| Microclimate influence on vegetation response to climate change is widely acknowledged, but often remains unaccounted for in climate change modeling. This study examined the effect of topography on white spruce (Picea glauca) climate response on steep south-facing river bluffs in the boreal forest in interior Alaska. Tree ring width index, and tree ring delta 18O, delta2H, and delta13C chronologies for white spruce trees growing at the base of river bluffs and on the upper bluff of three sites near Fairbanks, Alaska were compared in terms of overall temporal pattern and climate relationships among sites and topographic positions. Site location and topographic position had a significant impact on tree ring parameters and their relationships to climate at all three sites studied. Overall, the most significant climatic driver of white spruce tree ring stable isotopes on south facing river bluffs in interior Alaska was the amount of winter precipitation each site received. |
