At Thanksgiving in Kutztown, PA I was stunned to see a solid wall of arborvitae bordering a neighborhood. In Pittsburgh’s East End, arborvitae is always bare from the ground to 4-5 five feet up, eaten by our overpopulated deer. Here’s a row of arborvitae at Schenley Park golf course.
Why didn’t deer browse the Kutztown trees? My guess is that they are the Green Giant variety of Western arborvitaes. Davey Tree explains:
Deer don’t care for Western arborvitaes, like green giant, steeplechase or spring grove. So, if you plant these, they may leave them alone.
Though, when deer are starving, they become less picky and will eat almost anything, including those deer-resistant arborvitaes. If deer are a big problem in your yard, avoid arborvitae altogether.
In 1976 Jerry Kemperman and Burton Barnes discovered that 106 acres of quaking aspens (Populus tremuloides) in the Fishlake National Forest of Utah were actually all the same male plant, one root with thousands of suckers that grew into trees. It came to be known as Pando — “I spread.”
Pando weighs 6,600 tons making it the heaviest known organism on Earth and it is very old, though no one is sure whether it’s 10,000 or 80,000 or even a million years old.
However, almost as soon as Pando was discovered researchers found that sections of it were not rejuvenating because new sprouts were being overbrowsed by deer. In that part of the U.S. the species is mule deer (Odocoileus hemionus).
So they fenced it — twice — one fence in 2013, another in 2014.
Then in 2018 Paul Rogers and Darren McAvoy of Utah State University conducted a followup study sampling Pando’s health inside and outside the deer exclosure fences and concluded that the fencing was not working.
According to September 2022 Sci.News “The unfenced areas are experiencing the most rapid aspen decline, while the fenced areas are taking their own unique courses — in effect, breaking up this unique, historically uniform, forest. … Fencing alone is encouraging single-aged regeneration in a forest that has sustained itself over the centuries by varying growth.”
“One clear lesson emerges here: we cannot independently manage wildlife and forests.”
Aldo Leopold’s experience in his early career when he worked to eradicate wolves from the American West changed his perspective on trees and deer. At one point he shot an old female wolf and was there to see the green fire go out of her eyes as she died. He wrote …
I thought that because fewer wolves meant more deer, that no wolves would mean hunters’ paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.…
I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer. And perhaps with better cause, for while a buck pulled down by wolves can be replaced in two or three years, a range pulled down by too many deer may fail of replacement in as many decades.
In Pittsburgh the wind blew all day last Saturday with gusts as high at 35 mph. By Sunday morning, 6 November, most of the trees were bare.
I confirmed this at my favorite “leaf gauge” hillside in Schenley Park, above, after hiking at Hays Woods where bare trees sheltered the still-green leaves of invasive honeysuckle.
Deciduous conifers are finally showing their own fall colors. Larches are yellow, dawn redwoods (Metasequoia glyptostroboides) are orange.
The needles were dropping fast from this one in front of Phipps Conservatory.
Meanwhile half of the ginkgos (Ginkgo biloba) along Schenley Drive still had leaves.
Last year they weren’t bare until 20 November, below, but I predict they will be earlier this year.
Even if I couldn’t see them I can hear a clue that most of the trees are bare. The sound of leaf blowers fills my neighborhood. Maybe yours, too.
Fall colors were looking good in the City of Pittsburgh this week. A maple in Schenley Park turned shades of orange and red while the sunrise worked to match it.
This acorn in Schenley Park is a squirrel’s dream come true, the largest acorn native to North America. Bur oaks (Quercus macrocarpa also spelled burr oak) were planted in several places in the park more than 100 years ago, most notably at the main trail entrance near Bartlett Playground. This species withstands harsh conditions and is one of the most drought resistant oaks.
Goldenrods are blooming in the small meadow near Bartlett Playground.
During my walk to Schenley Plaza on 11 October I saw a peregrine fly toward Heinz Chapel’s scaffolding and disappear among the dense rods.
If he hadn’t moved I would not have found him. Ta dah! (See inside red circle.)
Amazingly he was easier to see through binoculars from Schenley Plaza tent. Too far for a photo.
It usually “snows” in late May in Pittsburgh but this year it happened in early June.
On 3 June a light breeze carried snow-like fluff above Nine Mile Run in Frick Park. I found a source in this open catkin that had fallen on the trail.
Another had not fully opened before it fell.
Both came from an eastern cottonwood tree (Populus deltoides) whose leaves look like this. There are only a few of cottonwoods in the Nine Mile Run valley but their seed dispersal is prodigious.
Pittsburgh is barely inside the eastern edge of the cottonwood’s range so the trees and their fluff are not common here. Read more about them in this vintage article.
(photos by Kate St. John and from Wikimedia Commons)
This gorgeous tree with large violet flowers is blooming now in Allegheny County. It grows fast, provides shade, looks beautiful and smells sweet. What could go wrong?
The princess tree (Paulownia tomentosa), also called empress tree or royal paulownia for Anna Pavlovna of Russia (1795-1865) is — or was — popular in ornamental gardens. It was first introduced to the U.S. from China in 1840 and planted in the eastern U.S. and Washington state.
Initially it was a gardener’s dream. It is easy to grow in full sun, thrives in many soil types including disturbed soil, is tolerant of drought and pollution and grows 15 feet per year. It also reproduces like crazy. One tree can produce 20 million winged seeds that are dispersed by wind and water.
And …
Paulownia tomentosa’s ability to sprout prolifically from adventitious buds on stems and roots allows it to survive fire, cutting and even bulldozing in construction areas; making it difficult to remove from established areas.
This one was chopped down but it came back stronger than ever. Notice the huge leaves.
Eventually botanists and gardeners realized that P. tomentosa is invasive. This map of paulownia’s occurrence in the U.S. …
… nearly matches the map of its State Invasive listings. Maryland and Massachusetts have outlawed it.
Years ago I knew of only one princess tree in Pittsburgh, this one next to the Schenley Bridge near the corner of Frew Street and Schenley Drive.
Then a few years ago a volunteer sprouted in Schenley Park near the tufa bridge over Phipps Run. When it reached 20 feet it was cut down and its roots were dug up. However, this spring there are four paulownias near the tufa bridge. The genie is out of the bottle. Uh oh!
Trees with stacks of white flowers are drawing our attention this week in Pittsburgh. Perhaps you’re wondering “What tree is this? “
Horsechestnuts (Aesculushippocastanum) originated in Greece but have been planted around the world for their beautiful flowers. When fertilized the flowers become the familiar shiny buckeyes I played with as a child.
In Pittsburgh we call the tree a “buckeye” though it is just one of many buckeyes (Aesculus) in our area including natives of North America: yellow, Ohio, and bottlebrush.
A close look at horsechestnut flowers reveals that some have yellow centers, others red.
Bees see and are attracted to yellow, not red, so when a horsechestnut flower is fertilized it turns red. The flowers are …
Are there red flowers on the tree? Come back in early fall to collect the buckeyes.
(photos from Wikimedia Commons; click on the captions to see the originals)
On a walk last week in Moraine State Park we found a pile of pine cones in various stages of undress. Some were uneaten, some were half eaten and many were stripped bare like the stem above.
We can know this because of the focus on pine cones, how the cones were denuded, and the sizeable midden. Conifer seeds make up the majority of the red squirrel’s diet and he defends his midden territory year-round against every other red squirrel.
Red squirrels are highly territorial and asocial with very few non-reproductive physical interactions. The majority of physical interactions are in male-female matings and between females and their offspring before the offspring disperse to their own territories. The non-reproductive physical interactions recorded (0.6% of all recorded behaviors in one 19-year study) were all instances of chasing an intruder from a territory.
Spring is here and tree sap is rising in western Pennsylvania. This month yellow-bellied sapsuckers (Sphyrapicus varius) are migrating through our area, pausing to drill holes in the trees to sip the welling sap.
How does a sapsucker know a tree is a good candidate for a meal? Can he hear the sap rising? Maybe so.
Seven years ago I learned that with special microphones we can hear the secret sounds of trees. Here’s an example from a Scots pine, recorded by Marcus Maeder’s trees project.
On Throwback Thursday learn more about the secret sounds of trees and listen to one in the video.
(photo from Wikimedia Commons, audio from Marcus Maeder’s trees project; click on the captions to see the originals)