“Why do all the trees die?” Taken from Paper around Lake Tahoe [emphasis added]. I think this mortality reaches the Cascades in the north of Oregon and Washington.
Jonathan Cook-Fisher, district commissioner of the Tahoe National Forest in Trackey, says: “It is moving from the west coast to the north. The pine trees are the first to go. There are some beetles, however The main driver seems to be covered in forest, which is a drought.
Abundant forests have not occurred in the last few years. It’s been a growing problem for the last 100 years (I can’t stand it). The forests of Sierra Nevada (and forests to the west) are accustomed to the regular fires of lightning. In an attempt to “grow” the fire, the trees grow rapidly and close together. The lightning caused the fire to burn to the ground, burning the brush and driving the fast-growing young horses out of the woods before the overstretches. Some large trees are better able to protect against pests and droughts.
In a scientific study in the Journal of Ecological Applications  Rebecca Weman and Hugh Saford on the effects of tree death on the impact of wildfires
“Our analyzes have identified pre-fire tree deaths that affect all wildfires.… Pre-fire deaths are on the rise, and all fires have increased.Historical recurrent forest managers have been using this information in recent times when tree death areas have been given priority for oil reduction treatments, as this is the first hypothetical study to document the relationship between fire deaths and subsequent wildfires.