Lichen and Moss Survey Walk

A magnifying glass

A camera or phone for photographing specimens

A notebook and pencil

A lichen identification guide (many free guides available online)

A local area map for creating a lichen distribution map

Walk slowly through a park, forest, or neighborhood with your eyes tuned to surfaces. Lichens grow on tree bark, rocks, stone walls, old fences, gravestones, and even concrete. They're everywhere once you start looking.

When you find one, examine it with the magnifying glass. Photograph it. Note the surface it's growing on, which direction it faces, and whether it's in sun or shade.

Classify each lichen by growth form: **Crustose** lichens are flat and paint-like — they can't be peeled off the surface. **Foliose** lichens are leafy with edges that lift off the surface. **Fruticose** lichens are bushy, branching, or hanging — the most three-dimensional type.

Survey mosses too. They grow in damp, shaded spots and hold moisture like tiny sponges. Note how they cluster in low light and north-facing surfaces.

Here's the science: lichens are bio-indicators of air quality. They absorb everything from the air — including pollution. Areas with many diverse lichen species have clean air. Areas with few or no lichens may have pollution problems.

Create a lichen map of your neighborhood. Mark where you found each type. Do patterns emerge? Are lichens more abundant in the park than near the highway? Your map tells a story about local air quality.

Lichens aren't plants — they're a symbiosis between a fungus and an alga. Two completely different organisms living as one. That's a fascinating conversation starter.

Don't pull lichens off surfaces — observe them in place. They grow incredibly slowly (some just millimeters per year) and damaging them sets back decades of growth.

The north side of trees typically has more lichen and moss growth — it's shadier and retains more moisture. Test this in your neighborhood.

Submit your lichen observations to iNaturalist. Lichen distribution data is genuinely useful to ecologists studying air quality and climate change.