Friday, November 8, 2013

November 7 2013 Ramble Report




This week's report is written by Don Hunter. The photos are selected from Don's facebook album.

Most people awoke on this morning to the sound of light rain, enough rain to make the gutters sing, but still, twenty-one brave souls ventured out and gathered at the arbor and were rewarded with a clearing sky and comfortable temperatures by the time Hugh called for readings.   Hugh, once again, through either magical incantations or sheer mind over matter, had managed to defeat the weatherman!  

 We had two readings today, the first provided by Ed Wilde, who read from William Bartram’s “Bartram’s Travels”, which describe his travels in the American South and encounters with American Indians between 1773 and 1777.  (The book's full title is “Travels through North and South Carolina, Georgia, East and West Florida, the Cherokee Country, the Extensive Territories of the Muscogulges or Creek Confederacy, and the Country of the Chactaws. Containing an Account of the Soil and Natural Productions of Those Regions; Together with Observations on the Manners of the Indians.”)
“Leaving the pleasant town of Wrightsborough, we continued eight or nine miles through a fertile plain and high forest, to the north branch of the Little River, being the largest of the two, crossing which, we entered an extensive fertile plain, bordering on the river, and shaded by trees of vast growth, which at once spoke of its fertility.  Continuing some time through these shady groves, the scene opens, and discloses to view the most magnificent forest I had ever seen.  We rise gradually a sloping bank of twenty or thirty feet in elevation, and immediately entered this sublime forest; the ground is a perfectly level green plain, thinly planted by nature with the most stately forest trees, such as the gigantic black oak (Q. tinctoria), Liriodendron, Juglans nigra, Platanus, Juglans exalta, Fagus sylvatica, Ulmus sylvatica, Liquid-amber styraciflua, whose mighty trunks, seemingly of an equal height, appeared like superb columns…”
(Ed’s note: I assume “thinly planted by nature” and “level green plain” meant grass grew between the trees.  For those not up to Latin names for trees, the forest consisted of black oak, tulip, black walnut, sycamore, shell bark hickory, beech, elm and sweetgum.)
“…To keep within the bounds of truth and reality, in describing the magnitude and grandeur of these trees, would, I fear, fail of credibility; yet, I think I can assert, that many of the black oaks measured, eight, nine, ten and eleven feet in diameter five feet above the ground, as we measured several that were above thirty feet girth, and from whence they ascend perfectly straight, with a gradual taper, forty or fifty feet to the limbs; but, below five or six feet, these trunks would measure a third more in circumference, on account of the projecting jambs, or supports, which are, more or less, according to the number of horizontal roots, that they arise from; the Tulip tree, Liquidamber, and Beech, were equally stately.”
Ed also provided the following facts regarding the Black Oak (Q. velutina):
·        The state record Black Oak is on the property of Our Lady of Perpetual Help, in the shadows of the old Fulton County Stadium, in Atlanta, Geogia.  It is 7.5 feet in diameter, 105 feet tall and has a crown spread of 135 feet.
·        The U.S. champion Black Oak is 9.5 feet in diameter, is 78 feet tall and has a 89 foot spread.

The second reading was provided by Don Hunter.  Don read a poem of his own writing, “Ode to the Common Crepe Myrtle”.

Gift of Michaux, brought to us from a place far in the East,

Your beauty, ere it be Summer or Fall, is something upon which the eyes can feast.

Your trunks, there may be many, grow both sinewy and smooth, reaching up in graceful lines that bring happiness to my heart.

It is a joy to touch you, to feel your cool bark and to marvel at its feel beneath my hands, it’s mottled patterns doth truly be nature’s art.

In Summer, your flowers are grand, in shades of purple, red and pink and, oh yes, even white!

Your crenulated flowers glow so brightly as to make one think that for just a moment they could burst, yes they might.

And when Summer finally draws to a close, and your flowers are shed,

You, chameleon like, turn your leaves from green to yellow and orange and red.

Yes, come Fall, your leaves all aglow, as brilliant and resplendent as any could be,

You are as beautiful a sight as one could see.

So go on and shine and glow as bright as you can ‘til Fall’s great blustery winds strip you bare,

Your graceful trunks and limbs alone holding sentinel ‘til Winter ends and Spring is again in the air.

After the readings, we left the arbor, walking past the Visitor Center and up to the Upper Parking Lot, where we walked the Orange Trail.  We briefly wandered off the Orange Trail, with a detour up Copperhead Creek, to view the folding in several rock outcrops (described by Dr. Gilles Allard in the Purple/Orange Trail booklet).  We returned to the Orange Trail, where we walked to the foot bridge and crossed the stream, heading back up to the Flower Gardens and the Visitor Center.  The main emphasis again today was identifying the forest communities, based on the observed flora and other characteristics and criteria.

Sourwood
Heading past the Visitor Center fountain, Hugh pointed out the Oak Leafed Hydrangea (Hydrangea quercifolia), which is beginning to turn red.  As we continued on, we came upon a large Sourwood (Oxydendrum arboreum) below the Upper Parking Lot, as well as many of them around the lots.

As we moved into the forest, at the head of the Orange Trail, we were reminded that we would be looking at the forest communities on our walk today.  The upper section of the Orange Trail is a Successional Forest.  The first trees to establish are the Short Leaf and Loblolly pines.  We see many of the Short Leaf pines in the canopy, as well as several dead and fallen pines on the forest floor.  The presence of many fallen pines indicates that the succession is changing over to oaks, entering the climax forest stage. In the developing forest,  pines are generally followed by Sumac and Tulip trees, in the order of succession.  The tulip trees remain in the canopy, even as it becomes more oak populated.  As we made our way down the trail, we were on an east facing slope and noticed many large American Beech trees (Fagus grandifolia), indicating a mesic setting.

Hugh points out pitch pits in bark of Shortleaf Pine
We made a brief stop at a Short Leaf Pine (Pinus echinata) to point out the distinctive, glands of the bark plates, which appear as small pits.  The needles of the Short Leaf Pine are present as two needles to the bundle at the tips of the limbs.  Also, with respect to the pine cones, the Loblolly cones have “prickles”, whereas, the Short Leaf cones do not.  At this location, we also saw a Sparkleberry tree (Vaccinium arboretum), growing in the middle of the trail, with it’s smooth bark and green foliage in the top of the tree. 

A little further down the trail, someone pointed out a cluster of Oyster Mushrooms (Pleurotus ostreatus) and a cluster of what appeared to be small Oyster Mushrooms growing in a cranny near the base of a large tree.  While viewing the mushrooms, we discovered that there was an active yellow jacket nest in the ground, no more than two or three feet from the base of a tree.  We survived with no one getting stung! Also here was a small patch of the emerging leaves of Tipularia discolor, or the Crane Fly Orchid.

Next, we came upon another rangy Sourwood tree and a High Bush Blueberry (Vaccinium corymbosum) with it’s distinctive bright green colored new growth limbs and twigs.

After moving through the gate we stopped at a Black Cherry tree (Prunus serotina), with Emily’s “burnt potato chip” bark but, upon closer examination, the typical horizontal lines associated with Black Cherry bark were still visible on the bark plates.  This tree is also associated with the successional forest and usually comes along with the tulip poplar and sweet gum.  Also of note at this location was that the moss on this tree was, as the old adage says, on the north side of the tree.

Headward erosion
Not far down the trail, is the beginning of the stream bed.  The head of the stream bed is advancing up the ridge, as headward erosion is occurring.  The soil forming the banks of the deep ditch are more or less sloughing off, generally during significant rain events, the material being carried downstream to the river. 

Just past a small Water Oak (Quercus nigra), a small sedge was found growing along the edge of the trail.  We were reminded that “sedges have edges” when trying to determine if a suspect plant is a grass or a sedge.  Below the sedge we saw a Climbing Hydrangea (Decumaria barbara) on a Red Oak tree (Quercus rubra) and a Lance Leafed Smilax AKA Lance Leaved Greenbrier (Smilax smallii) on a Hop Hornbeam tree (Ostrya virginiana). 

At the informational sign at this location, we are reminded that this is a successional forest, though it is far along in the process of succession, with many of the larger trees growing up into the canopy.  Along the trail we saw Wood Oats (Chasmanthium sessiliflorum), a smaller cousin to the River Oats (Avis’ Fish on a pole!), with it’s very small flowers and seeds all along the stem.

Southern Grape Fern with fertile frond
Next we had a lesson on distinguishing between the Southern Grape Fern and Rattlesnake Fern, both found in relative abundance along the trails at the Bot Gardens.  Both have similar looking fertile fronds but the Southern Grape Fern (Botrychium biternatum) which we saw at this location, has a fertile frond that grows from the ground, along with the other fronds, whereas the fertile frond of the Rattlesnake Fern, as well as the other fronds, grow from a stem above the ground.  The leaves comprising the fronds of the Rattlesnake Fern are also somewhat finer than those of the Southern Grape Fern.  Both ferns are fertile during an overlapping period in the late Summer so they can be mistaken, if not careful. 

To our right, as we walked down the trail, a spring could be seen breaking out onto the surface and quickly joining the, at this point, drier main stream bed, providing a significant amount of the total flow.  This is an obvious phenomenon but many times, streams such as the one along the Orange Trail seem to magically get larger, with respect to the amount of flow present, without contributions such as the spring.  This is not magic, of course, but science.  In hydrologic terms, streams such as this, flowing over generally unconsolidated material, are classified as either “gaining” or “losing” streams.   Where the water table is deep, surface water being conveyed by the stream will gradually leave the stream by migrating downward into the bed of the stream and seeking the water table found below at depth.  But where the water table is shallow, as is frequently the case as you lose elevation along a smaller stream as it nears a larger stream (our case), the bed of the stream will intersect the water table.  When this happens, the water table actually contributes to stream flow, by welling upward into and through the bed of the stream.

Sycamore fruits ("seed balls")
We saw a Crossvine (Bignonia capreolata) on a Hop Hornbeam and passed by a large Sycamore tree (Platanus occidentalis) , with it’s rough, lower bark and smooth upper bark.  A limb tip was seen on the ground below the tree with it’s spherical seed balls.  We also noticed a Broad Beech Fern (Phegopteris hexagonoptera), and not far away, a Decumaria, or wild, climbing hydrangea on a Musclewood (Carpinus caroliniana)  next to the trail.  Also seen were Sweet Shrub (Calycanthus floridus), Piedmont Azalea (Rhododendron canescens) and Wild Ginger (Asarum arifolia) along the banks of the stream.

At the Sitting Bench, we learn, on the informational sign, that we are in the Ravine and Lower Slopes forest community and have actually been in it for quite a bit as we made our way down the trail to this point.  Canopy trees here are Basswood, Beech, Bitternut Hickory, Northern Red Oak and White Oak.  The sub-canopy consists of Chalk Maple, Mulberry, Paw Paw, Redbud, Red Maple, Sweetgum and Umbrella Magnolia (which we have not seen).  The shrub layer is represented by Bladdernut, Paw Paw, Canadian Buckthorn, Painted Buckeye, Sweet Shrub and Wild Hydrangea.  A Chalk Maple (Acer leucoderme) was noted very near the informational sign.

Differential weathering makes gneiss folds stand out

Nice folds in gneiss rock
At this point, we hiked up the little side trail that follows a small stream, referred to as Copperhead Creek, up the hill to see some interesting features in the rock outcrops above the stream.   Retired UGA geology professor, Dr. Gilles Allard, has described the geology of the Purple and Orange Trails and this description is included as an appendix to the Botanical Garden’s pamphlet “The Plant Communities Along the Purple/Orange Trail at the State Botanical Garden of Georgia”.  The subject rock outcrops are seen high above the small stream approximately 150 feet from the Sitting Bench.  Visible in this outcrop of migmatitic gneiss are small, tight folds in the rock.  This can be seen in relatively fresh, broken surfaces, where the alternating layers of dark and light colored minerals reveal a wavy pattern of small, tight folds.  It can also be seen in parts of the outcrop that are covered in moss.  The minerals comprising the darker layers, seen in the fresher rock, are more susceptible to chemical weathering than those making up the lighter colored layers, which contain quartz and feldspar.  The layers that are more resistant to chemical weathering stand out in relief as the ridges seen in the wavy patterns.   

Beechdrops with fruits
Hugh on left; River Cane on right
A large American Beech tree can be seen at this outcrop, complete with Beech Drops (Epifagus americana) at its base.

After making our way back to the Sitting Bench, we continued downstream, seeing River Cane (Arundinaria gigantea) , a native bamboo, a type of grass.  After a massive privet eradication effort along the river and the stream, it was hoped that River Cane would flourish but Box Elder has become more prominent, not necessarily a bad thing.  Beech Drops were also seen here.

Liverwort
Hugh pointed out some liverwort (Conocephalum conicum) growing on a rock found at waters edge in the stream.  Most liverworts are small, usually from 2–20 millimetres (0.08–0.8 in) wide with individual plants less than 10 centimetres (4 in) long, so they are often overlooked. The most familiar liverworts, as we see in the stream here, consist of a prostrate, flattened, ribbon-like or branching structures called a thallus (plant body); these liverworts are termed thallose liverworts (Wikipedia).

Further down the stream, Hugh pointed out scattered wood fragments on the ground, the result of Downy Woodpecker (Picoides pubescens) activity up in the canopy.  Pipsissewa or Spotted Wintergreen (Chimaphila umbellata) was also seen here. 

Combed Toothed Mushroom
After we crossed the foot bridge to make our way up the hill to the Flower Garden, was some large leafed climbing hydrangea (Sp. ?) on a Musclewood.  Prior to leaving the forest, several nice Combed Toothed mushrooms (Hericium coralloides and Hericium ramosum), were seen on a fallen log. 

Baccharis in front of bridge
Immediately after walking out of the forest, Hugh gathered everyone on the foot bridge into the Flower Garden to point out the Groundsel Tree (Baccharis halimifolia), a large flowering shrub growing up from the ground below the bridge.  This is a coastal plain shrub, which seems to migrating farther north from the coastal area where it is normally seen.   



Sycamore Tussock Moth caterpillar
Before leaving the bridge, we saw the Fall Webworm caterpillar (Hyphantria cunea) and a Sycamore Tussock Moth caterpillar (Halysidota harrisii).

After making our way into the Flower Garden the solitary bee “condominium” was pointed out.  Hollowed out sections of round limbs are stacked here and provide a place for the bees to lay their eggs.

After arriving back at the Visitor Center, we adjorned to Donderos for refreshment and conversation, all glad that the rain had been so nice to miss us this fine morning.



Summary of Species Seen on this Ramble:

Flora

Oak Leafed Hydrangea (Hydrangea quercifolia)
Sourwood (Oxydendrum arboreum)
Short Leaf Pine (Pinus echinata)
Sparkleberry tree (Vaccinium arboretum)
Oyster Mushrooms (Pleurotus ostreatus)
Crane Fly Orchid (foliage) (Tipularia discolor)
High Bush Blueberry (Vaccinium corymbosum)
Black Cherry tree (Prunus serotina)
Water Oak (Quercus nigra)
Climbing Hydrangea (Decumaria barbara)
Red Oak tree (Quercus rubra)
Lance Leafed Smilax AKA Lance Leafed Greenbrier (Smilax smallii)
Hop Hornbeam tree (Ostrya virginiana)
Wood Oats (Chasmanthium sessiliflorum)
Southern Grape Fern (Botrychium biternatum)
Crossvine (Bignonia capreolata)
Sycamore tree (Platanus occidentalis)
Musclewood (Carpinus caroliniana)
Sweet Shrub (Calycanthus floridus)
Piedmont Azalea (Rhododendron canescens)
Chalk Maple (Acer leucoderme)
American Beech (Fagus grandifolia)
Beech Drops (Epifagus Americana)
River Cane (Arundinaria gigantean)
Pipsissewa or Spotted Wintergreen (Chimaphila umbellate)
Combed Toothed mushrooms (Hericium coralloides and Hericium ramosum)
Broad Beech Fern (Phegopteris hexagonoptera)
Wild Ginger (Asarum arifolia)
Groundsel Tree (Baccharis halimifolia)

Fauna
Downy Woodpecker (Picoides pubescens) (visual evidence)
Fall Webworm caterpillar (Hyphantria cunea)
Sycamore Tussock Moth caterpillar (Halysidota harrisii)

3 comments:

  1. We now think that the wood chips on the trail were the result of Downy Woodpecker activity, not Pileated Woodpecker. The change has been made.

    ReplyDelete
  2. "Hugh on left; River Cane on right"!! Big chuckles! Good one, Dale!

    ReplyDelete
  3. Especially enjoyed learning about geology and hydrology this week. Great report!

    ReplyDelete

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