The Secrets of Cloning

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Words and photos courtesy of Andrew Eberly

 

Fall is our busiest time for removing Autumn Olive (Elaeagnus umbellata) and other woody invasives. When I scan the fields for plants to cut, Autumn Olive tends to stand out, but with the diversity of different forms and textures in some areas, even that species can blend into the background and go undetected. One eventually develops a search image for whatever the target species is. I tend to focus on the silvery and persistent foliage of Autumn Olive, or the barred pattern created by the compound leaves of Black Locust (Robinia pseudoacacia). When a single species or set of species comes into focus over the “background noise” of different forms, interesting patterns emerge.

An island of Swamp Rose (Rosa palustris) growing in a wet meadow in Fauquier County. Members of the rose family are often prolific cloners. It is likely that much of this island is just one genetic individual expanding outward each growing season. This area was burned in the winter of 2022. Islands of thorny shrubs like this act as a refuge and a food source for many animals. When planning restorations, it is worth thinking about how to lay out the landscape to accommodate for this growth form.

I often notice that many of the more prominent species seem to occur in clumps, almost like islands where one species is particularly dominant. The islands are numerous in some areas while absent from others. Occasionally, they even seem to have a ring-like shape. At Clifton, Blackberries (Rubus sp.) and Coralberry (Symphoricarpos orbiculatus) dominate patches of ground throughout the grasslands, Black Locust occurs as a few large islands of dense, thorny saplings, Sassafras (Sassafras albidum) seems to grow in mounds of evenly aged stems, even the Lowbush Blueberry (Vaccinium pallidum) of the forest floor forms islands that hold on to windblown leaves in the winter, adding to their bulk.

This is an interesting and familiar pattern. I am reminded of many other grassland ecosystems I have worked in: Wild Plums (Prunus sp.) and Sumacs (Rhus sp.) in the Flint Hills of Kansas, mounds of Mesquite (Prosopis glandulosa) and Shin Oak (Quercus havardii) on the Rolling Plains of Oklahoma, “mottes” of Live Oak (Quercus fusiformis) on the Edward’s Plateau of Texas, thickets of Turkey Oak (Quercus laevis) in a Longleaf Pine (Pinus palustris) savanna in Florida, rings of grasses like Little Bluestem (Schizachyrium scoparium) and Blue Grama (Bouteloua gracilis) on dry prairies, walls of Alders (Alnus sp.) and shrubby Dogwoods (Cornus sp.) crowding stream banks in New England.

It seems to be a theme in ecosystems of many types, and I often wonder, are these really congregations of different individuals? Could the islands be just a single organism with lots of different stems emerging from one root system?

A large patch of Narrowleaf Mountain-Mint (Pycnanthemum tenuifolium) in Fauquier County. Like many mints this species is a master of spreading through rhizomes. This is also a prolific seed producer, it seems likely that a patch like this is expanding by both sexual and asexual reproduction.

Cloning in one form or another is a very common way for plants to propagate themselves. Many people may have heard of Pando, the Quaking Aspen (Populus tremuloides) in Utah that occupies 106 acres of land and has 40,000 above ground stems (trees) to its name. This is all a single genetic individual, connected by its roots to form the largest organism on the planet. King Clone is another famous clone, a Creosote Bush (Larrea tridentata) in the Mojave Desert that has been creeping underground and sending up new aboveground shoots for nearly 12,000 years. We have many local examples, indeed, most of our perennial grasses and forbs and many of our trees can produce new plants from some portion of their root system or underground stems designed specifically for cloning.

Several new shoots arise from a rhizome of Deer-Tongue (Dichanthelium clandestinum). This species forms clonal colonies in wet meadows. The rhizome has numerous roots growing form it and the purple area at the top is a bud where the cells that will become stems and leaves of a new above ground culm are waiting for warmer weather. If you remove the soil from a shovelful of turf from any given field you will notice that the top couple inches is full of rhizomes, all capable of sending up new shoots when conditions are right.

How do they do it? In many cases plants grow stems underground in addition to their aboveground stems. Underground stems are called rhizomes. Stolons are similar structures that hug the ground just above the surface. Rhizomes and stolons have buds at regular intervals from which new roots and shoots can emerge. Proper roots can also develop buds that become new aboveground shoots. Sometimes these underground buds take the form of bulbs like in daffodils (Narcissus sp.) or they emerge from thickened stolons like in potatoes (Solanum tuberosum). Aboveground stems that are members of a clone are called ramets.

In trees, cloning is especially prevalent in species that grow in disturbed areas like Black Locust, Sassafras, and Sumacs. In places where I have cut younger, more vigorous Tulip Poplars and Oaks, a flush of new buds seems to appear out of nowhere right around the edges of the stump. It is common to see Goldenrods (Solidago sp.), Mountain Mints, Ironweeds (Vernonia sp.), and many other herbaceous perennials growing in clusters. Colonies of Winged Sumac (Rhus copallinum) may expand across our shrublands at a rate of several feet per year while colonies of Indiangrass (Sorghastrum nutans) expand slowly, preferring to cluster their short rhizomes in tight bundles.

The ability to reproduce and spread underground has many advantages for plants that live longer than one or two growing seasons. When we burn or mow our fields in the early spring, we usually see a period of rapid growth afterwards. Most of this growth is generated by plants that may already be years or decades old, but were underground, where stored energy and protection from flames and freezing weather gives them a huge advantage over new seedlings.

Underground growth also allows individuals to search for patches of resources like water and fertile soil, that may not exist exactly where the seeds originally fell. Old ramets on less suitable sites will die off, while growth becomes focused in new areas with better growing conditions, allowing the entire clone to shift across the landscape.

A particularly hot fire killed many of the mature trees here on Back Creek Mountain in Bath County. The Sassafras (Sassafras albidum) in the understory is a highly colonial species, capable of expanding quickly from existing rhizomes to form a dense shrub layer. Many of the Scarlet Oaks (Quercus coccinea) are also sprouting from the root collar adding to the diversity of this temporary shrubland.

If cloning is so efficient, why produce seeds at all? The evolution of flowers and seeds is arguably one of the greatest achievements of life on earth. I don’t wish to diminish the importance of producing seeds. Combining the genomes of two different individuals creates genetic diversity, spreads beneficial mutations and allows organisms to adapt to a changing world. Coating your offspring in a protective shell and then sending them off to the far reaches is a great way to colonize new lands and reduce competition. Once seedlings have established though, it makes sense that you would want to be able to keep sending up new versions of yourself in case one gets burned, frozen, eaten, or chopped down.

At Clifton we have a few American Plums (Prunus americana) that were planted in the South Pasture in conjunction with the larger riparian tree planting effort along a small tributary. Plums and many other members of the genus Prunus love to grow in the form of clonal islands, thickets of densely crowded stems that offer Quail and other grassland birds much needed shelter. We usually try to mow right up to the base of our tree plantings, but I have slowly been trying to give the plums and other plants that love growing this way a little space to develop new shoots or “suckers”. Even if the existing main trunk is girdled and killed, once the root system has developed for a few years, new ramets should happily sprout nearby.

I think it is important to consider this tendency of many species to spread by cloning in our management decisions. How does one accommodate for this pattern of growth when planning restorations or managing land? It seems many people tend to view patches of blackberries or single goldenrod species or any “monoculture” as a hindrance to diversity. This is not always the case; diversity happens on many spatial (and time) scales. For example, many clonal patches take on a ring-like pattern with age. As roots and rhizomes creep outward from the original point of establishment, they utilize available resources and with their combined energy, they can crowd out other plants. Over time though, ramets in the middle of the clone begin to die off as resources are used up and the plant basically out-competes itself. The middle of the clone then becomes bare ground where seeds of new species, with different resource requirements can thrive. Maybe this can be seen as a slow-motion disturbance event, creating new niches in the ecosystem while the clone anchors the soil and provides cover to pollinators and seed dispersers.

Maple-Leaf Viburnum (Viburnum acerifolium) occurs as clonal islands in the forest understory.

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Spooky Native Plants (and Fungi)

It’s almost Halloween, so here are ten native plants (and fungi) with spooky names, stories, or associations to get you in the holiday spirit!

 

Bleeding Tooth mushroom (Hydnellum peckii)

Also called: strawberries and cream, Devil’s tooth, red-juice tooth fungus.

It isn’t clear how or why these young mushrooms “bleed” but it’s thought that if the fungus has to grow quickly then it has to expel extra water, which results in the “blood.” They can be found in the Appalachian mountains in our area, though they are widespread across the country and more common in the Pacific Northwest.

Eryne Croquet photo

Doll’s Eyes (Actaea pachypoda) 

Also known as White Baneberry. This herbaceous perennial is toxic to humans but its pollen is valuable for short-tongued bees and birds love the berries!

Miranda Kohout photo

Ghost Pipe (Monotropa uniflora)

Ghost Pipe is a wildflower disguised as a mushroom. Its phantasmal appearance is due to its lack of chlorophyll. Instead of using photosynthesis, Ghost Pipe (and other saprophytes) tap into the root systems of nearby trees via mycorrhizal fungi to obtain nutrients

Naomi Cappuccino photo

Dodder (genus Cuscuta)

Also called: Strangleweed, Witch’s Hair, Devil’s Guts

There are more than 200 species of dodder found across the world. These parasitic vines don’t have roots or leaves once they mature, so seedlings have to rush to find a host plant. They tap into a host’s vascular system for all their needs. Some species are host specialists, but others can cross a wide range of hosts, making them difficult to control.

Marina Giann photo

Bloodroot (Sanguinaria canadensis)

Bloodroot is one of our favorite spring ephemerals. It’s named for the red sap that comes from all parts of the plant (but especially the roots), which has historically been used as a dye as well as insect repellent. Bloodroot also depends on an interesting partnership for seed dispersal: the seeds have an elaiosome (a fleshy structure attached to the seed) that are attractive to ants. Ants carry the seeds to their nest, eat the elaiosome, then dispose of the seeds!

Eleanor Harris photo

Common Witch-Hazel (Hamamelis virginiana)

Also known as American witch-hazel, this native shrub is best known for its unique flowers, which are present through the fall and sometimes into winter! It has had a wide range of  medicinal uses throughout history and can still be found on the ingredient list for cosmetic products. The common name might come from the tradition of using witch-hazel branches as divining rods when looking for underground water sources.

Anthony A Simmons photo

Dead Man’s Fingers (Xylaria polymorpha)

Dead man’s fingers is a saprobic fungus and is usually found on or near the stumps of dead trees, which they use for nutrients. The name comes from the appearance of the mature “fingers” but this mushroom actually starts out as a light blue and fades to a shriveled dark brown by the end of its above-ground lifespan.

Phillip Neal photo

 Purple Pitcher Plant (Sarracenia purpurea)

Did you know that Virginia has native carnivorous plants? The purple pitcher plant is one of them! The pitchers fill up with rainwater and attract insects. Once insects enter the pitcher they can’t get out and they’re slowly broken down by the plant’s digestive enzymes. Despite that, purple pitcher plants are also host plants for a species of mosquito larvae (Wyeomyia smithii) and one species of midge (Metriocnemus knabi).

wewantashrubbery photo

Bleeding Heart (Dicentra eximia)

Also called: Fringed Bleedinghearts, Wild Bleedingheart

The common name for this native perennial comes from the heart-shaped flower and the dangling inner petals that suggest a drop of blood. It attracts hummingbirds and bees, including native long-tongued bees! Despite its delicate appearance, bleeding heart is fairly hardy and can bloom from the first warmth of spring to the first frosts of fall.

Zygy photo

 Devil’s Walking Stick (Aralia spinosa)

Also called: Hercules Club, Prickly Elder, Prickly Ash

This perennial tree is full of intrigue. It’s armed with prickles when it’s young enough to be at grazing height for herbivores, but some scientists theorize that since deer don’t seem to show much interest in devil’s walking stick anyways, that the prickles were evolved to protect the plant against larger herbivores like bison or elk!

mefisher photo

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Autumnal Animal Quiz

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Young Scientists Research Experience Results 2023

Our Young Scientists Research Experience is one of our favorite programs of the year!
Middle and high school students spend a week with us doing their own independent research projects. They come up with a research question, collect data to answer their questions, and share their findings during a presentation to friends and family.

We’re incredibly proud of the work these students did, and we’re excited to share their results with you!

If you’d like to sign up for next year’s Young Scientist Research Experience, you can subscribe to our email newsletter to be notified when registration opens.

Here’s a quick summary of all their hard work:
Lane found that spittlebug larvae prefer to inhabit goldenrod, blackberry, and crownbeard.
Logan found that Field Sparrows are more abundant in the fields we burn than in the fields we mow.
Grant found that bigger Redbuds have more pods.
Elyssa found that more aromatic Spicebush trees actually have more insects on them.
Liam and Loreli worked together to find that the habitat preferences of dragonflies and damselflies are almost opposite those of salamander larvae.
Sarah found that insects prefer to eat lighter-colored leaves and that insect damage doesn’t appear to affect leaf color.
We want to offer special thanks to Maggie Grady! Maggie was a student in this program for the last two years. She returned this summer as a research intern but also kindly agreed to help this week as a mentor. The students appreciated having a previous participant around for guidance and we loved having Maggie’s help for the week.
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Rappahannock News: Keeping Up With The Kestrels

The Clifton Institute was featured in this piece by Bob Hurley for Rappahannock News. Check it out!

 

https://www.rappnews.com/foothills_forum/keeping-up-with-kestrels/article_1a34fedc-1c0c-11ed-b803-ebca16997cf3.html

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Middleburg Life feature “Prescribed Burns: Restoring The Wonder of Native Grasslands”

Clifton was featured in the April edition of Middleburg Life! Check out the article below (starts on page 30)

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Virginia Society of Ornithology – Kestrel Tracking

The Clifton Institute’s own Caylen Wolfer was recently published in the VOS newsletter! Click on the link to read the full article:

 

VSO Newsletter Spring 2023 Vol 69 No 2-pages-1-3

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March/April 2023 Virginia Wildlife Magazine

The Clifton Institute was featured in the March/April 2023 issue of Virginia Wildlife Magazine! Click the link below to read the article.

March_April_2023Clifton article

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Clifton iNaturalist Challenge

 

Link to the Facebook group: https://www.facebook.com/groups/713710063547160/

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The Puzzling Piedmont: What Is It And Why Does It Matter?

Most of us living in Northern Virginia naturally break down our region into sections based on geographic, ecological and cultural similarities. The Blue Ridge Mountains form an undulating wall on our western horizon, clearly visible for many miles as a rugged line of forested mountains. The coastal plain encompasses the lowlands surrounding the Chesapeake on eastward, across the Delmarva Peninsula to the Atlantic, and everything in between we call the Piedmont.

From a strictly geographic point of view, everything below the higher peaks of the Blue Ridge all the way to the coastal plain could be considered the Piedmont, which is defined as a gentle slope leading to the foot of a mountain range. But the Piedmont of Northern Virginia is a diverse landscape that can be a little hard to pin down under one umbrella.

The Piedmont is important. A line of big cities marks its eastern edge. Why? This is where ancient crystalline bedrock first emerges from under the young, low-lying sediments of the coastal plain. Wide, tidal waters easily navigable by cargo ships encounter constricted, fast-flowing streams winding between the rocky hills. Mills requiring high gradient waters for power could load their products right onto big ships and send them across the world.

From an ecological point of view, the piedmont is a land of relatively high biodiversity. A jumble of different bedrock types, spread across a landscape of rolling hills and meandering valleys leads to diverse soils. The Piedmont’s position just below and east of the mountains makes for a milder climate with somewhat higher rainfall than areas just to the west of the Blue Ridge.

When trying to define the Piedmont geologically, things get much murkier. In fact, one could easily make the argument that everything west of a line from Culpeper to Warrenton to Leesburg is actually part of the Blue Ridge Mountains. How is that?

The “Piedmont” in these parts is actually divided into three very distinct regions geologically. To understand that better, let’s look at things in a cross section. Since the whole region is oriented from southwest to northeast, we will start in the southeast and head northwest.

As you travel 17 north from Fredericksburg, you transition from the young, undeformed sediments of the coastal plain to massively deformed crystalline rocks just west of I-95. This is a land of choppy hills, and narrow valleys. The elevation generally runs from 200’ to 400’ above sea level. The rocks under these hills are from the early Paleozoic era, when there was little life on land and the dinosaurs were still 300,000,000 years in the future.

The current hills are the eroded nubs of huge mountains from that time. Many of the rocks came from far away and were smashed onto the edge of the continent as the seafloor was subducted underneath, like how a fallen log will collect rafts of foam from the surface of a river as the water moves underneath. In Northern Virginia, this band of low, rolling hills is part of the Inner Piedmont Province. There is an Outer Piedmont farther south and east in Virginia, but it disappears under the sediments of the Chesapeake to the north.

The rolling hills of the Outer Piedmont with the Blue Ridge Mountains beyond. Between lie the lowlands of the Culpeper Basin. To me this is the most characteristic landscape of the Piedmont.

Just past the community of Morrisville, the landscape changes abruptly. The mostly wooded hills are gone and a flatter landscape of broad agricultural fields opens up. This is the Culpeper Basin. A relatively new addition to the geologic landscape of Virginia. By new, I mean there were dinosaurs walking around, and big trees, but no Atlantic Ocean yet, when this basin came into existence.

The basin is the result of a stretching force on the earth’s crust, opposite the force that pushed the rocks of the Outer Piedmont onto the eastern edge of the continent. The Piedmont rocks started to break free and slide away from the Blue Ridge Mountains during the Triassic period some 230,000,000 years ago. The gap in between was filled with sediments to form a flat basin where lava occasionally flowed across the land. The area would have initially looked like a portion of today’s Great Basin in Nevada and Utah. No major tectonic events have occurred since then and the landscape you see today is basically the work of 200,000,000 years of weathering and erosion sculpting this once dramatic rift basin.

Death Valley is an extensional rift basin in Southern California. The topography is likely similar to what the Culpeper Basin looked like in the Triassic and Jurassic periods with the Blue Ridge on one side and the Inner Piedmont on the other.

Just before you reach Warrenton, the landscape changes again. Hills once again dominate the scene. These hills are somewhat broader and taller than those of the Inner Piedmont. They are the remains of lava flows that occurred more than 530,000,000 years ago. The lava was metamorphosed into the greenstone of the Catoctin Formation. This rock is very resistant to erosion and stands high in ranges like Pignut Mountain, where The Clifton Institute is located, and the Watery Mountains just to the west. If you were to stand on the summit of these hills and look northwest, Catoctin Greenstone would also form the higher ridges on the western horizon. In fact, it used to cover everything in between but has been removed by weathering like a giant ice cream scoop, to reveal even older rocks underneath.

Standing on the Catoctin Greenstone of Wildcat Mountain looking west. Catoctin Greenstone also sits atop the high ridges of Mt. Marshal on the horizon. The whole scene is part of the Blue Ridge Anticlinorium.

The rocks under these mountains originated along the eastern edge of North America before the Inner and Outer Piedmont terranes came crashing in and long before the rifting of the Culpeper Basin. The whole slab of rock between Warrenton and Luray was shoved westward some 60 miles from its original position when Europe and Africa collided with North America, detaching it from its roots deeper in the crust and forming what is called a thrust sheet. The whole unit is called the Blue Ridge Anticlinorium or just the Blue Ridge Province.

The 3 geologic divisions show up well on satellite imagery. The mostly forested hills of the Inner Piedmont (outlined in purple) are dark green. The lighter swath of farmland and urban development to the west is the Culpeper Basin (outlined in orange), dark areas in the basin are forests covering lava flows where the soil is too rocky for farming. The Blue Ridge Anticlinorium is a mosaic of forested hills and fields bounded on the west by the higher mountains of Shenandoah National Park (outlined in blue.)

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