Lichen is a colonizer. It eats rock and releases minerals that other plants can use.
Most of the lichen on the stone below has died. It’s a good chance to see the eating it has done.
This story of succession from simple to complex environments appeals to human observers. We like a good story. The harshest of environments give a home to lichens, which then build the foundations of more complex ones.
It’s not so simple. Here in the grasslands, the whole soil surface is covered with lichen, or at least is when it’s healthy. The slope below is somewhere between unhealthy and intact. The lichen is there, but deer, constrained here by unnecessary orchard fencing, are causing them to cut it to bits. This can only end badly. In the meantime, however, let’s try to help the deer by looking at what the lichen is doing. So, well, look.
See that? In this complex, climax landscape, with bunchgrass the equivalent of old growth cedars on the Pacific Coast, the lichens, these simple rock miners of simple landscapes, are everywhere. They’re not mining rock so much as sand. The skin they make over the earth between these snow-crushed grassy tops of bunch grasses (that are really baskets holding water underground, with a bit of fluff showing up in the air to catch rain) is the force that holds this soil together. Not only that, but they mine minerals from the soil, that wash down into the underground baskets of the bunchgrass and are held there. Look, as well, at how the bunchgrass often caps itself with snow, which ensures unfrozen ground for this mineral rich water to pour down into the grass, and how the head of each grass is a little beaver dam preventing the minerals from growing further.
It has long been the practice of grassland managers to keep horses and cattle off the grass as much as possible, because of the irreparable damage they do to this crust. Deer, who pass through quickly, usually on their trails, do little damage, unless they are forced to stay. Then they are rototillers. Note how little bunchgrass survives when the crust is broken.
This is a landscape in which the first day of life after the glaciers and the last, today, are all present at once. When you break that (with a fence, let’s say), you return the land to the erosion the life here healed. Altering this environment destroys its sustainability. Without the bunchgrass’s barrels of underground water nothing will stop the snow from running down the hill and flooding everything down below — exactly those places the fences were meant to protect from the Earth. It is interesting that Canadian culture destroyed the water keepers, the beavers, here, out of ignorance, and now, in the waterless landscape of their absence is destroying their companions, the water-keeping grass. In this climate, where 11 times the water that falls from they sky evaporates into a sky dried by its trip over the Coast Mountains, losing water is to lose the land completely. These are not metaphors.