O.k. maybe I'm digging here, but as I was outside in the rain splitting a few logs, it dawned on me that some trees have a better ability to produce energy than others in a given timeframe. Not "which wood contains the most energy, but which trees grow the quickest that have the most energy content. So, I was splitting sumac, which is essentially a huge weed, and probably has about as much energy content as pine, but I'm sure grows roughly twice as fast, so Sumac produces consumable energy twice as fast. So which tree (wood) has the best energy cycle? Soft maples seem to grow pretty fast. if you think about it, Oaks aren't all that bad and have very high energy content when burned. Hickory has great energy content but take forever to grow, so would have s lower energy cycle rating. Anyone care to kick this around a bit? What this could be relevant for is which trees would be best used for farm raising for the production of pellets or compressed log/bricks.