Earlier this month, flooring manufacturer Carlisle added two new collections, Oyster Bay and Sunapee Lake, to its selection of wide plank floors, which are crafted from the heartwood of large, old-growth trees. The use of heartwood in American homes—an uncommon occurrence today—dates back 400 years to the time of the first New England colonists. The mature wood, located deep within the center of a tree, is not exposed to the elements, making it less likely to splinter and warp. The old growth also produce…