Sunday, April 26, 2009

A Small Victory At Herrontown

Most people know about the big victory won at the Princeton Battlefield in 1777. Few have heard, however, of the small victory of 2009 that took place at Herrontown Woods, on the other side of town, on a sunny afternoon this past Thursday.

There, the mighty resistance of an eight year old to taking a walk in the woods was overcome by an irresistible alliance of rocks and water.

Strident complaint dissolved into "Daddy, look at this!", as we headed upstream towards a picnic in a boulder field.

Contributing to the rout of homebound entertainment media was a frog presiding over a reflected forest.

Plenty of auxiliary forces were on hand, effective mostly with the accompanying adult. The opening buds of a witch hazel.

Some interesting stuff on the forest floor--here, a reddish-brown spiny fruit of the sweetgum, a flowering wood anemone, and some leaves of trout lily.

And the fiddle heads of Christmas fern perched on boulders.

Even the trails were strategically rock-strewn to add sport and comfort to the way home.

Friday, April 24, 2009

Insects on a Spicebush

Well, I'm at it again, cataloging all the enigmatic creatures that take an interest in various kinds of plants. Today--or actually several days ago, while the spicebush at Mountain Lakes were still in bloom--we feature the creatures who hover, alight and crawl upon Lindera benzoin, the native spicebush, relative of sassafras.

Spicebush, which blooms yellow and early, was drawing more pollinator interest than the exotic forsythia in my backyard, which blooms at the same time.

The tiny insect in this photo was very numerous, and took a very serious interest in whatever the flowers had to provide. The larger, beetle-like creature is probably the same as in the preceding photo.

This fly was very skittish. There were quite a few of this sort zooming around the bush, occasionally alighting briefly. It was mostly a blur, but when it stayed still for a second I could see it had a distinctive light-colored spot on the abdomen.

A Maple's Organizational Skills

I wish I were as organized as a red maple tree. While other trees are still waking up from their winter hunch, these maples have already flowered, formed seeds and have moved on to sprouting leaves. With the task of making progeny done for the most part, the rest of the year is gravy.

Unitarian Church Volunteers Restoring Habitat

Louise Senior calls these volunteer days "Into the Woods", which is where we all headed this past Sunday. Louise organized some volunteers from the Unitarian Church on Cherry Hill Road to start restoring the township-owned woods that borders the church. My job with Friends of Princeton Open Space is to assist such initiatives with some supervision and supplies.

Together, we cleared invasive shrubs and vines, finding amongst their dense growth some natives to save, including blackhaw Viburnum and American Holly.

In the photo, Dunbar Birnie pulls an old multiflora rose away from a forest clearing. The brush was piled back in the woods to make wildlife habitat.

I usually forget to take before and after shots, but here is the forest clearing choked with invasive multiflora rose bushes. This area was targeted for restoration because it is often wet, and open enough to get some sun to the ground.

Here is the transformation--a wet, sunny location ideal for all the various native wildflowers that thrive in such habitat. Some more invasives removal, a follow-up planting of native plants, and what has been a rather empty woods of evergreen trees will start offering a more varied diet for the local wildlife.

Thanks goes to Bill, David and Cathy Bauer-Koggen, Dunbar and Nick Birnie, Stan DeReull and Annette Sheldon.

Volunteers also potted “live stakes” of native elderberry, silky dogwood and buttonbush. Cuttings from these three species can be stuck in soil and, if kept watered and given some sun, will sprout roots and leaves and grow into full-sized shrubs. This small collection of pots actually holds 60 new plants.

The church is planning to have a followup workday May 17.

WaterWatch vs. Garlic Mustard

Cherry trees, planted back when the canal area was a cultivated entryway into Princeton University, add ornament to the towpath next to Turning Basin Park. Last year, the university student group Water Watch cleared out the invasive Tree of Heavens that were starting to shade out the cherries. Neither the cherries nor the Tree of Heaven are native, but the former is ornamental and non-invasive.

This spring, led by Laura Burke, some fifty students took to the water in canoes and cleaned the canal of water-borne litter.

A few of us stayed on land, clearing garlic mustard from the slope.

Because garlic mustard is a biennial, there were actually two generations of the plant present. We pulled only the second year plants, which were just starting to send up their flowering stalks. The smaller ones are first year plants, which we left because they won't flower this year. Many of them will die anyway, from overcrowding, before they reach the flowering stage next year.

If no plants are allowed to make new seed, eventually the seedbank is exhausted and the embankment will be clear of the weed. This is called "picking your spots", because the task of removing garlic mustard from all of Princeton would be overwhelming. It's also a way to learn new things through the conversations we have, in this case about backpacking the Camino de Santiago in Spain, and the challenges of prescribed burning in the Everglades.

Wednesday, April 22, 2009

Shad, Wood Ducks and a Reptile

I would love to report that shad are running in my minipond, which I dug where a small tributary of Harry's Brook once flowed, before my backyard was a backyard. The brook is connected to the Millstone River, which flows into the Raritan River, which empties into the ocean just south of Staten Island.

Who knows if shad ever made it up to my neighborhood, but the blooms of a solitary shadbush in the backyard tell me that somewhere the shad are running. The shrub is also called serviceberry, and will have delicious berries later in the season.

Migrating fish have lost my ecological address, but a lot of other wildlife have found it. Though the shad didn't make the walk up to my miniponds, I was surprised and flattered by a visit from a couple young wood ducks the other day. That was a first.

There was also a return visit from another wild creature who did make the walk, and whose presence doesn't so much flatter as cause the heart to flutter. Just beneath the reflection of trees on the water's surface, a reptilian presence soaked up some afternoon rays.

A snapping turtle, some 14 inches long, though who's going to try to measure. I thought he had left last year, but is back, bigger than before. We may take him for a short ride back down to the creek.

Friday, April 17, 2009

Upcoming Open Space Events

Mark your calendars for two upcoming events on the weekend of April 25-26:

Saturday, April 25: The Friends of the Charles Rogers Wildlife Refuge (FORR) will dedicate two new observation platforms overlooking the large Upper Marsh at the Refuge on Saturday, April 25, at 9:00 a.m. The marsh is an extraordinary place, totally unexpected in the Princeton landscape. It's also one of the best birding spots around. The platforms allow you to look out across an expansive, several acres marsh filled with life. The ceremony will take place at the first observation platform in the center of the sanctuary, which is located off West Drive in Princeton. It will be followed by a bird walk to look for early spring migrants in the Refuge and in the adjacent Institute for Advanced Studies Woods.”

Sunday, April 26: The Friends of Princeton Open Space (FOPOS) will be holding its annual meeting at 3pm at Mountain Lakes House, 57 Mountain Ave in Princeton. After a very brief bit of business, the featured speaker, Michele S. Byers, will speak on "Garden State Greenways". Michele is Executive Director of the NJ Conservation Foundation, and writes environmental columns that appear locally in the Princeton Packet and Trenton Times. I hear she is an excellent speaker, and from the title it sounds like she will give a good sense of how all of our work with FOPOS fits into the effort to preserve functioning ecological corridors in New Jersey.

Ms. Byers' talk will be followed by refreshments, after which I will lead a nature walk through Tusculum and Mountain Lakes.

FOPOS is celebrating its 40th anniversary this year!

What's the Buzz on Spicebush?

While the exotic but non-invasive forsythia blooms bright yellow in residential areas, the native spicebush is coloring the floodplains of natural areas with a subtler shade of yellow.

Pause long enough to take a close look at the spicebush shrubs and you're likely to find them abuzz with skittish flies of various sizes. The smaller ones allowed me to photograph them, but I had no luck getting a focused photograph of any of the other kinds.

These and other entries this year will focus in on how wildlife is served, or not, by the plant life in Princeton's preserves. Insects play a big role in making the solar energy captured by plants available to other wildlife such as birds. Though birds eat seeds and berries, they rely on insects for a critical part of their diet, particularly during spring breeding season.

Many insects, however, have not developed appetites for the many invasive species that have been introduced to this continent over the last several hundred years. These exotic plants, then, as they displace native species, may be depriving wildlife of the edible plants they need to survive. It's a compelling argument, and it will be interesting this spring to see how it plays out in the fields, and forests, of Princeton.

Native Spring Flowers of Mountain Lakes

The spring ephemerals are in bloom at Mountain Lakes Preserve. Their survival strategy is to emerge early, bloom, set seed and absorb solar energy for the next year. By the time the trees sprout leaves and cast a deep shade on the forest floor, these wildflowers are finishing up and getting ready to go dormant until the next spring.

The most common of these at Mountain Lakes is the spring beauty, which grows so abundantly along the driveway as to seem almost weedy.

Less common, surviving mostly in floodplains, is the beautiful trout lily.

Less common still (I've found a grand total of five of these in the whole preserve) are bloodroot, which actually keep their leaves into the summer.

Other spring ephemerals that you will be lucky to find in a few locations are windflower and toothwort.

The rarity of these wildflowers at Mountain Lakes is a legacy of the agricultural era, particularly the plow, which erased the soil's memory of past glories. Though the old fields eventually grew up in native trees, the spring flora don't have the capacity to quickly recolonize.

Browsing by deer has also played a role in suppressing wildflowers in Princeton's preserves, though the township's deer culling program is helping native species like the bloodroot to recover.

To Identify Trees, Look Down

The sidewalks and pavement of Princeton tell a lot about what sorts of trees are growing overhead. If you see lots of red when you look down, there's probably a native red maple above that has just dropped its small flowers.

Even when past the flowering stage, the trees still have a reddish tint this time of year, as the seeds (called achenes) begin to grow out of the red flower stems that remain on the tree.

A spent flower cluster colored pea green indicates a Norway maple.

This time of year, it's possible to travel down the street identifying every Norway maple in sight, with their distinctive shade of green. Norway maples were a popular exotic tree to grow at one time, but their very deep shade and allelopathic tendencies (they release chemicals from their roots that suppress growth of other plants) make it hard to grow anything underneath them. They have also proved very invasive in some parts of the country.

A collection of prickly balls on the street mean a native sweet gum tree is nearby.

These sweet gums line the 206 side of the Community Park soccer fields.

It's not the best tree to grow in a yard if you like to romp barefoot in the grass, but they can be impressive in other ways. When I lived in Ann Arbor, Michigan, where they are uncommon, a horticulturist at the university took great pride in a small sweetgum he had planted. The beautiful paneling in my parents' home was said to be sweetgum.

In natural areas, they tend to grow in floodplains, sprouting thickly in open areas.

Friday, March 27, 2009

Princeton--A Town of Idle Mini-Farms

Sometimes, returning home from travels can cause as much culture shock as going abroad. This time around, driving home after ten days in Spain, my neighborhood in Princeton looked suddenly very strange. Why, I wondered, are all the houses separated one from another? I had gotten used to seeing stand-alone houses in Spain only on farms we passed on the highway. In town, all dwellings were apartments or townhomes.

And what is all this vacant land around each house? What is it for? You mean we have to mow the lawns ourselves, with odd-looking, noisy machines? This perception--this "out of culture" experience--lasted only a few minutes before I again donned my cultural blinders and assumed the way we live our lives is normal.

In Spain (these photos are from the Extremadura region, where Pizarro came from), we only saw large expanses of "lawn" out in the country,

and the mowing was conveniently done by horses, sheep and cattle.

As is the case most anywhere, kids love to run out into a field of low cut grass, but in a pasture the grass is also serving to convert solar energy into something useful. Our lawns may look clean and subdued, but they grow nothing more than yardwaste.

So those were the few minutes of insight, gained through ten days of travel, that though Princeton is a town, it can also be seen as a particularly concentrated gathering of farmhouses, each surrounded by a miniature pasture that has long since forgotten its reason for being. With grazing animals long gone, we mow these pastures, not knowing quite why, other than that everyone else does, and it makes the idle land look tidy.

This is written at a time when two movements are pointing out how potentially useful these clusterings of idle mini-farms could be. The Eat Local movement sings the praises of vegetable gardens--in the backyard or right out front. Portions of schoolyards are being converted to vegetable gardens with great success. And environmentalists are encouraging us to convert parts of our lawns to native plant habitat.

Are these movements to be seen as radical change, or simply a means for the American landscape to find its way home after a very long and curious journey?

Exotic Plants and Disconnected Solar Panels

I tried googling exotic plants and disconnected solar panels, but didn't get much, despite the fact that they have a lot in common. Both plants and solar panels convert solar energy into forms that can be used in natural or human economies. A plant, if wildlife finds its leaves edible, transfers that captured solar energy up the food chain, from leaf to butterfly larva to bird. Solar panels transfer captured solar energy into a grid, to feed the machine world.

The leaves of exotic plant species--those that did not evolve in this area--are generally not edible to local wildlife. Many insect species, for instance, have become over countless millenia very specialized in their tastes, and will only eat certain native species. The energy captured in the foliage of most exotic plants, therefore, does not get transferred up the food chain. In that way, planting exotic plants in the yard is much like installing solar panels that remain unplugged.

The question can come up as to why one would want to plant something in the yard that's just going to get devoured by the local insect life, but there seems to be a balance struck. A few leaves are sacrificed, but the general appearance is not affected. I had one swamp milkweed plant stripped by monarch butterfly larvae, but that's been the exception. The response to that serendipitous "problem" was to plant more milkweeds, so there'd be plenty to go around the next year.

Thursday, March 26, 2009

Walls Go Green in Madrid

Here's a figure deep in thought on a plaza in the museum district of Madrid, Spain. It's a beautiful spring day. What could he possibly be so perplexed about?

Nearby, there's a garden with many kinds of flowers, some of which look suspiciously like foamflowers native to the U.S.

Some others look like hostas and wild geraniums. Nothing particularly unusual.

But wait a minute! They're growing on a wall! Now that IS something to puzzle over.

From the side of the wall, it looks like the plants are growing in nothing much more than a thin wool-like fabric with small pockets cut into it, and a strong nylon backing. One thing about wall gardens: They're easy to water. Water is released from the top of the wall and trickles down through all the vegetation below. And you get a big effect while using next to no real estate.

Monday, March 16, 2009

Deciding What Nature To Bring Home

It's usually hard to find the silver lining in back pain, but a few days of incapacitation caused me to glance over at the bedside table and notice a book that had been waiting patiently there for nearly a year. Bringing Nature Home, it's called, by an entomologist named Douglass Tallamy, and inside its cover is a more meaningful journey than I had been managing of late with all powers of mobility intact.

What does a scholar of the insect world have to tell us about our own? Take for instance the decisions many homeowners are making this time of year about what new plants to bring into the garden. We usually make these decisions based on what looks pretty, what will grow to the right size, what will provide privacy or hide an unwanted view.

All of these qualities matter, but if one´s seeking meaning in a garden beyond pleasing views, Tallamy provides as good a guide as any to how your garden can either shun the local ecology or become an integral part thereof. In so doing, he provides answers to some basic questions like the difference between native and exotic plants, and the ecological consequences of planting one or the other. Establish enough of these building blocks of understanding in your thinking, and you´ll begin to see how decisions made about backyard plantings will help determine the fate of many species of wildlife that are becoming ever more marginalized. Each of us in our own small way has the power.

As my back pain (negative but instructive) and the accelerating local initiative to make Princeton more sustainable (highly positive) began mixing with Tallamy´s narrative, I started developing a Unified Theory that would finally explain the hidden connections between nature, local economies, and the ecology of back muscles. All of this may come out in subsequent posts, along with the answer to the question, How is an exotic plant like an unplugged solar panel?

Saturday, March 07, 2009


An important meeting for the environmental future of Princeton is coming up on Wednesday, March 11. The public will get a chance to learn more about and comment on the Sustainable Princeton Plan. This is the document that will guide Princeton's community-wide shift towards greater sustainability. Everyone--residents, schools, businesses, local governments--has both a stake and a hand in this effort. Please come to this event, to learn and give input.

At the March 11th workshop (7 p.m., Suzanne Patterson Center behind Princeton Borough Municipal Building, One Monument Drive), the draft document will be summarized, general comments will be made, and then the participants will break into small working groups to discuss how to carry out specific actions of the plan. Light Refreshments will be available.
For further information, please contact the Princeton Planning Director Lee Solow: 609/924-5366 or

Additional information:

Sustainable Princeton Steering Committee, composed of municipal officials, representatives of Princeton groups and institutions, and local residents invites the public to participate in a Tuesday, March 11th, 7 p.m., workshop at the Suzanne Paterson Center , 1 Monument Drive, Princeton to review and comment upon the Sustainable Princeton Community Plan (SPCP). The draft plan outlines the goals and objectives of the Sustainable Princeton Initiative. The workshop will provide the input needed to finalize the SPCP and to launch the community on a course of achieving – and sustaining - a green and greener Princeton. Copies of the draft are available at the municipal buildings, the public library and online at

The SPCPoutlines goals, identifies the sectors of the communities that would be implementing these goals, and presents action plans for fulfilling the goals, as well as strategies for measuring/tracking progress. The six goals are: green the built environment; improve transit/transportation; build local green economy; protect health and natural resources; curb greenhouse gases; foster community. The sectors - schools, businesses, residents, government - would be tasked with implementing specific action plans.

Sustainable Princeton had its roots within the Princeton Environmental Commission, which asked the municipalities to form a Sustainable Princeton Steering Committee two years ago and to hire New Jersey Sustainable State Institute (NJSSI) to help the municipalities embark upon a cohesive and effective plan to make the Princetons a model of sustainability in New Jersey. With a grant from the Municipal Land Use Center of New Jersey, the municipalities were able to sustain the Sustainable Princeton Initiative and to develop the Sustainable Princeton Community Plan on which the public is being asked to comment.

Sunday, March 01, 2009

The Case of the Missing Babies

Princeton has quite a few natural areas, but in another way, I would say that we are not providing for the needs of kids for nature. Take for instance the strong need in children to witness the wonder of creation and growth. By this, I mean the birth and growth of baby animals. The breeding of dogs is largely left to professionals. Kittens are scarce, which may be just as well, given the toll stray cats can exact on local birds. Farms open to the public are few and require a drive.

What do we have to fill this void? Some people are lucky to have birds nest close to a window. My daughters have seen Monarch caterpillars grow into butterflies, and seen cicadas emerge from their shells. They were delighted to find baby goldfish in our backyard miniponds, and promptly gave them all names. But really this is slim pickins when compared to all the joy, wonder and learning that could be taking place. 

So, what do I tell my eight year old when she pleas to buy an exotic frog at the local store? We know that the trade in exotic pets, as with the importation of exotic plants, has contributed to the unraveling of our ecosystems, as well-meaning owners release exotic animals into the wild when they can no longer care for them at home. 

This situation is akin to the difficulties gardeners face when they seek out native plants to buy. What we have in both cases is a void in local native offerings that people then seek to fill by importing exotics. There are, fortunately, some steps being taken to supply local native plants to buy. The Friends of Princeton Open Space has held small native plant sales the past two years. Bowman's Hill Wildflower Preserve sells native plants, and other local organizations like Stonybrook Watershed Association and the Mercer County Master Gardeners have periodic sales. Most promising, in terms of scale and sticking to local genotypes, is D&R Greenway's efforts, which began with a sale this past fall. 

The more difficult problem is how to fill the void in children's lives, when demonstrations of nature's fecundity are so hard to find. I remember as a kid bringing a couple tadpoles home from some nearby pond and watching them grow legs in our aquarium. That's the kind of thing I have in mind. Though nowadays we're discouraged from foraging in the wild, there must be an alternative to teaching kids that nature is something they buy at the local store.

Friday, February 13, 2009

Nature Hike Sunday, Feb. 15

All yee cabin fevered,
You're invited to participate in a nature hike this Sunday, Feb. 15, at Autumn Hill Reservation on the eastern side of Princeton. Meet at 10:30am at the parking lot on Herrontown Road, north of Snowden Lane and south of Bunn Drive. Though the walk is primarily a chance to venture out of doors and explore one of Princeton's less-known preserves, we'll also be taking notes on the condition of the trails and signage, and acquiring the bare necessities for tree identification in the winter. We'll be talkin' twigs and bark to our hearts' content. These hikes stick to the trails, but conversations often veer far from the beaten path.
There may be some muddy patches, so wear boots. Below are some relevant websites.
Steve Hiltner
Natural Resources Manager, Friends of Princeton Open Space

Wednesday, January 28, 2009

Patterns In Carnegie Lake Ice

Such joy and mystery a frozen lake holds. The Princeton recreation department declared Carnegie Lake safe two days ago, and we managed to get out there before last night's snow came down, like a curtain on a fantasy play. The ice was smooth in places, a bit rough in others, whispering its secrets to us as we skated from hither to yon and back again.

There was the pleasure of joining the impromptu Skaters Without Borders club, of escaping the tyranny of counter clockwise motion imposed by all skating rinks, as if the whole population is incapable of turning to the right.

But most fascinating was the story the ice was quietly telling, through the language of its patterns, of how it formed. I have no idea how the ice makes eyes--those circles that look like a dark pupil with rays of the iris radiating outward.
The others? My guess is that the white plates embedded in the ice reveal that the ice froze some weeks ago, then broke apart, then refroze, capturing the leftover chunks in the new formation.

Snow then fell, obscuring the ice and preventing the township from testing the ice to declare it safe. During this time, an intrepid cross-country skier and two hikers traversed the lake, leaving their tracks. When the snow melted on a warm day, the tracks melted differently than the uncompressed snow, then refroze.

In other photos, a fish frozen in the season's amber of ice.

A gathering of geese left their unmistakable traces.

And broad lines traversing the lake give a mini-lesson in plate tectonics, showing where the expanding ice formed fractures.

Tuesday, January 27, 2009

Droop du Jour

Most of the year, this evergreen shrub is an inexpressive green blob in the yard, but nothing says cold like a Rhododendron. When the temperatures dipped down into the 20s and teens recently, most trees and shrubs looked unperturbed. But all the Rhododendrons in town struck a compelling pose, telling every passer by what they already knew: "It's cold out here!"


Spread the word. The township rec dept. has given the green light for skating on Carnegie Lake. I haven't been down yet, so don't know how smooth the ice is, but that's definitely the afterschool destination. Here's the website where the township provides up to date info on skating conditions at three locations in Princeton: