Butternut Redux--A New Generation Bears its First Crop

This has been a breakthrough year for those of us working to bring back the native butternut--a species laid low by an introduced canker disease.. 

Twelve years after I helped Bill Sachs collect one of the last known harvests of native butternuts in Princeton, the new generation has finally born a crop of its own. Butternuts, also called white walnuts, or Juglans cinerea, bear nuts similar in look to black walnuts, but are oval rather than round. 

Bill continued to harvest and plant butternuts from the TRI property for a couple more years, but that pair of trees was then lost, with one blown down and the other cut down, ironically as part of an environmental remediation of contaminated soil. Most of the other known specimens, solitary so unable to bear, at Herrontown Woods and Mountain Lakes, have since been lost as well, lending all the more importance to this new generation of trees, grown by Bill and planted around town. 

We planted multiple trees, for cross pollination purposes, at Mountain Lakes, Herrontown Woods, Harrison Street Park, and at the TRI property where the seeds had originally come from. 

The saplings needed to be caged, to protect them from the deer. I made the mistake of removing a cage when a tree was tall enough that the deer could no longer reach the leaves. Bucks proceeded to rub the bark off the trunk, reducing a promising tree to root sprouts. A post from a couple years ago tells of some of the persistence required to nurse a new generation towards maturity. Along with deer, the young butternuts have been in danger of being smothered by fast-growing Japanese honeysuckle and grape vines, and trees like sweetgums and mulberries that rise quickly to fill the sunny openings the young butternuts need to grow.  Gardening, even wild gardening with native species, teaches the necessity of followup. 

This year, the butternuts had to deal not only with the 17 year cicadas' heavy pruning, but also the expanding presence of spotted lanternflies. 

Adding to the young trees' burden were some galls, which Bill said were most likely caused by walnut leaf gall mites

But despite all of that, the long awaited flowering of this new generation was spotted in July, and a few nuts collected in fall that appear to be viable, offering hope of yet another generation to come.

This fall's harvest is mostly being planted to grow more trees. Bill plants the butternut seed "in tall pots to be kept outdoors for the winter. This has worked well in the past."

Here are some additional tidbits gleaned from correspondence with Bill. The "float test" is used to determine whether a nut is viable. If it floats in water, it lacks a viable seed inside. (Update: This is true if the nuts have just been gathered. Once they dry out, even viable nuts will float.)

Dehusking walnuts and butternuts:

"I don’t really know if it’s absolutely necessary to dehusk walnuts or butternuts before a float test, though I think it is prudent. If you have a lot of nuts the best way to dehusk them is to use an old cement mixer with rocks and water… since I don’t have an old cement mixer, I use a piece of ½ inch plywood about 18 in by 6 in. I put a butternut or walnut in the driveway or street, put the plywood on top and use my foot with pressure to roll the nut under the plywood. (Use gloves to handle the nuts if you don’t want to stain your hands.) The husk comes off pretty easily. Then I put the largely dehusked nuts in a bucket of water and use a still wire brush to complete the cleaning."

Identifying butternuts: "Butternut bark is characteristically a lighter gray with broader ridges than black walnut (but not always). Easier to tell for sure from a twig with a terminal and a few lateral buds. If you slit the twig, butternut will have a dark chocolate-colored, chambered pith, and the leaf scars typically have a hairy fringe (or mustache) along the upper margin. When the leaves are still on the tree the leaf rachis will be tomentose or pubescent (hairy). Not sure if this carries over to fallen leaves on the ground in the winter. Finally, butternut trees often have poor form. In contrast, black walnut has a buff-pink chambered pith, no hairy fringes along the top edge of the leaf scars and the rachis is smooth (among other differences)."

Some additional reading recommended: 

On butternut seed propagation/germination:

https://htirc.org/wp-content/uploads/2020/10/SeedPropagationProtocol.pdf

 

On butternut conservation:

https://www.extension.purdue.edu/extmedia/FNR/FNR-421-W.pdf

Walnut Art

A lot of people, when they hear the words "black walnut", will think of a tree that drops nuts large and heavy enough to be a hazard, is super frustrating to get any food from, and has the gaul (juglone, actually) to hamper the growth of plants unfortunate enough to find themselves growing beneath it. 

This merry crew has a richer take. Meet Ooh!, Totally!, and Ugh!, three well-crafted nuts who between them express the gamut of attitudes toward walnut trees. 

I applaud those endowed with the incredible patience needed to carve these faces (that would be squirrels), and a similar patience to search for the squirrels' underappreciated art amongst all of autumn's debris in the backyard (that would be my friends and occasional Ann Arbor hosts, Dan and Karen). 

Though they express the same common laments about their black walnut trees, they have at the same time become fascinated by the exceptionally hard and messy nuts that litter the ground every fall. 

As if developing a cottage industry, they gather the nuts, and extract the oils from the husks. 

Dan came up with a way to clean the oils off of the shells, using a forked spade as if he were churning butter. 

His motivation? To sand down some of the nuts to make picks that get an unusual sound out of his string instruments.

Their art-student daughter, Thea Bilich, demonstrated how the walnut ink works well for old master paintings.

All of which shows how a little curiosity and a spirit of experimentation can look beyond life's burdens to find a sky full of possibilities.

The Long Evolution of Deer Hunting in Princeton

Most hikers in Princeton have by now encountered warning signs posted at various preserves, giving notice that it's bow hunting season. The season runs from September to February, and is limited to a select group of skilled hunters vetted by the town. They use elevated deer blinds located away from trails, so there should be no risk of errant arrows. The warning is useful for encouraging people to keep themselves and their dogs on the trails.

Hunting is not allowed on Sundays, and also now is not allowed on Saturdays from 10-2. More info at this link. For those in the Riverside neighborhood, there's also info online about hunting at the University-owned Butler Tract.

As a botanist helping to manage habitats in Princeton, I cannot emphasize enough how important it is to manage the deer population. The deer prefer to eat native plant species, and too many deer leads to a decimation of the native flora. Into the void come nonnative plant species--stiltgrass, honeysuckle, winged euonymus, privet, etc.--that the deer reject. Over time, Princeton's preserved lands become increasingly inedible to the very wildlife  the land is intended to sustain.

A 2018 article in NJ.com summarizes the dilemma. It mentions how Princeton gained national attention when passionate protests arose soon after the township hired professional hunters in 2000. Amateur hunting had not proved sufficient. An ecologist is quoted in the paper, raising the central point that the biggest human intervention was not hunting, but instead the extirpation of predators like wolves and cougars. Then, when deer hunting was also banned in 1972, the deer population began to explode. 

The resulting imbalance is analogous to what Rachel Carson describes when reckless use of pesticides began wiping out the predators that had until then held insect numbers in balance. She describes predators as "critically important," because they contribute to the "resistance of the environment" that helps keep populations in check. She also speaks of the "truly explosive power of a species to reproduce once the resistance of the environment has been weakened." High numbers of deer are due less to having been displaced from their traditional habitat than simply through their capacity to reproduce, and a lack of checks that would otherwise keep them in balance with the carrying capacity of the land.

Unless people want to bring back predators like wolves and cougars, it is up to us to fill the void in predators we ourselves have created.

The traumatic learning curve Princeton has gone through over the past 20 years is analogous to what the great conservationist Aldo Leopold experienced a century ago. Born in 1887, Leopold earned a forestry degree and was soon writing management plans for preserved federal lands out west. An extraordinary documentary of his life and legacy, Green Fire, tells of how he at first believed that killing wolves and other predators out west would create a hunter's paradise. Instead, the absence of predators led to severe habitat degradation as surging numbers of elk ate vegetation down to stubble. 

Leopold was a contemporary of Oswald and Elizabeth Veblen, who donated Princeton's first nature preserve back in 1957, and I wondered if Leopold might have influenced the Veblens in their founding efforts to preserve land in town. Leopold bought the land in Wisconsin later made famous by his book, the Sand County Almanac, around the same time the Veblens were acquiring land in Princeton. The parallels caused me to search for Leopold's name in the fabulous online resource, Papers of Princeton.

What popped up was not a visit by Leopold to Princeton, but instead references to Leopold in past discussions about controlling deer numbers in town. In 1987--100 years after his birth--and again in 1998, Aldo Leopold's name is used to lend weight to arguments in favor of using hunting to bring down the burgeoning numbers of deer and related automobile accidents. 

What we learn from this history is how long and hard the fight has been to get a town to collectively acknowledge truths that were known a century ago, and surely long before then by others possessing the knowledge and keen observation skills of an Aldo Leopold or a Rachel Carson. 

Reading the 1987 article was also a chance to witness some of the dedicated environmentalists of Princeton in action. Tom Poole, whom I knew from working with the Friends of Rogers Refuge, stated at a township meeting:

"In my view it is much more humane to take a deer with a shotgun than with the bumper of a car," Mr. Poole remarked. He added that last August, the Animal Control Officer, Al Heavener, had to kill 23 wounded deer. "He nearly quit his job."

Elizabeth Hutter was another active environmentalist at that meeting, and "traced her feelings about deer, from joy at their proximity to tolerance at the damage, to "annoyance, frustration and anger."

A beautiful letter to the Town Topics, written by Tom Poole in 1998, shows how long has been the road to deer management based on ecological realities. He also mentions in passing the annoyance of leaf blowers, which is only now, 23 years later, beginning to be addressed. Even more extreme in the slowness of progress from awareness of a problem to action to solve it, the threat of climate change was first raised nationally in 1988, but scientists were aware of this most devastating of imbalances long before that, and still there is no coordinated action after all that time. Interestingly, climate change is stymying efforts to control deer populations, since mild winters make it harder to attract deer to feeding stations. 

Any success we have at finally stirring action on long-festering problems owes thanks to those who were priming the pump decades ago. 

Click on "Read More" to read Tom Poole's letter.