Oak. Elm. Rowan. Ash. Willow. Hazel. Forests of these trees used to cover Ireland, and they are indelible in the Irish memory, yielding an ancient alphabet, giving their names to places and people, and ever-present in the old poems and songs.

What would the old poets say now, if they saw that the landscape was no longer home to groves of gnarled, spreading oaks of the Old World forests, but the towering, upright conifers of the American Pacific Northwest? Sitka spruce for example, constitute slightly more than half of Ireland’s tree cover.

“I remember when I was young, being confused by their presence,” said Ruby Harris-Gavin(link is external), a graduate student researcher in the lab of UC Santa Barbara ecologist Hillary Young. “I knew that they weren’t a normal forest.” She knew the conifers were there for some purpose, though, but the significance of their presence wouldn’t be clear until years later, during her undergraduate studies at UCSB, when she returned every year to Ireland to visit family and noticed the growing number of spruce stands.