Wednesday, January 25, 2023

Princeton's Nowhere Land Might Have a Future

The municipality of Princeton's newsletter broke the news last week that the town has been awarded a $552,000 Climate Solutions grant to restore 45 acres of forest at Community Park North. Kudos to the town, and to FOPOS, which will help with the project. Now, what sort of forest, you might ask, is so degraded that it requires more than $10,000/acre to restore? I stopped by last week to have a look.

It's appropriate that the sculpture that now graces the entrance to the woods at the back of the Unitarian church parking lot appears to be in mourning. 

Many hikers who head down the trail won't notice anything amiss, but for me, Community Park North woods has the feel of a post-apocalyptic landscape. Walking its trails, you can imagine yourself to be one of the fortunate or unfortunate survivors after civilization has extinguished itself, leaving invasive species to overrun the wreckage. 

For a virtual tour, click on "READ MORE," below.

Monday, January 09, 2023

What Privet is This? Border Privet in Princeton

A botanist friend of mine, John L. Clark, asked one day if I knew which kind of privet we have here in central New Jersey. John's extremely knowledgeable about flora of farflung places like Equador, but he has some charming gaps in knowledge of local flora that I can sometimes help with. Though I knew there were different kinds of privet--European, Chinese, Japanese--I had long been content to just call any thick infestation of the shrub by the general name of privet, and think no further. All the species of privet are nonnative and invasive, so for management purposes, it's not necessary to know one kind from another. 

More important for management is to be able to distinguish the non-native privet from native shrubs with similar appearance, particularly the native blackhaw Viburnum. Both have opposite branching, but privet often has a terminal cluster of small black berries that linger through the winter. And many of the privet leaves linger through winter as well. 

The photo shows the difference in the shape of the buds. The longer bud on the top (curved here, but sometimes straight) is blackhaw Viburnum. The stubby, grayish buds on the twig below are privet. 
Sometimes privet's winter leaves can take on various shades of green, sometimes bordering on purple or brown. 

I was glad John persisted in his quest to find out which privet we have in central NJ. Having lived in the south, he at first assumed we have Chinese privet (Ligustrum sinense), but after posting a closeup of the flower on iNaturalist, he soon learned that we have Ligustrum obtusifolium, latin for border privet.

Posting another closeup, John pointed out various identifying characters of border privet: "Corolla tubular with small lobes (the tube longer than the lobes), Shoots pubescent (i.e., NOT glabrous)"

The Penn State post describes "a gradient of four different species: border (L. obtusifolium), common (L. vulgare), Japanese (L. japonicum), and Chinese (L. sinense)." But John has determined that we only have border privet here, probably because it is the most cold-hardy. When I lived in North Carolina, we had a mix of Japanese and Chinese, with the Japanese having much larger and glossier leaves. 

Thanks to Inge Regan and John Clark for these photos. Winter, by the way, is a great time to go after infestations of privet in the backyard or local woodlands. Come by Herrontown Woods on Sunday mornings after 10:30am and you'll likely see the Invasive Species of the Month Club clearing swaths of privet to make room for native species.

Sunday, January 08, 2023

Rogers Refuge Featured in the Princeton Echo

For the past two years, Princeton Echo has started the new year with a feature article about a local nature preserve. Last year, it was Herrontown Woods, and this year, Rebekah Shroeder wrote an extended portrait of the birding mecca Rogers Refuge and the volunteers who have cared for it since the 1960s. 

The Charles H. Rogers Wildlife Refuge is a hidden gem, a covert part of Princeton's beauty and ecological richness, accessed down an often passed but seldom seen gravel road called West Drive. Climb the observation tower just in from the parking lot and you will see a most unlikely vista for Princeton--a grand marsh.

Since joining the Friends of Rogers Refuge (FORR) nearly 20 years ago, I've gotten to know the many volunteers featured in the Echo article. 

The article draws primarily from an interview with Winnie Spar, an avid birder, poet, and FORR stalwart. 

Charles Rogers and Tom Southerland were the environmental activists who first called for protection for the wetland back in 1968. Tom Poole was another early advocate. Winnie's husband Fred Spar led the group beginning in 2005. Laurie Larson has been a longtime member who created and maintains the website, Lee and Melinda Varian provided critical leadership after Fred Spar passed away, and most recently, David Padulo has taken the helm. 

Important support, particularly for fighting the invasive Phragmitis, has come from the Washington Crossing Audubon and Partners for Fish and Wildlife. Winding through land owned by the American Water Company, the Refuge's trails are kept open by volunteers. The town of Princeton helps out, particularly with maintenance of the pump that augments the water naturally flowing into the marsh from the Institute Woods. The town also funds deer culling that has allowed native habitat to rebound. For my part, I was commissioned back in 2006 to write an Ecological Assessment and Stewardship Plan for the refuge. That assessment includes a detailed plant inventory. Mark Manning and his son recently conducted an inventory of dragonflies and damselflies, and the extraordinary list of bird sightings continues to grow. The article also mentions Betty Horn's work to maintain the University's Rogers Bird Room, and an online exhibit called Capturing Feathers: A Digital Collection of Bird Imagery.

Congratulations to the Friends of Rogers Refuge on getting well-deserved recognition in the Princeton Echo. The article will reportedly also appear in U.S. 1. 

Past blog posts about the Refuge can be found by putting the word "rogers" in the search box of this blog. Some examples:

Friday, January 06, 2023

Conspicuous Earth Hugging By Trees

An endearing feature of trees is their affection for the ground. People hug trees now and then, but trees spend their whole lives hugging the earth. Like humans, trees lust for the sky, but unlike humans they know that quest requires a good foundation, and find ways to hold on tight. Here are some of the more demonstrative embraces seen during a recent visit to Coconut Grove, Florida. All except the first were seen at Fairchild Tropical Botanical Garden.

Root flare is a sign of health in trees, but I'd never seen the likes of this. I'm calling it a kapok tree (Ceiba pentandra) after encountering this charming video that describes its buttressed base and the fluffy seeds that used to provide stuffing for life vests. 
The extravagant buttressing is reminiscent of the fins of a rocket that in this case can reach more than 200 feet tall, vaulting above the rainforest canopy. With seedpods packed with useful fiber, it's not surprising that the kapok is in the same plant family as cotton--the Malvaceae, also known as the mallow family. 

One of Princeton's native members of that family is the rose mallow hibiscus (Hibiscus moscheutos), fairly common along the shores of Lake Carnegie and in raingardens.
The ombu, a native to the Argentine pampas that goes by the latin name Phytolacca dioica, develops a conspicuously bloated base that with time can become convenient for sitting. If you haven't seen one, just imagine a 50 foot high pokeweed--our local Phytolacca americana with very similar leaves, flowers, and berries. 
I was impressed by this tree's buttressing, 
and even more impressed with this larger specimen.

With leaves like that, I was sure it was some sort of yucca, but no. The iNaturalist app called "Seek", my new botanical companion for the trip, called it Pandanus tectorius, a kind of screw pine. With those mangrove-like roots, it's not surprising that screw pines grow along coasts and are wind and salt resistant.

Native mangroves have similar adaptations. Though they have lost a lot of territory, as development has transformed the Florida coast, this one still finds some ground to hold onto.

Had to look at the plant marker for this tree with a bloated base. Surprise! It's the ponytail palm--the same species we have growing in our living room in Princeton. 

Another name for ponytail palm is elephant's foot. 
This tree's swollen base is the boulder that it is growing on.

Back in Princeton, at the Barden in Herrontown Woods, a white pine shows some flare for root flare.

Tuesday, January 03, 2023

Strangler Figs: Airborne Roots and Flying Buttresses

Coconut Grove, FL, where I was fortunate to spend a week with family for the holidays, is named after its palm trees, but the tree that will catch your eye more than any other is the strangler fig. 

How silly we are, these extraordinary trees seem to say, to think that trees should start life on the ground, have only one trunk, make their flowers seen and keep their roots tidily hidden. 

The strangler fig's logic is clever. How can a new tree survive in a tropical forest where existing trees cast deep shade and have a lock on soil nutrients? It starts its life as if on stilts, as an epiphyte high in the canopy, sprouting on the trunk of another tree. Oftentimes, the seeds, freshly digested by a bird, catch in the rough bark of a live oak, or a cabbage palm. Declaring itself improbably independent of nutrition from mother earth, it lives at first on air and rain, growing stems skyward and roots earthwards. When the roots reach the ground, the strangler fig's growth accelerates. The above ground portions turn into multiple trunks that envelope the host tree. That embrace can ultimately prove lethal, providing the strangler fig with a convenient supply of additional nutrients as the host tree rots away. 


More and more roots are sent downward, each one turning into yet another trunk when the roots reach the ground. Surely if one trunk is good, then many must be much better. The result brings to mind a cathedral replete with flying buttresses. 
The result of all this free-thinking, or if not thinking, then free-doing, is a tree you can walk through. 

This old beech tree in the Institute Woods in Princeton achieves a somewhat similar effect, though it's just one trunk that has rotted through. A closer equivalent in our forests is achieved in a more covert fashion. Trees like beech, sassafras, pawpaw, black locust, aspen, and the blackhaw Viburnum sprout new trunks as their roots spread underground, creating what appears to be a grove of trees that is in fact one individual.
Wikipedia lists 13 different species of strangler fig around the world. This one at Barnacle Historic State Park is the native Ficus aurea, whose fruits the sign says are edible. 

I'm guessing that many of the other strangler figs--those with myriad trunks like this impressive specimen at the University of Miami--are banyan trees from India.

On the left in this photo you can see some aerial roots growing towards the ground. 
Here's a closeup of a cluster of soil-seeking roots growing downward from a limb--another tree trunk in the making.

What little bamboo I saw in Coconut Grove paled in comparison to the expansionist aims of strangler figs. 

This fig appears ready to eat the pavement, 
while others drape themselves over walls, 
or probe the local infrastructure.

This strangler fig was so bold as to break into a tiger's cage.

Fortunately, there's no tiger living there now, just a couple of chickens. 

I forgot to mention the hidden flowers, which are borne inside the fruit and accessed only by a tiny wasp. Each species of fig has its own specialized species of fig wasp to fertilize it. For more reading, and some cool photos of just how tiny those wasps are, here's an interesting post. This Forest Service post describes the mutualistic relationship between the wasp and the tree, and says the U.S. has only two species of native fig. 

For anyone headed down Florida way, a good example of a banyan tree can be found at the Marjory Stoneman Douglas Minipark, named after the famed activist and author of The Everglades: River of Grass.