Butternut Redux--A New Generation Bears its First Crop

This has been a breakthrough year for those of us working to bring back the native butternut--a species laid low by an introduced canker disease.. 

Twelve years after I helped Bill Sachs collect one of the last known harvests of native butternuts in Princeton, the new generation has finally born a crop of its own. Butternuts, also called white walnuts, or Juglans cinerea, bear nuts similar in look to black walnuts, but are oval rather than round. 

Bill continued to harvest and plant butternuts from the TRI property for a couple more years, but that pair of trees was then lost, with one blown down and the other cut down, ironically as part of an environmental remediation of contaminated soil. Most of the other known specimens, solitary so unable to bear, at Herrontown Woods and Mountain Lakes, have since been lost as well, lending all the more importance to this new generation of trees, grown by Bill and planted around town. 

We planted multiple trees, for cross pollination purposes, at Mountain Lakes, Herrontown Woods, Harrison Street Park, and at the TRI property where the seeds had originally come from. 

The saplings needed to be caged, to protect them from the deer. I made the mistake of removing a cage when a tree was tall enough that the deer could no longer reach the leaves. Bucks proceeded to rub the bark off the trunk, reducing a promising tree to root sprouts. A post from a couple years ago tells of some of the persistence required to nurse a new generation towards maturity. Along with deer, the young butternuts have been in danger of being smothered by fast-growing Japanese honeysuckle and grape vines, and trees like sweetgums and mulberries that rise quickly to fill the sunny openings the young butternuts need to grow.  Gardening, even wild gardening with native species, teaches the necessity of followup. 

This year, the butternuts had to deal not only with the 17 year cicadas' heavy pruning, but also the expanding presence of spotted lanternflies. 

Adding to the young trees' burden were some galls, which Bill said were most likely caused by walnut leaf gall mites

But despite all of that, the long awaited flowering of this new generation was spotted in July, and a few nuts collected in fall that appear to be viable, offering hope of yet another generation to come.

This fall's harvest is mostly being planted to grow more trees. Bill plants the butternut seed "in tall pots to be kept outdoors for the winter. This has worked well in the past."

Here are some additional tidbits gleaned from correspondence with Bill. The "float test" is used to determine whether a nut is viable. If it floats in water, it lacks a viable seed inside.

Dehusking walnuts and butternuts:

"I don’t really know if it’s absolutely necessary to dehusk walnuts or butternuts before a float test, though I think it is prudent. If you have a lot of nuts the best way to dehusk them is to use an old cement mixer with rocks and water… since I don’t have an old cement mixer, I use a piece of ½ inch plywood about 18 in by 6 in. I put a butternut or walnut in the driveway or street, put the plywood on top and use my foot with pressure to roll the nut under the plywood. (Use gloves to handle the nuts if you don’t want to stain your hands.) The husk comes off pretty easily. Then I put the largely dehusked nuts in a bucket of water and use a still wire brush to complete the cleaning."

Identifying butternuts: "Butternut bark is characteristically a lighter gray with broader ridges than black walnut (but not always). Easier to tell for sure from a twig with a terminal and a few lateral buds. If you slit the twig, butternut will have a dark chocolate-colored, chambered pith, and the leaf scars typically have a hairy fringe (or mustache) along the upper margin. When the leaves are still on the tree the leaf rachis will be tomentose or pubescent (hairy). Not sure if this carries over to fallen leaves on the ground in the winter. Finally, butternut trees often have poor form. In contrast, black walnut has a buff-pink chambered pith, no hairy fringes along the top edge of the leaf scars and the rachis is smooth (among other differences)."

Some additional reading recommended: 

On butternut seed propagation/germination:

https://htirc.org/wp-content/uploads/2020/10/SeedPropagationProtocol.pdf

 

On butternut conservation:

https://www.extension.purdue.edu/extmedia/FNR/FNR-421-W.pdf

Walnut Art

A lot of people, when they hear the words "black walnut", will think of a tree that drops nuts large and heavy enough to be a hazard, is super frustrating to get any food from, and has the gaul (juglone, actually) to hamper the growth of plants unfortunate enough to find themselves growing beneath it. 

This merry crew has a richer take. Meet Ooh!, Totally!, and Ugh!, three well-crafted nuts who between them express the gamut of attitudes toward walnut trees. 

I applaud those endowed with the incredible patience needed to carve these faces (that would be squirrels), and a similar patience to search for the squirrels' underappreciated art amongst all of autumn's debris in the backyard (that would be my friends and occasional Ann Arbor hosts, Dan and Karen). 

Though they express the same common laments about their black walnut trees, they have at the same time become fascinated by the exceptionally hard and messy nuts that litter the ground every fall. 

As if developing a cottage industry, they gather the nuts, and extract the oils from the husks. 

Dan came up with a way to clean the oils off of the shells, using a forked spade as if he were churning butter. 

His motivation? To sand down some of the nuts to make picks that get an unusual sound out of his string instruments.

Their art-student daughter, Thea Bilich, demonstrated how the walnut ink works well for old master paintings.

All of which shows how a little curiosity and a spirit of experimentation can look beyond life's burdens to find a sky full of possibilities.

The Long Evolution of Deer Hunting in Princeton

Most hikers in Princeton have by now encountered warning signs posted at various preserves, giving notice that it's bow hunting season. The season runs from September to February, and is limited to a select group of skilled hunters vetted by the town. They use elevated deer blinds located away from trails, so there should be no risk of errant arrows. The warning is useful for encouraging people to keep themselves and their dogs on the trails.

Hunting is not allowed on Sundays, and also now is not allowed on Saturdays from 10-2. More info at this link. For those in the Riverside neighborhood, there's also info online about hunting at the University-owned Butler Tract.

As a botanist helping to manage habitats in Princeton, I cannot emphasize enough how important it is to manage the deer population. The deer prefer to eat native plant species, and too many deer leads to a decimation of the native flora. Into the void come nonnative plant species--stiltgrass, honeysuckle, winged euonymus, privet, etc.--that the deer reject. Over time, Princeton's preserved lands become increasingly inedible to the very wildlife  the land is intended to sustain.

A 2018 article in NJ.com summarizes the dilemma. It mentions how Princeton gained national attention when passionate protests arose soon after the township hired professional hunters in 2000. Amateur hunting had not proved sufficient. An ecologist is quoted in the paper, raising the central point that the biggest human intervention was not hunting, but instead the extirpation of predators like wolves and cougars. Then, when deer hunting was also banned in 1972, the deer population began to explode. 

The resulting imbalance is analogous to what Rachel Carson describes when reckless use of pesticides began wiping out the predators that had until then held insect numbers in balance. She describes predators as "critically important," because they contribute to the "resistance of the environment" that helps keep populations in check. She also speaks of the "truly explosive power of a species to reproduce once the resistance of the environment has been weakened." High numbers of deer are due less to having been displaced from their traditional habitat than simply through their capacity to reproduce, and a lack of checks that would otherwise keep them in balance with the carrying capacity of the land.

Unless people want to bring back predators like wolves and cougars, it is up to us to fill the void in predators we ourselves have created.

The traumatic learning curve Princeton has gone through over the past 20 years is analogous to what the great conservationist Aldo Leopold experienced a century ago. Born in 1887, Leopold earned a forestry degree and was soon writing management plans for preserved federal lands out west. An extraordinary documentary of his life and legacy, Green Fire, tells of how he at first believed that killing wolves and other predators out west would create a hunter's paradise. Instead, the absence of predators led to severe habitat degradation as surging numbers of elk ate vegetation down to stubble. 

Leopold was a contemporary of Oswald and Elizabeth Veblen, who donated Princeton's first nature preserve back in 1957, and I wondered if Leopold might have influenced the Veblens in their founding efforts to preserve land in town. Leopold bought the land in Wisconsin later made famous by his book, the Sand County Almanac, around the same time the Veblens were acquiring land in Princeton. The parallels caused me to search for Leopold's name in the fabulous online resource, Papers of Princeton.

What popped up was not a visit by Leopold to Princeton, but instead references to Leopold in past discussions about controlling deer numbers in town. In 1987--100 years after his birth--and again in 1998, Aldo Leopold's name is used to lend weight to arguments in favor of using hunting to bring down the burgeoning numbers of deer and related automobile accidents. 

What we learn from this history is how long and hard the fight has been to get a town to collectively acknowledge truths that were known a century ago, and surely long before then by others possessing the knowledge and keen observation skills of an Aldo Leopold or a Rachel Carson. 

Reading the 1987 article was also a chance to witness some of the dedicated environmentalists of Princeton in action. Tom Poole, whom I knew from working with the Friends of Rogers Refuge, stated at a township meeting:

"In my view it is much more humane to take a deer with a shotgun than with the bumper of a car," Mr. Poole remarked. He added that last August, the Animal Control Officer, Al Heavener, had to kill 23 wounded deer. "He nearly quit his job."

Elizabeth Hutter was another active environmentalist at that meeting, and "traced her feelings about deer, from joy at their proximity to tolerance at the damage, to "annoyance, frustration and anger."

A beautiful letter to the Town Topics, written by Tom Poole in 1998, shows how long has been the road to deer management based on ecological realities. He also mentions in passing the annoyance of leaf blowers, which is only now, 23 years later, beginning to be addressed. Even more extreme in the slowness of progress from awareness of a problem to action to solve it, the threat of climate change was first raised nationally in 1988, but scientists were aware of this most devastating of imbalances long before that, and still there is no coordinated action after all that time. Interestingly, climate change is stymying efforts to control deer populations, since mild winters make it harder to attract deer to feeding stations. 

Any success we have at finally stirring action on long-festering problems owes thanks to those who were priming the pump decades ago. 

Click on "Read More" to read Tom Poole's letter.

Celebrating the Life of Dorothy Mullen

Many in Princeton and beyond knew and loved Dorothy Mullen, for her spirit, generosity, community activism, and her many initiatives, most notably the school gardens and the Suppers Program. 

A memorial service will take place this Saturday, Oct. 30, at 10am at the Presbyterian Church in Lawrenceville, NJ. The service will likely be very crowded, but there will also be an opportunity to witness the occasion via zoom. 

I wrote a song called Dorothy's Garden after seeing Dorothy for the last time, back in the fall of 2019. The song on the video starts about two minutes in. I will play a recording of the song at the open mic after the service, and recite the lyrics. Here's the sheet music, transposed to G for easier reading, and a post from a couple years ago about the garden she created in her front yard, which is now being tended by the new owner of her house.

Lyrics to Dorothy's Garden

Take a walk in Dorothy's garden, In the springtime in Dorothy's garden. Sleepy seeds in the dirt so mellow, Dreaming flowers of white and yellow. Come and see in the garden, Dorothy's garden, Kale and peas and carrots. And some peace you will find there, Always find where the weeds are a feint memory. There are children in Dorothy's garden, Finding free figs in Dorothy's garden. In the strawberry patch they linger. Quiet joy their presence brings her. And the bees on the asters, flying past her-- She is the master gardener. And the okra and sunflower feel her love As they grow towards the sun far above. Someone's learning in Dorothy's garden. Worms are churning in Dorothy's garden. Plants are turning in Dorothy's garden Into Suppers from Dorothy's garden. And the roots they will roam, always finding a home, In the loam, under Dorothy's garden.

Princeton Finally Plants its Fuel Tank Raingarden

The raingarden in front of the municipality's fuel tank on Witherspoon Street finally got planted. Like just about every piece of real estate in Princeton, large or small, this raingarden has a long and turbulent history. It was presumably created to receive runoff from a roof the town had built over the fuel tank. The roof was meant to protect staff from rain while they poured fossil fuel in their gas tanks, but spurred passionate complaints from neighbors, who complained about the visual blight upon a main entryway into town. 

Thus began a long period of deliberation and rethinking, leading to the removal of the much-maligned roof, and consideration of whether to spend even more money to move the raingarden somewhere else, for whatever reason.

While humans hemmed and hawed, nature began populating the bare dirt with various weeds, leading to a post on this blog called Princeton's Fuel Tank Raingarden Wannabe, identifying the various weeds and discussing which would be worth keeping. If one knows and loves plants--knowing and loving being very much intertwined--it's pretty easy to develop a new raingarden planting simply by editing what pops up on its own, augmented by taking excess plants from an existing raingarden and planting them in another. Planting one raingarden makes the next one all the easier to create at no cost beyond time spent.

The town has its own logic, however, for better or worse. The raingarden was left untended for a couple years until the brick facade disguising the fuel tank was completed, and then in mid-October a host of plants were purchased and installed, along with a thick layer of mulch. 

Soft rush were densely planted at the lower end, with purple coneflowers and black-eyed susans on the slopes. 

Though the men may not have been overjoyed at the task, it was good to see public works employees working with hand tools, away from all the rumbling machines that burn the fossil fuels hidden behind this raingarden. 

Beyond the benefits of raingardens--filtration of runoff, groundwater recharge, food for insects and birds--they are above all a quiet space. Raucous lawn mowers and leaf blowers are of no use in a raingarden, where only quiet tasks like weeding and planting are needed. 

The relentless racket of custodial lawncare that people so resent in our neighborhoods is the sound of machines simplifying and dominating nature while they feed climate change. When was the last time you saw an employee, public or private, quietly using hand tools in a garden? That's what made this scene along Witherspoon Street special. 

A Threatened Old Bridge, and Dead Fish Along Harry's Brook

We mostly hear about collateral damage, but there can be a lot of collateral discovery in the actions we take to care for nature or history. 

When I saw a young man named Galdino tuckpointing some stonework along Snowden Lane a couple weeks ago, I asked him if he would look at an old bridge that straddles a tributary of Harry's Brook just down the hill. 

Before a new bridge was built beside it in 1965, this old bridge was used by the Pynes of Drumthwacket to reach their horses at "Pyne Ridge", and by the Whiton-Stuarts, the Veblens and Einstein to reach what we now call Veblen House. The bridge carried Princetonians out to Herrontown Woods during its first years of existence.

It's a beautifully made bridge, built of arched stones, and as you can see it is starting to slowly come apart, flood by flood, stone by stone. If it were to collapse, the town would have a big mess on its hands, with the stream blocked by rubble.

I have suggested that the bridge be preserved, repaired, and used as part of a bike/pedestrian route to give the Little Brook neighborhood safe access to Smoyer Park and Herrontown Woods. Currently, anyone walking or biking needs to "run the gauntlet" where Snowden Lane narrows between steep ditches from Overbrook out to Van Dyke. 

But town engineers claim the bridge is now owned by the neighbor. Curious that a private homeowner would be responsible for a bridge whose collapse would block a New Jersey waterway.

The collateral discovery was that we noticed a number of dead fish in the stream. I put one next to a walnut for scale, and sent the photo to a young naturalist named Felix who is learning about fish in the local streams. He told me it's a creek chub.

Hard to say what's going on. Fish kills can be caused by bacterial outbreaks, or low oxygen when the water gets too warm. Maybe the misuse or overuse of pesticides played a role.

What IS known, however, is that this lovely old, carefully crafted bridge is not going to mend itself. Galdino pointed out that the stone arch work is not just on the facade but extends the full width of the bridge. Proposed development upstream could increase the runoff headed towards this fine piece of history that speaks to a time when Snowden Lane was considered a country road.

A Beautiful Release Dove Lingers on Franklin Avenue

It's gone now, but for ten days, a beautiful white dove lingered at the street edge in front of a recently vacated house on Franklin Avenue in Princeton. 

The first time I saw it, I thought it strange, but kept driving. The next day, it was there again, and I stopped.

The fact is, I don't remember ever seeing a bird quite like this. It wasn't a rock dove, or a mourning dove, or a seagull. It looked like a displaced pet, yet when I approached, it suddenly flew up like a bolt of lightening, and made a breathtaking arc far above. It began to circle back, saw I was still there, then headed north beyond the trees. I had never seen such a fabulous flight. The next day, it was there again. The neighbors who told me the dove had been there a week and a half said it "looked like it was waiting for an Uber."

Might it have been a pet of the people who had just moved out? Maybe its homing instincts are such that it escaped during their move and returned to what it considered home. But neighbors didn't think the previous residents had had a pet bird. The dove walked about on the pavement, pausing to peck at the ground. 

 

After several days of seeing it there, and asking neighbors, none of whom knew where it had come from, I finally got serious about wondering what this bird was. Some internet research yielded two names for the bird: "release dove" and "java dove". Apparently they sometimes get included in wedding ceremonies, the idea being that the dove or doves will be released at a celebratory moment and fly up in the same breathtaking manner I witnessed, symbolizing the hoped for trajectory of the marriage, then dutifully fly up to 600 miles back to their owners until the next wedding gig comes along. They can also make symbolic appearances at funerals and public ceremonies. 

The wikipedia page reflects disagreement about the tradition of release, with concerns raised about the fate of the birds following the release--the logic being that the birds are white and therefore particularly vulnerable to attack by hawks and other predators. Breeding for the pure white feathers may cause attrition of their homing instinct, making them more likely to get lost rather than return to their homes. It's conceivable that's what happened in this case, though the bird looked very sure it was in the right place.

There's even apparent disagreement about the latin name for the bird, with one sentence calling it a domestic rock dove (Columba livia domestica) and another calling it a barbary dove, (Streptopelia risoria). 

Photos from 1950 show a dovecote near the Veblen House in Herrontown Woods--the metal structure on the right that looks like a rocket. Most likely dating back to the 1930s when the Whiton-Stuarts owned the property, the dovecote could have housed doves for eating, carrier pigeons for messaging, or pigeons that were bred for display. 

The dovecote is long gone from the Veblen House grounds, and the fate of the release dove on Franklin Avenue is a mystery. It may have flown off in search of food, been found by its owners, or been caught by a predator. But one thing now is deeply known and felt, and that is how astounding a dove's flight can be. 

Phyllis Marchand and the Benefits of Deer Culling

This past Sunday, Oct. 17, my Sustainable Jazz duo performed at a tribute to Phyllis Marchand at the DR Greenway's Johnson Education Center. 

Phyllis was mayor of Princeton Township for 14 years. For those accustomed to Princeton having an all-Democrat town council, it's astonishing to read that when Ms. Marchand was first elected in 1986, she joined a township committee that had been all-Republican.  Her long tenure preceded the merging of township and borough. Since I lived in the borough, she was not really my mayor, but her environmentalism has had a lasting impact on the natural areas I've helped to manage over the years. 

Among her many achievements, her courage in starting a deer culling program 21 years ago had all kinds of longterm benefits--dramatically fewer car accidents, recovery of native plant species, improved wildlife habitat, and a healthier deer herd. The culling program was very controversial at the time, with Mayor Marchand and other supporters having to endure heated criticism and personal attacks. 

The data are very strong on the benefits of annual culling by professional hunters. Here is some data collected for a post about deer hunting in 2013. Deer killed in roadway collisions dropped from the high of 342 in 2000 down to 68 in 2010. In 2019, 555 deer were killed in the township by vehicles and amateur hunters. In 2010, after ten years of professional deer management, the total number killed by vehicles, hunters and professionals had dropped to 286. Thus, one can say that investing in professional deer management actually has served to reduce the total number of deer killed each year. 

The township tried to save money by cancelling the deer culling in 2014, but deer numbers rapidly increased and the annual contract with professional hunters was quickly reinstated.

Given all of Phyllis Marchand's contributions to society through her long life, I had assumed that the deer culling issue was larger for me given my primary interest in nature. But the NY Times began its lengthy obituary with a detailed account of the controversy surrounding deer culling, including one sentence that is demonstrably false:

In the end, town officials declared the program a success because it had reduced collisions between deer and vehicles by 40 percent. But it didn’t solve the problem. The deer remain abundant, and while Ms. Marchand had contracted with White Buffalo for only five years, the town is still using its services.

The contract has been in place every year since 2000 except for one, and the deer herd is now small enough that many native plant populations have been able to recover. The obit doesn't mention the ecological benefits, but the article it links to does. Spicebush--a native shrub that is particularly important for bird habitat--is a dramatic example of recovery, once liberated from intense deer browsing. And the reduced browsing pressure has allowed many native wildflowers to bloom and provide nectar and pollen for insects. Having banished wolves and other predators of deer from the landscape, we then bear the responsibility to keep deer numbers in some semblance of ecological balance. Hunting is a way of stepping in to fill the void in natural predators. Mayor Marchand understood this twenty years ago, and weathered the storm to institute a policy that has proven its worth.

Phyllis Marchand, I've learned through her family, was a great fan of music sung by Nat King Cole and others. Sustainable Jazz usually plays all-original jazz and latin, but we added some of Phyllis' favorites from the American song book, including High Hopes, first sung by Frank Sinatra--a song whose lyrics can grow on you if you happen to have a dream. It's interesting to read in wikipedia that John F. Kennedy used a version of High Hopes as a theme song in his presidential campaign in 1960. 

What to Think of Black Vultures?

The other day, I was thinking about how much I love chipmunks, and how much my sister hates them. How do we reach opposite opinions about the same animal? Are the chipmunks that now run amok in her vegetable garden the same chipmunks I fondly remember from childhood, scampering over rocks, their cheeks puffed out with their latest gleaning of nuts? 

Vultures also tend to get mixed reviews. Some find them creepy; others laud their soaring skills and their ecological role of cleanup crew. There are two types in Princeton--the common turkey vultures and the less common black vultures that have been expanding their range to the north over time. Many people look up, see a bird soaring, and think it must be a hawk. More often it's a vulture, usually a turkey vulture, which is black with a feint streak of silver along the back of the underside of its wing. Black vultures' wings from below appear to be tipped with silver.

For years, black vultures have perched on the chimneys of the Veblen Cottage at Herrontown Woods. At first we considered them a bad omen, but then as we learned more about them we gained respect and began to appreciate their presence. The photo is by Julie Tennant, a neighbor to the preserve who has taken an interest in the birds. The vulture still has a ring of fluffy immature feathers around its neck.

Each spring a pair of black vultures raises its young in the corncrib next to the cottage. People of course want to take a peek inside to see the chicks, but we worry that loose dogs and too many visitors could ultimately scare the vultures away.

It looked like that had come to pass this summer when the vultures disappeared for awhile, but then we saw a chick out for a walk on the cottage grounds, its plumage very much in transition.

Four years ago, one of the two chicks was slow to mature, causing the family to linger far longer than usual, often perching on the chimneys of the Veblen Cottage. We were won over by the patience the parents showed as they waited for the second chick to mature.
 

It was odd, then, having learned to care about the vulture family, to encounter an article in the NY Times entitled 

"Black Vulture Attacks on Animals May Be Increasing." Ranchers out in the midwest are claiming they are losing newborn livestock to black vultures that have been moving north into new territory. 

It's not clear from the article whether the ranchers are losing healthy livestock, or if the vultures are moving in on calves that were stillborn or dying. 

We're used to thinking of animals as occupying distinct categories. Predators kill, scavengers do not. But it would be interesting to explore how much overlap there is between the two roles. I've been struck by how black vultures's bodies look more raptor-like than the bodies of turkey vultures. And there's a bird we'd see along roadsides in Patagonia called the Chimango caracara. By its appearance it looks like a hawk, and yet it more often plays the role of a scavenger.

American black vultures are also expanding their range in Patagonia, potentially competing with Andean condors for food. Articles like these could work against the trend of our feelings about black vultures, which in Herrontown Woods have evolved towards affection. For us, they are fascinating birds, wild and yet drawn to live on the edge of our world, raising their young, and perching on the roof of nearby All Saints Church. (photo by Peter Thompson)

Help Your Local Trail Crew -- Sew a Rock Net

Here's an indoor way to help out the volunteers who take care of nature trails in your local nature preserve. Sew a "rock net" for carrying the big stepping stones that help hikers get across streams and through muddy patches. I was corresponding with Alan Hershey of DR Greenway to update trail info for Herrontown Woods on NJTrails.org, and somehow the conversation turned to rocks--big rocks, the kind that work really well for trails--and how to get them to places too rugged for a hand truck. He recommended a rock net--a kind of cargo net developed by Deb Brockway, who has made several and steadily improved the design.

Below are instructions for anyone who has a knack for sewing and is looking for a good project. I know we could use one of these at Herrontown Woods, and other organizations could benefit as well. Thanks to Deb and Alan for this information.

The rock net, sometimes called a cargo net, looks like this:

Here are instructions from Deb:

Below are some helpful ideas from Deb on where to find materials:

"It is possible to buy a custom-made cargo net but they are relatively expensive, which is why I decided to make them. I have used 2-inch width recovery tow straps. The first straps I used I bought at Home Depot, which allowed me to feel the weight and clearly see the weave of the webbing. Those straps were no longer available from Home Depot, so I bought the next ones from Amazon and was not as pleased with the quality of the webbing (though there are lots of options, so I’m sure there are some with a tight weave). Next time around I will go to one of the online webbing sites to purchase it. That is a less expensive option and some of those outlets will cut all the pieces to requested lengths for no additional charge as compared to cutting a single entire length. The added benefit is that all of the ends would be (or should be) heat sealed when they arrive. If you cut the webbing you will need to melt all the cut ends to prevent fraying.

The attached document has additional information and sketches for cutting, assembling, and sewing a net like the orange one in the photo.

FYI… another option is to tie a net using thick rope. A trail crew I have worked with created such a net fashioned after a fishing net. It had a diamond net design, with knots tied at the junctures and some sort of gummy substance covering the knots."

Where Have All the Pollinators Gone? -- Summer, 2021

Wherein is discussed the season's paucity of pollinators, the curiously prolific presence of hornets, and possible causes thereof. 

With the coming and the going of this year's autumnal equinox, it's time to look back on a long summer and ask, "What happened?" Or, more precisely, "What happened to the happening that didn't happen?" 

There's lots of talk about how insects are in decline and that we need to plant more wildflowers to support them. A local ecologist and avid birder, David Wilcove, co-wrote an oped in the Washington Post about the danger posed by insect decline, and the need to better monitor populations, as is done with birds.

In past years, a summer's climactic buzzfest on the boneset

This year, there was a steep decline in pollinator numbers in Princeton. Each year I grow a banquet of wildflowers in my backyard for all manner of insects to feast upon. In past years, they'd come from near and far, their numbers building through summer, climaxing in late August in a buzzfest on the boneset. Though mountain mint is another great draw for insects, in my yard it was boneset in particular, clustered here and there in the garden, that in past years drew the multitudinous shapes and sizes of the insect world. Its broad disks of tiny white flowers seemed like a Serengeti in miniature, an open plain perched conveniently four feet above the ground, teaming with life. It was a chance to see the insects close up, they being so focused on the nectar or each other that they took little notice of me.

Then, two years ago, and again last year, the numbers of insects were down--still numerous but not enough to stir that late-summer's jazzy feeling of frenzied activity. 

2021: An astonishing diminishment

And this year? This year, boosted by the rains, the wildflowers grew to fabulous size. Broad arrays of blooms mounted on multiple stems stood at the ready. In early summer, while periodical cicadas held center stage, the numbers and variety of pollinators were building nicely. 

But then, as the wildflower meadow's heavy hitters--the cutleaf coneflowers, Joe-Pye-Weeds, bonesets and wild sennas--unveiled their fabulous blooms for the mid-summer festival of nectar, the insects were no-shows. Abundant flowers had few pollinators, and sometimes none at all. Diversity dwindled to some tiny somethings, a few bumblebees and even fewer honey bees. 

Sifting through possible causes for the decline

Possible causes for the dramatic decline have been offered: extreme heat, more homeowners fogging their yards for mosquitoes, expanding monocultures of lawn and invasive species. Or perhaps the climate-changed winters have messed with insect dormancy.

The rains of July, the rains of August

What I have particularly noticed over the past three years, however, is the increase in rain during the summer. Rutgers precipitation data for NJ show increased precipitation particularly over the past two years in July and August. Not only has there been more rain, but the intensity of the rain has increased. The sound on the roof is different--one can hear and even feel the extraordinary density and weight of the rain. The deep trauma of Hurricane Ida was the climax among multiple intense storms before and after. The ground and foliage are literally getting beaten up by these deluges. Insects try to hide during storms. Some live in the ground. The harder the rain, the fewer places to hide, and the more likelihood that a ground nest will be flooded out. All that sustained moisture could increase the risk of disease, which an entomologist friend says can play a big role in bee numbers. 

Some of us noticed other changes as well. Gladly, the numbers of odorous house ants invading our kitchen were down from previous years. Mosquitoes in our area seemed relatively rare in early summer, though numbers surged later in the season--tiny ones, probably asian tiger mosquitoes. 

A proliferation of hornets

What was most striking and very strange was a proliferation of hornets. Last year, I seldom saw them, but oftentimes this summer, approaching a patch of flowers, the first thing that would catch my eye was not pollinators but the hornets that can prey upon them. 

We have two kinds of insects called hornets. One is the European hornet, which looks to me like a stocky bee--black markings with a particularly thick yellow abdomen.

The other is the bald-faced hornet, a native insect with black markings and a whitish face. 

Both are hard to photograph because they don't land, but instead keep cruising around the flowers. Periodically they may bump into a bee that was minding its own business on a flower. The contact lasts a split second, then the hornet flies on. The purpose of this brief harassment is not clear. 

Here's a bald-faced hornet in adult and larval form, found on a fragrant of nest someone left at the curb. Both kinds of hornets live in nests that are in or hang from trees. The paper they make, by the way, is beautiful when looked at close up.

Why the proliferation of hornets, cruising relentlessly among the flowers with a sense of urgency but no clear goal? Maybe they just seemed more numerous due to the lack of other insects to catch one's attention. Or maybe the fact that they live in elevated, waterproof nests allowed them to better survive the intense storms. 

The seeds of change planted over centuries

In any case, this summer was not the lively pollinator party I was used to playing host to, both in my backyard and at our Botanical Art Garden (the "Barden") in Herrontown Woods. One interpretation is that the carbon dioxide we've been scattering to the winds is now coming home to roost, in the form of weird winters and intensified storms. In Princeton, basements flooded that had never flooded before. It's not a stretch to hypothesize that many bees also find themselves newly vulnerable to the merciless power of the rain. And then, on the sunny days when pollinators can make it to the flowers, there's the haunting background of patrolling hornets.

In a docile wasp, some small comfort

As students returned to the university, I remembered helping my daughter move in to Whitman College two years ago. In the courtyard, I had noticed thousands of wasps cruising just above the grass. It was a mating dance, of no danger to the parents and students passing by, of blue-winged wasps. I had recognized their distinctive orange abdomen from those that would frequent the flowers in my backyard, a mile away from campus. 

This year, I had seen only one in my yard, and wondered whether their improbable annual ritual was still playing out at Whitman College. 

What I found on Sept 2nd were perhaps a hundred wasps flying in their usual criss-cross manner a foot above the lawn. Some seemed fatigued by it all, and would abandon their flight to sit among the grass blades for awhile. Though their numbers were down from the thousands I'd seen two years prior, I was glad to see any at all. And a student sitting in a lawn chair, scrutinizing his computer, told me there had been many more ten days prior when students first began moving in. 

It would be nice to think that the paucity of pollinators I observed this summer was an isolated affair. But others around New Jersey have made similar reports. An entomologist friend who lives in Oregon told me that he's seen "a very significant decline in pollinators" this year, probably due to drought, though he also said that each species can vary in numbers year to year. 

An ark is built of something more than flowers

We take so much for granted in our lives. When something breaks, that's when one has to study up and figure out how it works, what went wrong, and how possibly to fix it. The insect world has been taken for granted since forever. Annual bird surveys benefit from a community of avid birders, but citizen scientists who are up to speed on the mind-boggling diversity of insects are fewer to come by. We thought we could just plant some flowers and the insects would come, but the needs appear to be far deeper than that. 

Mile-a-Minute Spreading into Princeton

 One of the more noxious invasive plants that has been spreading across NJ is Mile-a-Minute. It's a prickly vine that, though an annual that must grow back from seed each spring, grows so fast that it can cover large areas of roadsides and field edges. Over the past several years, I've been knocking out small infestations at the Princeton Battlefield and near Rogers Refuge, but this year I'm finding new patches springing up around town.

Then, driving my daughter to MarketFair along Canal Pointe Blvd a week ago, I saw a massive infestation that surely is a major source of the seeds that birds are then spreading across Princeton. 

The vine has a distinctive triangular leaf. Berries are just beginning to ripen. If you encounter it, put some gloves on, pull it out and put it in the trash. Putting it in the compost would allow the seeds to spread. 

The infestation along Canal Pointe Blvd is behind 701 Carnegie Center Drive. In the aerial, you can see rows of solar panels over the parking lot. To the left of the solar panels is a big mowed lawn, and to the left of the lawn in the photo is the unmowed land upon which the Mile a Minute is growing. My friend Peter researched the owner, which on the deed appears to be "BXP Carnegie Owner, LLC%G". The land has a farm easement, so is only valued at $39,000, which means the owner is paying next to no taxes to hold very valuable property, meanwhile expediting the spread of Mile a Minute and the associated nuisance it will cause. 

It's hard to photograph the cocktail of invasive species at the site. The white flowers are of white snakeroot, a native wildflower, which is besieged by a layer cake of stiltgrass, porcelainberry, and Mile a Minute climbing on top of it all. 

Further down the road is a series of trees damaged, perhaps by a small tornado or similar localized intense winds as the remains of Hurricane Ida came through on Sept. 1. Similar damage to trees was seen in Princeton Battlefield, where a row of mature white pines along the edge of the field was decapitated.

What we're seeing is the increasing impact of plants out of place (species that turn invasive after being introduced from other continents) and carbon out of place (carbon fuels extracted from underground that we burn, thereby releasing additional carbon dioxide into the atmosphere). Our machines have increased global warming CO2 by a whopping 50% over pre-industrial levels thus far. This year has felt like a radicalization of both invasive species and climate change. 

Treepedia Author to Speak at Veblen House--Sept. 24

Come this Friday, Sept. 24 at 6pm, for a free event next to Veblen House in Princeton. Author Joan Maloof is coming to Herrontown Woods to discuss her new book, Treepedia: A Brief Compendium of Arboreal Lore. The book has 100 short but stimulating profiles of extraordinary trees, forests, and the people working to protect them. 

The event will take place on the wooded grounds of Veblen House. The Friends of Herrontown Woods is hosting the event, which is sponsored by the Princeton Environmental Film Festival.

We're looking forward to meeting Joan and hearing about her book!

More information here.

A useful sampling of the book can be found here. 

Buy locally at a competitive price.

Labyrinth Books will be on hand at the event with copies of the book as well.

Butler Tract Meadows Restoration?

This is the story of what can go wrong if you plant a native meadow and then don't take care of it. Princeton University has been installing some native meadows, and some have done a lot better than others.

Just off of South Harrison Street, framed by Sycamore Rd and Hartley Ave, are some meadows that were planted in 2016 following the university's demolition of the Butler apartments. It was a well intended succession from graduate housing to native meadow, and when I took a look in 2019, the meadows were still hosting diverse native wildflowers. 

Two years later, these signs appeared: 

"Butler Tract Meadows is under an invasive management program for this year."

For most of the summer, it wasn't clear what that meant. The signs appeared early in the growing season, but I could find no sign of any action. 

 

This photo tells the story of what happened to the native meadow over the course of five years. The usual nonnative invasive species moved in and began to dominate, with mugwort foremost among them. The white flowering plant on the left is Japanese knotweed, which can form large monocultures as well. Bamboo is getting a foothold in the lower lefthand corner of the photo, and in the distance can be seen the sproutings of black locust, a native tree that nonetheless can move aggressively into native grasslands. 

Sericea lespedeza (L. cuneata) is another super-aggressive nonnative. Newer on the Princeton scene, it can rival mugwort in its capacity to displace diverse native plants, for instance along the gasline right of way that crosses the Princeton Ridge. 

And here's crown vetch, which climbs over everything around it. Both crown vetch and Sericea lespedeza were planted extensively along freeways to control soil erosion, reducing one environmental harm while creating another. 

I did notice a few native species still present, including this wild senna. The only practical means of shifting the balance back to the native species on this scale is through use of herbicides. Some people lump all herbicides together and pronounce them evil poisons--an indiscriminate rejection borne of their often indiscriminate use. But there are many kinds and many formulations, some far safer than others, and the aim as with medicines for people is to use as little as possible, in a targeted way. 

The way to reduce the use of herbicides is to be proactive and intervene early to kill the invasives when they are still few in number. That would have been something to do from the beginning, back when a more targeted, minimalist approach was possible. 

My friend Basha who lives across from the Butler Tract told me they had finally done some spraying. A week later, I took a look. Here you can see the black locust tree sprouts turning brown while many other invasive plants appear untouched.

This big patch of mugwort shows some sign of dieback, but pretty uneven results thus far.

I'm guessing that patch in the background of this photo was crown vetch. In the foreground is probably common cinquefoil (Potentilla simplex), which is native but a very rapid spreader.

It will be interesting to see how this goes. My experience is that institutions have always understood that lawns and landscaping take ongoing care, but they have yet to grasp that more naturalistic areas like meadows also need ongoing intervention. At the Butler Tract, they seem to be trying to figure out what that means.