Regional, ecological, and temporal patterns in Douglas-fir climate-growth relationships in the British Columbia interior.

How climate change will affect tree growth across species' ranges remains a critical knowledge gap. Tree-ring data were analyzed from 33 Douglas-fir stands spanning a wide climatic and geographic range in the interior of British Columbia to identify regional and ecological patterns between climate and growth. Populations growing in warm and dry climates had growth patterns correlated mostly to local annual precipitation, whereas populations growing in high-elevation wet and cold climates were more correlated to annual/winter snowfall/winter temperatures and quasi-periodic ocean-atmosphere climate systems. Populations growing near the climatic margins of the species' range had the strongest responses to climate variability. Examining these relationships over different temporal scales revealed that some climate-growth relationships have varied substantially over time. Our results indicate that in the interior of British Columbia, Douglas-fir growth responses to climate change will not be uniform over time and space.