Pacific Northwest forests and climate

We already know from over a century of observations in Western forests that climate exerts strong influences on forest ecosystems. The obvious relationships—like severe drought and forest fires, or warmer decades and increased survival of seedlings at upper tree line—have been well studied. Other effects, such as the combined role of climate in insect life cycles and their tree hosts’ vulnerability, are just beginning to be understood. So the idea that climate variability plays a role in forests is not new, nor is the idea that understanding that variability is critical for successful planning in forest management and forestry. But events like the 2002 Biscuit fire in Oregon, nearly 500,000 acres, or mountain pine beetle epidemics that impact entire watersheds synchronously over the West, give us pause.