You can spot plenty of native gray birch trees in the brush next to Bound Brook and Pole Dike roads in Wellfleet: just look for the chalky bark with the distinctive black scars shaped like chevrons. Betula populifolia is a pioneer species, and while the conditions alongside the tributaries of the Herring River — sunny with plenty of water — are its ideal, it can be the first to establish in dry locations, too. But as tough as gray birch is, it’s relatively short-lived. As if following those black arrows to the sky, intermediate species will soon outgrow B. populifolia and block its access to the sun, causing its early death.
