But climate change does pose at least a few dangers to oaks: pathogens and parasites. Winter's lowest temperature continues to rise in most places around the U.S., and so bugs can survive where normally they would have frozen. Beetles, wasps, moths, funguses and bacteria are currently harassing trees all over the country. And, of course, the trees are vulnerable to more extreme droughts, like the one that threatened Goose Island State Park in 2015. That's been the most dangerous event for the Big Tree in the past several years, says caretaker Jack Swayze of Davey, a tree consulting company.