Experts say a changing climate is raising concerns about how the saguaro will survive the 21st century in an environment that is getting hotter and drier. "If we're going to find any communities or ecosystems well suited to these climate stressors, the desert is going to be a pretty good one," said Benjamin T. Wilder, director of the University of Arizona's Desert Laboratory on Tumamoc Hill, where botanists began studying the saguaro 118 years ago. "I wouldn't bet against a desert species." Michael A.