Saturday, May 2, 2009

Auburn University, A River Runs Through It

Ten pound turtles, serpent-eating kingsnakes, three-feet long fish, and many other animals roam through the heart of Auburn University, and most people have no idea they’re even there. Inconspicuous and unassuming, Parkerson Mill Creek meanders through Auburn, providing habitat for numerous plant and animal species that are often more likely to be seen residing within natural marshes and wetlands than in the midst of parking lots, dormitories and the 80,000 people that cram into Jordan-Hare stadium during football season (War Eagle!).

But Parkerson Mill Creek has seen better days. The surrounding pavement does not absorb water like soil would; resulting in a greater amount of runoff into the creek, carrying with it increased pollution. Due to construction and culverts, natural flow patterns have been disrupted. When a creek is stuffed into a culvert the water pressure increases considerably. After a rain, when water levels are high, the creek blasts out of culverts and erodes the banks. Walking along the stream today will reveal many trees with their roots exposed, the water has washed away all the dirt beneath it. Occasionally, these trees are so undercut that they simply fall over.

A heavily degraded section of creek, with barren, eroded banks and litter strewn about.

Every Thursday this semester I’ve worked to help supervise a volunteer effort restoring and revitalizing Parkerson Mill Creek. One of the primary goals is to address perhaps the most insidious threat to stream health, invasive species. An invasive species is any organism introduced into an area other than where it belongs and that has a negative influence on native species. In our region, perhaps the most well-known example is the kudzu that blankets the natural vegetation in central Georgia. This plant is native to Japan and it smothers other plants, out-competing them for sunlight and nutrients in the soil. Over time, the kudzu eliminates other life in the area.

As is often the case with the most damaging invasive species, kudzu was introduced deliberately. It was once thought to be an excellent form of erosion control, and farmers in the Southeast were urged to plant it on their property. Now, we can’t get rid of it. Chinese privet, another Asian species, was introduced to the Southeast as an ornamental plant. Today, Chinese privet and kudzu dominate Parkerson Mill Creek.

The volunteers and I work along the banks of the creek, clipping kudzu, chopping down privet shrubs, and hauling it all to a nearby dumpster. These species have become so abundant and overbearing that the creek becomes almost entirely shaded, resembling a dark tunnel enveloped by kudzu vines and the overhanging branches of the larger privet branches. Our hope is to clear the area of the invasive species and plant native vegetation, like sapling willow trees, instead. Ideally, the willow trees will take advantage of the lack of competitors and thrive. This leaves less nutrients and light for the invasive species to use and discourages them from taking over, although it is likely that they will never be completely eliminated. Hopefully, the willow roots will also help hold the soil in place, reducing the amount of erosion.

A section of creek that we helped restore. Note the willow trees dominating the bank.

I’ve only been involved in the project for a few months but it has been running for several years, coordinated by Eve Brantley. There are already signs of progress; I found two-lined salamanders hiding alongside the stream and a school of small fish darting back and forth within the creek bed. Perhaps most exciting (to me, at least) were numerous water snakes and a single kingsnake, a three foot long gar hovering in one of the deeper pools, and a large snapping turtle moseying along the stream. All of these animals can indicate a healing habitat, but there is still a lot of work to do.

On my last day, a larger than usual number of volunteers showed up to help. Some eagerly grabbed trash bags and filled them with the broken bottles and plastic bags that are typical of your standard litter crop within our natural areas. Others helped remove vines or some of the larger privet shrubs.

I introduce the volunteers to the Parkerson Mill Creek project

Towards the end of the afternoon and after the volunteers had left, I stood along a bridge that spanned the creek where we had spent most of our time and reflected on the semester. After months of work, we had removed the invasive vegetation from only a short stretch of creek, but the difference was striking. Hopefully this will be a prime spot for willow saplings next spring and their limbs will provide natural cover for wildlife.

As I watched the water cascade over the rocks in the creek bed, I began to hear an eastern towhee sing in the neighboring woods as it investigated the leaves for something to eat. A tufted titmouse suddenly arrived and began hopping from rock to rock over the stream, illuminated by the sunlight that now reached the water. Although we have done considerable damage to so much of our natural areas, we can sometimes restore them through hard work, sweat, and perseverance. The wildlife may be waiting to return.

The stretch of creek where we spent most of our time this spring. Note the dense invasive species in the background and the open foreground, where it has all been removed.

If you're an Auburn University student and interested in helping out on the creek next semester, click here

To get involved in stream restoration in general,
Click here for Alabama opportunities
Or here for Georgia opportunities

4 comments:

Charles said...

Keep up the good fight!

David Steen said...

Thanks Charles, power to the people.

Nicki said...

This is a wonderful post. As always, beautiful writing and great ecology. Keep up the good work!

David Steen said...

Thanks Nicki. Anyone that's interested in natural areas, in NC in particular, should check out Nicki's blog: http://trianglenaturalist.blogspot.com/

Dave