What Meriwether Lewis’s Journals Tell Us About Today’s Climate

In early March 1806, the Corps of Discovery led by Meriwether Lewis and William Clark waited out the winter at Fort Clatsop, near the mouth of the Columbia River five miles southwest of present-day Astoria.

 

They had succeeded in reaching the Pacific but wouldn’t return east for weeks. In the interim, they meticulously reworked their journals. Lewis, a naturalist, sketched and cataloged more than 250 plants, half of them new to the expeditioners.

 

President Thomas Jefferson had anticipated encounters with unfamiliar species, and instructed Lewis to “observe growth and vegetable productions … and the dates at which particular plants put forth or lose flowers or leaf.” Jefferson had trade value in mind, but 210 years later it is Lewis’ record that has value, in a way that neither he nor anyone else of his era could have predicted.

 

As a climate change intern at the Lewis and Clark National Historical Park, I’ve spent hours upon hours scouring the explorers’ weather observations and field drawings. It’s jarring to compare then and now. Temperatures today are measurably warmer, and Lewis’ drawings of skunk cabbage and evergreen huckleberry place their bloom weeks or even months later than when they flower today.

 

Does it matter if our hillsides, fields and gardens blossom earlier than they used to? Yes. Plants are our most sensitive biological indicators of a changing climate. They respond to variations in temperature, precipitation, and growing degree days, which are a measure of heat accumulation. And as their cycles modify, the co-evolved interactions of plants and pollinators is breaking down.

 

The Island Marble butterfly — a beautiful white and green creature that lives only in the Pacific Northwest — prefers to lay its eggs on one species of mustard plant. That plant is now blooming on such an accelerated schedule that when the caterpillars finally arrive, the mustard leaves are too developed for the insect to consume. If they can’t eat, the eggs that lead to pollinating butterflies are at risk.

 

Bees pollinate a third of the world’s crops and up to 90 percent of wild plants, but in some areas they are flying before flowers produce the nectar that bees feed on. Scientists have identified similar suspected mismatches between seabirds and fish.

 

Nature’s dominoes are tumbling all across Oregon.

 

At Fort Clatsop, I organize visitors and community members in a growing “citizen scientist” movement that helps researchers understand the changes underway in our environment. Thousands of volunteers statewide are now adding to the Project Budburst ecological record by tracking the progress of native red alder, Sitka spruce and other native species documented by Lewis and Clark. Unlike the famed explorers, you can download an app at budburst.org that lets you share when leaves unfold and flowers and fruit appear.

 

A ranger here at the historical park likes to say “the best time to plant a tree was 200 years ago. But the second best time is today.” If we had the luxury of a continuous record of plant observations since Lewis and Clark’s time, we’d be in a much better position to gauge how climate change is affecting plants today. But we don’t … so let’s be sure those in the 23rd century do.

 

I know, I know. For many, climate change has become a controversial topic. I get that. But this isn’t that.

 

This is the storyline our plants are narrating, and the sooner we start recording their activity, the sooner we advance knowledge of our changing world. Call it a “Corps of Phenology” — but rather than making history, we’ll be shaping the future.