High-resolution multispectral satellite image and a postfire ground survey reveal prefire beetle damage on snags in Southern Alaska

Abstract

Alaskan spruce forests are exposed to both fire and spruce beetles [Dendroctonus rufipennis (Kirby)]. To understand the influence of spruce beetles on the process through which fire affects ecosystem function, we developed a reconstruction technique to measure prefire damage to trees caused by the spruce beetle. We validated our evaluation of prefire tree conditions using a high-resolution multispectral satellite image by comparing our results with a postfire ground survey. The prefire tree conditions determined by the two methods coincided well with each other. This result suggests that combining high-resolution multispectral imaging and postfire ground surveys of spruce beetles on snags is a powerful tool to determine the prefire condition of a forest in a changing boreal forest ecosystem.