Purple Muhly Grass and Piedmont Prairies

One of my favorite native prairie grasses is purple muhly. It's common name comes from its latin name, Muhlenbergia capillaris. The species name, capillaris, comes in turn from the latin word for hair, referring to its fine texture. Each fall, these two specimens in my neighborhood turn into purple clouds. Though I've never seen purple muhly growing wild hereabouts, there are other native prairie grasses to be found along the gasline right of way and the towpath: switchgrass, Indian grass, little bluestem, broom sedge, and big bluestem.

The one place I've seen purple muhly growing in the wild is in Durham, North Carolina, in a little piedmont prairie remnant that I'm proud to say we just saved from development. A flurry of emails and some timely intervention by city council members spared the roadside prairie from being obliterated by a "sidewalk to nowhere". Convention requires that a sidewalk be built, whether pedestrians would have any occasion to use it or not, and the typical landscaping imposed is turfgrass. The result, in this case, would have been to destroy an ark that had carried more than 100 species of native wildflowers, grasses and shrubs safely from colonial or pre-colonial times to the present. The complex interaction of plants, soil and hydrology is distinct to that site, so moving the prairie was not an option.

The prairie remnants in Durham have some kinship with our Princeton Ridge, in that both are characterized by underlying diabase rocks from which their soil is derived. The soil has a distinct chemistry that in turn supports a distinct flora. Princeton is at the northernmost extent of the piedmont, which extends down through North Carolina and beyond.

Why Does Black Locust Grow Next to Historic Houses?

One of my favorite trees, black locust, generally gets a bad rap. Though native to the Appalachian Mountains, it is considered invasive elsewhere and portrayed by many as a bad actor in the garden.

And yet, large and noble specimens can be found growing next to more than one historic house in the Princeton area. Walk behind the Clark House at Princeton Battlefield and you'll find two big specimens towering over the house (on the right in the photo).

Brearley House in Pennington similarly has five big specimens (a couple can be seen on the left). The Veblen House in Herrontown Woods has remnants of a mature grove of black locust close by.

The black locust shows up not only in the yards of historic houses but also in the histories of great men. There's the story of how Lincoln spent much of his time as a young man splitting rails and fence posts from black locust logs. John Muir is said to have had his first, fateful botany lesson under a black locust tree on the campus of the University of Wisconsin in Madison.

One potential downside of black locust is its capacity to sprout abundantly from roots after being cut down. This can be annoying in a garden, and in areas of the country with prairie remnants, it reportedly can become a woody bully, shading out these highly sun-dependent habitats and re-sprouting aggressively if cut down or burned. In groves where it was grown for making decay-resistant fenceposts, however, its resprouting from the existing root structure conveniently reduced the time between harvests.

The criticism that black locusts take on the web--thorns, brittle branches that fall in windstorms, aggressive sprouting--conflicts with observations in my neighborhood, where there are several beautiful specimens in people's front yards that the owners are very pleased with.

Black locust is a fast-growing tree that offers first rate fence posts, firewood that burns unusually hot and clean, abundant flowers for the honeybees, and an appealing contrast between dark, craggy limbs and dissected, light-green leaves. These are the features that may explain its presence in historical landscapes.

The Birthday Ducks

Our two backyard ducks turned one today.

What does one do for a duck on its birthday? A nice little pool full of fresh water is a good start. It wouldn't be right for a duck to be a duck out of water on its birthday.

Hard to believe they were once a living version of rubber duckies, little more than a day old, freshly delivered from California in a cardboard box to the Princeton post office out on Route 1.

If any month can be called normal for receiving ducks in the mail in New Jersey, it's definitely not November. Still, things worked out. They and their baby mallard companions lived their first days and weeks in a spare bathtub with furniture provided by our younger daughter. The accommodations came with all you can eat oatmeal and starter food from a farm supply store just up the road.

From day one, they were ready to follow us anywhere, including an extensive hike in the local nature preserve.

That is they, down by her feet.

Daisy, upper left, is a Pekin duck with a mass to wing ratio that makes flight beyond a few feet problematic, but I like to think that her impressive size and personality is helping give hawks second thoughts about swooping in.

The other ducks, particularly the mallards, could have flown off long ago, but have apparently found our wildflower and shrub-strewn backyard sufficiently entertaining and bountiful to hold their interest. They get along fine with our two chickens and live together in the homemade coop. (The mallards have since moved to the country, which is a separate post.)

The mini-ponds were a plus during the rainy spring and summer, though lack of heavy rains in recent months has left them dry.

Molly, on the right, is a runner duck who expresses a lot of her duck thoughts and feelings by bending her neck in various directions as she walks. The tub gets filled with runoff from the roof, and can be tipped over and emptied if mosquito larvae show up, or if the ducks make the water muddy.

The ducks are quiet most of the time, but can get into conversations. Neighbors tell us they like hearing them, and the sounds must come as a surprise to users of the public park behind our house.

Beyond an occasional coop cleaning, there isn't much more to having them than opening the coop up in the morning, giving them food and water, and making sure to close the door of the coop at dusk after they've gone back in. It's nice to have pets that really enjoy the yard.

When it comes to ducks and giving, we get far more than we give, with each of the ducks bearing an egg a day.

Happy birthday, Daisy and Molly!

Gone Fishing

This is not what I was doing during a recent pause in PrincetonNatureNotes posting, but hard not to like this scene, taken a month ago at Sourland Mountain Preserve. There's a pond next to the parking lot.

What I have been doing is a different kind of fishing expedition, writing theater pieces having to do with climate change, working with the Rotary Club of Princeton to gain access to the Veblen House and cottage to begin restoration work, and working with the Ellerbe Creek Watershed Association to save a rare piedmont prairie remnant in my former hometown, Durham, NC from being destroyed by a "sidewalk to nowhere".

In fishing, one can only control where and how, not the final result. One has no power to command. Writing a theatrical piece starts with an idea, but whether the words will emerge from the well is hard to predict. Trying to save a publicly owned historic house or a historic prairie also involves a lack of ultimate control, with only an alluring proposal and persistence to influence the result. On the surface, climate change may not seem a promising subject for theater. The house and prairie don't look like much from the outside. But any fisherman knows that you don't judge a body of water by its surface, but by the riches underneath.

Mysterious Insect

Most insects are mysterious to a botanist, but this one, encountered about a month ago at Princeton's Rogers Refuge, down from the Institute Woods, was particularly so. Something had used a purple loosestrife leaf to hold what looked like a miniature bundle of cotton candy.

The remains of a caterpillar were still there. My crack research team is on the case, with a breakthrough expected any day.

Migration Update--Monarchs and Red Knots

This year's count of monarchs overwintering in the mountains of Mexico is ongoing, as the monarchs continue to arrive. There's an update page, apparently updated weekly. Here's an update from Nov. 10:

As of November 10th, there were 10 trees filled with monarchs at El Rosario Sanctuary. This compares to 60 trees on November 1, 2011.

You can see how the numbers have fallen, with the change in U.S. farming practices, particularly widespread adoption of Roundup-Ready GMO corn and soybeans, being a big factor in the decline.

Another extraordinary migration threatened--The Red Knot

Below is info from Delaware Riverkeeper on a proposal to list the Red Knot--the robin-sized bird that flies nearly 19,000 miles each year, from southern Patagonia up to the arctic and back--as threatened. There's a quick link provided where you can put your vote in for increasing the designation to "endangered". Long-distance migrating species are the most affected by changes in climate, because their arrival at different locations along the way need to be well-timed with available food sources that will fuel the next leg of their journey. This link takes you to a previous post with more info on the red knot, the heroic efforts to save it, and its annual stopover in New Jersey to feast on freshly laid horseshoe crab eggs.

Speak Out to Save the Red Knot, a Delaware Bay Shorebird, from Extinction
Support the Proposal to List the Red Knot Under the Endangered Species Act – But Urge a Listing of Endangered Rather than Just Threatened.
Red knots that migrate through Delaware Bay have declined by 75 percent or more since the 1980s.  The current number of these beautiful birds hovers around just 25,000 in our Delaware Bay population.
While the Delaware Riverkeeper Network filed in 2005 to have the species listed for protection as early as 2005, only now, as the result of litigation, has the US Fish & Wildlife Service finally gotten around to proposing an increased level of protection the birds so desperately need.
Today the US Fish & Wildlife Service is proposing to list the Red Knot as Threatened under the Endangered Species Act.  This step is vital if we are to protect the species from extinction, but it is equally important that the level of protection be that of Endangered, not just Threatened.
Please take a moment and send your letter today.
http://www.delawareriverkeeper.org/act-now/urgent-details.aspx?Id=155

Fantastical Sculptures of Firewood and Living Plants

This wood, holding carbon and sunlight harvested locally, will come in handy when it's fully seasoned, four seasons from now. In the meantime, it must be dreaming fantastical, cellulosic dreams of all the marvelous shapes it could take if only its owner were a more ambitious sculptor.

Such marvels on the internet make this past year's garden house of firewood, already stripped down as its curved walls are fed to the stove, look even more modest.

More fantastical and totally awesome than the firewood sculptures in the first link are these horticultural "live art" sculptures. Thanks to Marge for the link. Below is a description:

"Once every three years, there is an international competition in horticultural sculpture, called "mosaiculture," in a major city in the world. This year it is Montreal . This is not topiary but rather creating sculptures out of living plants. The greatest horticulturalists in the world, from 20 different countries, submitted plans a year in advance. Steel armatures were then created to support the works (some 40 feet high); they were then wrapped in steel mesh and filled with dirt and moss and watering hoses. Then they ordered 3 million plants of different shades of green and brown and tan, and these were grown in greenhouses all over Quebec . In late May, these horticulturalists came to Montreal and planted all of their plants in the forms at the Montreal Botanic Gardens, and they have been standing for three months now. There were 50 major sculptures along a path two miles long. They were incredible. If you would like to visit a few and walk along the path with me, click on or paste http://myvirtualgarden2.blogspot.com/2013/09/mosaiculture-exhibition.html."

The Color-Coded Forest--Nature's Halloween

This time of year, the forest does its own inverted version of Halloween. Rather than obscuring their identity behind costumes, the trees and shrubs reveal their inner identity. As the chlorophyll fades away, the leaves show each species' true colors, which had been there all along, hiding behind the green facade. These bold declarations make it suddenly easy to identify every bush and tree in the forest, near or far. In this photo, a small sweetgum tree shows its yellow, with Photinia behind it tending more towards brown, and the still green bush honeysuckle rising farther back. Flowering dogwood pokes in some burgundy at the top center of the photo.

Some species are tricky, varying their color depending on location. In front of the Princeton Shopping Center (no photo here), the winged euonymus shrubs lining the old gas station site turn brilliant red in full sun. Given less sunlight, as here, growing at the edge of the woods, they turn a modest pink.

In deep shade, their leaves turn white in the fall.

The native euonymus--Hearts-a-Bustin, which is currently extremely rare locally--also can turn this uncanny, ghostly white.

Very dramatic has been the Japanese maples growing next to the Veblen cottage out at Herrontown Woods, whose condition makes it seem to some a haunted house out in the forest.

The color coding can be useful for surveying the extent of species that are proving to be invasive, like this wisteria that's gone rogue around the Veblen House,

as well as for finding rarely occurring natives like this hazelnut, standing out from the surrounding honeysuckles.

Hazelnuts are real loners. There are three scattered specimens at Mountain Lakes, and only two found thus far in Herrontown Woods and vicinity.

Sourwood and Other Trees of Christ Congregation

Each year about this time, I make the pilgrimage to the Christ Congregation church to see their two beautiful sourwoods--a native tree I first encountered in the understory of North Carolina's piedmont woodlands. It's rarely planted in Princeton, and for some reason the USDA site shows it as indigenous to most eastern states but not NJ.

On Walnut Street, across from Princeton High School, the church has an interesting history with trees--a controversial one that came down some years back (see below), a new one coming up, and some nice mature specimens.

My visit happened to coincide with some bulb planting by Dwight Wilkinson, who declared he was a proud member of the PHS class of '62. The bulbs went in around a magnolia tree planted in memory of the church's five founders, one of whom was Dwight's father.

The magnolia turns out, like the sourwood, to be a species more typical further south--a southern magnolia (M. grandiflora). This particular cultivar, according to Dwight, is more cold-tolerant, with bright coppery undersides to the leaves.

The sourwood's distinctive golden seeds--its genus name Oxydendron refers to the finger-like rows of seeds--contrast with the brilliant red foliage. Dwight was glad to finally learn the tree's identity.

The two sourwoods are on the left, with an impressive specimen of American holly on the right.

The other side of the church is a good place to compare the mottled bark of the Korean dogwood (Cornus kousa)

with the cobblestone-patterned bark of the native dogwood (Cornus florida).

The controversial tree that came down years back was a big beautiful pin oak that was sacrificed so that the church could install solar panels in back, on the flat part of the roof. The relevant shade tree commission (borough?) defended the tree, but the church group brought data to the Princeton Environmental Commission, which I was on at the time, showing that the solar panels would reduce CO2 emissions by many times more than what the tree could absorb over its lifetime. Plus, the panels shade the roof from the sun much like a tree, and may provide some insulation in the winter. Only after considerable persistence did the church finally get permission to take the tree down. Even though the tree had looked to be in excellent condition, the town arborist later told us the cut portions showed signs of bacterial leaf scorch.

Monarchs Arriving in the Mountains of Central Mexico

I'd like to think that this monarch, which visited our backyard garden in Princeton, NJ on September 20 to feed on some ironweed nectar, is arriving today at its overwintering site in the mountains of Michoacan, north and east of Mexico City. The red triangle at the bottom of this map shows their destination. It's quite a feat for them to zero in on the tiny spot on the earth whose microclimate cradles them through another winter. The last leg of their journey, buoyed by favorable winds and guided by the mountains, is described here.

Another site offers insights into their arrival's cultural significance:

"Every year, the first monarchs traditionally arrive at their winter home in Mexico by the first of November. People connect the arrival of the monarchs with two events that take place in Mexico at the time, the corn harvest and Dia de los Muertos."

Be well, monarch. May your children's children visit us next year.

When Races Come to Greenway Meadows

What does a botanist do while waiting for the cross-country racers to come? Admire the seeds of common milkweed poised to take flight,

and the coppery tones of broomsedge (a native prairie grass).

It never occurred to me to run any distance anywhere, but what a great way to get kids out in nature, crossing countryside, taming a trail through a wild landscape, testing inner nature in a natural setting. Greenway Meadows: where the bright colors of running shoes meet earthtones, and toned muscles take to the hills.

Trouble For Princeton's Trees

To inoculate you for the news carried in this post, I'd like to point out that wishful thinking is not the same as hope. In fact, to the extent that it postpones action, wishful thinking can be thought of as the enemy of hope. Bad news is much more easily accepted if we feel confident in our capacity to work together as a community to respond.

Princeton has a real challenge ahead if it is to keep its protective canopy of trees in coming decades. There are the losses in recent years due to storms like Hurricane Sandy, the ongoing attrition as some pin oaks and red oaks succumb to Bacterial Leaf Scorch, and then there is the gathering storm just to our west of the emerald ash borer. Through a recently completed tree inventory, Princeton can now look at the numbers, and they don't add up--the number of trees likely to be lost dwarfs the number of trees being planted.

Doing the Math

Here are the numbers, rounded off for easier math, as presented by Bob Wells of Morris Arboretum, who directed the inventory and integrated it with an earlier survey of borough trees done by Jim Consolloy. These are only the trees growing in the street right of ways. Trees in parks, preserves, and on private property are not included. Of Princeton's 19,000 street trees, 3000 are in poor condition--unlikely to live beyond the next five years. Another 6000 are in fair condition, with an estimated life expectancy of 5-15 years. Even those trees in good condition are threatened by a growing collection of invading insects and diseases, along with the increasing weather extremes associated with climate change. For instance, some of Princeton's 1400 pin oaks and red oaks will continue to be lost to Bacterial Leaf Scorch.

Compare those numbers with the current replacement rate. Princeton purchases and plants about 60 trees each year along the streets. Its tree crew takes down about 250 trees each year in parks and along streets. The numbers offered up by the tree inventory estimates the annual loss of street trees to be a minimum of 600. By this math, we will be losing ten trees for every one being planted. And this doesn't even take into account the imminent arrival of the Emerald Ash Borer.

http://www.tinleypark.org/index.aspx?nid=648

Emerald = Less Green

Perhaps most worrisome is the looming threat to Princeton's most common tree, the ash. We can expect to lose most of our 2200 white and green ash trees along the streets in coming years, plus the tens of thousands in our woodlands. The culprit is the emerald ash borer (EAB), an insect that hitch-hiked to southeastern Michigan in wooden packing crates from China, then proliferated to kill 50,000 trees before anyone knew what it was. Since its identification in 2002, EAB has been radiating out across the midwest, killing tens of millions of trees, including a relentless spread eastward through Ohio and Pennsylvania to the border with New Jersey. A map at this link shows New Jersey essentially surrounded by infestations in bordering states.

As chance would have it, the original EAB infestation occurred just north of Ann Arbor, MI, where I used to live. The city of 100,000 had to spend $5.8 million removing 10,000 trees. Interestingly, ash continue to sprout in the woodlands there, and can grow to 6 inch diameter, but the chances of their growing to maturity are slim.

Princeton has dealt with threats to trees in the past. A bacterium called Bacillus thuringiensis (BT) has been used to reduce the impact of gypsy moths. According to Greg O'Neil, Princeton's arborist, the wooly adelgid's attack on our eastern hemlocks was slowed down by pesticide, after which the pest appears to have "cycled through", allowing many hemlocks to survive.

There is, however, no known control for emerald ash borer other than individually treating each tree, and even then the results are mixed. As an added complication, Imidacloprid, the most frequently mentioned systemic insecticide for protecting ash trees, may be contributing to the decline of honey bees.

What To Do

The sooner we acknowledge the depths of the challenge we face, the more proactive we can be, and the better the prognosis for Princeton's tree canopy. There are a number of actions that can be taken. Treatment for ash trees that are particularly cherished is best undertaken before the emerald ash borer arrives. To better spread the work of removal over a number of years, some of the younger or less healthy ash trees can be taken down and replaced with another species before the invasion hits. The municipality should at least be planning for the extra staff needs and the seven figure expense coming down the pike.

The big question is how to replace so many trees with a limited budget. The more gaps in the street canopy, the more pavement is exposed to the sun, which through the "heat island effect" causes the town to be hotter than it need be in the summer. At $200 a piece, new trees aren't cheap, and then there's the planting and followup care to insure they survive.

One approach I'm exploring, as a member of the Princeton Shade Tree Commission, is transplanting "volunteer" trees that sprout in people's yards. Some species are more appropriate than others, and determining where to plant them along the street requires some guidance. Perhaps we can come up with a guide, and motivated neighbors could take initiative in their neighborhood to identify gaps and work with willing homeowners to get trees planted in an optimal place and manner along the street. Given the infinite reasons that can be summoned for inaction, such an approach will only work if people see how their own needs can be met by participating in the collective endeavor of shading our streets.

For me, the hope lies in the growth force and the natural affinity people have for trees. It's remarkable how quickly the red oak in this photo, which sprouted on its own in my next door neighbor's yard not that many years ago, has grown large enough to cast much-needed shade on our driveway.

Neighbors a couple doors down have transplanted volunteer trees to key spots in their yard--to shade the house, provide habitat for birds, and provide buffer from the street. After just a few years, they are robust young trees--a white oak, pin oak, American elm and tulip poplar. Another friend is growing a pawpaw and a fig in a sunny spot in their backyard--going for food rather than shade.

Each kind of tree has its strengths and potential drawbacks and vulnerabilities, but after years in which Princeton's landscape was dominated by mature trees, it's refreshing to see young ones coming on the scene, filling the voids, reaching for the sun.

Related to this, the opening reception for an art exhibit entitled "The Fallen and Unfallen: Trees in Peril" is Nov. 1 at the DR Greenway, 5:30 to 7:30. More info here. With paintings and photographs, it celebrates trees while also identifying some of the threats they face, in little snippets of info like this one.

Rogers Refuge--The Care and Feeding of a Nature Preserve

Where in Princeton can you look out upon a marsh, and see or hear hundreds of species of birds along the nearby trails over the course of a year? Rogers Refuge is a star among Princeton's nature preserves, but it keeps a low profile in the lowlands just down from Institute Woods and just up from the Stony Brook.

A nondescript sign on Alexander Street, just before the canal bridge, directs you on to a nondescript road called West Drive.

Take West Drive to a fork in the road, where another sign, a little more emphatic, points you down the left fork, a narrow gravel road that winds through Stony Brook's broad floodplain. Watch out for potholes and cars or trucks coming the other way--a small water plant is located back there. There's a small parking lot on the right, with a path leading to an observation tower.

The Friends of Rogers Refuge help manage the property. Members Lee and Melinda Varian hauled the stone to improve this trail, a bit farther down the road from the parking lot.

The short trail leads to a birdblind.

Friends of Rogers Refuge (FORR) is associated now with Friends of Princeton Open Space, which is a certified nonprofit and can accept donations in FORR's name. Though the refuge adjoins the Institute Woods, the land is actually owned by the American Water Company, which teams with the town of Princeton to maintain a pump that keeps the marsh marshy during droughts. Both the Washington Crossing Audubon and American Water have provided some funding at various times to help with FORR's management of the refuge.

It's a great example of how preserves often need human intervention to sustain the quality of the habitat. Partners for Fish and Wildlife, part of the federal government, came in years back to knock out the highly invasive exotic Phragmitis reed that was taking over the marshy area. That is an ongoing battle, as will be the more recently arrived porcelainberry, seen here climbing up a tree, which has proven its kudzu-like invasiveness not far away at Princeton Battlefield. It's very difficult, as distracted humans, to nip these invasions in the bud, while the undistracted plants are quietly growing and expanding 24/7.

It is the friends group of volunteers that plays such a critical role in identifying problems, then harnessing and coordinating the resources of these private and governmental entities to protect this special habitat down along the Stony Brook. That, along with the labor of love that goes into maintaining the trails, replacing handrails on the observation tower that were hollowed out by carpenter bees, and all the other acts large and small, are gifts back to a nature that feeds us with its beauty and diversity.

Though the periodic meetings of FORR must deal with problems like invasive species and concerns about the downward trend in migratory bird numbers, much of the discussion is a sharing of joy at what birds were recently seen, which species are becoming more numerous as the habitat improves, and which guests the birdhouses have been hosting.

(The house in the photo looks great, but the less ornamental bluebird houses scattered through the preserve have been getting more tenants.)

Lots of other posts about the refuge can be found by typing the word "rogers" (no quotes) into the search box at the top of this website.