"Dam Nation" Film Showing Friday

The Princeton Environmental Film Festival, scheduled this year for March 19-29, has other film showings scattered through the year. One is coming up this Friday at 7pm, with a showing of "Dam Nation" at the Princeton Public Library, followed by a talk by StonyBrook-Millstone Watershed Association staff. They've been trying to get a couple small dams removed along the Millstone River, which the StonyBrook merges with at Carnegie Lake. The Millstone flows towards the ocean, past Kingston and Princeton's wastewater treatment plant, then merges with the Raritan River 20 miles further downstream, just before contributing water to the treatment plant from which Princeton's drinking water comes. This is a working river, serving us in so many ways, but it also has some nice scenic stretches, almost all of which can also be accessed by riding a bike along the canal towpath.

Removing dams allows migratory fish like shad and eels to get where they need to go. One question I'd have is, if the lower dams are removed, how do the fish get over the Carnegie Lake dam? You can get to know the mighty Millstone a bit in a post about a fun kayak trip we took down the river four years ago--our journey to the source of Princeton's drinking water.

Patterns in Carnegie Ice, 2015

Some of us laid low by the flu hadn't noticed Lake Carnegie's quiet transformation this week into the ultimate sustainable ice rink. Sustainable, that is, in terms of low carbon footprint. A friend whose home overlooks the lake called to tell me, and the town hotline at (609) 688-2054 confirmed the good news.

We dug out our skates, went down to have a look, and found the ice looking right back at us in its own mysteriously retinal way. "Here's lookin' at you, kid."

(The university website stated that this was the first skating since 2007 (see Winter in Residence), but posts on this website document more recent opportunities, including February, 2014, January 2014, and January 2009. There was some exquisite, though not skate-worthy, ice back in 2010, a photo of which made it into a traveling exhibit as part of Princeton University's Art of Science collection.)

Along the far shore, the ice was white with lots of smaller ganglial patterns below the surface.

This large vein of dark ice, too, was sealed beneath a smooth skating surface, like a giant coffee table with patterns protected by a glass top.

Bubbles large and small were suspended in solid ice.

Towards the Washington Road bridge was a cluster of bubbles that appear to rise in columns

from some unknown source below.

Elsewhere, shallow imprints suggestive of goosefeet but too varied in size and shape, possibly created as the surface softened then hardened again.

More slight imprints, finger-sized,

and larger plates of ice more easily explained as fragments from an early freeze that broke apart on a warm day, then were captured in a more recent, deeper freeze.

This shard was ten feet long.

A white line of crinkly ice extended towards the Harrison Street bridge, suggesting a seam where giant plates of ice rub against each other.

Every now and then, in various locations on the lake, an indescribable sound would zip by beneath us--not a big crack or a boom, but an elastic sound, more like when you kick a doorstop spring. Probably arises out of a slight shift in the ice as it adjusts to forces of expansion and contraction.

The beavers sure looked like they'd been busy over near the towpath, but more likely maintenance crews have been doing tree work along the canal and simply broadcast the chips rather than haul them away in a truck.

The glow of the western sky captured the feeling of gratitude for water's wizardry, as some particularly organized families and friends gathered to share a warming drink beneath the spreading limbs of an ash.


(Weather looks conducive at least through this Saturday, but call the town hotline before heading out (609) 688-2054. There are also flags on the shore that signal whether conditions are safe. Ponds at Smoyer Park and Community Park North are not safe as yet, according to the hotline.)

Skating Today (Jan. 15) On Carnegie Lake

I'm just re-emerging from a long bout with the flu, and a friend calls and says the ice is glorious, deep and dark. Check Princeton Recreation Dept. hotline, (609) 688-2054, for details.

New Dimension in Playground Equipment

Playground equipment is typically a 3-dimensional structure built on flat, 2-dimensional ground. What happens when the ground itself becomes 3-dimensional?

The result is that the ground itself becomes playful, so that the kids interact at least as much with the ground as with the play equipment, rolling down the slopes, exploring the play of gravity on the suddenly niche-rich topography. Though carpeted with artificial turf, the pockmarked appearance is to some extent more natural than flat, given that American forests become pockmarked by the uprooting of trees in storms. The park is in Washington Square in Manhattan.

A Remembered Path

One of the photographs in an exhibit of Annie Leibovitz's photography at the NY Historical Society gallery (next to the Natural History Museum) is of the "Sandwalk" that Darwin would walk several times daily. It was his "thinking path", one of many examples of how walking in nature has long been associated with expediting thought. Writing about the exhibit at the VeblenHouse website stirred a childhood memory of another scientist who loved walking in the woods so much he continued to do so even after going blind:

Growing up next to Yerkes Observatory, on the outskirts of a small town in Wisconsin, I would walk to school along a path used fifty years prior by the astronomer Edwin Frost to get from his home to the observatory. He became blind later in life, but would still walk through the woods to his office every morning. A wire was strung from tree to tree along the path, so he could guide his way with the crook of a cane held against the wire. Pieces of the wire could still be found in the trees when I was exploring around there as a kid. For many years, my youthful mind mixed one Frost with another, believing that the Frost who walked that path was Robert Frost, the famous poet.

There were many wildflowers, planted or growing naturally, along that path. Walking it years later, in my twenties, the canopy of oak/hickory was full of birdsong, one of which sounded just like a lick Charlie "Bird" Parker would often end his phrases with, using the third, fifth and second notes of the major scale. Old articles, easily found now on the internet, describe the blind astronomer's ability to tell temperature by the tempo of cricket sounds. One goal for the new year, along with working on trails at Herrontown Woods, is to revive some of these stories of connection to nature.

A happy new year to all whose paths cross with Princeton's nature and PrincetonNatureNotes.

Some Good News About Monarchs

We didn't get a Christmas tree this year. The kids weren't interested, apparently having entered a post-materialist world where the smartphone cornucopia renders most other possessions unnecessary. To fill the void where a Christmas tree once stood, I'm imagining evergreen trees in a forest high in the mountains of Mexico, densely decorated not with lights and tinsel but with monarch butterflies.

Not until this month did word arrive that the monarchs had finally made it safely to their mountain forests of Mexico. November 26, more than three weeks later than usual, the main population showed up, larger than last year's record low, but still with a long way to go to recover. Among them may be the few scattered monarchs seen in Princeton in late summer. May they have a safe overwintering, and much milkweed in the new year.

Addendum, Dec. 30: We may have a concept here, that each gardener, by planting milkweed, and each farmer, by allowing milkweed to grow, might contribute to the decorating of oyamel fir trees in that small mountainous area where monarchs congregate each winter. What other species engages so broadly with a continent, then congregates in such ornamental fashion to make its status known each winter?

Needle Ice Creates a Vaulted Pebble Palace

Heavy rains followed by a hard frost December 7 made the garden path crunchy underfoot. A closer look revealed miniature pillars of ice with pebbles on top.

Water flows up from the soil via capillary action, with the upward motion continuing above ground as a column of ice fed from below. Needle ice is a surface form of the frost heaving that can loosen soil, slowly lift rocks towards the surface, and work mischief on asphalt.

The capillary action that allows water to move upwards in the soil is counterintuitive, and helps explain how trees completely surrounded by asphalt and concrete can still get water.

Some Horticultural History: Dogwoods at Princeton Battlefield

Here's a little story that shows how the past can enrich the present and inform the future. Two years ago, I was over at the Princeton Battlefield, in that immense mowed field on the north side of Mercer Road (the side with the columns), and noticed a pattern in the wooded edges of the field.

It's most obvious during April, when these flowering dogwoods advertise their position, but you can see it as well in the autumn when their leaves turn radiant colors.

The dogwoods are spaced all around the edge of the field, but on the left side they've been completely overgrown by vines. It's a matter of time before the shade and weight of the vines weaken and ultimately kill the trees.

Hopefully, a workday to cut the vines can be arranged soon with the Friends of Princeton Battlefield. Recent Veblen-related research of old newspapers has solved the riddle of who planted the trees and when, and may provide further impetus for action to save the beautiful trees. Turns out the trees were donated back in 1976 by the Dogwood Garden Club, which still exists. Among its current projects is care of one of the gardens near the Princeton swimming pool entry. The relevant text from the article is in bold.

Town Topics, 2 December 1976

The annual Christmas Auction and Bake Sale of the Dogwood Garden Club will be 5 held Thursday, December 9. 1 in the home of Mrs Michael ; Jensen, 18 Riverside Drive ' West Co-hostesses will be Mrs William Alston, Mrs. Joseph Pierson, Mrs. Richard Olsson and Mrs. Frederick Wightman Jr. Mrs. Dudley Clark will serve as auctioneer. All articles to be auctioned have been made by the members and all proceeds will be used in cooperation with the Mercer County Park Commission to continue the restoration and maintenance of the memorial garden around the home of Mrs. Oswald Veblen in Herrontown Woods. In honor of the Bicentennial the club recently gave 25 dogwood trees to the Princeton Battlefield Preservation Society to be planted on the grounds. 

Teaching 9th Graders About Invasive Species

I was invited by my daughter's 9th grade biology teacher, Alexis Custer, and her colleague Jayne Ricciardi, to come in and speak to four classes over the course of a day at Princeton High School. The subject, invasive species, is full of subtleties and contradictions. Plants are good. They're the producers, ecologically speaking, while we're among the consumers. And yet, some of the thousands of imported plant and animal species are wreaking ecological havoc.

Though our culture tends to associate destructive consequence with ill-intent, most or all of the destructive consequence of invasive species was unintended. For example, the burmese pythons now altering the ecology of the Everglades were introduced by pet owners who released their exotic snakes into the wild when they got too big to keep at home. The collective consequence of seemingly humane individual acts can undermine a whole ecosystem.

Adding to the irony, an overabundance of one of the most beautiful and iconic native creatures of our woods, the white-tailed deer, is magnifying the damage by eating primarily native species, giving the invasives a big competitive advantage.

A more positive side of the story is that people can have a positive, healing effect on nearby ecosystems, by restoring balance. Most satisfying was telling the students about the high school's wonderful ecolab wetland, which is fed by an "old faithful" sump pump that keeps the wetland wet year-round with groundwater steadily being pumped out of the school's basement, several stories below their classroom. It's a great example of how people can create rich, productive habitats for plants and wildlife by working with nature, rather than against it.

The kids were attentive through the 45 minute talks. School curriculums, when they teach ecology, often focus on distant ecosystems like the Amazon or the arctic. This was a great opportunity to introduce the students to the ongoing ecological drama waiting to be explored in the town where they live. I hope they get out and walk the trails leading through Princeton's many nature preserves.

And what a sweet thank you note came in the mail from all the kids!

A Thanksgiving Weekend Walk Through New-Old Herrontown Woods

The parking lot was packed for our Thanksgiving weekend walk in Herrontown Woods. Forty people, all told, most of whom stayed for the full two hour venture up and over the Princeton ridge and back again. I explained that the preserve had, as in a fairy tale, gone into a deep slumber over the years. The trails had become overgrown with thorny multiflora rose, and blocked by fallen trees. The house and cottage were boarded up. Landmarks like the cliff had become obscured and forgotten. Then two years ago, what came to be known as the Friends of Herrontown Woods set about clearing the trails and making the preserve welcoming again.

Neighbor Ed Simon, who leads stewardship efforts at nearby Gulick Park, added some context, describing how a corridor of preserved open space in northeastern Princeton extends from Bunn Drive eastward through Herrontown Woods, with Smoyer Park nearby and Gulick Park beyond that. An overarching vision would be to develop synergy and connectivity between all of these elements, which include nature trails, history, the active rec of Smoyer Park, and remnant farm elements.

One of my favorite parts of the walk came early on, when I mis-spoke. Our first stop along the trails was at a solitary hazelnut shrub growing beneath a grove of trees with dark, chunky bark. As I was telling everyone about these trees, which I identified as tupelos (black gum), I gazed up into their canopies far above and noticed what looked like fruits on the twigs. Tupelos would not have that sort of thing. What I was seeing was beginning to contradict the words I was saying. Then one of the participants presented me with the fruits of persimmon that she'd found on the ground. Hmmm, there must be a persimmon tree around somewhere. Then I realized. The trees we were looking at were persimmons, not black gums. Though possibly wild, this dense grove of persimmon trees could also have been planted long ago as part of the farm. Impressively, they had grown fast enough to keep up with the forest rising around them after the farm was abandoned.

Second stop was the Veblen cottage, then a side trip to the Veblen House, where I got to tell a bit of the history of the Veblens and the first owners of the house, the Whiton-Stuarts.

Then a hike up the slope of the ridge to the cliff, where everyone enjoyed the view from the thirty foot dropoff. That's Sally Curtis holding the camera.

From the cliff, we crossed the pipeline right-of-way and entered the beech forest, which looked like a wonderland with the tawny beech leaves still attached to the trees. Not far in, we hung a right, heading off trail to the north, where a mysterious expanse of water was recently discovered by some of us in the Friends of Herrontown Woods.

Here, in this flat pancake of land at the top of the ridge, which serves as a giant sponge that captures rainwater then slowly feeds it to the tributary of Harry's Brook that flows down through Herrontown Woods, a bulldozer long ago dug an L-shaped pool. A lively discussion ensued about its original purpose. Had they used the bulldozer to push up rocks for use somewhere else in Princeton? Seemed to me there were plenty of boulders available on the surface of the ground, with no need to dig. I used a stick to push down through the muck to solid bottom. Three feet deep.

For now, I'm sticking with the swimming pool theory, but it would make a great skating rink if we get a cold spell.

We then headed back to the trail, past the boulder field, and down along the creek whose broad, flat headwaters we had just visited. What a treat to lead such a walk, and introduce or reintroduce so many people to this reawakened preserve.

Monarch Status and Glyphosate, Part 2

As mentioned in a previous post on this year's monarch migration down to Mexico, the weekly migration updates on the Journey North website stopped abruptly on November 11, with the main mass of monarchs still not having arrived in the mountain groves. No more news? What happened? Did the monarchs ever arrive? I emailed the website on Nov. 28, and got a same-day response from an Elizabeth Howard, with this good news:

"We're been waiting for news that the mass arrival has occurred--and just received word yesterday (that it happened the day before). We will be updating the sites soon-- maybe before Monday."

Great, the monarchs arrived, though nearly four weeks later than usual, and I'll feel better when their website is actually updated.

Another communication received, far less friendly, was an anonymous comment concerning the use of the herbicide glyphosate in habitat restoration. Part of the fallout from the massive use of glyphosate on genetically modified "Roundup-Ready" crops has been the demonization of glyphosate and everyone who uses it. The targets of criticism, in some people's minds, should include not only Monsanto and farmers, but also managers of nature preserves who may put a dab of glyphosate on the stumps of invasive shrubs so they don't grow back. Sure, I wrote, in what I thought to be a fairly insightful post, lets rail against the massive use of glyphosate on more than 100 million acres of farmland that once offered monarchs enough scattered milkweeds to prosper. But it's the massive use, not the chemical itself, that is the problem.

Antibiotics provide an analogous situation. Their power can be wisely used in medicine, or abused when indiscriminately given to animals in their feed. It would be unfair to vilify a doctor's careful prescribing of antibiotics because of industrial agriculture's wild excess. And the vilification of preserve managers, who use micro amounts of highly targeted herbicides in their work, is similarly unfair.

Personally, I haven't used herbicides of any kind in years, but any serious attempt to restore balance to a forest, to take on a monstrous, smothering stand of wisteria or thousands of winged euonymus and honeysuckle choking a hillside, will necessarily require some use of herbicide, well-timed and minimally applied.

If the anonymous commenter or anyone else would like to send an email, with name attached, I'd be glad to correspond on this subject. Maybe we can learn something from each other. In the meantime, a hope that the monarchs did in fact arrive and will be safe through the winter.

Nature/Culture Walk This Sunday at Herrontown Woods, 2pm

With temperatures predicted to climb into the 50s, I'll be leading a nature and culture walk through Herrontown Woods this Sunday, Nov. 30, at 2pm. We'll be exploring the remarkable features of Princeton's first nature preserve, including a hidden cliff, a boulder field, quarried stone, the traces of an 1870 microfarm, and a mysterious large excavation that may have been intended as a swimming pool.

The event is the first since the Friends of Herrontown Woods (FOHW) received official nonprofit status. Members of the group have made critical interventions at Herrontown Woods and Autumn Hill Reservation over the past two years, clearing and improving long-blocked trails, and taking steps to save and repurpose the buildings left behind by the visionary mathematician Oswald Veblen and his wife Elizabeth, who began Princeton's open space movement by donating Herrontown Woods as a public preserve in 1957.

Meet at the parking lot for Herrontown Woods, the entrance to which is across from Smoyer Park, near the eastern end of Snowden Lane. For any questions, check the "About Me" info up on the right of this webpage for contact info.

Leaf Stacking Demo

Before there were leaf blowers, before there were rakes, there was leaf stacking. In this video, stack-master Perry Sugg demonstrates the traditional method of leaf stacking passed down through the generations in his home town of Princeton, North Carolina. Stacked leaves can be carried by hand, without the need of implements, tarps, bedsheets, or containers of any kind. In 2008, Perry traveled north to Princeton, New Jersey, to bring hope and empowerment to a people worn down by the drone of leaf blowers. He is ably assisted by Sofia, Maya, Anna, and spunky cairn-poo Leo.

For those in a hurry, skip to 1:10 in the video for the demonstration.

"Viva la leaf stacker! Down with the leaf blower!"

An internet search for "leaf stacking" yielded this completely different form, a game played by two to build a leaf mountainette one leaf at a time. Poetic and vaguely Bergmanesque.

Rescuing Carrots On an Organic Farm

Even grey, drizzly weather can have a warm feeling of victory to it, the day after helping to save a crop of carrots from an impending freeze. The urgent call for help came via forwarded email yesterday, from Chickadee Creek Farm, run by Jess Niederer, just down the road from StonyBrook/Millstone Watershed Association. Nothing like a deadline to get the juices flowing.

A field of carrots was ready for harvest and a potentially damaging snow was forecast. It was a good excuse to get out of Princeton and see where some of the food for the Thursday farmers markets comes from.

Go to a farm, they say, and you'll be greeted first by animals. The chickens were happy to see us, though we had little to offer them, compared with the windrows of leaf compost they had been scratching at. During the mass urban rejection of leaves in the fall, it can be healing to visit a farm, where the wealth of nutrients in leaves are welcomed and put to use.

That's Jess on the left, with lots of bags scattered about, already filled with carrots. Harvest was made much easier by a machine that had loosened the soil's grip, but also made the crop more vulnerable to a freeze. Carrots grew so densely, in five foot swaths separated only by enough room to accommodate a tractor tire, that the soil seemed to be solid carrots.

The density made for a big harvest, and occasional promiscuity among the carrots.

The field had a well-coiffed look, coated with ferny carrot foliage. One nifty technique for weeding Jess described is to walk through the field with a propane torch just before the carrot seeds germinate, and knock out any early weeds.

After harvest, the foliage is left on the ground. One of the concerns going into the winter months is to have as much of the soil covered as possible--with crops or annual rye. Otherwise, the wind can secretly, invisibly carry topsoil away. This field won't rotate back to carrots again for at least three years.

Elsewhere, many shades of kale led veiled lives,

and an allee of miniature kale palmtrees lacked only Playmobile people for scale.

Today, a followup email arrived from Jess with a report:

"By my calculations, that's 4649 pounds of rainbow carrots and 500 pounds of watermelon radishes that we snatched from the jaws of the weather beast. Great work! Thank you, thank you, thank you. As Karla said yesterday, it takes a village to raise a farm!"

That's a warm feeling to carry us through a chilly Thanksgiving weekend.

Strange Goings On With Monarchs

Things are getting a little weird with this year's monarch butterfly migration. The Journey North website (they cover the journey south as well) is the only source of news I've found thus far, and their latest post is a puzzler. The reporter down in Michoacan, Mexico had found a small batch of butterflies clustered on a couple trees on the traditional days of arrival during the Day of the Dead, Oct. 31 to Nov. 2. Millions more were forecast, but as of Nov. 11, they hadn't arrived. Here's part of the report:

"He told me that in El Rosario no colony or even a cluster has been formed yet, and only an average quantity has been observed overflying the area. 

He confirmed the impressions that the way the Monarchs are arriving is very unusual and, being optimistic, it may be that they are flying too high up. 

Last, he told me that they have news that the massive colonies are possibly coming from the state of Tamaulipas."

No updates since then. I want to say, "Come in, Michoacan. Do you read me? Over."

Tamaulipas, according to google maps, is nine hours northeast of the traditional wintering grounds for the monarch. My concern has been that the migration behavior is somehow dependent on massive numbers, and that the migration could begin to break down if the population drops too far.

The Corn Snafu Deepens
Another twist on the decimation of monarch habitat due to Roundup Ready corn:

Most farmers have switched to Roundup Ready corn and soybeans, due to higher yields. Marginal lands and roadsides previously allowed to grow habitat conducive for monarchs have been returned to cultivation. But NPR reports that the massive corn harvest this year could actually make farmers more dependent on government subsidies. A corn glut outstrips demand, lowers prices, farmers don't get a return on their heavy investment in seed, fertilizer and pesticides, and government price supports kick in. Meanwhile, trains are increasingly being used to transport oil, causing the risk of spoilage to increase as it becomes harder to get the corn and soybeans to market.

In other words, a situation unhealthy for monarchs is proving problematic for farmers as well. For anyone curious about how or whether the government should intervene, this article makes for an interesting read.

Misplaced Matter Maligned

"I don't understand why people put leaves in the road, because that's, like, where they drive."

- a certain daughter of mine

These leafy fluff monsters appeared a day or two ago, cluttering gutters and hogging nearly the whole lane. One's on a side street, the other at one of Princeton's busiest intersections. One block apart, they are likely the work of one landscape service that came through whenever and dumped them wherever, indifferent to whatever rules might apply. There's reason to pillory these billowy blobs of spent tree garb. According to the schedule for Section 1, they arrived on the street too late for the last pickup of the season, which means even more staff time will be needed to double back and mop up these muppety, maplely masses of misplaced matter.

Saving Seed

One season's beauty begets another's. Seeds plant themselves well in our backyard, but sometimes I collect some, flattering myself that I'll have the time, ambition, and discipline to plant and tend them. Wait until the stem below them has turned brown, be messy (i.e. spread the wealth), take only a small portion from any one plant. For better or worse, I put them in plastic sandwich bags whose plastic is not completely airtight. Usually they get marked with name, date and location, but it's also good to get familiar with their appearance, so you can identify a plant even when it doesn't have leaves or flowers.

Here, the seeds of ironweed,

late boneset,

Joe-Pye-Weed,

wild senna,

summersweet,

buttonbush,

an attractive sedge,

green bulrush, with its airborne offspring ready to take root when they fall to the ground,

woolgrass (another sedge),

tan masses of deer-tongue grass, their seeds long gone.