Items by J. Madeleine Nash
In California's White Mountains, scientists ponder the fate of beardtongues, bristlecone pines and butterflies in a rapidly warming world.
Rare and tiny spring-dwelling creatures are threatened by everything from invasive species to Las Vegas' plan to pump groundwater from a rural part of Nevada.
Ecological consultant Stuart Weiss believes that carefully managed grazing could help save a rare California butterfly from extinction.
Paleo-oceanographer James Zachos points to evidence of the last time climate change acidified the oceans, some 55 million years ago.