Wednesday, December 24, 2014

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?

Saturday, December 20, 2014

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.

Friday, December 19, 2014

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. 

Friday, December 12, 2014

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!

Saturday, December 06, 2014

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.

Wednesday, December 03, 2014

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.

Friday, November 28, 2014

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.

Thursday, November 27, 2014

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.

Wednesday, November 26, 2014

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.

Monday, November 24, 2014

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.

Sunday, November 23, 2014

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.

Sunday, November 16, 2014

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,


wild senna,



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.

Friday, November 14, 2014

New Cultural Artifact Discovered at Herrontown Woods

Members of the Friends of Herrontown Woods just found another cultural artifact to add to the mix of nature and culture along the corridor of preserved land called the Princeton Ridge East. To the various farmsteads and quarry operations can be added this curious imprint in the flat woodland at the north end of the preserve, carved by a bulldozer many decades ago and now left to slowly fill in with leaves. The "L" shaped hole appears to be several feet deep, and runs 100 feet in one direction, 50 in another.

Is it more evidence of quarrying, or might it be a mid-20th century attempt at a groundwater-fed swimming pool that I had heard rumor of years back?  I've written an account of the off-trail adventure that led to this discovery at the website.

Sunday, November 09, 2014

Monarchs and Glyphosate

It's time for a little Sunday sermon about good and evil, as it pertains to monarchs and herbicide. (I must be channeling my grandfather, who was a chemistry professor during the school year and a minister during the summer.) But before that, a brief, italicized update on the monarch for context:

Monarchs made their traditional appearance in the mountains of Mexico on the Day of the Dead, which is celebrated from Oct. 31 to Nov. 2. By November 2, according to JourneyNorth, the first several thousand arrivals had clustered on evergreen trees in Michoacan, with millions more still channeling south from Texas. Chip Taylor, who has made the monarch his life's work, predicted numbers at least double of last year's record low. 

That's the good news, but the cards are still stacked against the monarch, as long as agricultural practices in the central U.S. and elsewhere are geared towards exterminating the milkweed the monarch depends upon for building its numbers each year as it migrates north. 

Now for a little talk about the good, the bad, and the (far less emotionally gratifying) inbetween. It's human to want to draw a nice, clean line between good and evil. Mixing the two tends to diffuse the delicious, heady, mobilizing energy that drives many political movements. That nice, clean line also saves big-time on the mental energy required to make fine distinctions. But when it comes to chemistry, good and evil are often not inherent in a substance itself, but are more a matter of how much and where.

Take, for instance, the harsh portrayals of glyphosate, which has become famous or infamous as the active ingredient in Monsanto's herbicide, Roundup. It's now broadcast widely to kill weeds in farm fields, and has had a devastating effect on milkweed populations critical for the survival of monarchs. Because of its relatively low toxicity and price, it's also used in very small and targeted amounts by land stewards working to restore forest and grassland habitat. Since the patent expired, glyphosate can be purchased from other companies than Monsanto. Shall we paint with a broad brush, and implicate all who use it as collaborating to poison our world? This assertion I heard made recently by a resident at a town council meeting. She also said, falsely, that glyphosate "is half of Agent Orange, and that's all you need to know."

One doesn't need to make false assertions about glyphosate to question the way it is being used on such a vast scale. As Maraleen Manos-Jones explained as part of a recent, edifying panel discussion at the Princeton Public Library, Monsanto's "Round-up Ready" corn and soybeans now are grown on more than 100 million acres of cropland in the U.S.. Because the crops have been genetically modified to be unaffected by glyphosate, farmers can spray their fields indiscriminately, exterminating all weeds, including the milkweed the monarchs need to survive. Cornfields used to have enough milkweed growing in and around them to support monarchs as they migrated north. No longer.

Meanwhile, even unfarmed areas such as roadsides are being managed in ways detrimental to the monarch. Herbicide use along roadsides and powerline right-of-ways, from my observation, is on the increase, and mowing in August and September wipes out flowers that could nourish adult monarchs, as well as any milkweed the caterpillars may be feeding on.

That, plus the increasing extremes of weather, are the stark reality monarchs now face, and Ms. Manos-Jones is as good as any at sounding the alarm. She was the first non-native woman to find the monarchs' overwintering grounds in Mexico in the 1970s, and by her telling has risked her life to defy the Mexican mafia that, along with local peasants in need of wood, has been cutting and fragmenting the dense forest the monarchs use for winter shelter. To drive home the threat, she used an aerial photo of the forest, showing a patchwork of clearcuts right next to a grove of evergreen forest turned orange by clustering monarchs. She's involved in a program to plant tree seedlings in logged areas.

But she also falls prey to a black and white apportionment of good and evil. Glyphosate is portrayed as a poison, pure and simple. That clear line may stir passion and a following. The thought of any herbicide getting into the body prompts a feeling of violation. But by laying blame on the molecule rather than on how it is used, people who use the herbicide responsibly are wrongly vilified. The indiscriminate casting of blame begins to bear resemblance to the indiscriminate use of herbicide.

At the other end of the political spectrum, one argument used to question the existence of climate change is that carbon dioxide is a good molecule, necessary for plant life, and so couldn't possibly be doing any harm. But carbon dioxide is beneficial or harmful depending on how much and where. Even as a diffuse molecule in the atmosphere, its concentration has a big effect on the planet. In enclosed spaces, artificially high concentrations of carbon dioxide can, like carbon monoxide, be lethal.

As appealing and convenient as it might be to brand glyphosate as an unmitigated evil, it's the least toxic among herbicides that land stewards have available. Now, the question often comes up, why must any herbicide ever be used for habitat restoration. Why don't land stewards just dig up the invasive shrubs? I would have asked the same if I had nothing more than a backyard to tend to. 100 acres of land choked with non-native shrubs whose foliage the wildlife refuse to eat is another matter. We could leave it be if we didn't want wildlife to have an edible landscape. We could dig the shrubs out if we had infinite time and energy, and didn't care about mass disturbance of the soil. Or, we could use tiny, targeted amounts of low-toxicity herbicide in much the way a doctor prescribes medicine.

The comparison of herbicide to medicine is useful. Ever since Silent Spring, environmentalists have been devoted to freeing the landscape of the scourge of chemicals. When it comes to our bodies, however, environmental and medical thinking are seemingly at odds. Many of us prefer organically grown food, yet willingly ingest chemicals in the form of medicine. For instance, we don't view antibiotics as poisons, but instead make a clear distinction between their beneficial, small-scale, targeted use as medicine, and the much criticized, indiscriminate use of them in cattle and poultry feed. Interestingly, the vast scale of current glyphosate use has led to a sharp increase in resistance in weeds, much like indiscriminate use of antibiotics has led to resistant pathogens.

The best medicine targets the pathogen in the body without affecting the healthy tissues. This is precisely what land stewards do when they dab a bit of glyphosate on the cut stump of an invasive shrub in the forest. A healthy skepticism about herbicides need not preclude applying the same distinctions drawn by medicine. In a forest that's been thrown out of balance, glyphosate can play the role of an antibiotic that, in small, directed doses is very low-risk, helpful and even critical, but becomes problematic when overused.

The three other panelists exemplified this more nuanced, pragmatic view.

Michael Gochfeld, Rutgers professor and co-author with his wife of "Butterflies of NJ", delved into the data on monarch population swings year to year. Most memorably, he described how profoundly weather affects the annual butterfly counts that often last only one day. Even if the sun just disappears behind a cloud, the butterflies are apt to disappear as well, and not get counted. He encouraged all interested to participate in the butterfly counts through the local chapter of the North American Butterfly Association.

Robert Somes, a biologist with NJ DEP's Nongame and Endangered Species Program, said that concerns about monarchs are bringing attention to the work he and others are already doing to manage public lands for rare or endangered species. They use prescribed burns to promote habitat for the Aragos skipper, and clear invasives with a mix of minimal herbicides and mechanical methods. This work benefits local as well as migratory pollinators.

Flo Rutherfeld, of the New Jersey's World of Wings Museum, was the last to speak, and gave some tips for gardening that caters to butterflies. Have a variety of plants that will provide flowers from as early in the season to as late as possible. Morning Cloaks and Question Marks overwinter as adults, so are out and about in the spring. Monarchs will spot wildflowers more easily if they are clumped. Leaf litter is important for overwintering butterflies and moths. Some species even use decomposing leaves as their "host plant".

Invasive species are also impacting monarchs and other butterflies. Gochfeld said that Hairstreak number may be dropping due to an invasive ant. (An account of how native ants have a symbiotic relationship with the caterpillars of Coral Hairstreaks can be found here. Invasive ants often displace native ones, severing the symbiotic relationships that have evolved among native species, with cascading consequences.) Rutherfeld mentioned a non-native milkweed called dog-strangling vine that is causing problems in the northeast. An Ontario website called InvadingSpecies describes how this invasive plant interferes in multiple ways with monarch reproduction:

"Impacts of Dog-Strangling Vine
  • Dog-strangling vine forms dense stands that overwhelm and crowd out native plants and young trees, preventing forest regeneration.
  • Colonies form mats of interwoven vines that are difficult to walk through and interfere with forest management and recreational activities.
  • Leaves and roots may be toxic to livestock. Deer and other browsing animals also avoid dog-strangling vine, which can increase grazing pressure on more palatable native plants.
  • The vine threatens the monarch butterfly, a species at risk in Ontario. The butterflies lay their eggs on the plant, but the larvae are unable to complete their life cycle and do not survive."

Friday, November 07, 2014

Fall Colors in and out of the Woods

Walking through Herrontown Woods, catching some color to carry me through the winter. Browns and yellows dominated. Beech leaves from green to yellow to copper.

Winterberry leaves that donated generously to the local insect society.

A solitary crabapple persisting in the shade.

Winged euonymus, or burning bush, grading pink to white, their colors doused by deep shade--

colors that in their customary brightly lit gas station habitat would be brilliant red.

Elsewhere in Herrontown Woods, along the flat top of the Ridge, the wind conspires to highlight the distribution of wineberry, flipping the leaves over to expose the white underneath.

The uncommon color of the gratefully numerous maple-leaved Viburnums.

After all that preceded on the walk, this burgundy jumped out at me from one of the few southern arrowwoods in the woods. (Viburnum dentatum)

The same arrowwood in full sun at the Princeton Healthcare Center has a different hue.

With more color from ginkgos to absorb on the walkway.

The catalpas guard the entryway,

with elephant ear leaves.

While the persimmons across town, growing up to the pedestrian bridge over Washington Rd on campus, go begging, their Princeton orange just beyond reach.