The aim of the Pacific Northwest Permanent Study Plot Program (PNW-PSP) is to study and quantify the long-term dynamics of forest vegetation. We manage more than 140 plot installations across a diversity of forest types in Oregon and Washington. These include coastal forests of spruce and hemlock, Douglas-fir-dominated forests of the western Cascades, higher-elevation forests of mountain hemlock and silver fir, and ponderosa pine forests in Central Oregon.