WHITE RIVER JUNCTION – While some outdoorsy Vermonters spend their summer leisure time fishing, boating, or gardening, others find enjoyment spotting decomposing logs along wooded trails.
Eastern Red-backed Salamander on Mount Cardigan, N.H. © Pia Carman, VCE
On a sunny June day, the Vermont Center for Ecostudies summer interns took a hike on Mount Cardigan and excitedly herped all the way to the top. When seeking out downed woody debris for flipping, we looked for soft, dark-brown logs, which are rich in nutrients and moisture, making them a favorite hiding spot for salamanders and other secretive herps. A common sight when you eagerly turn over a log is your friendly neighborhood Eastern Red-Backed Salamander (Plethodon cinereus). These little guys are slithery, brown and red, and so small they don’t need lungs: instead, they can breathe through their skin.
These small but mighty creatures are one of the most common terrestrial vertebrates in the moist hardwood and mixed forests of New England. There, they play a pivotal role in maintaining forest health, preying upon small invertebrates like ants, spiders, snails, centipedes, and beetles. By controlling these organisms, which include numerous fungivores, red-backed salamanders contribute to the breakdown of woody material and leaves into soil.
Wolf’s Milk-slime (Lycogala epidendrum) on Mount Cardigan, N.H. © Gita Yingling
Given this relationship, it was easy to assume that the bright red splotches on a log concealing a red-backed salamander were a fungus. Curious to find out what fungus we found, we turned to iNaturalist. A quick search yielded a surprising result: these little blots on the log were not fungi at all. They were a slime mold amoeba called Wolf’s Milk-slime (Lycogala epidendrum).
With a name that sounds like something out of a low-budget werewolf flick, the Wolf’s Milk-slime lives a fascinating life. As amoebas, they are single-celled organisms that spend most of their life invisible to the naked eye but occasionally aggregate to form a single mass of many individuals called a fruiting body to reproduce (which is what we were lucky enough to witness in person). In the immature stage of this fruiting body, its insides contain a pinkish slime, which we confirmed by popping one of the fruiting bodies we found. When mature, the fruiting body’s slime turns to a gray powder of spores. This fascinating enigma of an organism feeds on cells, spores, and particles of fungi, plants, protozoa, and other organic matter.
If you take a moment to stop and look, a great deal can be learned from just a single log. Along our journey to the summit, we found two species deeply intertwined with the cycling of matter in forests. Our observations showed us one organism that consumes invertebrates, which consume fungi, which consume organic matter. In the slime mold, we also found an organism that feeds on both fungi and decaying wood. Learning about these two species came from a chance encounter. So, next time you’re out in the field or on a hike, try turning over a few logs. You will probably find amphibians, and if you’re lucky, you’ll also find the fruiting body of a plasmodial slime.
Pia Carman and Gita Yingling are staff members at the Vermont Center for Ecostudies.
Pia Carman, Vermont Center for Ecostudies
Gita Yingling
