the most "productive" but I won't know until I have experimented a lot more. In any case, I have already made up my mind to pursue bamboo in many different directions and I am beginning to understand why it has been mentioned high on just about every list regarding permaculture. If there is a bamboo nut out there with a lot of varietal experience, I would love them to chime in with their insights regarding biomass and the like........thanks!