What kind of living things can you explore in late fall? Well, we had already checked out leaves multiple times and it was becoming harder to find insects, arachnids and other creepy crawlies. There wasn't much fresh fungus around, so what next? Lichen! We can explore this unique organism all year round and it is even more obvious in late fall and winter.
What is a lichen? It's a composite organism made up of fungus and algae or cyanobacteria. The fungus acts as the support and the algae produces food through photosynthesis. The rest of the nutrients, water, and gases are provided from the air around it. Many scientists believe this to be a mutually beneficial or symbiotic relationship, but some are wondering if the fungus actually entraps and enslaves the algae. Whatever is going on, it seems to work for lichen, because there are between 12 and 20,000 species worldwide.
Lichen grow on all sorts of surfaces or substrates. We found them growing on rock walls, gravestones, tree bark, dead sticks, and even on soil. The fungus is able to hold onto almost anything, so it is one of the first things to grow in an area that has been disturbed. Lichen, for the most part, don't harm their habitat by growing on it as they are not getting any nutrients from it. We found more types of lichens on gravestones than on any other substrate.
We also observed three different growth forms of lichen: crusty, leafy, and shrubby.
Crusty lays flat against the surface it grows on and cannot be scraped off without taking the substrate off with it. Leafy looks like lettuce leaves and is usually attached in only a few places to the substrate. Shrubby is stringy and often looks like a beard that hangs down or a small bush. It is usually attached in only one spot.
Crusty and leafy seemed to grow everywhere, while shrubby was only found on gravestones and there wasn't much of it. It also looked like crusty grew first and leafy and shrubby grew on top of it. We noticed many colors of lichen - gold, orange, many shades of green, gray, and even white. At first glance, lichens didn't seem too interesting, but after our initial exploration, we came up with all sorts of questions to investigate.