…They’re a key part of Pacific Northwest ecosystems, though they rarely dominate the forest, often living alongside firs, hemlocks, alders and maples. These trees are the Pacific Northwest’s iconic western redcedars (Thuja plicata). …They’ve been recorded to live for over 1,500 years. But these trees are now dying. For at least a decade, struggling and dead western redcedars have been reported throughout the Pacific Northwest. But the cause and extent of the dieback (a condition in which a tree or plant begins to die from the tip of its leaves or roots inward) have long remained unknown. Now we have the answers. The dieback is widespread, and the cause appears to be climate change. What’s more, we now know that the dieback could be the beginning of the end for the species in many parts of the Pacific Northwest. …The major climate event impacting the trees, say the researchers, has been the drought.