Wednesday, August 16, 2023

Princeton's Fuel Tank Raingarden Threatened By Lack of Early Intervention

A couple years ago, the town planted this raingarden next to the fuel tank on Witherspoon Street. They put in some pretty cultivars of showy native species like black-eyed susan, purple coneflower, and St. Johnswort, then mulched it all carefully. Everything looked under control, as gardens do when they are first planted.

Even this summer, with flowers blazing, it looks like a success. 

But I can see that the seeds of its ultimate demise have already sprouted. This botanical drama has played out many times before--raingardens that failed for lack of strategic intervention when aggressive weeds started to move in.

Most deadly is the mugwort that has become established and is quickly spreading. That one invasive species alone could obliterate the intended plants in a few years.

Nutsedge, too, spreads rapidly.

Along with foxtail grass, 

and barnyard grass, the nutsedge is obscuring a nice stand of soft rush the town planted two years ago. 

More easily dealt with are the ragweed--a native weed with allergenic green flowers--
a flamboyant patch of crabgrass, 
and what looks like a patch of black medic. The mulch laid down two years ago surely helped, but its capacity to stifle weed growth clearly didn't last.

And what's this vine, crawling out over the other plants? Ivyleaf morning glory is a new one for me. 

Back in late April, when this photo showed the mugwort looking tamable, pullable, sprayable, I alerted the town that early detection and rapid response is what's needed to keep the weeds from taking over. The response was that a public works crew weeds the garden once or twice per year. That's not how a raingarden works. I know from long experience. Catch the aggressive weeds early, and the raingarden will ultimately become very easy to maintain. 

Vikki Caines, a longtime member of the Recreation Department who recently retired, kept beautiful gardens growing in areas near the community pool. But that was a labor of love, done in her spare time. It's love, of a parental variety, that leads one to acquire plant knowledge in the first place, and then to grow a garden and anticipate its needs, and check for weeds, much more than once or twice per year. 

How can your typical institution--where staff lack plant knowledge, motivation, and the flexibility in routine needed to catch problems early--successfully tend to a botanically complex raingarden planting? For the past 30 years, I've watched as many native raingardens and meadows planted by towns or universities have incrementally failed for lack of early and ongoing intervention by a knowledgeable caretaker. Maintenance requires more knowledge than installation, because the caretaker must know not only the intended plants but also the many species of weeds that inevitably try to move in. Yet we see over and over that money is invested in design and installation, while maintenance is deprived of funding and respect. We have doctors and nurses to care for people, but precious few plant doctors to care for landscapes. 

A bit of good news: Last year, I wrote a google review of the Betsey Stockton Garden planted on top of the Princeton University's Firestone Library, pointing out that white clover and other weeds were invading the flower beds. Whether the review had an impact, I can't say, but the university is taking better care of the meadow planting this year.

Related Posts:

Followed two years later by:

Cindy Taylor, Princeton's First Open Space Manager, Moves On

It was a brief but extraordinary tenure for Princeton's first Open Space Manager, Cindy Taylor. Her hard work and accomplishments made abundantly clear the importance of the open space manager position in town government, validating the view of all of us who fought long to have the position created, and the wisdom of the current council in funding it.

Cindy served as primary contact within town government for the nonprofits that take care of Princeton's open space at Marquand Park, Mountain Lakes and Herrontown Woods. Among her many activities, she compiled an inventory of open space in Princeton, worked with the Environmental Commission on updating the Environmental Resource Inventory, and helped apply for habitat restoration grants. In my many communications with her, I would have to say she was impeccable, sending us detailed notes from meetings, and attending quickly to our various requests. 

After a year and a half on the job, she is leaving for a job in Mercer County open space. We thank her for setting such a high standard of public service.

(Photo plucked by TapInto Princeton from a zoom video of a council meeting)

Friday, August 11, 2023

The Invasive Grass Fueling Wildfires in Hawaii

Hawaii didn't used to get pummeled by highly destructive wildfires. What has changed? A big part of the answer lies in the interaction between climate change and invasive species. 

Begin with a couple paragraphs buried in a NY Times article:

The area burned annually by wildfires in Hawaii has quadrupled in recent decades. Declining rainfall and rising temperatures have left the islands more susceptible to blazes, climatologists say.

Invasive grasses that are highly flammable have crowded out native vegetation in some areas, and climate change has exacerbated dry and hot conditions in the state, allowing wildfires to spread more quickly.

But what invasive species? A University of Hawaii website points to one that has been particularly destructive:
Guinea grass (Megathyrsus maximus), a nonnative invasive grass in Hawaii, forms dense stands that outcompete native plants and has very high fine fuel loads that greatly increase fire potential, spread, and severity.

Wikipedia describes guinea grass as a tough customer, growing ten feet tall. Though it can thrive in full sun, it can also tolerate shade, allowing it to invade native woodlands and thereby increase their vulnerability to fire during droughts. Native to Africa, the grass was introduced not only to Hawaii but also to south Texas.

How did guinea grass get to Hawaii (also spelled Hawai'i)? Wired provides an answer:

When Europeans arrived in the late 18th century and established plantations for growing sugarcane and pineapple, they also brought invasive grasses. Now the economics have changed, and those fields lie fallow. But the grasses have spread like a plague. “Those fire-prone invasive species fill in any gaps anywhere else—roadsides, in between communities, in between people’s homes, all over the place,” says Pickett. “At this point, 26 percent of our state is covered in these fire-prone grasses.”

This stuff is highly sensitive to short-term fluctuations in rainfall. The grass will grow like crazy when the rains come, then quickly desiccate when the landscape dries. “When we get these events like we’re seeing these past few days—when the relative humidity really drops low—all those fine fuels become very explosive,” says fire ecologist Clay Trauernicht of the University of Hawaiʻi at Mānoa.
An article in ABC News explains how the more intense and frequent fires affect the soil and human health: 
Elizabeth Pickett, co-executive director of the Hawaii Wildfire Management Organization, a nonprofit working with communities to prevent and mitigate fires, lamented the changes wrought by fire.

Invasive and fire-prone grass species have moved in over time and during a fire they can burn into native forests, which means the forests are replaced by more grass, Pickett said. The soil burns and sloughs off, leading to massive post-fire erosion that smothers coral, impacts fisheries and reduces the quality of the ocean water, she said.

The state is windy and the dust blows for years, harming human health, she added.

“When you lose your soil, it’s really hard to restore and replant. And then the only thing that can really handle living there in many cases are more of those invasive species,” Pickett said. “It’s systemic. Air, land and water are all impacted.”
A Philosophical Footnote
It's important to note that both climate change and the spread of invasive species are largely unintentional. Our world is threatened by excess carbon dioxide and other planet-heating gasses--lowly biproducts of our economy and lifestyles. We are used to thinking of collateral damage as minor and incidental, and tend not to judge people by what they do unintentionally. In fact, the cumulative impact of unintentional acts is the central threat we face. We live our days trapped in a predicament in which humanity, largely well-meaning, is allowed to collectively and unintentionally create problems, but not allowed to collectively and intentionally solve them. 

Additional reading: Thanks to a comment (see the critical comment and my response below), I found a couple more interesting articles about guinea grass. One gives a good overview of guinea grass as both an excellent, deeply rooted forage grass for cattle, and a weed that has disrupted ecosystems and croplands around the world. The other invests the grass with cultural connotations.

Other Invasive Grasses Fueling Fires in Hawaii

My friend Fairfax sent a link to another informative article that mentions three other introduced grass species fueling fires in Hawaii: fountain grass, buffel grass, and molasses grass. It also stresses that these and other highly flammable introduced grasses are altering fire ecology in the mainland U.S. as well.

What Guinea Grass Has in Common With Japanese Stiltgrass

Some people aren't aware the extent to which grasses affect our lives, for better and for worse. Corn is a grass, as are sugar cane, bamboo, and sorghum. In Princeton and up and down the east coast, the most dominant invasive grass is Japanese stiltgrass, which like guinea grass can grow in sun or shade, and uses what's called C4 photosynthesis to fix carbon from the atmosphere. Plants that use the C4 process--corn also being an example--are more efficient than other plants that use C3. Stiltgrass has invaded most areas of Princeton, growing from a zillion seeds each spring to blanket large expanses of woods. Wildlife don't eat it, so as it takes over, the landscape becomes increasingly inedible. I've long wished that someone would come up with a highly selective herbicide that would impact only C4 plants. If stiltgrass's impact on eastern habitats hasn't been sufficient to stimulate research, maybe the fire hazard in Hawaii will get researches to take a look.

Friday, August 04, 2023

Four Kinds of Honey Bees in Northern Thailand

These bee hives look like something Winnie-the-Pooh might stick his paw into. The hives are made of hollowed out sections of tree trunk. The photo was taken by my daughter Anna, who was traveling this summer in southeast Asia. 

To escape the heat, she and her boyfriend headed up into a mountainous region in northern Thailand called Chang Rai, where the residents drink three kinds of tea and grow four kinds of honey. She was surprised to learn that the black, green, and white teas all come from the same plant--the same species of tea. But the four kinds of honey are not made by the same kind of bee. This is four kinds of honey made by four species of bees. Thailand, it is claimed, has the greatest bee diversity in the world, including half the world's species of honey bees, and in this tiny village the various honeys they produce are an important part of the diet. 

There's the honey we're familiar with, and then there's another one that tastes like apricot jam. A third, produced by the stingless bee, has a fermented fruity flavor like Kambucha. 

Another species, the asian giant honey bee (Apis dorsata), can't be kept in a hive, so villagers climb trees to reach the honey. Wooden footholds are placed in the tree trunk to expedite the climb. The giant honey bees don't stick around all year, but instead migrate up to 200 kilometers, returning to the same branch six months later.

The asian honey bee (Apis cerana) produces less honey than our honey bee, but is much easier to take care of

A Brief Account of Life in a Mountain Village in Thailand

Their first night in the village, they were surprised to be awakened at 3:30am by the robust crowing of roosters, so raucous that the whole village has little choice but to rise and begin its day. Chickens run loose, apparently free of local predators that might consume them before people have a chance to. Once a year, a tiger passes through the area, apparently without raising much concern.

The town runs on solar energy, but lest one think this mountain village an idyllic integration of humanity into nature, daytime brings cooking fires and the burning of refuse. The villagers are conditioned to the resulting stew of smoke that can linger in the valley, but it registered as noxious and toxic to Anna. 

Some of the refuse is plastic, which we're all told releases toxins when burned. What plastics do the villagers have if they grow their own food and have few possessions? Though they cook delicious meals most days, there are times when villagers may not feel like cooking, and so pull out store-bought noodles and tomato sauce, the plastic wrappings from which end up getting burned in the refuse pile. 

This is not much different from my own experience growing up in a small village in Wisconsin in the 1960s. One of my chores was to burn the garbage, plastic and all. In autumn, we'd rake some leaves into piles to jump into, and others into piles to burn. We'd toss acorns into the glowing core of the fire and wait for the popcorn-like explosion. On brisk, sunny fall days, the whole village became suffused with what registered as a sweet and endearing aroma of burning leaves. Even after moving to a city, the 1930s house we moved into had an incinerator in the basement for burning trash. And in the 70s and 80s, when I played jazz gigs in smoke-filled bars, it was not until the next morning that I'd notice the wretched smell of stale smoke in the clothes I had worn. 

There have been efforts to promote cleaner air in remote mountain villages around the world. Some students, before entering Princeton University, sign up to spend a "bridge year" in a foreign country doing good deeds, one of which is helping build cleaner burning stoves for villagers in Peru and elsewhere. You'd think the villagers would be grateful for a home less choked with smoke, and maybe they are, but the capacity of the body to become conditioned to abuse is both impressive and exasperating.

Lots of interesting reading out there on bees. Here's some info about eight species of honey bees around the world.

Thursday, August 03, 2023

The Pleasures of American and European Elderberries

One of my favorite shrubs, the elderberry, took on new facets and dimensions this year. 

When I was a kid, we'd drive out to the countryside and harvest its berries, clustered on broad disks. What they lacked in size they made up for in numbers. Brought home in big brown paper grocery bags, they were soon on their way to becoming delicious jelly and pies. We made jelly out of wild grapes, too, but elderberries had a flavor all their own. It took a little time to strip all those small berries off the stalks, but the reward lasted all year.

How we managed to beat the birds to the berries back then is a mystery. Though we grow the shrub in our backyard in Princeton, the catbirds often make quick work of the berries.

Elder Flower Syrup

Fortunately, there's something amazing to be made of the flowers, and this year, we finally made it. One summer many years ago, a friend had served me an elder flower drink that was revelatory, but somehow I got the idea that only the flowers of the European species (Sambucus nigra) could be used. Searching today's internet, that distinction appears to have dissolved. The elderberry native to the eastern U.S., Sambucus canadensis, makes perfectly fine elder flower syrup. 

Our friend Joanna served as mentor and activator, directing us to pick the clusters when all the flowers were open but still fresh. For best flavor, one website suggests picking the flowers in mid to late morning. 

Some Caution

Some recipes are less concerned than others about including any fragments of the green stems, which are toxic. Only the flowers and the cooked ripe berries are edible. We stripped the petals off the stems by hand, which is time consuming but delivers good results. 

Making the Syrup

Recipes vary online, but all use lots of sugar and sliced lemons, which are added to the flowers along with some citric acid. Pour in boiling water and let it sit, covered, for most of a day, then pour through a cloth to get the syrup. We had to call around to supermarkets and hardware stores to track down some citric acid. 

Pour a little of the syrup in chilled water, white wine, or prosecco. It was a big hit at our Veblen Birthday Bash at Herrontown Woods. 

Elderberries Join a New Family

One bit of news from the turbulent, restless world of scientific nomenclature: the elderberry has been uprooted from its long-running membership in the Caprifoliaceae family and now rubs phylogenetic branches with Viburnums and a couple other genera in the Moschatel family, also known as the Adoxaceae

A Curious Variety of European Elderberry

On a recent roadtrip, I encountered a strange, purple shrub in a couple gardens. I was surprised that the botanist I now carry in my pocket, better known as an app called Seek, was calling it an elderberry. "Black tower" elderberry, perhaps--one of many bred varieties of the European elderberry. It's pretty, and different, but it's not something I personally would plant. Each gardener evolves differently, but for me, the sequence of interest across fifty years went from vegetables, to roadside weeds, to pretty ornamentals that were native or not (a black tower elderberry would be in this category), then to the community of native species that coevolved together over ions. It's a fidelity deeply rooted in a sense of place. 

Johnny Elderflower Strikes Again

If some combination of the abundant flowers and berries breeds in you a love of native elderberries, you can easily go forth and propagate them using 2' long cuttings from the dormant stems. The bushes are typically found in wet, edge habitat where there's some sun. Hopefully you'll emerge from your winter dormancy before the elderberry bushes, because they leaf out earlier than other native shrubs. Press the bottom end of the "live stake" as deeply as possible into soil to make roots, leaving a few buds above ground to make leaves. I've used this highly economical approach to propagation in many places over the years, most recently in a wet, open woodland area at Herrontown Woods. The act of planting is deliciously lazy, but followup is needed in the form of watering during droughts the first summer, and protecting them from deer browsing with wire cages. If things go well, in a few years the special flavors of elderberry will be all the easier to be had in Princeton.