On Syracuse University Week: Trees need a long time to adapt to climate change.
David Fastovich, assistant professor of geography, explains why.
Dr. David Fastovich was a Postdoctoral Scholar in the Bhattacharya Paleoclimate Dynamics lab at Syracuse University and will soon be starting as an Assistant Professor in the Department of Geography at the University of Georgia. Dr. Fastovich conducts research at the intersection of ecology and paleoclimate dynamics, studying both the physical mechanisms behind past climate changes and how forest ecosystems responded to those changes. By linking paleoclimate dynamics to ecological responses, his work helps us better understand how trees and forests adapt to climate change to prepare us for the challenges posed by global warming. He uses a range of tools—including computer climate models, fossilized pollen, and molecular fingerprints left by prehistoric plants—to reconstruct past climate conditions and trace how ecosystems evolved alongside them.
Why Trees Need Centuries to Adapt or Migrate But Climate Won’t Wait
The Earth has experienced incredibly warm conditions that allowed the dinosaurs to flourish and ice ages that pushed many plants and animals to extinction.
Fossilized pollen grains in the bottom of lakes and oceans record how trees have responded to these past climate changes – individual trees slowly migrated and followed their climate habitat which formed new forests and dissolved others. This window from the past raises alarms for us today: forests cherished by nearly all cultures, across the entire world, face extinction if they cannot move fast enough to keep up with their moving climate habitat.
If the Earth gets warmer for a year, a decade, a century, or a millennium, how long will it for trees and forests to fall into balance with the new climate? The complexity of climate makes answering these questions difficult – while one year may be warmer than the year before it, it may be in a century that is colder than the previous century.
To answer this question and contend with layered climate changes, we borrowed a statistical tool from sound engineering – the same type of mathematical approach that noise-cancelling headphones use to filter out airplane engine noise. A clear image of how forests respond to climate changes across timescales emerges when applying this tool to geologic evidence of past changes in tree populations. When climate changes from millennia to several centuries, individual trees can migrate fast enough to track their climate habitats. However, for climate changes that happen faster than 150 years or so, trees are unable to migrate fast enough and must brace and continue to grow in their new inhospitable climate home.
Since current climate warming is happening faster than the 150 years it takes for trees to respond to warming, the forests that we care about are globally threatened.
Read More:
[Science] – Coupled, decoupled, and abrupt responses of vegetation to climate across timescales
