
Despite recently retiring from the US Geological Survey, he is now busier than ever researching the crisis in the world's forests and serving as an adjunct professor of ecology at the University of New Mexico. He has been dubbed as a "tree coroner" due to his desire to understand how trees are dying from climate change. It appears to be prescient.Ĭraig D Allen has been on forest death-watch for much of his career. This research follows efforts by one group of tree enthusiasts to attempt to replicate and plant the largest of these giants to protect their ancient DNA in what they call "living libraries". In the last few years, however, scientists have started to unpack the importance of ancient tree genetics, with mounting evidence showing they will play a critical role in the future of the Earth's forests. And we are also mainly in the dark about how those trees that have survived will fare in a hotter and drier world. We also lack knowledge about the genetics of trees: especially the effects on the gene pool of cutting down virtually all of the biggest, most robust trees for lumber over many centuries. The Caribbean mangrove forest that defied destruction.



That's not nearly cold enough to kill pine beetles, which make their own natural antifreeze.

If they do, it is usually just for a day or two. These days wintertime minimum temperatures rarely get below -18C (0F) or so. The coldest temperature on record in Montana is –57C (-70F). When I first moved to Montana in the late 1970s, temperatures of -34C (-30F) or even below -40C (-40F) were common in winter, sometimes for weeks at a time. While the native bugs were the proximate cause, the underlying reason for the unprecedented mortality in my home state and throughout the Rockies was that winters had stopped getting really cold. I felt powerless and grief-stricken as I saw these giant, sky-scraping trees fading all around me, realising there was nothing I could do to stop it. The next year the number of dying trees grew exponentially. I soon discovered they were being brought down by mountain pine beetles, pernicious killers the size of the eraser on a pencil that burrow into the tree. In 2005, several of the centuries-old ponderosa pine trees on my 15 acres (0.06 sq km) of forest in the northern Rocky Mountains in Montana suddenly died.
