Category Archives: Natural history

The Green Tide

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Kudzu is one of those things that seemed like a good idea at the time. It was introduced in the United States from Asia at the Philadelphia Centennial Exposition’s Japanese Pavilion in 1876, and in the South at the New Orleans Exposition in 1884-86. It seemed like a miracle plant. It was hardy and fast-growing, it tolerated poor soil, livestock liked to eat it, and it had a wonderfully fragrant flower. What could possibly go wrong? By the 1930’s, it was promoted as a livestock food for farmers to grow. By 1935 it was promoted as an erosion-control plant, and Soil Conservation Service nurseries began producing seedlings. According to the New Georgia Encyclopedia, between 1935 and 1942, Soil Conservation Service nurseries produced a hundred million seedlings. They were  spreading this stuff everywhere.

By the 1950s, people were having second thoughts. Today it has been reported as an invasive species in states from the Deep South, as far up the Atlantic coast as Connecticut, and in Oregon and North Dakota.

And right here just down the street from us.

I, for one, do not welcome our kudzu overlords

I, for one, do not welcome our kudzu overlords

Kudzu has a kind of mythic and yet comical status in the South. One of the Atlanta television stations had a news helicopter that used to routinely report on the various objects that kudzu was covering, from abandoned houses to old school buses. I suspect that it’s not so funny if it’s your property that the kudzu is invading.

Look out Zeke!

Look out Zeke!

This is on Lavender Trail across Fouche Gap Road, where kudzu has covered several boulders that mark the edge of the road at the dead-end turnaround.

One of my uncles, since deceased, liked to tell tales. He had a small farm and was pretty familiar with farming. He said that kudzu was great food for cattle, but if you planted it in a field, although the cattle would eat it, it would eventually spread beyond the fence. He said the only way to safely plant kudzu was to put a fenced area within a cattle pasture and plant kudzu within that interior pen. The cattle would then eat any kudzu that tried to spread outside the pen. It was hard to know whether to take him seriously or not.

This is what can happen if kudzu is not controlled. I found this image online, but it’s not an uncommon sight around here.

Online image of kudzu covering trees

Online image of kudzu covering trees

The kudzu on the mountain was blooming this week. Kudzu blooms have a deep, strong, sweet odor. Sometimes you can smell the blooms from quite a distance. In this case, I had to pull a bloom close to my nose to smell it last weekend. By this weekend, although the blooms were still visible, I couldn’t detect any odor at all.

Kudzu flowers

Kudzu flowers

There is a patch of kudzu growing across the street from one of our neighbors down on Fouche Gap Road. Now it has spread to the ditch in front of their house. I’m afraid it’s a mistake to allow that to happen.

I am keeping an eye on the kudzu growing on the property next to our neighbors on the other side of Wildlife Trail. It has covered and killed several large trees, and it’s trying to send tendrils across Lavender Trail. That would put it in the yard of our neighbor on the other side of Lavender Trail. Our neighbor’s yard and Wildlife Trail serve as a firebreak, but I don’t entirely trust it.

The little armored one

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For the last couple of years we have been noticing odd holes in the ground around our yard, generally in warmer weather. They have been conical and about a four or five inches deep. For a long time I didn’t see anything to explain them. We have had possums and raccoons since we moved up to our house, and they never dug holes like that. And then one night not too long ago I saw the culprit. It was an armadillo.

Armadillos are a relatively new arrival in northwest Georgia and northeast Alabama. Both the Georgia Department of Natural Resources and the Alabama Department of Conservation and Natural Resources, as well as a University of Georgia site, indicate that they are common in the southern and central parts of the state, although one source says they have extended their habitat as far north as Rome. I can attest to that.

They are typically nocturnal and shy, so you might not see them in person. Aside from the characteristic cone-shaped holes they dig, the main indicator that armadillos are present is their carcasses along highways. I can’t remember the first time I saw a dead armadillo at the side of the road, but it was not too long ago. Now their bodies are common, at least in northeast Alabama. I regularly drive between Huntsville, Al, and Rome. The stretch of road from Huntsville to Scottsboro, Al, is about 40 miles. Two weekends ago I noticed a few dead armadillos and started counting. There were about 10 carcasses along the eastbound side of the 40-mile drive. I say “about” because sometimes it was hard to tell what a particular carcass was. Ten is actually quite a large number. That’s more than the number of possums or raccoons I see in that distance.

What does it say about the population if there were 10 dead armadillos along 40 miles of highway? How many crossed the road safely, and how many are there in the large areas of forest and farmland on either side of the road? I can’t think of any reason that there would be a concentration of armadillos right on the road, so I think of the highway as a representative slice through an armadillo range. I think that means there is a pretty large population of armadillos in that area.

They are interesting animals. You might be led to think that they are marsupials like possums, but they aren’t. They’re mammals just like us. One strange thing about them is that they produce four identical offspring from a single fertilized egg. They live in burrows and feed mainly on insects, grubs and worms; hence the holes. They also eat some vegetable matter and, apparently when the opportunity arises, small vertebrates. Unfortunately, they may end up being a danger for ground-nesting birds. Some researchers have found quail eggs in their stomachs, and some remote cameras have caught them eating the eggs. They also apparently eat sea turtle eggs on occasion.

We aren’t sure whether they eat cat food like possums and raccoons. Based on the Web sites I have read and on our own experience, there doesn’t seem to be any particular type of bait that will entice an armadillo into a live-capture trap. Possums and raccoons fall for peanut butter on saltine crackers, but armadillos aren’t interested. One site recommended making a wide, angled fence to funnel the armadillos into the trap. Apparently they are not attracted to peanut butter, but they are fairly stupid. A .22 rifle is the recommended population control tool.

So why would we want to control their population? There are some problems with armadillos. If you like well-manicured lawns, you don’t want them around. We don’t have anything remotely resembling a lawn, so that’s no worry. The old fear of leprosy seems not to be warranted. One site said that the only documented cases (two) of transmission from wild armadillos to humans were in Texas and apparently resulted from eating raw or undercooked armadillos. This will not be a problem for us. There has been only one reported case of rabies in armadillos, in Texas, and no known cases of transmission to humans.

In general I am not in favor of having non–natural non-native species populate an area. There may be some examples that are either positive or neutral, but there are plenty of other counter examples, like the fire ant. Fire ants have also colonized northern Georgia within the last 50 years or so, and it seems that there are no natural predators of fire ants in Georgia. Their sting is very painful, about like a good, solid hit from a wasp, or possibly even worse. But it turns out that the armadillo eats fire ants. So maybe things will even out.

A tale of two rivers

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Last Friday on my way back to Rome from Huntsville, I stopped at the Little River Falls overlook to see what had happened to the flow since I saw it three days earlier. The river was down, but not very obviously. Here is the picture from a week ago last Tuesday (April 30) and from last Friday (May 3). You can see some differences. More rock is visible to the left in the second figure, but in general they look pretty similar.

Little River Falls, Tuesday, April 30

Little River Falls, Tuesday, April 30

Little River, May 3, 2013

Little River, May 3, 2013

After I got home, Leah and I went into town to eat. We stopped to get a picture of the Oostanaula River. This is a picture of the river Friday afternoon looking downstream from a pedestrian bridge towards the Second Avenue bridge.

Oostanaula River, May 3

Oostanaula River, May 3

Just downstream from the highway bridge there is an old, abandoned railroad bridge and just downstream from that, the Oostanaula flows into the Etowah River to form the Coosa River. Downtown Rome is to the left in this shot; Broad Street crosses the Etowah just up from the confluence of the two rivers. If you boated down the Coosa into Weiss Lake (watch out for the old Mayo’s Lock and Dam, because you have to portage around that), you could find the mouth of the Little River.

The Oostanaula was muddy, but the color was closer to a murky olive than to the red clay it sometimes shows immediately after heavy rain. The Little River was pretty much clear in both of the shots I took.

When I stopped at the Little River on Friday, I met a National Park Service volunteer who had a clipboard with an interesting figure. The figure showed a week-long history of the water flow in the Little River where it empties into Weiss Lake, not very many miles downstream from the waterfall.

Here is a figure I got from the USGS showing the period from just before the weekend of April 27-28, when we got a lot of rain. It includes last weekend, when we got some more rain. I put red diamonds on the chart showing the levels on Tuesday and Friday when I took the pictures. The Y-axis is on a logarithmic scale, which can be hard to read, so I added some additional numbers.

Streamflow on the Little River

Streamflow on the Little River

You can see that the level on Friday, about 450 cubic feet per second, was roughly half what it had been on the Tuesday before. A cubic foot is about 7.5 gallons, so 450 cubic feet per second is about 3375 gallons per second. An olympic pool is about 660,000 gallons according to Wikipedia, so it would take a little over three minutes to fill at that flow. That doesn’t really sound like that much.

The Park Service volunteer showed me a picture of the falls from a few years ago when the flow was about twice the maximum of the April 27-28 weekend, or over 20,000 cubic feet per second. The photo was impressive. He said the record high flow was about twice that number, which would be really impressive, and probably scary from the overlook.

This is a figure showing streamflow for the Oostanuala River for the same period. I think the flow when I took the picture above was probably around 17,000 cubic feet per second.

Streamflow on the Oostanaula River

Streamflow on the Oostanaula River

As I said in the earlier post, the Little River is a short river with a small watershed compared to the Oostanaula River, so it responds quickly to changes in the local rainfall. The Oostanaula itself is about 50 miles long, about the same as the Little River, but it is formed by two other rivers, the Conasauga, about 93 miles long, and the Coosawattee, about 50 miles. The Little River drains an area of about 200 square miles. The total Oostanaula basin is about 2150 square miles, more than 10 times larger. It’s no wonder it takes longer to respond. The tan colored triangles in the plots show the average stream flow for the two rivers. The Oostanaula is about 3000 cubic feet per second on average during this period, while the Little River is around 200 or 300 cubic feet per second, or about one-tenth as much. It seems reasonable that the stream flow is proportional to the area drained.

But there is another interesting difference between the two rivers. The Little River responds very quickly to rain, and then again when the rain stops. You can see how quickly the river flow drops during the week, when there was no rain. It started raining again late Friday and the river flow jumped up again pretty quickly. You can see a period when the rain stopped for a while over the weekend, and then started up again. Compare that to the flow of the Oostanaula. The Oostanaula began to drop after Friday, May 3, but slowly compared to the Little River. It increased again last weekend when it started to rain again. There is a segment with no data for some reason, but you can follow where the curve would be.

One of the interesting things about these figures is how this kind of behavior shows up in other physical systems. Most people have experience with cast-iron frying pans and also with aluminum foil. You know if you fry eggs in a cast-iron pan, the pan will stay hot for quite a while after you take it off the stove. And you probably also know that if you have a pan covered with aluminum foil in a hot oven, you can touch the aluminum foil almost immediately after you take it out of the oven. If you plotted the temperatures against time, the cast-iron pan would look like the Oostanaula, and the aluminum foil would look like the Little River. In my business, we would say the cast-iron pan is thermally massive, and the aluminum foil is thermally lightweight, or thermally responsive. I think it’s pretty cool stuff, but that’s just me.

I plan to keep my camera handy, and if we have some really heavy rain, I’m heading over to the Little River. I want to see just how scary it can get over there.

Not so little river

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We had a lot of rain towards the end of last week, and then a little more on the weekend. There were flash flood warnings in the area, and the Oostanaula River was high and muddy. My drive over to Huntsville takes me over the Little River right above a waterfall, so Tuesday morning I thought I would see what the falls looked like.

Little River Falls

Little River Falls

The falls here are somewhere between 45 and 60 feet high, depending on which source you believe. It’s not too high, but high enough to kill people when they are swept over the edge. The end of the Alabama Highway 35 bridge is to the upper right in this shot. I posted another shot of this waterfall a little while ago. (If you click on the link to the previous post, you can tell something about the time of day when I took these two, otherwise similar pictures.)

According to the National Park Service Web site for the Little River Canyon Natural Preserve, the Little River is unique in that it forms and flows for essentially its entire approximately 50-mile length on top of a mountain. It flows generally from northeast to southwest on Lookout Mountain.

Lookout Mountain was the site of a Civil War battle fought on its slopes near Chattanooga, Tennessee. It’s probably better known now for its tourist attractions. If you have driven the backroads in the Southeast, you have probably seen a barn roof with a painted message saying “See Rock City.” There are also signs saying “See Ruby Falls.” Rock City is a tourist attraction near Chattanooga on top of Lookout Mountain. It’s a jumble of sandstone boulders that the fanciful can imagine to look like a city. The owners help that illusion with various elf or gnome figures located here and there. Ruby Falls is an actual waterfall deep inside Lookout Mountain in one of its many, many caves. You can take an elevator down to see it.

Lookout Mountain is very different from Lavender Mountain and the other mountains around Rome. Our mountains are what you expect when you hear the word “mountain”; they have slopes that lead up to a ridge, and on the other side of the ridge, slopes that lead down to a valley. Lookout Mountain and most of the other mountains to the west towards Huntsville, Alabama, are part of the Cumberland Plateau. They have slopes that lead up to a relatively level region that can be miles wide before you reach the downhill slopes on the other side. If you were put down five miles to the west of the Little River bridge, you would not know that you were on top of a mountain. On the other hand, you could probably walk from the Little River bridge to the eastern slope in about fifteen minutes. The width of the mountain makes it possible to contain a river, but the hard sandstone cap also limits the flow of the river. In dry weather, it shrinks to a trickle.

Little River Canyon

Little River Canyon

In this image, the waterfall and the bridge are at the top center. The Little River makes a big loop, with the highway running very close along one side. The edge of the mountain is where the highway curves and runs down along the right side of the image. This is a steep slope.

There is some question about how the Little River ended up on top of the mountain. One theory is that the limestone that lies beneath the sandstone cap was eroded by an underground stream, and eventually collapsed, leaving what we see now as a canyon. The other theory is that some unknown event caused a rift to form, which was eroded over time into the current canyon.

The Little River flows into Weiss Lake, which is formed by a dam on the Coosa River. The Coosa is formed by the confluence of the Oostanaula and Etowah Rivers in Rome. The rivers around Rome flow through wide floodplains, and they pick up a lot of mud during heavy rain. They are normally green, which indicates a good burden of organic material and sandy silt, but they are relatively clear. My father and I paddled a canoe a few times on the Oostanaula when it was flowing normally. When I dipped my paddle into the water, it gradually disappeared into a swirl of faintly glimmering silt. This weekend, the rivers in Rome were rich, red and opaque. On the other hand, the Little River was clear, even though it had a much higher flow than normal, mainly because it flows over rocky land and doesn’t pick up much muddy runoff even in heavy rain.

I think I know what the Little River would look like down at Weiss Lake. The Little River’s water would look dark as it flowed into the lake and gradually extended in tendrils into the muddy water. We used to see something similar where the Oostanaula met the Etowah. When I was growing up, there were mines along the Etowah that made the river muddy all the time. The Oostanaula’s green water and the Etowah’s red water mixed reluctantly at their junction, right at the end of Broad Street in Rome. The red eventually won, and the Coosa was muddy as it left Rome. Some years ago the mining runoff along the Etowah was stopped, and now it’s green like the Oostanaula. But right now, the Etowah and the Oostanaula are both very muddy, and I’m sure the lake is, too.

Marshall Forest

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The Marshall Forest Preserve is a 300-acre site with a large area of old-growth pine-hardwood forest located near the Coosa River just outside Rome. There is apparently some debate about whether it contains any true virgin forest, but it at least has been undisturbed by human activity for more than 100 years. The old growth forest covers about a quarter to a third of the 300 acres. It was designated a National Natural Landmark in 1966. We had never been there, so last Monday Leah and I went to take a look. One thing I wanted to see was longleaf pines, since I have become a fan.

This is what the forest looks like.

Leah in the distance

Leah in the distance

This and the other photos here were taken with my phone.

The part we saw was hilly and fairly open, with quite tall trees and relatively sparse undergrowth. It’s a mixed pine and hardwood forest, which is what we see on Lavender Mountain as well. But the pines in particular are significantly larger.

Leah with a loblolly pine

Leah with a loblolly pine

This is a big pine for our area. I estimated the height of a similar tree at 80 to 100 feet.

I think it’s possible to differentiate between a loblolly and a longleaf by the bark, but I can’t do it. I have to look up towards the crown to see the foliage. These pines are tall, and surrounded by hardwoods, so their crowns are not easy to see. But I was able to find one next to the path.

Me, with longleaf

Me, with longleaf

I don’t look happy, but I am. This longleaf is larger than the largest one I have seen on Lavender Mountain, and I think it’s significantly taller.

This is how hard it is to see the needles on these trees.

Looking towards the top

Looking towards the top

There are a lot of oaks and hickories in the Marshall Forest, but I saw very few chestnut oaks, which is the variety that seems most common around our house. The Nature Conservancy Web site says that there are chestnut oak stands here in addition to the pine-oak and mixed hardwood stands.

I wouldn’t expect this forest to be a particularly good environment for longleaf pines to survive, since they typically do not compete well with hardwoods or our other types of  pines. The Nature Conservancy site says, “It is thought that periodic ice storms (like the 1993 blizzard) and fires open the canopy for pine growth, preventing domination by a single plant community.” We didn’t see many open areas, but we did see several very large downed trees, all of which were pines. They appear to have been uprooted fairly recently, probably by one of the strong storms we had a couple of months ago.

I wasn’t sure what to expect of the Marshall Forest, and I don’t think we saw enough for me to draw any conclusions about it. The part we saw looked similar to some parts of the forest on Lavender Mountain that have not been disturbed for a relatively long period. That was not too much of a surprise since the Marshall Forest is located at the base of Mount Alto, which is the same sort of environment we have on Lavender Mountain. Mount Alto is visible from our deck as the first long ridge visible to the east. I don’t think we saw any hardwoods that were noticeably larger than the hardwoods on Lavender Mountain, but the pines were definitely larger. The only place near here that I have seen loblollies that tall is along Redmond Road, which is the boundary between Berry College and the western part of Rome. I lived on Redmond Road until I was a teenager, and I can remember the very tall pines along that road. Most of those trees were removed when Redmond Regional Hospital and some other medical offices were built.

I think one possible indicator of the level of human disturbance to a forest is the presence of poison ivy. I am (or used to be) very sensitive to poison ivy, so I look carefully when I walk in the woods. There is a lot of poison ivy around our house, mostly at the edge of open areas like the roads, but I saw only one small plant in the Marshall Forest, next to the path. So that is one difference between the forests of Lavender Mountain and the Marshall Forest.

I want to see more of the forest, so I’ll be going back. We met two men and a dog on the trail, so I think it will be safe to bring Zeke with me the next time I go. And the next time I will make sure to put a memory card in the camera.