Encounters With Old-Growth Forest

Ever since attending the induction of Rutgers' Meckler Woods into the Old-Growth Forest Network, I've wondered whether any woodlands closer by could be rightfully considered old-growth. Rare is the woods that was never logged. The forests we typically encounter are of more recent vintage, having mostly grown up from abandoned farm fields. There's a valley at Herrontown Woods with giant tulip trees whose massive roots have lifted the ground around them, as if perched on a pedestal of their own making. Might these and the nearby big oaks and hickories meet the standard? And what exactly is the standard for deciding? Below is an account of encounters with old-growth, old stuff, and different forms of timelessness during recent travels.

When we headed north from Princeton to attend the wedding of a young couple in upstate NY, we had no idea that the theme of the trip would turn out to be old stuff and old growth. On the way up, we stayed overnight with friends whose house is filled with old furniture--a grandfather clock, of course, but also what may as well be called grandfather chairs that had been inherited or adopted from the curb, valued for their uniqueness and style regardless of how practical they might be. Each chair around the dining room table, each lamp, vase, and bureau, had a story behind it. A crank telephone perched on the wall in the kitchen, ready to call up the whisperings of distant ancestors. I found great comfort in this approach to stocking a house, even if a chair's quirky ergonomics didn't conform to modern expectations.

The next morning, we walked through Borden's Pond, a second growth woods whose scattered "wolf" trees and sedge meadows also have a story to tell. When the area was logged long ago to make pasture, farmers left a few scattered trees as shade for the livestock. Those trees, lacking any competition, with sun all around, grew thick lateral branches, so different in shape from the straight, younger trees--the "second growth"-- that grew up after the pasture was abandoned. This can't be called old-growth, I suppose, but it certainly has individual trees that go way way back.

Conveniently, the route to the wedding took us by Landis Arboretum, which too had some craggy old trees, standing next to the farmhouse. In the woods beyond, though, was an area declared to be old-growth, with a series of signs explaining how to distinguish old-growth from the second growth forest all around.

Don't expect big trees only, but a few big trees lingering in a mixed age stand. Around six old trees per acre is typical. In this photo, only one of the trees can be considered old growth, in this case a hemlock extending back 250 years. 

Really old trees lose their symmetry, with thick upper limbs and tops broken off by storms endured over the centuries, creating what's called a "stag-headed top." Look for mounds and pits on the forest floor--undulations caused by the lifting up of root balls as trees fall. And look for coarse woody debris on the forest floor in different stages of decay, where stable conditions and slow decay have allowed opulent growth of moss and fungi. One of the interpretive signs offered a clever way to judge a tree's age, not by its diameter or height--since some trees grow much faster than others--but by how far the moss has managed to grow up the trunk. 

One week later, I was in Durham, NC, where I started a watershed association 26 years ago, creating a string of preserves before moving to Princeton. I always get together with my botanizing buddies when I visit, and this time Perry Sugg, Cynthie Kulstad and I decided to stop by the 82 acre Glennstone preserve I had worked with a developer to create. We were walking down a sewerline right of way, with no particular destination in mind, when I thought of a special place to visit.

Just down the hill from the remains of a summer cottage, next to a rocky creek, are the remains of a spring where the owners of the cottage must have gotten their water. A small pipe sticks out of this half circle of stone, near the bottom. The ground there is consistently wet, but I've never seen water actually flowing out of the pipe. Last time I'd been there, I'd found a robust patch of JoePyeWeed, a tall wildflower found nowhere else in the preserve. This was also the only place I've seen smooth alders in the area. Apparently, the stable water source allowed the plants to survive droughts.

On this visit, armed with awareness gained at Landis Arboretum in upstate NY, I was able to focus in more on what sorts of trees were growing nearby. Past logging had left only narrow corridors of the original forest intact. Buffer regulations had forbidden harvest of trees within fifty feet of the stream. One tree in particular caught my eye, a towering shortleaf pine. 

The rough bark at its base brought to mind the Landis Arboretum signage:

"The bark changes on most species when the trees are over 150 years old, looking very different from the bark of younger trees.

Excellent signs include balding bark, shaggy bark (separating or curling strips), craggy bark (deeply grooved, fissured bark), and platy bark."

On this particular shortleaf pine, the bark changed dramatically about 20 feet up, from shaggy to smoother, platy bark extending to the top. That would suggest the tree is well over 150 years old.

The bark at the base was deeply grooved. 

Other large trees with distinctive, eccentric bark rose from the creekbanks. I doubt that this narrow band of mature trees along a stream would fit the definition of old-growth forest, even if the trees were old enough. The Network prefers stands of at least 20 acres. If there had been time, we could have followed this narrow band of old trees downstream, to better dream of what this woods had been before the logging. 

Late afternoon light caught the tops of these towering remnant trees rooted in a distant time yet still growing towards the sun. The experience of being there in that charmed hollow was not unlike the sense of timelessness felt while staying in our friends' house with furniture firmly rooted in the past. 

Keeping with the theme of old stuff, the young couple's wedding reception took place in the Hotel Utica, dating back to 1912, with massive, ornate chandeliers and tree-like columns. The groom's father was happy his son had chosen a place so steeped in history, but mourned that the glorious woodwork had been painted over during a recent renovation. 

It was the groom's father's idea to include an antique phone booth at the reception, where wedding guests could leave a message for the newlyweds, using an old dial phone. 

Click on "read more", below, for text from the Landis Arboretum's interpretive signage, describing in more detail the qualities to look for in old-growth forest.

 

Touring a New Preserve in Plainsboro--Bulk Farm Nature Center

My friend James Degnen called me up recently, and with his deep baritone voice invited me to explore the Bulk Farm Nature Center--a new nature preserve in Plainsboro, NJ. A former tree nursery, the preserve has cherry blossoms in the spring, leaf color in the fall, and lovely vistas through the winter. Note: The back portion of the preserve, with trails that reach the Millstone River and a bald eagle nest high in a tree, is closed from January through July, to avoid the bald eagles' nesting activity. 

Acquired in 2008, the property took fifteen years to prepare for public use, opening in September, 2023. Some soil contamination was found, likely requiring a lengthy bureaucratic process of remediation.

Though the 80 acre preserve is easily accessed at 179 Cranbury Neck Road, you'll need to navigate past the unusual name. It's called a Nature Center, but there's no building, and "Bulk" refers not to any particular aspect of the preserve, but instead to the family that once owned the farm. Like those housing developments that are named after whatever natural feature was destroyed during the course of development, this nature preserve may ironically be named after a building demolished after the land was preserved. Similarly, the gravel road bisecting the property is called Homestead Drive, leading presumably to a homestead that no longer exists.

A trail map is available online. 

James explained that the soft gravel of the Homestead Drive is to be avoided in favor of the mowed trails winding back along either side. 

Though lacking any topography, the preserve's trails take you through a varied landscape with broad vistas across meadows. At first, the meadows are solid with goldenrod, but deeper in some of the native grasses--broomsedge (as in "Andropogon Trail") and purple top--become more prevalent. 

The map conveniently marks where benches can be found, built to last well into the next century. 

The groves of nursery trees prove yet again that it's easier to plant a tree than to sell it.

Most trees are small, but somewhere towards the back right of the trail system we encountered an extraordinarily large river birch.

Towards the back of the preserve, you reach a gate that will be closed and locked for the first seven months of the new year. Bald eagles nest in a tree near the river, and are not to be disturbed. 

It not being January yet, we were able to hike all the way to the back of the preserve, and see the very impressive eagle nest. The tree appears to be a red oak fighting a bad case of bacterial leaf scorch. 

Beyond the eagles' nest, the trail ends at a tranquil spot along the Millstone River. James said the water continued to flow through the long drought this fall.

On the way back, James partook of a pet pleasure--releasing milkweed seeds to the wind.

One curious plant you may encounter in the expansive meadows is this shrub with red stems. Though multiflora rose is a highly aggressive, thorny invader of our natural areas, it is sometimes slowed down by a disease that spread to NJ from the midwest. Called rose rosette disease, the disease stunts the leaves of the multiflora rose and turns the stems red, particularly in sunny locations. 

A gray birch's bark doesn't flake like the bark of a white birch. Both of these birch species are native further north.

The hike took about an hour. Thanks to James for making me aware of this new preserve a fifteen minute drive from Princeton. James' rich baritone voice, by the way, is in demand for doing voice-overs, and we collaborated back in 2019 on a film project in which we recast The King's Speech as a call for action on climate change. 

Past adventures up Plainsboro way:

The Plainsboro Preserve is Anything But Plain

Kayaking Up the Mighty Millstone Marsh

And another tree nursery turned nature preserve, in Lawrence Township: 

The Lost Meadows of Maidenhead Meadows

Botanizing With Seek at Indiana Dunes National Park

Things were going our way as we pulled into Indiana Dunes National Park. Swinging around the south side of the Great Lake on our way to Michigan from Chicago, we decided Indiana Dunes would be a good spot to see the shoreline. The cheerful attendant at the gate offered different options for admission. One was a $20 yearlong pass to all national parks for a senior like me. Now, that's a major perk for what still seems pretty modest longevity. 

A visit to the Chicago area offers a chance to see some wonderful restorations of the region's native habitats--prairies, oak savannas, wetlands, dunes--achieved over decades, in part through a consortium known as Chicago Wilderness. Bur oak savannas had disappeared altogether under a sea of nonnative buckthorn, and had to be recreated through botanical research, invasive plant removal, and the reintroduction of fire. 

It was surprising to learn that the Indiana Dunes, a product of receding glaciers and fluctuating lake levels that exposed sandy beaches to the wind, is the fifth most biodiverse national park, and is called the "Birthplace of Ecology." In 1986 Professor Henry Cowles of the newly formed University of Chicago started bringing his students to the dunes to study how a plant community develops over time. The dynamic dune landscape provided a gradient of stability ideal for studying plant succession, from the raw windblown sand of the lakeshore to the complex diversity of species growing on the older, more stable dunes further inland.   

Many of the dunes were mined and carted away long ago for sand. That any survive is a long story, told on wikipedia, featuring Chicago botanists and conservationists like Henry Cowles and Jens Jenson. Some credit for preservation is also due to a woman who in 1915 abandoned city life in favor of a shack on the dunes. Drawn to the spiritual power of the landscape, Alice Mabel Gray became known as "Diana of the Dunes", and advocated for their preservation. She's featured on the interpretive signage in the park.

"Her unusual, free-spirited lifestyle fascinated local townspeople and newspaper readers here and across the country, bringing national attention to the Indiana Dunes at a critical time of early conservation efforts."

Alice Gray's story triggers memories of Thoreau, and a character who lived on the beach in one of Steinbeck's novels--Cannery Row or Sweet Thursday. Thoreau spent two years at Walden Pond; Gray lived on the dunes for nine. 

For me, it was a chance to botanize. The pleasure of learning plants--their names, their shapes--is that you'll encounter the familiar no matter where you go. If you've gained some familiarity with the plant world, you'll find a lot of New Jersey in Indiana, and vice versa.

Look! There are the three shapes a sassafras leaf can make,

and the scalloped leaves of witch hazel. 

And for those plants I didn't readily recognize, I had an ambassador in my pocket, ready to provide an introduction. The phone app I use is called SEEK--a popularized version of iNaturalist. The fun thing about it is that you can point your phone's camera at a plant and the plant's name will appear on the screen. No need to take a photo. It's as if an ID label were hung conveniently on nearly every plant you pass by. 

This shrub, with its three leaflets and distinctive seedpod, reminded me of bladdernut (Staphylea trifolia)--a large native shrub that grows in only a few locations in Princeton's nature preserves. SEEK--my "pocket botanist"--called this dune plant Common Hoptree, Ptelea trifoliata. Turns out that bladdernut and common hoptree are related, being in the same Order: Sapindales.

The pine trees perched on the dunes looked familiar, with their short, paired needles. SEEK, with infinite patience, reminded me: Jack pine. I read about them fifty years ago when first discovering the elegance of fire ecology. Jack pines have serotinous cones that only open when heated by a fire sweeping through. The seeds then fall on the mineral soil ever so conveniently left exposed and fertilized by the flames--yet another clever adaptation of plants to periodic fire. In the midwest, and even in New Jersey, the reintroduction of fire into the landscape, in the form of controlled burns, has been an important element in the restoration of habitats like prairies and oak savannas.

SEEK reassured me that this was in fact winged sumac, just like the winged sumacs that have been spontaneously popping up as we restore the habitat in the Barden at Herrontown Woods. Maybe not "just like." The characteristics of a species can vary across its range, like accents in speech. 

There's a whole long list of invasive species that supposedly grow on the Indiana Dunes, but I didn't see any. What a great feeling to visit a habitat where native plants are thriving. The one weed I saw was the native horseweed. It can cover whole farm fields, but here one was growing all by its lonesome, as if on display, in a crack in the concrete. 

Another bit of luck: a threat of rain had kept the crowds away, making us one of the few witnesses to a beautiful beach and highly swimmable Lake Michigan water. Having arrived with no expectations, the beauty and a cool swim sustained us through the rest of a day of travel.

A few observations collected on the SEEK app:

Common Hoptree, Ptelea trifoliata

Tall boneset, Eupatorium altissimum

Shining (winged) sumac. Rhus copallinum

Flowering spurge, Euphorbia corollata

False boneset, Brikellia eupatoriodes

Holden Arboretum Studies Resistant Beech and Ash Trees

Herein lies a post about the long, patient work that begins when something goes wrong with the world. With the introduction of beech leaf disease into North America, things have gone very wrong. Another noble, native tree species, towering and strong, is proving no match for a microscopic nematode. When this happens--yet another example of collateral damage from international trade--scientists mobilize to seek understanding and possible remedies.

In recent blog posts about beech leaf disease, I've mentioned Holden Arboretum. Holden happens to be located east of Cleveland, close to where the disease was first noticed back in 2012. Visiting family in Cleveland this summer during a band tour, I reached out to Holden staff to see if I could stop by to witness their research on the disease. 

Tucked behind some 3000 acres of gardens and ponds, forests and fields, is a research station where Holden is devoting staff and greenhouses to a collaboration with the U.S. Forest Service and others to test resistance not only beech leaf disease, but also to the introduced insects that have decimated two other native trees--ash and hemlock. 

I learned primarily about their research on beech and ash trees.

AMERICAN BEECH

Where did the nematode that causes beech leaf disease come from? According to Rachel Kappler, Holden's Forest Health Collaborative Coordinator, who generously came in on a Saturday to give me a tour, they have identified the island in Japan from which the nematode came. It was not a species from Asia's mainland. 

Holden's main endeavor is to seek out beech that show some resistance to the disease, and test that resistance. 

Rachel first grows seedlings that can be used as root stock for these tests. The root stock serves as the bottom half of a graft.

When trees are found that have lingered in the landscape while others succumb, Rachel then grafts cuttings from these "suspiciously healthy" trees onto the prepared rootstock. 

Once the grafts heal,

the trees can be tested for resistance. Measured numbers of nematodes are applied to the buds, documented with colored tags, and the tree's resistance to the nematodes is then observed.

The nematodes are small enough to enter the buds between the overlapping bud scales. The tiny worm-like creatures inhabit the leaves all summer. Then in fall, exiting the leaves through the stomata--the openings on the undersides of the leaves through which the tree breathes--the nematodes transfer to the new buds to overwinter.

Each step in the process of testing resistance takes time and consistent attention. Rachel says some promising means of speeding research are in the works. Promisingly resistant trees can be propagated using only their leaves. The leaves are cut, a particular root hormone applied, then the leaf is stuck in soil medium to grow. This approach could potentially avoid the need to grow root stock, grafting, and the time it takes for grafts to heal.

As for treatments for the disease, she says soil applications of phosphite have mostly been experimented with on smaller trees because it's easier to study at these smaller scales. Similarly, using chemical sprays on the trees' foliage requires just the right timing, and a thorough coating, which makes larger trees very difficult and expensive to spray. They are experimenting with pruning to allow better air circulation and thereby reduce the moisture that the nematodes like.

ASH TREES

Research on resistant ash trees is a little farther along. Rachel showed me a grove of young green ash--protected by a deer fence--that are being tested for resistance to the Emerald Ash Borer (EAB), which spread through Ohio nine years before Beech Leaf Disease. This is the same introduced insect that has decimated Princeton's ash trees.

Rachel explained that the ash can defend themselves from the burrowing insects in three ways. One is a blockage that prevents entry. Another is to react by building a wall around an ash borer that has gotten in under the bark. Another is to somehow deprive the ash borer of nutrition, so that it becomes stunted. 

Sticky boards are used to monitor the presence of Emerald Ash Borers at the site.

When I told her that I had only seen one adult Emerald Ash Borer in my life, despite the hundreds of millions of ash trees killed, she pulled one off of the sticky board.

In this closeup, the Emerald Ash Borer is on the left; a native ash borer, far less destructive, is on the right. Though they are similar in appearance, it's the difference in behavior of the introduced species that has proven lethal.

She said that ash trees become vulnerable to EAB attack fairly early in life, certainly under ten feet high. While some of the ash trees being tested in the grove are dying due to EAB (perhaps these are the controls in the experiment), 

many are doing well, showing some degree of resistance. 

The green ash that have proven resistant to the EAB must not only be able to survive at low EAB levels, but also when the Emerald Ash Borer is present in high numbers. Rigorous testing helps avoid later marketing an ash variety that ultimately could prove vulnerable. 

This scar is evidence of an inner struggle by the ash to fend off the borer. The tree tries to build walls around the EAB larvae. 

Rachel described an autoimmune reaction, observed in black ash up north, in which the tree is too aggressive in blocking off passages, interfering with its own circulation. 

She talked about the physical aspects of doing research on trees and their pathogens. The wooly adelgid that plagues our hemlocks is hard to study, in part because it can be hard to apply the soft insect to test trees without squashing its soft frame, so they use its eggs. Nematodes are much easier to count and apply to branches.

Expanded greenhouses suggest Holden is expanding its efforts to nurture trees resistant to imported insects and disease. 

One bonus from my visit was that Rachel took an interest in our efforts in Princeton to bring back the native butternut (Juglans cinerea), and has put us in touch with someone studying the species.

If, as beech leaf disease takes its toll on beech trees in Princeton, we see some trees that "linger" and remain "suspiciously healthy," we'll want to notify Holden Arboretum, to aid their ongoing search for resistant trees. 

A thunderstorm prevented me from exploring the many gardens at Holden that day, including a treetop walk and tower. And then there's the Cleveland Botanical Garden closer into town, with which Holden recently merged. These are some good botanical destinations in Cleveland, with a mission that extends far beyond the city, and an engaging origin story.