BTU's for a cord of wood?

Man, someone has a good splitter that looks like a huge task in its own right? Wonder what type of wood they have there?

Has there ever been a discussion about what type of wood is used? I'm no professional on it but I have burned wood in my fireplace for 20 some odd years and found that not all wood is created equally, and that some wood burns better than others when it comes to heat and what is left in the flue. I have found that pine is one of the worse for me as it not only pops much in the fire place but because of the pine oils, it also makes a mess of the flue. Every year I have to do an excessive flue cleaning. But with a box elder there is no popping and burns very clean and hot, oak is nice for heat too but is too expensive to burn when it can be used in building, structural uses and designing interiors. Anyway just my perspective.

Still a Student,

Dave