Leader of Today’s Ramble: Gary Grossman

Authors of Today’s Report: Linda Chafin, Don Hunter

The photos that appear in this report were taken by Don Hunter unless otherwise credited. Photos may be enlarged by clicking them with a mouse or tapping on your screen. Not all of Don’s photos from today’s ramble made it into the Ramble Report, so be sure to check out his Facebook album at this link.

Nature Ramble Rainy Day Policy: We show up at 9:00 a.m., rain or shine. If it’s raining, we will meet and socialize in the conservatory (bring your own coffee); if there is a break in the rain, we’ll go outside and do a little rambling.

Today’s Emphasis: Ecology of Piedmont rivers and streams

Announcements and other interesting things:

Today’s ramble leader is Gary Grossman. After 41 years of research and teaching in animal ecology, with an expertise in riverine and fish ecology, Gary retired as a UGA Professor Emeritus in 2022. He is the author of 150+ scientific articles, and has also published many poems, creative nonfiction pieces, and short fiction in more than 50 publications. He has also published two poetry books and a graphic memoir My Life in Fish—One Scientist’s Journey. He is also the creator of a Youtube channel – openecologyresources – “designed to provide open educational video resources for studying ecology, behavior and natural history of animals and plants in North America.” Below are links to two essays and three poems that Gary published in Salvation South, an online publication that is “a refuge for Southern storytellers and a haven for Southern readers, [a] publication for every writer and reader who wants to celebrate the culture of the American South and to see beyond its historical baggage and current divisions.”
Will the Rivers Still Run?
Window Splat: The Great Southern Brood of Cicadas
Three Poems: Paying Attention on the Baldwin Grade, Bomb Cyclone in Athens, and Quartering an Apple

Terry announced that Cumberland Island is once again in the news and in need of advocates. Wild Cumberland, an organization that is dedicated to protecting the wilderness, native species, and the ecology of Cumberland Island by educating the public, is seeking to block proposed land exchanges on the island and invites its supporters to comment on these plans.

Very interesting article! How Scientists Started to Decode Birdsong: Language is said to make us human. What if birds talk, too? An article in the New Yorker by Rivka Galchen. If you don’t have a subscription, you should be able to see a few articles per month for free.

Let’s remember to keep our eyes open next summer for Maple Leafcutter Moth Holes (scroll down a bit). Naturally Curious, by Mary Holland

Today’s Route: We left the Children’s Garden, heading down through the Lower Shade Garden, to the entrance road and the ADA path to the Middle Oconee River. From there, we walked the Orange Trail downriver to the beaver pond wetland. Crossing over the boardwalk, we reconnected to the Orange Trail and followed it along Humphrey’s Spring Branch and back up to the upper parking lot.

Don’s Pre-Ramble Observations:

Ramble Observations:
On our way to the river, we noticed changes in the vegetation in the Shade Garden and right-of-way that confirm what today’s cool morning temperatures were telling us: it is finally, blessedly, Fall in Athens.

The overwintering leaves of Cranefly Orchid have recently emerged from their underground corms. Cranefly’s new leaves are usually green on the upper surface and bright purple on the lower surface. Occasionally the upper surface will be a dark brownish-purple, as seen in the photo, left. Sometimes the upper surface is green with raised, purple dots (right). Whatever the pattern and location, the purple pigment  – one of several different types of anthocyanin – serves as a sunscreen, protecting the leaves from excess sunlight now until late spring when the leaves will wither and the plants prepare to flower in late spring.

Coralbead is named for its juicy berries that are translucent and seem to glow in the sunlight. It’s a high-climbing or sprawling vine, reaching 12 or more feet in length. Coralbead is sometimes called Carolina Moonseed, referring to the seed (right) that is etched with a crescent moon.

Common Wingstem (left) and Southern Crownbeard (center) are both in the wingstem genus Verbesina and both are thriving in the cane patch. Common Wingstem has alternate leaves, Crownbeard has opposite. A few shoots of River Cane (right) have sprouted from the extensive network of underground rhizomes that underlies the cane path.

As we approached the river, Gary stopped to read “American Sycamore,” a poem he published in the Trouvaille Review in 2022.

American Sycamore

It is a ghostly obelisk,
breathless among the paused
leafless gray soldiers of the forest.
Post and water oaks, shagbark
and mockernut hickories, red and
chalkbark maples, and silverbells.
So many trees hold up the cobalt
southern sky.
White on white echoes through
the Georgia woods in January
and the visual music pulls my eyes
back to the solitary sycamore, trunk
shedding a few last puzzle pieces
of elderly taupe bark.
Forty-nine years ago I met the
companion who now walks beside
me on the trail—today we are
the wrinkled, white-barked, trees
of the town.

Water level in the Middle Oconee River is extremely low. October is typically the driest month of the year in Athens and this year it follows two months of below average rainfall except for the rain brought by Hurricane Helene.

Gary introduced today’s topic by talking about the current condition of the Middle Oconee River. Piedmont rivers, before cotton farming’s reckless practices took their toll, typically ran clear, with bedrock bottoms. Most Piedmont streams, such as the Middle Oconee, have enough sediment accumulation that it would take, with no further additional sedimentation, more than 500 years for it to be flushed further downstream. In his 1791 Travels, documenting his explorations in the south, William Bartram wrote that he could see dinner plates lying on the Oconee River bottom, 30 feet below the surface. It’s estimated that loss of top soil in the Piedmont averaged 7 inches with up to 12 inches lost in some counties. The result? Sediment accumulations in some Piedmont rivers is more than 15 feet deep and has completely buried some riverside buildings such as grist mills. Anyone interested in learning more about historic soil erosion in the south can read these two great resources:
Stanley W. Trimble, Man-Induced Soil Erosion on the Southern Piedmont, 1700-1790
Paul Sutter, Let Us Now Praise Famous Gullies

Despite this history, Gary described the fish fauna in the Oconee River as fairly diverse. Overall, riverine faunal diversity in the southeast U.S., including fish, mussels, and amphibians, is the greatest in North America, excluding Mexico, and the diversity of freshwater mussels is the highest in the entire world. Regarding diversity in the Middle Oconee River, Gary said the stretch of the river here at the Garden could easily have 25 or more species of fish. Most of the species are small fishes, such as minnows, chubs, and darters. Before damming, most rivers had at least one species of larger fish, such as Largemouth Bass. Many of the rivers in the southeast U.S. once had riverine bass species that were endemic to those streams but fisherman and fisheries programs have moved some of these species to other locations. The Spotted Bass, endemic to Alabama, has become one of the most common bass species in the southeastern river systems. The introduction of species to areas outside of their endemic range has resulted in many hybrids.

Riverine fishes fall into two major categories: (1) fish in the water column – from the surface down to but not including the substrate – and (2) fish that live and subsist on a variety of plant and animal material on or in the substrate. Darters, for example, feed only on the bottom and have a diet that is mostly aquatic insects. There are two sources of energy for the animals that live in rivers: allochthonous (material that comes from outside the river, such as leaf litter and other woody debris) and autochthonous (material that originates in the river itself, such as biofilm and aquatic plants). The Middle Oconee River is largely allochthonous; much of the river bottom is covered with leaves and woody debris. One consequence of the relatively smooth and level sediment layer in Piedmont river bottoms is that leaves and other organic debris are easily swept downstream even during normal flows; rocky bottoms, on the other hand, offer nooks and crevices where leaves and branches are trapped. The sediment itself may have mineral nutrients but they are not available to foraging fauna.

As we moved along the Orange Trail beside the river, we paused to discuss the characteristic landforms of a many southeastern floodplains.

Standing on the levee between river and the floodplain, we could easily view the slough on one side and the river on the other. Less than ten years ago, the slough was an impenetrable thicket of Chinese Privet that transpired much of the standing water. Once the privet was removed (thank you, Thomas Peters!), an astonishing diversity of plant species showed up. The sloughs are also prime breeding ground for a variety of amphibians. A wide variety of frog species, perhaps up to ten species, can be found in these areas at one time or another, including Spring Peepers, Southern Cricket Frog, Southern Leopard Frog, Upland Chorus Frog, Cope’s Gray Tree Frog, Green Frog, Bird-voiced Tree Frog, and Narrow-mouthed Toad.

A springtime view of the slough at the Garden with Butterweed in full glory

Many Piedmont rivers are lined with sandy berms called levees. These form when the river repeatedly overflows its banks and soil carried in the floodwater is deposited on the floodplain. The heaviest and largest soil particles – sand – fall out first, forming sandy levees along the river’s bank. As the floodwaters continue to move across the land, finer soil particles – clay and silt – settle out, forming deep layers of fine-textured soil that can hold water for long periods. Semi-permanently flooded areas called sloughs or back swamps form in the lowest areas of the floodplain. These are a distinctive floodplain feature here at the Garden that usually remain flooded throughout the winter and spring. Today there was no standing water. An in-depth look at southern floodplains is in Charlie Wharton’s The ecology of bottomland hardwood swamps of the southeast. Dr. Wharton’s survey of natural communities at the Botanical Garden, including the floodplain, is available here.

Some facts about the Oconee River watershed:
– The river’s name derives from the Oconee people who lived in present day Baldwin County (county seat Milledgeville) at a village known as Oconee Old Town. Source.

– The North Oconee and the Middle Oconee rivers flow about 60 miles each before coming together about a mile south of the Botanical Garden on the edge of UGA’s Whitehall Forest. The headwaters of the North Oconee are located just south of Lula, and the headwaters of the Middle Oconee arise slightly northeast of Braselton. These two rivers, plus the Apalachee River, form the Upper Oconee Watershed which drains all or part of 18 Georgia Piedmont counties. Source. Source.

–Athens/Clarke County is the largest municipal user of surface water in the basin, with two surface water withdrawal permits that total an average of 28 million gallons per day. Source.

–The Oconee River and its tributaries drain about 5,330 square miles of land before joining with the Ocmulgee River to form the mighty Altamaha near Lumber City. Source.

The sunny, open marsh at the confluence of the river and the small creek once called Humphrey’s Spring Branch was originally created by beaver. In the 1990s, the pond was permanently dammed and converted to a pollution filtration pond with the goal of absorbing waste products from UGA’s nearby hog research facility. The hog facility has since been re-located to an outlying county but the low dam is still in place. Neither beaver or beaver-chewed trees have been seen in many years. The marsh is dominated by Rice Cutgrass and sizeable patches of Duck Potato. Interestingly, there is only one small patch of Cattails on the western edge of the marsh. Cattail has the reputation of spreading aggressively and outcompeting all other aquatic plants; perhaps the dense growth of Cutgrass has kept it in check. Other plants in and around the marsh, below, include Water Hemlock (left, in August), Arrow Arum (center, in July), and Winter Grape Fern (coated with mud today, right).

While along the banks of the stream, Gary talked about the nests built by a small fish called Bluehead Chub (below) that inhabit this stream. Male chubs pick up small stones from the stream bottom in their mouths and drop them at a nest location, creating a domed underwater structure. Nests may be up to 3 feet long and contain thousands of stones. Females are drawn to the nest sites and release their eggs which fall between the stones where they are protected from predation. The nest-builders then release their milt which fertilizes the eggs.

SUMMARY OF OBSERVED AND DISCUSSED SPECIES

Daddy Longlegs Order Opiliones
Rattlesnake Master Eryngium yuccifolium
Joro Spider (web construction) Trichonephila clavata
Cranefly Orchid Tipularia discolor
Blue Mistflower Conoclinium coelestinum
Carolina Coralbead Cocculus carolinus
Red-bellied Woodpecker Melanerpes carolinus
Spotted Cucumber Beetle Diabrotica undecimpunctata
Tall Goldenrod Solidago altissima
River Cane Arundinaria gigantea
Southern Crownbeard Verbesina occidentalis
Spotted Sandpiper Actitis macularius
Largemouth Bass Micropterus nigricans
Alabama Bass Micropterus henshalli
Eastern Gray Squirrel Sciurus carolinensis
Chinese Privet Ligustrum sinensis
Bullfrog Rana [Lithobates] catesbeiana
Spring Peeper Pseudacris crucifer
Southern Cricket Frog Acris gryllus
Southern Leopard Frog Rana [Lithobates] sphenocephala
Upland Chorus Frog Pseudacris feriarum
Cope’s Gray Tree Frog Hyla chrysoscelis
Narrowmouth Toad Gastrophryne carolinensis
Green Frog Lithobates clamitans
Bird-voiced Tree Frog Hyla avivoca
Butterweed Packera glabella
Winged Elm Ulmus alata
Beaver Castor canadensis
Rice Cutgrass Leersia oryzoides
Duck Potato Sagittaria latifolia
Cattail Typha latifolia
Water Hemlock Cicuta maculata
Arrow Arum Peltandra virginica
Southern Grape Fern Sceptridium [Botrychium] biternatum
Furry Oak Leaf Gall Wasp Callirhytis furva
Water Oak Quercus nigra
Bluehead Chub Nocomis leptocephalus