Friday, November 13, 2015

The Plainsboro Preserve is Anything But Plain

(This is an elaboration of a previous post.) A trip to the Audubon Society's Plainsboro Preserve this fall turned a number of notions on their heads. Plain became rich. Far became near. Small became large, and down became up. Reattach the "s" to "plain", and you get "plains", as in fruited plains, and a better sense of how Plainsboro got its name. For those of us who seldom venture beyond Princeton's bubble, it's a surprise to learn that New Jersey's inner coastal plain begins just across Route 1 from the hilly last hurrah of Princeton's piedmont. And with that geologic transition comes a floristic transition I had mistakenly thought would begin much farther south, not within the fifteen minutes it takes to pull into the Plainsboro Preserve's parking lot.

Witness fall colors like these, reflected in an improbably large lake, and any lingering notions of "plain" as in plainness quickly dissipate.

My intrepid guide for this journey of discovery was James Degnen, who has been visiting the preserve for years and has informally adopted a lesser known trail around the lake's eastern side. The trail fades at times, but it's impossible to get lost if one keeps the lake close on one's left.

The first surprise came with a glance down at the ground. Sand and gravel--strange to find so close to Princeton's clay.

He showed me a series of sandy beaches (a sandy beach in inland NJ?), which would be an inviting place to swim, if not

for the sheer dropoff just a few feet out. The quarry operation, now long gone, cut some 60 feet down into the sandy plains.

Though those little bluestem grasses in the photo can be found growing in Princeton,

this bushy bluestem cannot. Also known as Andropogon glomeratus, it's a resident of coastal plains and can be distinguished by its swollen plume on top.

Nor does Princeton host a field like this, radiant with blueberry bushes. Why haven't the trees shaded these blueberries out long ago?

Credit or blame goes to the beavers, whose habitat work is evident everywhere along the edges of the lake.

We may love sweetgum trees for their fall color,

but the beavers love them for their inner bark laden with sweet gum. Their preference is so strong, and the sweetgums so numerous, that we saw no other species of tree being touched by the beavers.

Some sweetgums they leave standing, to cling to life with only small strands of intact bark to maintain flow between root and canopy. One could say this is detrimental, but by sabotaging the normal progression to mature forest, the beavers are maintaining a younger landscape of shrubs and forbs that is every bit as important and beautiful a habitat.

At water's edge, the green of alder mixed with the yellow of summersweet (Clethra) and the sweetgum's bright red.

We found a few freshwater clams, or at least the remains, whose identity might be found in the master plan recently completed for the preserve.

In the gravel near the shore, the impressions left from fish nesting in the spring are still evident.

And what's this glistening white along the shore? Feathers, of geese, of which skilled bird counters counted 25,000 one evening a year or two ago. Through the winter, they use the lake as an overnight refuge after foraging all day in corporate landscapes that dot the NJ landscape.

Two winters ago, when an extended cold snap froze most open water to the north, 2000 snow geese took up brief residence on the lake, an awe inspiring sight, with their brilliant white against the dark background of winter woods.

On our visit, only four Canada geese gave the slightest hint of such abundance.

Plainsboro Preserve is a study in contrasts, between thick woods and open field, and most of all between areas that have been radically altered and those that have not. We walked through mounded landscapes, where dirt was piled up, back in quarry days. Some might point to the trees as evidence that the disturbed areas are now mended, but the area remains stripped of its plant diversity, with little more than Japanese stiltgrass to populate the ground.

In low ground, made passable by dry weather, tussock sedges build their pedestals,

remnant cables sprout and big steel boxes once used as anchors now anchor themselves as permanent mementos of a bygone era.

One anchor actually looks like an anchor, now being slowly grown over and around by a tree.

In contrast to the radically altered areas, a beautiful glade on the far side of the lake sprouted wildflowers rather than cables, and the same lichen that grows an hour south in the pine barrens.

Add to these the summersweet, blueberries, bushy bluestem, the sandy soil, and this field of switch grass, and you have a pine barren in miniature, albeit without the pines, just fifteen minutes from Princeton.

Further around the lake is the outlet, where pipes have been added over time to deal with the overflow from ever larger storms. It's interesting to check out google maps, and learn that the water that leaves this lake in Plainsboro Preserve travels westward, ultimately draining into Lake Carnegie. In this way, Plainsboro is connected hydrologically to Princeton, even though it's closer to the ocean and in a different geologic zone. The Princeton Environmental Resource Inventory , a book I helped to write, provides some useful related info on p. 17.

One sight that rankled a bit, after a glorious walk most of the way around the lake, was Chinese bushclover, which lines the trail on the west side of the lake. Its small seeds are said to be indigestible by wildlife, so the plant's aggressive displacement of native species creates a largely inedible landscape. A big, big problem in North Carolina, where it has escaped from erosion control plantings, it's becoming more numerous in NJ.

There was some evidence that land managers are taking a cue from the beavers and cutting down invasive shrubs like autumn olive.

This plant looked really familiar, seen decades ago in the northeast.

This is where most people walk--a wide path leading back to the visitors' center,

where a row of bee hives

begets rows of honey.

Always nice to have informative signage,

and a good harvest of color in the mind, to last us through winter.

Check out the programming, like monthly moonlit walks, on their website.


  1. I'm putting this on my list for 2016

  2. Yes me too I love abandoned quarries

  3. Great pictures & writing! Thanks.