From far away, the clearing is small and silent. But among the sprinkle of trees, a small group of volunteers stand in pairs around shallow dips in the ground.
Each dip is marked by a small flag. A volunteer is standing in one, holding a tool that looks almost like a Pogo stick with a spike at its end instead of a spring. The volunteers have been shown how to hold it, how to push this tool – called a probe – into the sunken earth about every 6 inches, across the middle, then up around the edges where it rises.
It’s not so hard. Here, the soil is soft, and the air is cool…