Redwoods Record Ancient Ocean Climate
The tallest trees on the planet, the coastal redwood, trapped a record of the Pacific Ocean within their ancient wood.
Centuries of fog from the ocean left a chemical signature in the rings of the massive redwoods (Sequoia sempervirens) that was distinct from the chemicals left by rainwater. A recent study identified that difference and used it to reconstruct the climate patterns of the past 50 years. The same method could produce a Pacific Ocean weather report stretching back to the Roman empire.
“Redwoods are restricted to a very narrow strip along the coastline,” co-author Jim Johnstone said in a press release. “They’re tied to the coastline, and they’re sensitive to marine conditions, so they actually may tell you more about what’s happening over the ocean than they do about what’s happening over land.”
Coastal redwoods can live for nearly 2,000 years. However, until now, the erratic patterns of the trees’ rings limited their usefulness in reconstructing climate from the size of growth rings, a technique known as dendrochronology. Coastal redwoods may grow incomplete rings that don’t always complete the circle around the trunk. This makes it difficult to count the rings to learn the trees’ age or measure the rings to learn about the weather in each year of the trees’ lives.
Read the full story here.