How a meadow keeps its own diary
Every spring, a fine yellow layer settles on ponds and lakes. Most of it sinks, and the record it leaves can last for thousands of years.
That layer is pollen. Each year it is buried by mud and more pollen, and over centuries the thin layers stack up into an archive of the plants that grew nearby.
Reading the layers
Every species makes a grain with its own shape. Count the grains in each layer, and you can tell what the landscape looked like long ago.
“The mud doesn’t forget. It just waits for someone to ask the right question.”