Forest mortality and recovery

As climate changes, forests will experience increasingly long and intense droughts, and the effects of these droughts, and management to mitigate the effects, needs to be better understood. We have conducted a variety of studies to identify the drivers of tree mortality observed following extreme drought in California conifer forests. We have used statewide aerial observations of tree mortality to quantify the interacting effects of site aridity and forest density in explaining mortality patterns. We have surveyed field plots in paired treated (thinned and/or prescribed burned) and untreated units to quantify the effect of pre-drought density reduction treatments in promoting forest resistance to drought and in facilitating regeneration of resilient forests following drought mortality. We are currently using tree rings to understand how these density reduction treatments affect the response of tree growth, and associated carbon sequestration, to droughts. In addition, we are evaluating mortality detections from remote sensing datasets in subalpine forests to understand the environmental drivers of mortality patterns in these forests.