The Noble Sporophyte

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Moss sporophytes emerging from a clump of moss. By Bob Blaylock. Image licensed under creative commons by Wikipedia.

Moss sporophytes are tiny, slender structures that pop out of moss in droves. Their beauty, diversity, fun-factor, and cute little caps continually amaze me. Like a big buzz cut, they tickle my hand as I graze them. If I am lucky, they are ripe and release their spores in a small flurry, sending a miniature cloud of dust eight inches forwards. The spores melt away into the air, quickly invisible to the naked eye. Usually, I brush the clump again and again, and the sporophytes repeat the trick until the caps are emptied of their spore dust. Eventually, some of the spores will germinate to grow new moss plants.

Once the caps pop off the sporophytes, you can tell they are ripe or almost ripe. By Hermann Schachner. Image licensed under creative commons by Wikipedia.

Over the five years that I earned my living teaching outdoor programs, I taught several hundred people about sporophytes. I would have the group help me find a promising patch of moss, and with reverent enthusiasm, I would show my students the petite sporophytes. Then, I would share the three reasons that sporophytes had captured my heart to become one of my favorite things in the forest.

First of all, I didn’t know that they existed until I was in my 20s, and once I knew to look for them, I saw them almost everywhere there was moss. This was an astounding discovery, and one of the most poignant, eye-opening experiences of my college years. I had been oblivious to the ubiquitous and entertaining sporophytes all around me, and it was amazing to have my eyes opened just by learning to look for them.

An example of moss sporophyte diversity and elegance. By Vaelta. Image licensed under creative commons by Wikipedia.

An example of moss sporophyte diversity and elegance. By Vaelta. Image licensed under creative commons by Wikipedia.

Next, I would demonstrate the gorgeous diversity of the sporophytes. The stalks are often iridescent, and many of them exhibit a gradient of hues. For example, some range from gold to deep, metallic purple.The spores are also often brightly colored, sometimes in surprising ways. I have dissected sporophytes that revealed bright orange, white, or dayglow green spores. And the stalks are always fine and flexible, which means that they “boing” in a tactilely-satisfying way.

Finally, I would show the participants, adult or child, how fun sporophytes are by running my hand through the tuft. If I judged the clump well, and was lucky, a cloud of spores would gently whiff from the cluster of stalks. Everyone would take turns helping the spores fly free. Invariably, some excited participants would spend the rest of the program looking for other clusters of ripe moss sporophytes.

A close-up of a sporophyte capsule. By Bernard DuPont from France. Image licensed under creative commons by Wikipedia.

A close-up of a sporophyte capsule. By Bernard DuPont from France. Image licensed under creative commons by Wikipedia.

Moss sporophytes illustrate some of the most important reasons that humans need the natural world. They invoke wonder, are beautiful and fun, boggle minds with their diversity and scale, and inspire curiosity. For those who have never really noticed them, they encourage humility by reminding us how little we see and understand each day, even when it’s right in front of us. Moss sporophytes provide an opportunity for people to interact with nature in a hands-on way, and in doing so, people help the little plants send their spores into the wind. The experience is tactile, guilt-free, and doesn’t require any special equipment.

As the spring rains feed the forests, fields, and yards around you, keep an eye on your local moss patches. The mossy marvel of a ripe sporophyte might be waiting at your feet.

The moss life cycle. The green moss is the gametophyte, which gives rise to sperm and eggs, which combine to grow a sporophyte from the tip of the gametophyte. The spores germinate to grow more gametophytes (the green moss). By Htpaul. Image licensed under creative commons by Wikipedia.

The moss life cycle. The green moss is the gametophyte, which gives rise to sperm and eggs, which combine to grow a sporophyte from the tip of the gametophyte. The spores germinate to grow more gametophytes (the green moss). By Htpaul. Image licensed under creative commons by Wikipedia.

The Colors of Faoilleach

We’re in the middle of faoilleach – the Gaelic season comprising the last three weeks of winter and first three weeks of spring. Before you groan over the absence of green, and wish yourself in the lime lighting of a June forest, take time to notice and celebrate other colors that hint to the great awakenings of spring.

Magenta

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Beneath their pearly coats, the emerging catkins (spikes of single-sex, drooping, petal-less flowers) of the pussy willow glow magenta. Their presence is a cherished ritual of the seasons, Sigurd Olson writes, “In a world seething with mistrust, suspicion and clashing ideologies, pussy willows may be vital to the welfare of man and his serenity”.

Burgundy

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Look for the deep burgundy color in the male catkins of speckled alder as their flowers begin to develop. As the male catkins begin to expand, the color brightens. Eventually the burgundy shifts toward yellow as the pollen develops. Note the smaller scarlet female catkins nubs above (these will transform into the cone-like structures that persist throughout the winter).

Ivory

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Ivory hairs gleam in newly opened shadbush buds. They help insulate the flowers from spring cold snaps. Soon clusters of 5-petaled propeller-like white flowers will emerge. The flowering time is an important seasonal clock – marking when shad swim upstream to spawn (hence the name) and the period when colonists who died over the winter were buried, hence another name—serviceberry.

Auburn

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Look for the bursting auburn flowers of silver maples lining streets and rivers, especially noticeable against a bluebird sky. This fast-growing and short-lived species carries its male and female flowers separately, although sometimes on the same tree.

Silver

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Catkin tips shine silver as they emerge from flower buds of trembling aspen. Male and female catkins are found on separate trees. Despite millions of fluffy seeds produced, strict germinating constraints limit the success of these seeds. Thus aspens rely on root sprouting clones to earn their title of most widely distributed tree in North America.

Crimson

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Spring sun vividly reddens Red Osier Dogwood in early spring. The brilliance of color, generated by anthocyanin pigments in the bark, is determined by light intensity. In shaded areas, its stems and branches still grow, yet in greener tones.

If you’re impatient for the mints and emeralds, limes and jades, you can force the color. Simply place a twig in a jar with water near a window and be comforted by the return of green that will reveal itself outside in time.

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Ellen Gawarkiewicz is a first-year graduate student in the Field Naturalist Program.

Restoring the American Elm

An arborist harvests flower buds from an American elm in Charlotte, Vermont. Photo credit: Gus Goodwin, The Nature Conservancy.

The flower buds from Mrs. Waters’ elm tree are 35,000 feet up in the stratosphere on an express flight to Ohio. The goal is to get them there before they dry up. When they arrive, scientists will lay them on wax paper, collect their pollen as it falls from the stamens, and use it to hand-pollinate the flowers of Ohio elms that are receptive and waiting in the lab. These buds may be the key to restoring the American elm to dominance in the floodplain forests of the Eastern United States, a focal project of The Nature Conservancy (TNC) and floodplain ecologist Christian Marks.

The buds’ progenitor, a four-foot diameter American elm in Charlotte, Vermont, named Henrietta, has beat the odds. Located merely a stone’s throw from four other elms, all of which have succumbed to Dutch elm disease (DED), Henrietta is noticeably larger and healthier. Though she (also a he—American elms bear “perfect” flowers, with both male and female parts) has signs of DED on two branches, the remainder of the tree is healthy enough to produce flowering buds, a luxury that the sick elms around it cannot afford. Normally, trees exposed to DED die within a year of exposure[i]. That this one has not– and that it continues to flower—suggests it may possess some degree of resistance.

After scientists cross-pollinate the Vermont and Ohio elms, they will tend the branches until they set seed. When the seeds mature into small, wafer-like samaras, evolved for wind dispersal, the Ohio scientists will airmail them back to Marks (wind dispersal by mechanized means) who will then grow them to seedlings and plant them in one of TNC’s floodplain forest restoration preserves. But that’s not all. What’s to say those young seedlings won’t succumb to the same fate as their not-so-fortunate relatives?

For Marks to know that Henrietta is a stalwart, he must subject her offspring to a potentially fatal injection of DED when they reach one inch in diameter. Though it will be some time before we find out if Henrietta is truly resistant, the offspring of buds collected from other trees in 2011 and 2012 are approaching the requisite diameter for testing. And while “absolute resistance” is the stuff of science fiction, previous studies conducted through Guelph University in Canada found a heightened level of resistance in 25% of lab-pollinated offspring reared from large, healthy elms[ii]. Marks is hopeful for a similar (or better) result from his Vermont/Ohio crosses, which were selected not only for their size, but also for their proximity to elms that have succumbed to DED.

If Marks and his colleagues succeed in cultivating a DED-resistant American elm, this stately canopy tree may eventually be restored to its position in the highest strata of the floodplain forests in the Eastern United States and Canada. And though we may not be alive to see it regain canopy dominance, we can celebrate that the elm’s capacity for water uptake may reduce the severity of future flooding events, bald eagles may return to nest in its branches, and our children will once again walk to school beneath trees for which many American streets were named.

Perhaps this dream begins with the plump red buds bound – at this moment – for Ohio.

American elm flower buds. Photo credit: Gus Goodwin, TNC.

[i][ii] Christian Marks, personal communication, 9 March 2016.


Hannah Phillips is a first-year graduate student in the Ecological Planning Program. She is grateful to Christian Marks, Gus Goodwin, and The Nature Conservancy-Vermont, for welcoming her on this outing, to Mrs. Waters for offering samples from her tree, and to Chea Waters Evans for cleverly naming the tree Henrietta (after Henrietta Lacks).


Evergreen and Everlasting: The Long March of the Lycophytes

Artist’s rendering of a Carboniferous swamp. From “The World Before the Deluge” by Eduard Riou, 1872. Public domain work of art.

Artist’s rendering of a Carboniferous swamp. From “The World Before the Deluge” by Eduard Riou, 1872. Public domain work of art.

In the murky, humid forests of the Carboniferous Period, organisms grew to remarkable size. Dragonflies as big as Cooper’s hawks ruled the air and three-foot-long scorpions prowled the earth. The swampy water concealed beasts like the dawn tadpole, a predatory amphibian as long as a pickup truck. The canopy showcased elegant tree precursors: spore-bearing lycophytes a hundred feet tall.

Today, dragonflies are rarely any bigger than a clothespin. Tadpoles are tiny and harmless, and scorpions could fit in your palm (not that you’d want them there). This widespread diminution may be related to a dramatic decrease in atmospheric oxygen concentration since the Carboniferous. Even the lycophytes have had to shrink to survive. Yet three hundred million years after their age of supremacy, lycophytes persist in forests from the poles to the tropics. We call them clubmosses. They are usually less than four inches tall.

In early November, clubmosses leap into view on the forest floor, bright green runners in a matrix of brown. These evergreen plants are not actually mosses, but true vascular plants more similar to ferns and horsetails. At first glance they are easily mistaken for conifer seedlings; hence the common names ground pine and ground cedar. Lateral stems called rhizomes carry them across the ground. Periodically they send up vertical shoots, which emerge out of the leaf litter to capture sunlight. Having evolved before the seed, clubmosses disperse by means of spores, which most species carry in tiny kidney-shaped pouches packed together on a club-like appendage called a strobilus.

Ground pine (Lycopodium obscurum) with strobilus.

Ground pine (Lycopodium obscurum) with strobilus.

Wind-borne clubmoss spores are easily dispersed, but they have a long road and two life phases ahead of them. After germination, spores develop into tiny, often subterranean organisms called gametophytes. The gametophyte phase is responsible for the production of sex cells, which join at fertilization to form embryos. The embryos develop into the second life phase: sporophytes, charged with the production of new spores. This is the more familiar life phase we see above ground. Note, however, that not every clubmoss has a club: years may pass before sporophytes are capable of manufacturing new spores. Development from the gametophyte to the mature, strobilus-endowed sporophyte can take between six and fifteen years.

Clubmoss spores ripen in the fall, when a light tap to the strobilus is enough to release them. If you stroll through a miniature forest of lycophytes at this time of year your feet will stir up a cloud of gold. This fine powder has been put to use in a litany of applications: as a wood-filler in violins and guitars, a lubricant on condoms and surgical gloves, a hydrophobic coating for pills, and a homeopathic remedy for intestinal disorders. Crime scene investigators once used the spores to dust for fingerprints. The powder is highly flammable; early flash photography relied on the ignition of clubmoss spores. We have incorporated the spores into fireworks and magic tricks, theatrical productions and military operations. For more routine combustion, we turn back to the clubmoss’s progenitors: the giant lycophytes that ruled the swamps of the Carboniferous are burned today as coal.

Ground cedar (Diphasiastrum digitatum) with branched strobili.

Ground cedar (Diphasiastrum digitatum) with branched strobili.

Vermont’s woods can seem a little dull this time of year. Perhaps it will enliven your walk if you pause to remember that you are in the presence of prehistory. The tiny clubmosses at your feet have thrived on earth for hundreds of millions of years. With every step you are releasing spores that could have sealed a violin or cured a stomachache or solved a crime. Instead, because of you, they’ll go on to form a new generation of this enduring lineage.

Information gathered from Cathy Paris, Bernd Heinrich’s The Trees in My Forest, Mary Holland’s Naturally Curious, Encyclopaedia Britannica (retrieved from http://www.britannica.com/science), and Biology of Plants by Peter H. Raven, Ray F. Evert, and Susan E. Eichhorn.

Julia Runcie is a first-year student in the Ecological Planning program.

Hardy Kiwi: Delicious, Decorative, Destructive

Hardy kiwi vines on forest trees.

Hardy kiwi vines on forest trees.

By Jessie Griffen

While living and working at a yoga retreat center in western Massachusetts for the summer, I learned to meditate during exercise. In early August, with the end of the field season in sight and too much left to do, I jogged trails that I still needed to map. As I ran, my mind noted small observations about the forest: a patch of partridge-berry here, huge hemlocks there. Instead of focusing on these thoughts, I tried to only notice them and let them pass by. But as I turned a corner on a trail through hardwoods, downed branches and trees startled me into active observation.

A mat of green vines with distinctively red petioles blanketed the understory, and wound ominously up trunks. Stunned by the scene, I halted. A group of walkers noticed me staring. They asked jokingly if I was searching for bears. I mentioned the vines, but didn’t want to explain what I had found: hardy kiwi. Continue reading

Field Notes 2015: Human Nature and The End of Nature

Screen Shot 2015-09-07 at 2.31.05 PMNature is in peril. Biodiversity is plummeting. Species are going extinct 100 to 1000 times faster than normal. How many times have you read an introduction beginning that way? It’s depressing because it’s true. The ensuing article or book usually offers plenty of advice on what actions we must take to stem the tide of extinction and climate change and how to convince the uninformed public to care about it. But what about us — conservationists who already care about the deterioration of the natural world as we know it and who struggle with it emotionally? How can we find solace?

The current issue of Field Notes, the annual publication of UVM’s Field Naturalist and Ecological Planning programs, reflects on how we can continue to delight in nature even as we stare these sobering environmental issues in the face.

Read or download the issue »

Beyond the Jeep Road Sits Coyote — Wilderness in 2015

Southwestern desert

Southwestern desert

By Levi Old

On the first day of a 90-day expedition, our team made camp at the end of a jeep road. The afternoon sun, low in the sky, blanketed the desert’s red and orange rocks. Daylight quickly shifted into dusk. The rocks faded into shapes, and dropped shadows on slick rock in the crescent moonlight. The wind-worn surfaces that stood so vibrant in daytime were gone.

After dinner and a meeting about the next day’s plan, we embraced the opportunity to sleep out in the open. I found a flat boulder, climbed into my sleeping bag, and looked up at the night sky. The 10 students wandered around searching for sleeping spots, chatting with nervous anticipation and preparing their new equipment for a night’s rest.

“I bet this never gets old,” said Ben, 20, from Wyoming.

“Seriously,” agreed Lily from New York, “I’ve never seen stars like this before.”

I peeked over the lip of my sleeping bag and noticed the students gazing at the night sky.

The two college students traveled far from their comfortable existences to attend a three-month wilderness leadership course in the heart of the southwestern desert. Along with my colleague, I was their instructor. Around us, there was a more distinguished instructor— wilderness. Continue reading

In Search of New England’s Sequoia

By Sam Talbott

Photo page 2I inherited many things from my dad: blue eyes, an affinity for two-cylinder engines, and a passion for woodworking. A set of long-handled carving tools made the journey north from Massachusetts to Vermont with me. I left behind a stout wood lathe, a former resident of the local vocational high school. Between its dark-green metal housing and the exposed 2×4’s of the garage is a well-kept pile of saw dust and wood chips.

If you were to plunge a soil auger into this pile, you’d see a resemblance to “varves” left behind by freezing and thawing cycles of glacial Lake Vermont. Large wood chips give way to fine sawdust—evidence of increasing from 60 to 400 grit sandpaper. The red layers are not redoximorphic reactions, but rather the presence of redwood, Honduran rosewood, and other species not found in the typical New England northern hardwood forests. Continue reading

Zombie Aspen Leaves

populusleaves-550x410By Bryan Pfeiffer

Rotting and fallen to earth, they might appear dead. But they are not quite dead. They are the undead: zombie aspen leaves.

Find them as you walk the brown autumn paths – yellow leaves with a patch of green tissue radiating from the base of the midrib. Here in Vermont, these are mostly quaking aspen (Populus tremuloides), but I also find the green on big-toothed aspen (P. grandidentata) and, rarely, eastern cottonwood (P. deltoides).

When a friend and I first encountered these some years ago, I collected a few and queried a handful of smart botanists for answers. Many had theories; none had an explanation. It wasn’t until I put a leaf under a dissecting microscope that I found the explanation to be less zombie than something from the film “Alien.” The beast lies within.

populus-caterpillar-moth-550Residing in a tiny pocket of tissue near the base of the green patch is a translucent caterpillar not much more than 2 millimeters in length. It’s feeding in there; I could see the frass (caterpillar poop). With help from Dave Wagner, the renowned entomologist at the University of Connecticut, our critter turns out to be a moth in the family Nepticulidae, probably Ectoedemia argyropeza or most certainly a member of that genus.

“The really cool thing is that the larva secretes an anti-senescent substance that keeps part of the leaf alive – probably a cytokinin,” Dave wrote in an email. Cytokinins are plant hormones that promote cell division. In this case, it seems, the caterpillar keeps part of a leaf alive so that it can keep eating.

This moth is also parthenogenetic; females can produce fertile eggs without help from males, which, as it turns out, are quite rare.

For now, however, the caterpillar will continue to dine in the verdant patch of an otherwise dead leaf. It will pupate for winter. And the tiny adult will emerge to fly in spring. Many species in this genus are black and white with orange scales around the head. But don’t expect to find one. Your best bet for discovering this animal is to watch the trail for patterns in poplar leaves this fall.

And if you’re raking them up, please note that some of those leaves, well, they could be saying, “I’m not dead.”