Pat’s Wildways: Rotting Wood

It’s been a while since I’ve walked the trails around Willow Pond in Fort Clinch State Park. With all the rain we have had in the past couple of months, much of the bike trails through the park have been closed, part of the main road was flooded, and no doubt the Willow Pond area was heavily impacted, too. But now the water has receded and it was time for me to check it out.

The Willow Pond area is made up of “borrow pits” where soil was excavated years ago to build the roads through the park. These areas are now a series of ponds covered with duckweed and hiding alligators, no doubt. A warning sign at the parking lot off the main Fort Clinch road warns wary visitors about their presence and it is always a good idea to be on the alert, although I doubt you will ever see one. A number of years ago, naturalist Carl Watson showed me an alligator nest and a few babies nearby, but aside from that, I've never seen one in all the times I’ve walked here.

I always see something different when I walk around the Willow Pond area. I most often enter at the south end near the “Beware of Alligators” sign. Within a short distance, I take a little jog to the left and usually sit for a while on a well-placed bench beside an open pond near where that Mama Gator had her babies so many years ago. But on this walk, it was different. The bench was now partly surrounded by high water from the pond.

Further along the trail, I could see how the water rose to cover the pathway. It was still very muddy in some areas, but helpful rangers or volunteers had cut palmetto fronds to cover it in some areas to make walking a bit easier. In some areas, the mud was covered in deer tracks, and in some places, wild hogs had wandered by, too. But mostly the tracks were people, lots of people who traversed through the mud too.

At one place I diverted off the main trail to another bench and then I noticed a dead tree with lots of dirt piled up at its base. What was this? With a bit of internet sleuthing I determined that this was insect frass, a powdery substance secreted by hard-working termites that were decomposing the tree. And then I noticed another tree nearby with lots of holes that looked like the work of birds, raccoons, or some other predator looking for the insects within the decaying trunk. As I walked further along, I spotted mushrooms on fallen logs and on the trunks of dead trees still standing.

I just returned from fieldwork in Serbia, where one of my biodiversity colleagues, Gabor Mesaros, is an expert on beetle diversity. It turns out that Serbia is a hot spot for beetles. Who would know? And at least one of these beetles, the hermit beetle, only exists in areas where old deciduous trees collect humus from decomposition and insect activity in tree hollows.

Lots of species besides this particular beetle are dependent on old and dead trees for their survival. These trees or snags are an important component of the biodiversity found in natural forests. At Fort Clinch, like other state parks and protected areas in the United States, these old trees are left in the woods to provide habitat for a myriad of other species. Some animals burrow under the dead trunks to make dens, woodpeckers and other birds extract the insects from beneath the bark, and many types of mushrooms grow on the rotting wood, converting it into fertile soil that enhances the growth of plants around it.

Leaving the dead trees in the forest seems like a good idea, right? Well if you are protecting a forest for its biodiversity that is a surety. But in Serbia, here’s the thing. Most of the forests here are managed for the wood. Foresters remove old and dead trees and sometimes plant more to harvest at a later date. And all of this activity results in a loss of biodiversity in the forests, a depletion of native species, and a “cleaner” but less interesting environment.

My trip to Serbia and my conversations with Gabor has left me with a deeper understanding of the value of old and dead trees to the health and diversity of a forest. And it took my recent muddy walk through Willow Pond to bring this message home.

Pat Foster-Turley, PhD is a zoologist on Amelia Island. She welcomes your nature questions and observations. patandbucko@yahoo.com