Not long ago I found myself returning from a long tour in the woods. After climbing up and down steep hills all morning I was now descending down one final hillside. The long hike had taken a toll on my legs, and my feet felt heavy, as if my boots were made of iron. I caught my toe on the branch of an old log that graced the forest floor, and as I fell forward my pants cuff became entangled on the branch. My large body mass and gravity pulled against the long arm of the log and wrenched it out of its place on the forest floor. As I lay spread-eagled on the thick mat of dead leaves I glanced back to see what had tripped me up. I noticed that this old log, perhaps in place for more than 10 years, had been rolled over. As I picked myself off of the ground and dusted myself off, I noticed a lot of activity in the shallow crevice left behind where the rolled over log had once been nestled into the forest floor. A white-footed mouse, a red-backed salamander, centipedes, beetles, and other insects all scurried about. I stood watching this for a few moments when it occurred to me that in some ironic way my clumsiness had opened my eyes to a world that was very active, but not very apparent. I had just finished hiking miles in search of a new adventure, when right here under my feet, not a quarter mile from my house, there was a whole world to be explored.
The forest food web finds its foundation in the soil. Leaves, branches, and leaves fall to the forest floor where they begin sometimes a short, and sometimes a very long cycle of being reorganized, and recycled into useful food for plants and animals alike. For example, when an oak leaf falls to the forest floor many small animals like beetles and springtails fragment the leaves into small pieces which the fungi can start decomposing into smaller bits of organic matter. Bacteria and algae also serve to break the plant material down into soil-like particles. Protozoa, springtails, and nematodes graze on the organic matter converting the remaining plant material into soil. These creatures, in turn, are often consumed by mites. A centipede is apt to eat a mite, and in turn be consumed by a rodent. And, of course, every predator in the forest loves to dine on rodents. This is a simplistic view on the soil food web. For example, we know that some nematodes feed on fungi and some fungi feeds on nematodes.
In trying to understand how vast and mystifying this world is consider this. In ¼ teaspoon of soil over 100 million bacteria, one million actinomycetes, and 100,000 fungi may reside just waiting for some new organic material so that they may convert the matter into soil. Of course, the exact populations of these organisms are highly dependent upon soil chemistry, including soil ph, available oxygen, organic matter composition on the surface, and the type of subsoil present in the observed area .
The organic material, highly processed by the available microorganisms, is available in the form of nitrogen, carbon, and nutrients, all necessary ingredients to host new plants in their journey through a life in the forest.
The soil of the forest is rich in animal life. It may contain mollusks such as slugs and snails, annelids such as earth worms, many varieties of insects, and countless vertebrates, all dependent upon the decomposition of plant materials for their part in the soil food web.
My long forest journey, ending in an accidental observation, will remind me of just how complex forest ecology can be. Perhaps I will now be more aware of just how far I need to go to seek true adventure, and while I’m sure I will still journey longer distances in search of wild flora and fauna, I will also take a little time to explore the vast, infinite world found directly beneath my feet.
Originally written in January 2007