Just the opposite here. Spruce lasts longer than the other wood, birch aspen & cottonwood. You got Aspen there , right. It's on the list of hardwoods
Yes we do have aspen, but as you are already aware, standing dead aspen trees rot very quickly, and our firewood permits only allow us to cut standing dead trees. Pretty much any standing dead aspen around is already rotten. Besides I have found that the Lodgepole pine seems to burn better than aspen anyway, despite the fact the lodgepole is classified as a "softwood", and aspen as a "hardwood". This BTU chart seems to support that. In reality I have about four choices of standing dead trees to choose from, lodgepole pine, spruce, douglas fir, and ponderosa pine. There is some larch around, but most of it is too far for me to drive. It's a pity because it is the highest BTU wood available. So, of the four choices ponderosa pine and spruce rank lowest on the BTU scale, and both can be a pain to split by hand, and neither can I reliably find <20% moisture content. Douglas fir is almost as abundant as lodgepole pine, but it's not that easy to split either, and I can rarely find it already <20% MC, and it oozes pitch all the time which I find irritating. That leaves me with lodgepole pine, which is the most abundant, easiest to access, easiest to split, highest BTU, doesn't ooze pitch, and best of all, it can be burned right away because it is already <20% moisture content. So for me pine, lodgepole pine at least, is the best firewood.
In the -dead standing Aspens defense- I burn quite a bit of it. Once split, keep it off the ground and it burns fine. But it's not my first choice of firewood. Lodge Pole is my first choice for what I have around here. I've burned Doug-Fir, Spruce, and Ponderosa. Not a lot, but enough to see the difference between them and Lodge Pole. I burn the Aspen because of the abundance of it. For the overall effort and end-heat, Lodge Pole wins.
I always get a chuckle or two when the whole-"Can I burn Pine?" topic comes up. Lotsa joking, warnings about ED and balding, etc. It's all good. Truth- split some, dry some, and try it. Dry is the key! Check BrianK's video feed of dry Pine burning over 15 hrs. in his Ideal Steel.
