Can one of the most biodiverse ecosystems in the world survive the looming threat of climate change?
View from the high Andes mountain range in Peru. Photo by Dano Grayson.
As climate change continues to threaten ecosystems worldwide, scientists and AAF advisory board members Miles Silman and Dave Lutz have been looking into what this rapid 21st-century warming will mean for Andean cloud forests. Their study of the migrating trees of the Andes warn that this unique ecosystem, closely connected to the Amazon rainforest, could be in grave danger.
Because of its hard-to-reach location, scientists estimate that only a fraction of the wide variety of plant and animal species there have been discovered. Temperature changes quickly on the steep terrain of the Andes, limiting the range in which different species can grow to only a few hundred meters. For this reason, seedlings sprout at a higher elevation during periods of global warming in order to remain in equilibrium with the warming climate. This causes the phenomenon known as timberline migration, where species gradually move uphill with changes in climate.
Silman and Lutz, with a team from Wake Forest University, carried out the first-ever high resolution study of the issue using climate change projections based on satellite images and computer modeling. Their startling findings? The unprecedented rate of projected temperature gain over the next century will be driving plants uphill faster than ever before. To combat temperature change and remain healthy, plants would have to move 3,000 feet up the mountain.
So what’s the problem? The studies show the migration necessary for the forests to survive would take almost 4,000 years in a protected area and 18,000 years in unprotected areas. Trees can’t grow through the ecotone, the transition zone between trees and grassland, which seems to be barely moving in the face of climate change. Scientists aren’t sure why, though they suspect human intervention and slow growth rates may be partly to blame.
Current conservation strategies are focused on mitigating human impact from cattle grazing and frequent human-set fires to allow the forest to evolve naturally. Though conservationists normally refrain from interfering in natural ecosystems, the researchers say intervention is urgently needed to save the unique species of the region from extinction.