Almost 400-year-old pear tree

How long can a tree live?  Trees are nearly immortal, the result of meristems and indeterminate growth.  Many die not because they are too old, but because as a sessile organism they are subject to accidents.  Trees get bigger as the get older and as a result big old trees sort of out grow themselves.  They become too big and their structural integrity begins to fail; they just break apart usually helped by storms.  Supposedly this pear tree was planted in Plymouth nearly 400 years ago.  Pears are slow growing trees, and they can be pruned to keep their crowns in proportion to the rest of the tree.  So inspite of many near catastrophes, this colonial pear tree has survived.  Still that's quite remarkable.  TPP has a yellow pine barn beam about 6 x 7 inches from a barn constructed in the 1880s, and one corner of the beam has a strip of bark, so we can assume the tree was cut for timber in about 1880.  The growth rings do not go to the center of the tree, but you can easily count growth rings back into the early 1500s when it was already a tree 10-12 inches in diameter.  So this was probably also a 400 year old tree, there abouts.  Actually while trees this old are now news, it's because we've become a tree-destroying, lumber and paper craving culture with no respect for our elders, big, old trees.