New research has found that up to 20% of all Sierra Nevada conifer trees in California are no longer compatible with hotter and drier local environments due to climate change.
These
"zombie forests" will eventually die out and be replaced by vegetation
that is suitable for the new environmental conditions on the West Coast,
researchers forecast.
- Avery Hill, a Stanford researcher involved in the study, said the trees more vulnerable to the changing weather are in lower elevations, where the conditions are warmer and drier.
- The
research team looked at vegetation data dating back to the 1930s, when
cooler and damper conditions were more hospitable to cone-bearing trees.
- The
problem has been caused primarily by higher temperatures and less
rainfall, but also by logging and more frequent and destructive
wildfires.
- The average elevation of Sierra Nevada conifers has increased by 112 feet over the past 90 years.
- Hill
argued that lower-elevation conifers have slowly died out over that
period, whereas the cooler air found at higher elevations has allowed
the trees to continue growing there.
- The research team published detailed maps
showing stable conifer distribution and the areas in California where
conifers have been the most impacted by the changing climate.
