"Almost 1,000 oyamel firs ( Abies religiosa ) have been transplanted to a mountain in Michoacán, where they are growing at elevations beyond what was considered the species’ upper limit. If the trees survive over the next few decades, they could help to shield the migratory eastern population of monarch butterflies ( Danaus plexippus ), which spend the winter roosting in oyamel fir forests, from the impacts of climate change. This population of monarchs, which migrates up to 4,500 kilometres from the United States and Canada to Mexico, has declined dramatically since the 1990s, owing to climate change and habitat destruction."
"Each year, hundreds of millions of monarch butterflies over several generations find their way to the high mountains of central Mexico. There, they overwinter by clinging to the branches of the sacred fir tree Abies religiosa in massive blankets of fluttering orange and black."
"This migration miracle is threatened as global warming in the coming decades pushes temperatures too high for the forests of this revered tree to survive, even at the summits of the mountains where they now grow. But a recent experiment suggests this rare habitat might survive, if humans help the trees make a journey of their own."