Orderly Nature

This is part of the small sea-wall that prevents erosion around the bridge over the river Ythan. The wall looks flat in the photograph, but in reality it rises from the shore at an angle of about 45 degrees. You can't believe anything that you see in a photograph!
The horizontal bands are an example of zonation, the way in which plant and animal communities organise themselves in distinct bands, dependent upon their relative abilities to withstand such environmental pressures as salinity, temperature and desiccation etc. The zones here are brown fucoid seaweeds on the shore, green algae, a black lichen, a yellow lichen and then finally the green sward of the salt marsh. Nature just loves a bit of order!