RE; the last three posts, it is the difference between old growth timber and new growth timber. Buildings and houses built 100 or more years ago have wood milled from trees that were around from before we were a nation. the wood is very strong and stable. Wood harvested today is grown as a crop and harvestsed long before it has a chance to fully mature. This includeds plywood The better plywoods have many more plys (layers held together by a layer of adhesive) which helps hold the wood and helps with the stabilization of it. There are many engineered wood products in use in construction these days that rely heavily on adhesives to structurally stabilize the wood mother nature didn't have the chance to. As a carpenter I worked on houses from many different era. Houses that were 100 years old had exterior trim that was in great shape just as strong as it was 100 years ago (unless there was an issue and water infiltrated for extended periods of time from behind it without being discovered), where as wood especially pine needed to be replaced on homes that were just 5 years old. Another thought on trees grown as crops are the trees grown for paper. Everyone trys to tell you to save a tree and go paperless, if that would happen all those trees planted for paper would NOT grow into a mighty tree. Those trees would reach the height they were bread to reach and just die. It is a crop planted to be harvested to make paper for the books we read the bills we get even the traffic tickets we get.
Sorry for the rambling it's hard to stop once I get going.
Dan