As a logger (veneer and pulp) many years ago I cut down a hollowed out tree now and then. What couldn't be used for veneer went into the wood-stove.
Most 'tree' cutting was done in mid-winter (less destruction to the ecosystem I was led to believe) and piled on landings for pick up throughout the year (as prices fluctuated) primarily because "trees had less moisture" during winter, reducing hauling expenses.
A standing tree in winter (rotten or live) will generally be dryer than the same tree in spring (sap run) or summer (nutrients to leaves and/or more absorbent) making for 'lighter' loads for same volume when compared w/ summer cut wood. Just my own personal observation.
the tree weighs* less* in the winter--because its* DRYER* ok sounds good-
now that we have established this how can we incorporate it into beekeeping benefit--sounds like we are advancing into the category of venting through osmosis--say did the part of the tree that contained the bee cavity weigh the same as the rest of the tree or did that part weigh more--??? RDY-B