Monthly Archives: November 2011

Searching for Squirrels, Finding the Night

Written by Rachel Garwin

A week ago, I joined my friend Teage (a Field Naturalist alum) and a group of his UVM students on an “owl prowl,” Teage’s own euphonic term for a night hike.  We gathered at the edge of Centennial Woods, where gauzy tufts of white pines and bare hardwood twigs strained the clear moonlight.  A wall of darkness met our eye-level gaze, while the raspy sounds of drying beech leaves in the understory added to a sense of disquiet.  The primary goal for the evening was to listen for flying squirrels and call them in.  Before we entered the darkness, however, we observed a requisite pre-night-hike ritual.

Since leaving a well-lit environment too soon for the darkened woods might lead to undesirable confrontations with tree trunks and branches, Teage informed us about night vision while our eyes adjusted.  Human eyes require 20-30 minutes to become accustomed to low light conditions.  Coincidentally, it finally gets dark about 30 minutes after the sun first sets.  The students oohed appreciatively at the revealed secret of the universe.

I considered Teage’s implication, reflecting on whether twilight length was consistent enough to provide a uniform selective pressure.  The period between sunset and full dark (termed “Civil Twilight”) varies with latitude and season, as it reflects the time the sun takes to drop 6° below the horizon.  On the same night, civil twilight in Burlington, VT, lasted 9 minutes longer than in Bogota, Colombia, a city near the equator.  Atmospheric conditions and local weather can also affect our perception of available light from the setting sun, which increases variability.  Pole-to-pole variation aside, the length of civil twilight appears consistent enough at low and middle latitudes to suggest the plausibility of the relationship (though it does not prove it).  What mechanisms would select for correctly timed physiological processes?  Perhaps some hairy, fanged predator was involved?

Suddenly, I heard Teage ask, “Rachel, do you have anything to add before we head into the woods?”

Bits and pieces of the night hikes I used to lead rushed to mind.  Out of the torrent, what would be most relevant to this group of students?  Our pupils dilate to accept more light, just like a camera aperture changes size.  Our eyes comprise not only lenses (e.g., the cornea) that focus light, but also a receptor structure (the retina), which translates received light into neural signals our brains can understand.  The retina, in turn, is made of two types of cells: rods and cones.  Rods are far more abundant (about 17 for every cone cell); however, the cones are concentrated in the center of the retina.  Responsible for receiving color and fine resolution, cone cells are better suited for working in high-light environments.  Rod cells cannot understand color, but they register exceptionally more light than cone cells.  The operational ranges of the two cells overlap to some degree; in true twilight, both cells help parse the dim picture before us.

Instead of a long-winded physiology lesson, I settled on a practical and safety-oriented piece of advice.  “If you’re having trouble finding the trail in the dark, try using your peripheral vision.  Your rod cells—the receptor cells that are really good at picking up light—are arranged on the periphery of your retina, so that part of your eye sees better in low light conditions.”  With that, we were off.

As the trail contoured the side of a hill, I followed it with my feet as much as with my eyes.  Hard packed dirt spotted with only a few fallen leaves firmly resisted my feet, whereas my wandering steps sunk into noisy leaf litter.  After a few quiet minutes, we angled from the trail and picked our way down the gentle slope.  Looking out of the bottom of my eyes—as if I wore tiny slivers of half-moon spectacles—proved the best technique for avoiding the tangle of hardy ferns and woody shrubs.  Teage motioned for us to stop; this would be our first attempt to call the flying squirrels.

I listened intently.  Wind gusted through the upper boughs of white pines and red maples.  Still-hanging, papery beech leaves rubbed together, sending bursts of unwarranted excitement running through my mind.  Sirens howled close-by.  One of Teage’s students fired up the iPod, and high-pitched “chip chip chip” alarm calls radiated into the night to serve as bait.  I cupped my hands around my ears to exclude the droning car engines circling the outskirts of the woods.  Still nothing.  Perhaps the squirrels’ huge eyes, dominated by rod cells, picked us out as we muddled through their habitat.

I relaxed my eyes and marveled at the increased input from my peripheral vision.  Intermediate wood ferns stood distinct from the ground; before, they had dissolved into the dimness.  It seemed we had been away from bright light long enough for rhodopsin, a photopigment in the rod cells, to build up.  Rhodopsin and other photopigments in the cone cells help increase light sensitivity within the receptor cells, though at different rates and degrees. Cone cells, which never develop the light sensitivity attained by rod cells, take only 5-7 minutes.  Rod cells, however, may need over 30-45 minutes to achieve full light sensitivity.  In the presence of too much light, these photosensitive compounds break down; enough time in dark conditions is thus needed for photopigments to build up to a functional level.

The flying squirrels proved reticent, so we walked through the underbrush back to the trail.  The undergrads hesitated less between steps, and they seemed to run into fewer obstacles.  After walking a circuit across Centennial Brook and back along the lower slope on the other side, we paused to make their eyes’ night adaption more explicit.  Crouched beneath a closed hemlock canopy, we covered our left eyes and stared at the flame of Teage’s lighter with our right ones.  I smiled, startled by the pervasiveness of the “Pirate Patch” myth.  As lore would have it, pirates did not wear eye patches to cover gaping eye sockets.  Instead, they kept one eye in darkness to allow them to see below and above deck without needing time for rhodopsin to develop.  While no historical evidence supports this story, the folks at MythBusters put their weight behind its plausibility and likely had a role in its propagation.

Teage flicked off the lighter, and we switched our “eye patch” to the light-blinded eye.  Most students commented they could see more precisely with their night-adapted eye than with the light-blinded one.  Removing my hand, I winked back and forth at the hemlock boughs above.  Sure enough, my left eye discerned individual twigs against the dark sky; my right eye saw only fuzzy dimness.  While not proof that Blackbeard covered one eye so he could rush up to a darkened deck from a lamp-lit cabin, our experience supported the possibility.

We emerged from beneath the dense hemlock canopy onto a grassy hillside, where moon-cast shadows danced at our sides.  No longer relying on peripheral vision, the students carelessly walked down the trail towards home.  I smiled.  An hour ago, they had hung together timidly in similar light levels, still uncomfortable with moderate darkness.  Now they practically ran.  While the flying squirrels had remained elusive, the students found something more powerful: the ability to stride confidently through the night.

The Leonids Meteor Shower: A Pre-Turkey Feast for the Eyes

Written by Emily Brodsky

The alarm went off at 3 AM.  I lay on the cabin floor, my breath visible in the cold night air.  The fire, which had been blazing at bedtime, by now had dampened to a few glowing embers.  Imagining the dazzling show that awaited me outside, I resisted the temptation to return to my warm and peaceful slumber.   Instead, I emerged from my puffy cocoon, and tiptoed about the cabin to rouse the adventurous souls who had committed to my pre-dawn wake-up call.  Groggily, we donned our winter coats and hats, and dragged our sleeping bags into the chill of a mid-November night.  We were on a mission to observe one of the universe’s great spectacles: the annual Leonids Meteor Shower.

After stumbling down a dark, wooded path, we planted ourselves in an open field and eagerly fixed our eyes on the sky.  The stars were shrouded by stratus clouds.  We waited.

After half an hour or so, the clouds parted and revealed one of the most awe-inspiring sights I’ve ever witnessed.  For several hours, sparkling streams of light rushed over our heads in all directions.  They varied in color from white to blue to yellow, and I don’t know if I imagined it, but I swore I could hear them zooming through the sky.  The show went on until the meteors were outshined by the light of dawn.  After the final stragglers passed overhead and the darkness began to lift, my friends and I clapped and cheered.  We had witnessed not just a meteor shower, but the great meteor storm of 2001.

Thanksgiving-time brings well-stocked dinner tables, family and friends, and cozy, tryptophan-induced naps.  A less-known fact is that it also brings meteors.  Just before the holiday rolls around each year, one can stumble into the out-of-doors in the dead of night to watch these glittering speed demons as they race across the sky. How do the Leonids put on their marvelous show, and why does it happen with such consistency?

The orbit of the comet Tempel-Tuttle happens to intersect with Earth’s, and when the comet passes by every 33 years it leaves a dense trail of debris.  As the Earth passes through the lingering dust cloud each November, thousands of particles crash into the atmosphere.  These sand grain to pebble sized particles, called meteoroids, travel through space at speeds up to 162,000 miles per hour.  Space is a vacuum, meaning matter is scarce; thus, nothing slows the meteoroids as they speed through the galaxy — that is, until they collide with the matter-laden atmosphere of Earth.

When meteoroids strike, they push up against the gaseous molecules of the atmosphere with incredible force.  The astronomical equivalent of a 10-car pileup occurs, with molecules squishing together in front of each meteoroid, and the resulting pressure generates so much heat that the meteoroids reach boiling point.   The meteoroids continue to move through the atmosphere, vaporizing layer by layer and releasing a tremendous amount of heat.  As the heat releases, the meteoroids and surrounding molecules glow.  From our vantage point 50-75 miles below, these hot, disintegrating particles appear as the streams of light we call meteors, or shooting stars.

The Tempel-Tuttle dust cloud is one of several that Earth passes through consistently.  The predictable display produced by this annual event is called the Leonids because its radiant, or the point from which the meteors appear to radiate, is the constellation Leo.  Other meteor showers include the Geminids in December, the Lyrids in April, and the Perseids in August — their radiants being Gemini, Lyra, and Perseus, respectively.

Although the Leonids have been known to cascade over the sky in numbers up to one-hundred-thousand or more per hour, typical displays are not so prolific.  The last exceptional shows (known as meteor “storms”) were in 2001 and 2002, with meteors-per-hour estimates of up to 3,000.  More commonly, the Leonids shower produces 10-15 meteors per hour.  The numbers depend on a variety of factors, including solar wind and dust cloud density.  Visibility depends on cloud cover and the moon phase.  To see the Leonids in their full splendor, conditions must be just right.

Sadly, the last-quarter moon will be shining near Leo during this year’s November 17-18th peak, resulting in low visibility and a relatively weak show.  Still, I plan to look.  Since that wonderful night in 2001, I have lain in various fields and hiked up mountains to observe the Leonids.  Every year, they seem to be blocked by clouds.  I’ve never been disappointed, however, as the experience of watching celestial events like meteor showers goes beyond the objects themselves; it’s also about the adventure of being outside at an ungodly hour, enduring sleepiness and cold, and sharing an unusual moment with friends.  I encourage you to go out in the wee hours of November 18th; whether you’ll see a shooting star, I cannot guarantee, but I can assure you that the excursion will make you feel alive.

Land Tenure and Perennial Agriculture

by Connor Stedman

It’s harvest time in New England.  Farmer’s markets are filled with apples, winter squash, root vegetables, and the final weeks of greens before the hard killing frosts arrive.  For people who enjoy local food, it’s worth thinking about the needs and challenges of farmers while enjoying the bounty of the season.  There’s a significant generational shift taking place in agriculture right now; as older farmers retire, more and more young farmers are taking their place.  And one of the biggest challenges for young, beginning farmers, is finding and retaining access to land.

Because of the local food movement that’s developed in the U.S. in the past decade, many regions of the country have excellent markets for beginning farmers.  Urban and suburban farmers’ markets, grocery stores that carry local food, and CSA (Community Supported Agriculture) programs all can provide reliable income to beginning farms.  But many of those markets are near major metropolitan regions or are in wealthier semi-rural areas.  In both of these types of regions, land is priced for housing development rather than for agriculture.   So there’s a devil’s-bargain situation for farmers here, where the already-high initial capital and infrastructure requirements for agriculture get much more expensive for farms located close to their ideal markets.

Because of this, young beginning farmers (who usually lack access to significant financial resources) often enter into semiformal or informal arrangements with wealthy landowners in order to run the farm businesses they want to be running.  Many of those arrangements end up being unworkable, leading to those farmers losing land access in just a few years.  Without solid financial and legal agreements, farmers’ ability to stay on their rented or leased farms long-term can be very tenuous.  So educating new farmers should include training in how to enter into those financial and legal agreements, as well as just training in farming practices.

But it’s also helpful to think a little more deeply why stable, long-term land tenure matters.  One might think, annual farmers can easily pick up and move in between growing seasons if they need to.  After all, they replant their crops every year anyway!  But there’s a huge opportunity cost to moving locations – the time, energy and money spent moving could all be spent in other ways if the farmer didn’t need to move.  Beyond that, the real value of long-term tenure is being able to build soil fertility and knowledge of the farm over time, as well as long-term market and customer development.  Most farmers would like to stay in one place for a long time if they could, and many young beginning farmers aren’t able to because of the issues discussed above.

All of that, though, is doubly true for farmers growing perennial cut flowers, fruit and nut trees, or certain medicinal plants like ginseng.  These long-term perennial crops produce for many years without replanting.  This reduces the negative ecological consequences of annual agriculture (such as soil erosion and ongoing heavy pest insect pressure) while also reducing the economic costs of re-tilling and replanting every year.  Furthermore, since perennial crops don’t fully die back at the end of each growing season, they hold and sequester carbon from the atmosphere over time and help to mitigate global climate change.  On the other hand, these crops can take years to develop their full yielding potential.  It can take over a decade to recoup an initial investment in a perennial crop planting, especially for slow-growing crops like nut trees or certain medicinal plants.

This has particular implications for the development of diverse, ecologically sustainable perennial farms, rather than just single-crop monocultures.  Because diverse perennial agriculture systems often aren’t simple – they require significant planning, observation, and adjustment over time.  That, plus the land access and tenure issues, means that there are major disincentives to invest, both for financial backers (like banks) and for the start-up farmers themselves.  So that, in turn, means there continue to be few good working examples of diverse perennial farms!  Then, when one of the few existing examples fails, it adds up in many peoples’ minds to some version of “I guess perennial agriculture just doesn’t work.”  But of course, many startup businesses fail.  And early failures in a “still-learning-how” field are not surprising – but nor do they indicate that the concept or process is unsound.

Because, perennial agriculture is one of the most important strategies available for healing the planet through sequestering carbon, restoring damaged land, and creating resilient local economies.  Figuring out reliable, consistent strategies for the land access and tenure problem would open the doors much wider for experimentation, research, and enterprise development around perennial farming, which would help shift agriculture from extractive to regenerative practices on a larger scale.  In other words, this isn’t just about beginning farmers – land access is a bottleneck, and therefore leverage point, for the larger ecological and economic transition towards sustainability.

 

Will You Need a Warmer Hat This Winter?

by Carly Brown

A few weeks ago I tied my laces, donned my hat, and set off for a long run down Spear Street, from Burlington to Charlotte and back again. Partway through my run I saw it crossing the road without any signs of hurry, proudly displaying its black and rusty fur: the woolly bear (Pyrrharctia isabella). I immediately looked up to check for oncoming traffic, then dodged out into the road, lunged, and swiped the fuzzy caterpillar. Without breaking stride I carefully set it on the roadside it was moseying to. Some feet down the road I repeated my behavior. My mind clicked back to middle school when I learned that a long rusty stripe means a mild winter. Is that true? And what are woolly bears when they are not cute, furry, caterpillars? Never mind what passing cars must think about my woolly bear lunge.

Wolly bear (Pyrrharctia isabella) caterpillar

Wolly bear caterpillar (courtesy IronChris, http://en.wikipedia.org/wiki/File:IC_Pyrrharctia_isabella_caterpillar.JPG)

The woolly bears that we see in the fall will overwinter as caterpillars under plant debris in the cold snow environment. In order to survive the winter chill, the caterpillars produce a substance, called a cryoprotectant, which acts much like antifreeze. When spring begins to show its face, the caterpillars emerge from the leaf litter, begin to eat new plant growth, and then form a pupa to eventually emerge as the Isabella tiger. This moth is a relatively nondescript yellow-brown moth with several darker spots on its wings. Woolly bears have two generations per year. This means that the newly emerged moth lays its eggs, which hatch to complete the cycle through woolly bear and moth in the summer. The eggs that these new moths lay will hatch into the woolly bears that overwinter.

Isabella tiger moth (Pyrrhartia isabella)

The Isabella tiger moth (Pyrrhartia isabella) (courtesy Steve Jurvetson; http://flickr.com/photos/44124348109@N01/501714313)

Do these fuzzy caterpillars tell us something about the winter to come? The legend is that the longer the rusty brown stripe on a woolly bear, the milder the winter. Conversely, a narrow rusty band predicts a harsher winter. There have been a few attempts to correlate the size of the stripe with winter conditions. One of the most well known studies was by biologist Charles Corran in the 1940s. For the first few years of his study, the prediction of the woolly bear was correct, but there was more than enough evidence to disprove the common myth in the years to follow. Some suggest that the length of the rusty stripe may actually tell us something about the harshness of the winter and spring that occurred the year before.

I know deep down that the woolly bear myth is just that—a myth. That doesn’t stop me from doing a few extra lunges to save a woolly bear or two and check out the length of the rusty stripe. Curious about what this winter will bring? I suggest that you join me in the woolly bear lunge.

Curious Chipmunks

by Nancy Olmstead

Crouching chipmunk

A curious chipmunk (photo courtesy of Gilles Gonthier, http://flickr.com/photos/46788399@N00/291562671)

A month ago I was walking in the woods and it seemed like I couldn’t go more than a few feet without disturbing another chipmunk.  The little brown stripe-y streaks were running all over the place, stopping to chirp and chatter at me as I passed.  Don’t worry, buddy, I don’t want your nuts.

We’re having a mast year in the northeast.  The oaks, beeches, and other masting trees are making a bumper crop of seed, which chipmunks eat and store by the cheekful.  This probably explains the superabundance of chipmunks.  The eastern chipmunk, Tamias striatus, can tell when the fall harvest is going to be good.  So they go all out making babies over the summer.  Some of the animals I’m seeing now are probably this year’s offspring, rushing to find, secure, and fill their burrows before settling down for their long winter rest.

Eastern chipmunk with full cheek pouches

Eastern Chipmunk with cheeks filled of food supply, Cap Tourmente National Wildlife Area, Quebec, Canada (image courtesy of Cephas, http://commons.wikimedia.org/wiki/File:Tamias_striatus_CT.jpg)

Scientists have also studied this phenomenon in red squirrels, and chipmunks may be similar.  After all, chipmunks are a kind of squirrel.  They belong to the family Sciuridae, the sciurid rodents, which includes chipmunks, ground squirrels (e.g., prairie dogs), marmots (e.g., woodchuck), and tree squirrels (e.g., gray and red squirrels and flying squirrels).  Red squirrels are also known to anticipate high seed crops and reproduce accordingly.  Females may even have a second litter in the summer that precedes a big fall.

But how do chipmunks and red squirrels know that it’s going to be a good year?  The jury is still out on that question.  It’s hard to measure what individual animals are using as a cue to guide their reproductive “decisions.”  (And by using the word “decisions,” I don’t mean to imply that chipmunks and squirrels have consciousness, just an instinct to reproduce when certain cues are present.)

Scientists involved in these studies have suggested that the visual stimulus of an abundance of flowers may clue the squirrels in, but that explanation is less convincing for chipmunks, who spend more time on the forest floor than up in the tallest trees.  Chipmunks may be able to smell the upcoming bounty by homing in on the subtle scent of all those beech, oak, and maple flowers.  However they do it, it’s pretty cool.

Natural Destinations: Dead Creek Wildlife Management Area

by Cathy Bell

(originally posted on vtdigger.org)

Every autumn, thousands of snow geese take a break from their 5,000 mile southbound migration to rest and feed at Dead Creek Wildlife Management Area in Addison, Vermont.  Journeying from their breeding grounds on the Arctic tundra to their winter range in the mid-Atlantic and southeastern states, the snow geese are but fleeting visitors to the Green Mountain State, descending on our cornfields from October into early November.

The bright white feathers of a snow goose’s body contrast with tips of the wings, which look as though they have been dipped in paint of the richest black.  Young birds are brushed with gray on their backs, giving them a dirty appearance.  Here and there among the flocks are dark gray individuals with white faces.  These steely-looking birds, commonly known as “blue geese,” are the same species as the white ones.  Snow geese of either coloration are far prettier, to my eye, than our resident Canada geese.  Getting to see these visitors from the north is a seasonal treat.

Snow geese

Snow geese at Dead Creek

Hoping to find some snow geese, I went to Dead Creek on Saturday, October 30.  The day started out sunny but clouded up as the big Halloween nor’easter worked its way towards New England.  Driving down Route 22A from the north, I made a right turn onto Route 17.  I had gone less than a mile from Addison Four Corners when I saw a wheeling flock of waterfowl.  Backlit, the winged forms did not reveal any details of their plumage, but the size and flight pattern didn’t seem quite right for Canada geese.  Even as I thought to myself that I must be in the right place, I saw a turnoff on the south side of the road.  I pulled off the highway, shut off the ignition, and hopped out of the car, binoculars in hand.  Looking to the south, I felt my jaw drop in wonder.

About 800 geese were in a field very close by, in easy sight of a viewing platform with interpretive signs.  Hundreds more were in a distant depression.  From the knot of people with binoculars and spotting scopes a quarter mile to the west, I guessed there was another—possibly even bigger—group of geese over there too.  Aerial photo counts that weekend documented more than 4,600 geese in the area, but few people braved the chill wind of the gray afternoon to witness the impressive spectacle.

A northern harrier, its white rump patch catching the watery light, startled the nearest geese into rising from where they rested and fed.  Within moments, the nervousness of a few waterfowl swept through the flock, and hundreds of birds were in the air, honking their discontent in a higher-pitched and more tremulous voice than that of the familiar Canada goose.

Though I looked carefully, I failed to find any Ross’s geese among the swirling clouds of white waterfowl.  Snow geese and Ross’s geese are two distinct species, though very similar in appearance; the rarer Ross’s is more diminutive in build and has a smaller bill.  I later read on the Vermont bird listserv that there were indeed two Ross’s geese at Dead Creek that afternoon, but they were the needles in the haystack of thousands of snow geese.

I may have lucked into witnessing the peak of this year’s snow goose migration, but there’s still time for you to see the spectacular waterfowl as they pass through Vermont.

At 2,858 acres, Dead Creek Wildlife Management Area is administered by Vermont Fish and Wildlife and includes extensive reaches of cattail marsh and stretches of open water.  The geese, however, are concentrated in upland agricultural fields.  The designated goose viewing area along Route 17 is the best place to see the birds, but a little farther south, Gage Road can provide good sightings as well.

Moreover, though the snow geese may be the star attraction, there is more here for inquisitive visitors to enjoy.  Northern shovelers and green-winged teal dabble in the shallow, ponded water of the fields, and once in a while a pectoral sandpiper passes by overhead.  A quarter mile west of the goose viewing turnoff, Route 17 crosses the still, murky waters of Dead Creek.  Mallards and black ducks ply the waters here.  Just over the bridge, a left turn takes you down a gravel road towards a hunters’ camping area.  Look along the reedy edges of the water for great blue herons and wood ducks.  Despite its name, Dead Creek is a lively place.

The creek flows northward, parallel to the southernmost portion of Lake Champlain.  Just seven miles north of where it flows under Route 17, the creek joins with Otter Creek and soon wends its way into the lake.  Its meandering path has been modified by the addition of dams, and today, the state actively manages water levels in the flooded impoundments.

The snow goose hunting season runs from October 1 – December 29 in the Lake Champlain waterfowl hunting zone, with a daily bag limit of 25 birds.  Portions of the Dead Creek Wildlife Management Area, including the upland areas south of Route 17 near the viewing area, are managed as a refuge where no hunting or other public access is permitted.

More information, including maps and directions, is available from Audubon Vermont and Vermont Fish and Wildlife.

Young Scientists Plot for Smart Urban Forestry

by Liz Brownlee

“Wait until you see the accuracy of our plot,” calls the lab team.

The four undergraduates burst with pride, oblivious to the prickling raspberries and thick brush that edge the Intervale forest.

They stop me midstride.  As their lab teacher, I’m fully equipped with aerial maps, GPS, first aid kit, phone, and extra rain gear.  I’m planning to cruise through this pasture towards the soybeans and into the swampy forest.  My goal is to check in with teams at twelve more study plots, spread over the 350 acres of forest and fields.

This lab project is a real, on-the-ground application of their natural resource training.  Most weeks these first-year students learn the basics of field work in big, broad fields (fisheries, stream ecology, forestry, etc.). The field data they record in their weekly labs is important: they use it to learn how to create papers, reports, and essays.

This week, though, the data is headed to city hall.  We’re studying the Burlington urban forest to help the city make informed decisions about valuing and managing the forest.

I need to check in with the next group. It’s incredibly important that the teams describe each plot with accuracy and efficiency.  I know that all the teams are anxious to prove their worth, to share their budding knowledge and field skills.  But this team’s stories cannot wait.

Elliot, a bright-eyed skier from Utah starts first.

The maple we used to mark our plot was so big, our measuring tape couldn’t reach around it, he says.

Aptly named and observant, Hunter chimes in.

There was a deer trail, but that’s it – otherwise it’s untouched.

Eric, a tattooed, intelligent former Marine, knows this isn’t entirely true.

How should we record the land use on this plot, Liz? This isn’t a park, and it’s on the farm but not cultivated land.

We brainstorm the forest’s values: recreation and flood control top the list.

I change my route, unable to leave the pull of their enthusiasm.  Elliot fires questions as we walk the farm’s puddle-filled gravel road.

We didn’t see any sign of invasive species like emerald ash borer – that’s good, right?  And the ground was covered in mud from the hurricane and the flood – do you think the forest will rebound before teams come next year?

The team answers most of their questions before I can chime in, and I know that I’m no longer needed.  I head for the next site when Carly, another lab teacher with twenty more students, calls from the Old North End of Burlington.  We check in, cars honking in the background on her end.

Over two hundred UVM students are taking the pulse of the forest, from tree height and canopy dieback to ground cover and plant-able space. They’re studying over one hundred plots throughout the city, and all in just two weeks.  We’ll crunch the numbers with a program called iTree that’s being used worldwide.  The city will use the results to decide where and what to plant next, and how to properly value a forest that cools homes, mitigates pollution, and absorbs storm water runoff.

They’ve tracked changes in the forest’s health.  They’ve built confidence as budding natural resource scientists.  And next year, two hundred new students will do it all again.