If your pollen allergies have gotten worse there’s a good reason for it. A study of North American pollen trends in the last 30 years, led by William R. L. Anderegg, found that pollen season is starting earlier, lasting longer and has higher pollen counts than in the 1990s because of climate change.
Right now in Pittsburgh we are at the height of pollen season. Recurring hot weather, 15+ degrees above normal, caused the oaks to bloom early and pollen so intense that my car turned yellow while parked at Anderson Playground for just an hour last Friday.
Allergy sufferers get a double whammy here because the pollen is added to Pittsburgh’s poor air quality making it particularly dangerous for children and people with asthma and respiratory illness.
So, no, you’re not imagining it. Pollen season in North America is bad and is still getting worse.
Scientists predict that average pollen counts in 2040 will be more than double what they were in 2000.
More flowers bloomed and more trees leafed out as hot summer weather continued this week.
I saw a few bluets (Houstonia) and spring beauty (Claytonia) at Knob Hill Community Park yesterday.
In Frick Park on Thursday this box elder (Acer negundo) was blooming and leafing out at the same time.
But many native trees still looked bare, such as the oaks on this hillside.
The slowness of native trees made last weekend the perfect time to see the invasive extent of Callery pears (Pyrus calleryana). Native white-flowering trees, such as serviceberry and wild cherry, were not blooming yet so the only white trees in the landscape were the Callery pears.
On 8 April at the Ridge Road interchange on the Parkway West (I-376) I found thick stands of Callery pears as far as the eye could see (first 2 slides below). The trees gained a foothold in disturbed soil after construction of the Ridge Road interchange in 2006 and Settlers Ridge shopping center in 2009. The third slide shows Callery pears in the woods at Wingfield Pines.
Hot weather this week is speeding up spring and Pittsburgh’s redbuds are bursting into bloom. Yesterday at Frick Park I found most buds ready to burst with a few branches in full bloom.
Redbuds seem to be everywhere now but this wasn’t always the case.
Seven years ago the Western Pennsylvania Conservancy launched Pittsburgh’s Redbud Project to beautify Pittsburgh’s riverfronts. Envisioned by landscape architect Frank Dawson, the goal was to make Pittsburgh as beautiful with native redbud trees as D.C. is during the Cherry Blossom Festival.
They originally planned for 1,200 trees but by now they’ve planted three times that many along the Allegheny, Monongahela and Ohio riverfronts. The project also inspired redbud plantings in Pittsburgh’s parks and neighborhoods by Pittsburgh Parks Conservancy and Tree Pittsburgh.
While traveling in Ecuador last month I saw balsa trees growing in the wild and learned that Ecuador supplies 95% of the world’s commercial balsa wood. The driving force behind these exports is an environmental paradox.
Balsa (Ochroma pyramidale) is a pioneer tree of tropical forest clearings, native to Central and South America. It is so fast growing that it can grow 6-9 feet a year and reach full height of about 100 feet in only 10-15 years. The trees are short-lived, lasting only 30-40 years.
Inside the living wood the cells are large, thin-walled and full of water so that the tree stands upright. When cut and kiln dried the wood is very lightweight and sturdy.
In the wild balsa trees are widely spaced at about one tree per acre (2-3/hectare) but to meet commercial demand balsa is grown in plantations containing 400 trees/acre (1000/hectare). Plantation trees are cut at 6-10 years old because much of the wood in older trees — the core and outer layers — is commercially useless.
Most of us are familiar with balsa wood in toys and woodworking.
This balsa wood bridge won a physics contest in 2006. It weighs only 60.95 grams (0.134 pounds) yet it supported 14.51 kg (31.989 pounds).
Ecuadorans made ocean-going rafts of balsa logs long before the Spanish arrived in the 1500s and it is still used for rafts today. (Balsa is the Spanish word for raft.)
But none of these uses are the driving force behind increased Ecuadoran balsa exports.
Balsa wood is a component in wind turbine blades. According to GE which manufactures wind turbine blades at Castellon, “Workers make the blades from fiberglass fabric and balsa wood. Then, the blade is covered with an airtight foil and the team installs a network of tubes that pumps in and distributes the resin that will hold it together.”
Plantations provide 60% of Ecuador’s balsa wood but the remaining 40% is coming from wild trees in the rainforest. Using satellite images and on-the-ground followup Mongabay and Global Forest Watch have documented deforestation in Ecuador, especially east of the Andes in the Amazon watershed. According to Mongabay:
The Pastaza River Basin is one of the areas most affected by the balsa industry. There, the Pastaza, Bobonaza, Curaray, Villano, Copataza and other rivers are used as logging access routes, with satellite imagery showing their banks increasingly pockmarked by deforestation. Sources tell Mongabay Latam that the logging has been so intense that balsa has been completely removed from some areas.
…[And now] loggers are starting to harvest other timber species in areas that have been denuded of balsa.
“The same loggers and traders that one year ago arrived from [the cities of] Quevedo, Esmeraldas or Guayaquil are now arriving to look at what else is there,” Páez said.
“There is an ongoing process of deforestation of valuable tree species in Indigenous territories” with no monitoring by the authorities, she added.
NOTE about the eBird map: eBird maps show where birders have found birds and reported them on eBird. The blank spots on the Ecuador map do not indicate an absence of birds but instead an absence of birders or an absence of Internet access.
(photo and map credits are in each caption; click on the captions to see the originals)
My favorites were the early crocuses. Native to Bulgaria, Hungary, Albania and the former Yugoslavia, these woodland crocuses (Crocus tommasinianus) are often seen in gardens but someone in my neighborhood planted them in a grassy front yard. Because the flowers bloom before the grass grows they are in no danger of being mowed.
On Pitt’s campus Cornelian cherry trees (Cornus mas) produced yellow flowers.
Red maples (Acer rubrum) bloomed next to Carnegie Museum …
… and at Frick Park the maple branches looked thick with tiny flowers, including yellowish pollen-bearing ones.
This week, tiny leaves opened on jetbead (Rhodotypos scandens) and a few honeysuckle bushes. Unfortunately invasive plants are first to leaf out.
The coming week will be like a wet blanket: above freezing, gusty wind, lots of rain.
The sunrise was gorgeous and cold last Wednesday when a group of us decided to walk at Jennings in Butler County. We saw few birds but there were ice heaves, buttress roots on an elm, and the seeds of old man’s beard (Clematis drummondii).
When old man’s beard is in bloom it’s called virgin’s bower, transforming it from a young woman to an old man in a matter of months.
My friends who live north of the city have not seen many dark-eyed juncos at their feeders this winter, but juncos are definitely present at the Frick Park Environmental Education Center. Charity Kheshgi posted photos of our recent trip to Frick.
This week’s rain dampened outdoor activities but there were still some things to see.
Chainsaw tree “trimming” continues in the city. This red oak had a hollow core so it was chopped down in late December at Anderson Playground in Schenley Park. Can you count the rings and determine its age?
On 3 January rain flecked the camera as Ecco stopped by for a visit. Notice how wet his head is!
On 4 January the rain finally stopped and the moon shone at 8pm.
When the cold snap ended on 28 December the ice thawed and the creeks began running again. Listen to the sound of Panther Hollow Run in Schenley Park on 30 December 2022.
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.