Friday, February 19, 2010

Vines in Winter

Fortunately, Mountain Lakes Preserve has not been invaded by Bermese pythons (check out NOVA this coming Tuesday on PBS), despite the appearance of this poison ivy vine. It looks like it grew a winter coat, but poison ivy vines are always hairy, which rhymes with scary.

In this photo, the poison ivy is almost as big as the tree its climbing on. Looks like an angler stashed some fishing line inbetween the two.

Further up, it looks like the tree has lots of branches, but these are actually the vine's lateral shoots, which will bear flowers and berries later on. What we have here is essentially a poison ivy tree held upright with the help of a "donated" trunk.

The vine with the shaggy Irish setter-like bark is wild grape.

Native vines like poison ivy and wild grape tend not to grow in a way that would strangle the trees that support them.

Japanese honeysuckle, on the other hand, was spiraling up this shrub in a way that would eventually choke it. The trunk of the shrub was already getting distorted by the vine's tight grip. Note exotic honeysuckle vine's stringy bark, lighter in color than wild grape.
Turned out that the shrub was an exotic Asian photinia, so we cut both the shrub and the vine.

Asian bittersweet is very common at Mountain Lakes, identified in winter by its gray bark and large size. I had hoped to learn to distinguish it from native bittersweet before starting large scale removal, but it's likely that no native bittersweet remains in the park, or has lost any clear identity through hybridization with the exotic species.

Thursday, February 18, 2010

Snow as a Visual Aid

It's usually very difficult to photograph a woods so that you can see individual plants clearly. The result tends to be a green blob, whether the woods is degraded or healthy. Snow can change all that. Look in the middle of this photo, and you can see how snow highlights and makes visible hundreds of invasive winged euonymus shrubs that have sprouted from seed on a slope between Mountain Lakes and Coventry Farm.

Meanwhile, the blackened snow lining city streets helps reveal what in other seasons is rarely noticed: all the soot and crud left behind by auto exhaust, oil drippings, and the gradual wearing down of tires and brake linings. All of this gets swept into the local creek, which in this photo is Harry's Brook, flowing under the road where it dips down in the distance.

Given enough time, the snow will turn completely black with soot. This crud is what we are feeding to all the aquatic life in the local streams.

Monday, February 15, 2010

Throwaway Culture Lingers On a Branch

One day a few weeks back I heard a great beating of wings in the backyard. Could it be the hawk I'd seen coming through now and then, which a birder friend told me might be an immature redtail looking for a nice feathery snack for lunch?

I turned towards the sound and saw ..... a plastic bag caught on a limb, flapping noisily in the wind. It fooled me several times more during the windy days that followed, and even when it wasn't playing with my expectations, it was stirring memories:

..... of documentaries at the recent Princeton Environmental Film Festival that told of vast gyres of plastic trash collecting far out in the ocean. The plastic absorbs pollution from the water, then gets inadvertently swallowed by fish or whales, whose stomachs slowly fill with toxic, indigestible plastic.

..... or the time a decade back when I visited the far south of Argentina's Patagonia. There, the summer wind blows so strong it can yank a plastic bag out of your hand and send it sailing down the street, to catch on distant fencelines or any plant brave enough to grow more than a few inches high. Some fields of desert scrub, downwind of town, fooled me, too, appearing at first glance to be in full bloom, decked out in the white of fugitive plastic.

From its perch high in a backyard tree, that's what a deceptive bag is saying to all who will listen: "Don't be fooled. Little things add up."

A Flurry of Activity at Mountain Lakes

Even before the snowstorms hit last week, this winter has been marked by a flurry of activity at Mountain Lakes, with a blizzard to follow, come summer.

Here, two FOPOS board members, Clark Lennon and Tim Patrick-Miller, are removing invasive shrubs from an area near the Mountain Lakes House, as part of a beautification of the grounds that's starting to gain some momentum.

A couple hundred yards southeast of the house, visitors to Mountain Lakes may have noticed some pink ribbons showing up in one area of the woods. The trees have been numbered, measured and mapped so that a location can be chosen for a clearing, to be used as a staging area for the dam restoration and lake dredging work scheduled to begin in July.

Much discussion has gone in to selecting an area that will disturb as few of the marked trees as possible. Township engineers have been working closely with FOPOS (Friends of Princeton Open Space), which holds the conservation easement on the property and has to approve various aspects of the proposed work.

For those interested, the township will present its plans for the dam restoration and dredging project, and accept public comment, on March 1st at 7pm in the Main Meeting Room of the Township Municipal Building.

Wednesday, February 10, 2010

Patterns in a Backyard Pond

A backyard minipond serves as a canvas for nature's artwork in the winter. Embedded in the beauty is many a physics lesson: the rock that melts the ice above, the leaf that melts the ice below, the bubbles trapped beneath and within, and the forces at work in forming all those loops and squiggles.
The impulses of kids to walk on ice or try to break it are safely explored on a shallow minipond like this.

We were surprised to discover that beneath the ice was not water but air. After the ice forms, the water beneath continues to be absorbed into the underlying soil, leaving a gap.

Seeing Promise in a Puddle

Some people might look at this December scene and see a drainage problem. I see a spot begging to become a wetland garden, so that some small portion of stately but static grounds can be devoted to habitat and color.

Wind at Work

Question: How could the wind fashion snow to look like a cross-hatching of shingles?

Answer: Until a better one comes along, Bob Dylan's answer will have to do.

Inadvertent Habitat

Until I started using firewood in December,

it hadn't occurred to me how perfect a woodpile is for storing acorns, sheltering a nest of mice,

or biding over the next generation of moths until spring.

The mice may well have provided food for the screech owls that nested in one of our trees last year.

In the future, I'm thinking of making enough woodpiles that some may stay through the winter, as compact habitat serving the varied needs of varied critters.

Stickseed Seeds Stick Around

This was one of my sharings at a December meeting of Procrastinators Anonymous--workpants so intimidatingly covered with stickseed burs that they remained in a heap in the basement for four months. My mind of big ideas resisted this nit pick picking project until winter slowed me down.

Stickseed (Hackelia virginiana) is deceptive in multiple ways. In the borage family, it starts out in the summer looking like a classy plant with ornamental possibilities. But its flowers turn out to be tiny, and instead of reaching some point of mature beauty, it fades into the background and sets a trap. The leaves dry up, leaving only a delicate frame that holds aloft hundreds of burrs through fall and winter. I've learned to keep an eye out for this plant, lest I become yet again an unwitting disseminator of its seeds.

Living Fossils in Princeton

Still Life of the Still Living:

Ginkgo biloba--leaf and twig with "short shoots".

A very informative article describes three tree species that are living fossils, a term used for species that are found both alive and in the fossil record, and have few living relatives.

Along with the ginkgo, the article mentions sweetgum and dawn redwood. All three can be found growing in Princeton. Sweetgum is native to North America, the others to Asia.

Tuesday, January 19, 2010

Deer Accident Data for Princeton

I just spoke to Princeton's animal control officer, who told me that Princeton township's deer control program has markedly reduced the number of auto accidents involving deer. When the program was started, around 2000, there were 346 accidents involving deer. The number of accidents has been dropping since then, and has leveled out over the past several years at 70 to 90 accidents per year.

What happens to deer that are killed by automobiles? There was a time when some of them were taken to Coventry Farm, where a lady used them to feed the vultures. She developed quite a following in the vulture community over time. These days, a contractor carts them away and turns them into fertilizer.

Friday, January 08, 2010

Reviews of Movies at the Library Environmental Film Festival

I've posted some reviews of upcoming movies at the Princeton Public Library's Environmental Film Festival at my PrincetonProject blog, which deals with issues of sustainability in Princeton.

Wednesday, January 06, 2010

Mountain Lakes in Winter

The recent cold spell made for lovely patterns of ice on the upper dam at Mountain Lakes Preserve. Warmed by the sun, these columns of ice were starting to break off of the face of the dam, as if from the face of a glacier, sending ripples of sound through the thin ice covering the lake.

Dirt! The Movie

Tomorrow, Jan. 7 at noon, there will be a showing of Dirt! The Movie at the Princeton Public Library. The movie documents how vital and multifaceted our connection with dirt is. Though often treated as something inert and expendable, dirt is portrayed in the movie as teaming with life, utilized not only for growing food but also for play, spirituality, water filtration, home construction, pottery, and even energy production. Interviews in India, Africa and the U.S. provide a broad portrait of how dirt is used and related to in different cultures.
I'll give a short presentation afterwards about local soils, including some surprises about how gardening values like fertility and earthworms don't necessarily translate well to lands dedicated to preserving biodiversity.

FILM: Dirt! The Movie

12:00 p.m.

Directed and produced by Bill Benenson and Gene Rosow


Running time: 90 minutes

Wednesday, December 30, 2009

Free Sustainable Jazz Performance, Saturday, Jan. 2, 5:45

Come hear the Sustainable Jazz Ensemble perform this Saturday at the opening night party for the Princeton Public Library's annual Environmental Film Festival. We'll start soon after the discussion following the excellent bicycle movie "Veer". We'll be playing music I composed since moving to Princeton six years ago, with titles like The Case of the Kidnapped Kalypso, Fresh Paint (composed while breathing latex fumes in a freshly painted room), Lejos de Aqui (Far from Here), Lunar Eclipse (composed while forgetting to check out the lunar eclipse that was going on outside). Phil Orr's on piano, Jerry D'Anna's on bass, and I'll be playing saxophone.

There will be some light refreshments available later in our performance, but you're welcome to byof, since it's happening around dinnertime.

Info on all the extraordinary movies to be shown over the next two weeks can be found at

Friday, December 25, 2009

A Bluejay in a (not so) Bare Tree

My daughter gave me a tree drawing today, which fits in well with what I had started writing about an oak tree not far from our house:

Oaks are among the most giving of trees. They play host to more than 500 species of butterflies and moths--more than any other kind of tree hereabouts. When I lived in the Midwest, my backyard looked out upon two massive bur oaks that, as the squirrels traveled their long limbs, seemed like whole cities unto themselves.

You'd think, at this time of year, as trees stand stark against the wintry sky, that the oaks' giving would be done until spring. Most do appear lifeless and abandoned. So it was surprising to be walking in the neighborhood one recent sunny afternoon and look up to find an oak full of birds hard at work, harvesting a largely invisible crop. Four bluejays, three nuthatches, two mourning doves, and a flicker in a bare tree, or so a song might go. Most acrobatic were the bluejays, clinging upside down to wispy twigs to pluck the pin oak's small acorns, then bracing the morsels between their feet while they pecked them open.

On this day of giving, a time to celebrate trees, both giving and given.

Tuesday, November 24, 2009

Invasive Shrub Color

In fall, the local woods become a color-coded forest, making it easy to tell at a glance what species are growing where. Trying to take at least some advantage of this, I headed out in a car to survey where Asian photinia has invaded our nature preserves. The combination of its yellowish orange color and customary growth form aid in identification from the road.

Here's a new invasion getting going up on Mt. Lucas.

Once Photinia has lost its leaves, the honeysuckles are still green, revealing just how extensive is their invasion of the woods. That they hold their leaves long after native woody plants have dropped theirs suggests that the exotic honeysuckles evolved in a climate with a longer growing season.

Mountain Lakes Projects--Butternuts, Plant Rescue

Have a spicebush! As part of a planting project around Mountain Lakes House, Friends of Princeton Open Space board member Tim Patrick-Miller led a plant rescue on the old lower dam at Mountain Lakes. The dam will be enlarged this coming year, burying all existing vegetation. All told, we rescued five spicebush shrubs and four swamp rose.

In another project, initiated by Princeton resident Bill Sachs, we planted 20 butternut seeds outdoors, then covered them with metal screening to prevent pillaging by squirrels.

The butternut is a rare native tree threatened by an imported canker disease that is reducing their numbers even further. Bill, who edits the Nutshell, a newsletter for the Northern Nutgrowers Association, has been scouting out where these trees can still be found in Princeton. Until we get DNA analysis, we won't know whether the trees found are the native butternut, or a hybrid with an imported species.

Native shrubs fall color

Both these shrubs are native, but I've never seen them in the wild. That may have to do with their natural range being the southeast. They've been widely planted in the north, for obvious reasons. The first is oak-leaved hydrangia (Hydrangia quercifolia).

This dwarf fothergilla (Fothergilla gardenii) was planted at Mountain Lakes House, and has been left alone by the deer.

Salamanders at Herrontown Woods

While digging around the foundation of the historic Veblen House (soil and landscape timbers had been pushed up against the wood siding--not a great way to preserve wood), I came across some salamanders.

One played a game of peekaboo, crawling under a dandelion leaf after I let it go.

"Snakes with legs" is one way to describe how they move, but their soft skin and improbably tiny feet confer an air of vulnerability.

Friday, November 13, 2009

Red Berries in the Forest

There are lots of red berries in the woods right now. Consistent summer rains have made for a bumper crop. Here's some help in distinguishing between them all.

Asian photinia (Photinia villosa) is a robust exotic shrub that reaches twenty feet high and can be found singly or in dense stands. The leaves are "obovate", meaning they are often widest towards the tip. The berries are in terminal clusters.

Winterberry (Ilex vericillata) is a native shrub typically found in lowlands. At Mountain Lakes, its leaves are still showing a little green, and the berries are tight against the stem, rather than in terminal clusters.

Swamp rose (Rosa palustris) is another native, also found in lowlands. Its hips are larger than those of the exotic multiflora rose, and its thorns are not curved backwards like the fishhook-shaped thorns of multiflora rose. Also, the thorns of swamp rose are more dense towards the base--the opposite pattern found on multiflora.

I'm calling this Viburnum dilitatum, the linden Viburnum--an exotic shrub that is proving fairly invasive. It's leaves could be mistaken for the native Viburnum dentatum, but are wavier and less toothed along the edges.

Wednesday, November 11, 2009

Photinia Spreading in Princeton's Woodlands

Asian Photinia (Photinia villosa) is a shrub that land managers in the Princeton area are targeting for removal from natural areas. It was sold by Princeton nurseries many decades ago, and has begun invading the local woodlands. Why are we so worried about this shrub that turns a pretty golden color in the fall, with bright red berries?

There are many reasons. For one, the shrub appears not to be edible for wildlife, and 2) the shrub has shown a capacity to out-compete the native shrubs and forbs wildlife do use for food. The spreading monoculture of Photinia in the forest understory is rendering the landscape less and less hospitable for the native diversity we seek to nurture.

An additional reason for focusing on Photinia is that it has yet to spread across New Jersey. Action now in the Princeton area could prevent Photinia from becoming a statewide pest.

This is a typical sight under berry-producing Photinias: a dense clustering of seedlings that leaves little or no room for native species to survive.

Photinia is very easy to spot this time of year. Nearly all native species have already dropped their leaves, making the woods a color coded picture of various invasive species. Honeysuckle shrub leaves are still bright green, Photinia's are golden yellow.

Here's what the woods looks like after a very dense patch of Photinia has been cut and stacked. Not as pretty, to be sure, but it's the first step in restoring a more edible native landscape for wildlife that will also be pleasing to the eye.

Homeowners are encouraged to identify and remove Photinia. Though it may be appealing from the standpoint of its deer resistance, the spread of the berries threatens the ecological balance far beyond the boundaries of one's backyard.

Spicebush Swallowtail Caterpillar

A Friends of Princeton Open Space board member found this caterpillar on her front door one day in July, and just recently found out what it is. Though we have lots of the butterfly's favorite host plants--spicebush and sassafras--growing in Princeton woodlands, particularly since the browsing pressure of deer has been reduced, I have never seen one of these caterpillars. The one that showed up at Brownlee McKee's door might have something to do with a spicebush her landscaper planted just two weeks prior, and so it's hard to know if this particular caterpillar originated in Princeton, or was transported with the shrub from some distant nursery.

Below are her notes, and a link she found to a wonderful photo portrait of all the different shapes a spicebush swallowtail takes as it grows towards adulthood. Thanks to Brownlee for sending the photo and info.

07/16/09 Spicebush Swallowtail caterpillar on front door of house within a couple of weeks after setting a Spicebush 15 feet from the door. How the 'pillar got there, past 10 feet of boxwoods, over five feet of brick paving, and a foot or two up the door, is a mystery. It was a striking sight, with the sun bringing out its bright yellow against the dark green of the door. In this picture the pale background and some shadow dulls the bright yellow.

Here's a website with many photos and more info.

Japanese Maple--Very Pretty, Kinda Scary

At the old Veblen farmstead at Herrontown Woods, the delicate leaves of Japanese maple decorate the woods next to the old cottage that once served as the world famous mathematician's study.

Japanese maple in all its varieties is one of the most gorgeous trees around, but the way it can sprout copiously in people's gardens has always made me wonder what could happen if it got loose in the woods. That's what's happening at Herrontown Woods--the kinda scary aspect if one values native diversity in the natural areas people have worked so hard to preserve. Sure is pretty, but the wildlife may not be sitting pretty if they find it inedible.

Saturday, November 07, 2009

Butternuts and Bladdernuts

It's a pleasure to encounter a new kind of native tree for the first time--one rooted in this continent's deep history, a new-old friend. I first heard of butternuts (Juglans cinerea) as a rare relative of the walnut that was becoming even more rare due to an imported canker disease.

An opportunity to finally see one came after meeting Bill Sachs--Princeton resident and editor of the Northern Nut Growers Association newsletter, The Nutshell--who is beginning a quiet campaign to find and nurture various kinds of native nut-bearing trees in town.

He recently recruited me as an extra pair of eyes to search for any companions to a butternut he had found in a private woodlot near Carnegie Lake. Butternuts have distinctive bark, with lots of long, flat "ski runs" zigzagging down the trunk. Red oaks have this feature as well, but the vertical plates are not nearly so dense.

We soon found a second tree, with many nuts beneath it. The nuts look like oblong walnuts. Whether these trees are pure butternuts or are the result of hybridization with Japanese walnuts will have to await genetic analysis.

Later in the search, we came upon a lovely overlook of Lake Carnegie, with rock bluffs populated by uncommon species. This photo shows bladdernut, whose seeds (not really nuts) can be found inside the "bladders." This is the third population of this native shrub that I've found in Princeton.

The rock bluffs have an ancient quality to them, as if the rock has been buckling slowly over the eons from its own weight.

Though we didn't find any more butternuts, Bill also identified a persimmon tree by its bark--a female with a few fruits still clinging to the branches.