A wonderful little partnership.

My new flash attachment arrived today! So here's one of the first shots, of course:

Lichen sp, Lyons Woods Forest Preserve, Lake Co, IL, 1/13/2014

This is a lichen, a symbiotic partnership between a fungus and an algae, either a cyanobacterial or chlorophytal colony. (Identifying lichens is something I haven't tried - maybe later I'll figure out which one this one uses.) The algal component provides food, since they can photosynthesize, while the fungal component traps water in it's hyphae (thread-like filaments that make up a fungus), as well as secreting enzymes that can break down wood or even rock to provide nutrients that the algae needs. This ability to create food out of nothing but rock, air, water, and light means that lichens are typically the very first organisms to colonize new land -- whether it's from retreating glaciers or recent volcanic eruptions.

This method of nutrition also means that lichens are very sensitive to airborne pollutants. Many species do not do well in even moderately polluted environments, and other species still tend to absorb certain pollutants, most notably metal ions. Biologists, being no dummies, have used these tendencies to examine how air pollutants move across the landscape -- as biomonitors, in ecology-speak.

They can also be indicators of other environmental changes -- Paltto et al. looked at the effects of secondary succession in unused wooded pastures in northern Europe, and found that as new woodland began to develop between the ancient oaks that characterized these pastures, lichen diversity decreased. They argue that to maintain these lichens (20 of which are listed in the Swedish RedData book), land managers should be actively preventing secondary succession in these ancient pastures. (1)

I find it interesting (and encouraging) that there are biologists calling for active preservation of what is, in fact, an entirely anthropogenic landscape -- but that's a topic for another day.

It's all too easy to be amazed by the big things in our landscapes, Bald Eagles, Redwood Trees, the Grand Canyon. But I remember reading somewhere that humans are just about midway in the grand scale of the universe -- that the ratio between  a single atom and us is about the same as between us and the universe as a whole. That leaves an awful lot of room for fascination with the little things, like a little lichen at the base of a tree.

(1) Paltto H, Nordberg A, Nordén B, Snäll T (2011) Development of Secondary Woodland in Oak Wood Pastures Reduces the Richness of Rare Epiphytic Lichens. PLoS ONE 6(9): e24675. doi:10.1371/journal.pone.0024675