U.S. softwood lumber imports from offshore suppliers fell sharply in the fourth quarter, extending a second-half fade after a scorching start to 2021 had pushed volumes to multiyear highs.  North American exports offshore, meanwhile, gained measured ground later in the year after a lackluster first half. Unprecedented congestion and delays at ports worldwide slowed foreign trade for much of 2021.  Transportation challenges disrupt supply timelines  Scarce containers and vessel space, steep cost hikes, and extensive disruptions in ground transportation to ports challenged importers and exporters all year. It is unclear how extensively ...