Sunday, February 10, 2013

Wetland Woes

Wetlands are a very special environment both for the ecosystems that they support and the plants that call them home. As you may know, wetlands are areas that absorb excess water from runoff, rivers and creeks. Wetlands may stay wet for all or part of the time. They help filter out pollutants from the water that passes through them; they also help control erosion.  The plants and animals that live in wetlands are specially adapted to these conditions.
Boardwalk through Heritage Park wetland

Sometimes they become homes to opportunistic plants that appreciate plentiful moisture. Chinese privet (Ligustrum sinense) is one such plant in the southeastern U.S. Privet thrives happily in moist areas like wetlands and streamsides; it also does just fine during dry spells. The plant spreads by both seeds and roots and can take over an area in just a few years. Activities known as “privet pulls” are conducted in many natural areas in attempts to clear out the thickets of privet that crowd out native plants.

Privet fruit

That picture of a boardwalk over a wetland shows the "cleared" area. The rest of the boardwalk was crowded by large stands of privet, much of it dripping with fruit even this far into winter. While birds will eat some of the fruit, it is not their favorite. Berries from the native spicebush, elderberry, winterberry and swamp dogwood are long gone, preferred by the birds for both taste and nourishment.

The picture to the right shows an area of Nickajack Creek (just past the boardwalk) that is so choked with evergreen privet that you can't even see the banks. Visitors to the park probably think that is what a "native" woodland looks like.

Yesterday the Georgia Native Plant Society held its annual privet pull at an adopted section of Heritage Park in Mableton, GA. GNPS members have been pulling privet out of this area since 2001, one section at a time.

The progress has been remarkable and it has inspired the county to eradicate more privet using other volunteer groups.
Privet tagged for removal

GNPS has also introduced a program to help visitors both learn more about this invasive and become active in removing it. Signs are posted explaining the infestation and advising that plants marked with pink tape can be removed by anyone that wants to help. GNPS volunteers come back and dispose of the plants pulled up and tag new candidates.

I spent part of the day removing pulled up plants and tagging new ones. I also removed other plants like English ivy and Japanese honeysuckle.

Cleared area on left, still infested on right

But I also spent time enjoying the park, appreciating the cleared areas and the native plants that are recovering their territory.
Betula nigra saplings on streamside of path;
green behind is privet

The trees of the area are typical of wet areas: river birch (Betula nigra), sycamore (Platanus occidentalis), boxelder (Acer negundo), red maple (Acer rubrum), and beech (Fagus grandifolia) plus some more upland trees like tuliptree (Liriodendron tulipifera) and sweetgum (Liquidambar styraciflua). Somewhere there was an oak (Quercus) in the red oak group; I saw the leaves on the ground.

Elderberry leaves come out early in the season
Shrubs include spicebush (Lindera benzoin), elderberry (Sambucus nigra ssp. canadensis), winterberry (Ilex verticillata) and swamp dogwood (Cornus amomum). Also some evergreen ferns and rivercane (Arundinaria gigantea) were present, but it's hard to tell what other perennials are here because they are dormant now.

GNPS volunteers have planted some perennials in cleared areas based on what is found on adjacent properties: ginger (Hexastylis arifolia), trout lily (Erythronium umbilicatum), toothwort (Cardamine), and Virginia bluebells (Mertensia virginica). All were visible today (although not yet blooming).

Sycamore trees arch over the ruins

I walked further along the wide 1.7 mile trail, following Nickajack Creek all the way to the ruins of the Concord Woolen Mills. The spread of privet varied widely, sometimes unbearably thick, other times very sparse. I hope that continued volunteer work with reduce it over time, allowing the native shrubs to return and support the wildlife. I heard very few birds in the woods, but I know they'd come back. 

Concord Woolen Mills was burned during the Civil War in July 1864 but rebuilt and destroyed two more times before being abandoned. The steel reinforcements were added by Cobb County to preserve it.
Carolina jessamine (Gelsemium sempervirens)

As I walked back, I spied a few yellow blossoms lying spent on the trail. Looking up (way up!), I saw the evergreen Carolina jessamine (Gelsemium sempervirens) growing in the trees. It is an aggressive native vine that, properly sited, provides late winter blooms among it's glossy green leaves.

Although this was the annual privet pull, GNPS volunteers pull privet year-round. Come help on one of our monthly workdays. It's a good way to learn more about native plants and environments at the same time you are helping.


  1. It looks like the annual pull was productive! We have been busy pulling privet and Japanese honeysuckle on the adjacent lot which we just purchased. It is amazing how much space there is once these invasives are eradicated.

  2. Thanks for another very informative post. I've pulled lots of privet myself and I'll look to see what GNPS has going on near me.

  3. It's Japanese stiltgrass that has borked my own little proto-wetland---I didn't get around to pulling it at the time, and now, being an annual grass, it's left a thick smothering of thatch alongside the bank. But at least it's an annual--I can't imagine the privet problems! Oof!

  4. It was a beautiful day and amazing how much privet we pulled. Very satisfying to see the new open spaces we made for the return of natives. The 'regulars' who work so hard on this GNPS restoration project are so committed and have done remarkable work in this park.