The Invisible Forest
I count 37, 38, 39 . . . I look up and blink, then focus on the beetle poster across the room. Once my eyes have adjusted, I turn to the paper next to my microscope and write "39 @ 2 mm" on the line for species number 362.
I am halfway through the leaf litter sample I collected last summer from a shady slope deep in the Ozark forest. When finished, I will have found 1,233 individuals and 68 species, all in a handful of leaf litter.
My partner, Sarah Heyman, and I study the insects, spiders, mites and other arthropods (animals with jointed legs and an exoskeleton) living in Ozark forest leaf litter. Our study is part of a multi-year project to examine the effects of different logging practices on the plants, animals and nutrient cycles of the forest.
We included leaf litter arthropods because they play a major role in transforming fallen leaves, branches and trunks into nutrients for plant growth. Although fungi and bacteria are responsible for most of the decomposition of plant materials, arthropods can double or triple the decomposition rate through their feeding activity. They also are an important part of the forest food chain, because they can concentrate proteins and minerals needed by vertebrate predators.
We have 36 5- x 5-meter permanent plots scattered randomly throughout the Conservation Department's Current River Conservation Area in Shannon County. Half are on northeast facing slopes and half on southwest facing slopes. Using random plot locations allows us to generalize from individual plots to the whole forest, since every slope has an equal chance of being picked for a plot.
Random locations are good for science, but they can be rather trying for scientists, since no thought is given to how easy it would be to find a plot the size of a couple of parking spaces in hundreds of acres of forest.
Fortunately, with over a dozen other studies taking place in the same forest we can hardly go 100 meters without bumping into some other project. Over the years, we have found our plots using pink and orange grid lines (for mapping bird locations), aluminum fences (for trapping reptiles and amphibians), white paint-marked vegetation plots and giant plastic cones (for measuring acorn production) as landmarks.
Our plots are marked with yellow flagging and paint and with plastic pipes driven into two of the corners. Using the pipes, we lay out tape measures to