TUCSON — Each specimen in a strangely beautiful “treehouse” laboratory here tells a story of resilience — from droughts and floods to catastrophic wildfires and bitter winters, some occurring thousands of years ago. Nowadays, though, much of the work at the University of Arizona’s Laboratory of Tree-Ring Research is about the future of a planet that’s squaring off against global warming and its cascading disasters. Armed with the largest collection of its kind in the world — 700,000 samples and counting — scientists are trying to better comprehend what’s ahead by translating the autobiographies that trees record in their rings. The basics are known: Rings reveal a tree’s age, with thin rings indicating drier years and wide rings, wetter years. Pockmarks on rings identify years of extreme cold; blackened blotches are burn scars from fires a tree survived. “Climate variability drives tree-ring variability,” said fire ecologist Thomas W. Swetnam.