Red oak acorns on the branch, August 2023 (photo by Kate St. John)
25 October 2023
By late October leaves and nuts are underfoot and still falling. Red oak acorns that were green on the branch in August litter the footpaths and sidewalks now.
Red oak acorns on the ground, Sept 2020 (photo by Kate St. John)
Underneath black walnut trees it’s hard not to misstep on the yellow husked nuts. You may even be hit by a black walnut detached and dropped by a squirrel gathering nuts above you. Squirrels save time by crawling all over the tree and detaching lots of nuts. Then they scurry down to collect them. Ouch!
Keep looking down and you may find unusual nuts and seeds like these.
Magnolia cucumber tree lea and seeds, Sept 2011 (photo by Kate St. John)
Even without leaves, you can identify the trees above you by knowing the nuts at your feet. This fall I’ll run a series on identifying nuts found in western Pennsylvania.
Meanwhile to kick it off …
Adam Haritan explains a few trees you can identify without even looking up in this 15-minute Learn Your Land video.
Bright red maple leaf near Phipps Conservatory, 16 October 2023 (photo by Kate St. John)
21 October 2023
Fall color’s peak in southwestern Pennsylvania used to be around the 12th of October but climate change has pushed it later, closer to the 21st, as you can see in the PA fall foliage prediction for 19-25 October.
This week I found bright leaves on red maple trees, at top, and yellow on buckeyes and hickories.
Schenley Park leaves are yellow and green on 16 October 2023 (photo by Kate St. John)Yellow and orange maple leaves, Frick Park, 18 October 2023 (photo by Kate St. John)
Frick and Schenley are dominated by oaks whose color will peak in the next two weeks. Meanwhile their few red maples turned red from the top down and have lost their leaves in the same order. The maples are gorgeous up close but you can’t see them from a distance because the tops are bare.
The top of this red maple is almost bare, 16 October 2023 (photo by Kate St. John)
Tomorrow night the northwest wind will bring migrating birds overnight and patchy frost on Monday morning.
“Some tea with your river, Sir?” asks the caption on the satellite photo below where Rupert Bay meets James Bay in Quebec, Canada. James Bay’s incoming tide is pushing Rupert Bay’s tea-colored water upstream.
In woodland and wetland settings, tea-colored water indicates that natural plant and water processes are occurring.
Frequently, water in streams and rivers becomes tea-colored from naturally occurring tannins, a chemical found in many plants around the world. The tannins can leach out of plants and plant debris and into groundwater, lakes, rivers, and streams. Although they can make the water more acidic, it’s important to note, tannins are not harmful to fish and wildlife.
This process occurs in many waterways that run through wooded areas and wetlands with high levels of plant mass and organic matter. Because there is always water flowing through these areas, tannins leach out of plants into the water, making it appear tea-colored.
Tannins leach from all kinds of plant debris, especially soaked bark, leaves and pine needles in the north woods. There are tannins in this magnified Woody Dicot Stem: Tannins in Early First Year Tilia. Its caption reads: “Many cells in the periderm, cortex and pith contain dark staining tannins.”
And there are some special lakes on Florida’s Panhandle coast where the tea-colored water flows into the Gulf of Mexico. This video describes the dune lakes of Walton County.
Tannins are OK to drink though they may not taste good. In fact, it’s the tannins in tea leaves that make the beverage tea-colored.
Orange water deposits are bad.
Bright orange deposits are bad, even when the water is clear. In western Pennsylvania the orange color comes from abandoned coal mine drainage. Here the outflow of a polluted culverted stream dumps into Chartiers Creek near Bridgeville. Yuk!
Inflow of abandoned mine drainage into Chartiers Creek near Bridgeville (photo by Kate St. John)
Blacklick Creek in Cambria County, PA is another example.
(credits are in the captions; click the links to see the originals)
p.s. GEOGRAPHY! Though far inland, James Bay is tidal because it is the southern tip of Hudson Bay which connects to the Atlantic Ocean. This watershed map shows Hudson Bay watershed in green. Note the tiny red circle I added for the location of Rupert Bay.
Sticky tape put on trees by an unknown Frick Park visitor, 19 Sept 2023 (photo by Michelle Kienholz)
20 September 2023
Six years ago, when spotted lanternflies (Lycorma delicatula) were a new plague in North America, no one knew if they would destroy Pennsylvania’s forests but scientists assumed the worst and warned accordingly. However, they also conducted long term studies of spotted lanternflies’ effect on Pennsylvania trees and agriculture. For PA trees there is happy news: Spotted lanternflies are not a danger to Pennsylvania forests. There’s no need to protect our trees from lanternflies because they are not hurting them.
Penn State subjected four species of trees to four years of spotted lanternfly super-infestation by surrounding the trees with mesh nets that kept hordes of lanternflies inside. Silver maple, weeping willow, and river birch were barely phased by the bugs and did quite well in the third year of the study. The bugs’ host plant, the invasive tree of heaven (Ailanthus altissima), did not grow during the plague.
“If you have a vineyard and you have lanternflies on your grape vines, you should be very worried because they can kill grape vines,” Hoover said. “But if you’re a homeowner and you have large trees on your property and you have lanternflies on them, I don’t think you should worry about it.”
Yesterday an unknown visitor to Frick Park put sticky tape on some trees. Here’s what one section killed: 12 spotted lanternflies, 25+ pollinators (yellowjackets), 70 warbler-food insects (tiny flying insects). More beneficial insects died than lanternflies. Needless to say the tape has already been removed. (Click here to see how sticky tape kills birds!)
Sticky tape deaths in Frick Park, 19 Sep 2023 (photo by Michelle Kienholz)
Sticky tape is bad and pointless. If you put it up, remove it.
Spotted lanternfly honeydew below ailanthus tree turns black with sooty mold, Schenley, 25 Aug 2023 (photo by Kate St. John)
27 August 2023
In Schenley Park’s Panther Hollow there are only a handful of Ailanthus altissima trees (Tree of Heaven) which I rarely paid attention to until recently. A couple of weeks ago I noticed that the plants and ground beneath those trees were wet, though it had not rained. This week the leaves and ground are black. Both phenomena are a by-product of the spotted lanternfly (Lycorma delicatula) invasion.
Spotted lanternflies (Lycorma delicatula) are sucking insects that pierce the bark of their host plant, Ailanthus, and sip the sugary phloem that travels from the leaves to the rest of the plant. (Phloem flow is orange in the diagram below.)
If there were only a few lanternflies we would never notice the honeydew but when a large number coat a tree the honeydew is hard to miss, especially for the consumers of honeydew: bees, wasps, hornets, ants and butterflies.
Sugary honeydew eventually grows sooty mold. Everything with honeydew on it turns black.
Sooty mold is a fungus that appears as a black, sooty growth on leaves, branches and, sometimes, fruits. It is non-parasitic and not particularly harmful to plants apart from being unsightly. Potentially, it could affect the plant’s ability to use the sun for photosynthesis. If you can rub the black growth off with your fingers, it is probably sooty mold. If you cannot rub it off, it is most likely something else.
The mosaic is made of cells in the woody stem of a one year old tuliptree (Liriodendron tulipifera), sliced thin and magnified 100 times. The colors and shapes are specific to the species and its age. The description indicates that things change at lot in a one year old tulip tree.
The mosaic slice was photographed in 2014 at Berkshire Community College in Pittsfield, MA from a sapling that probably grew in Western Massachusetts.
When a tulip tree grows up it has leaves and flowers like this.
Tulip tree leafout, Schenley Park, 28 April 2014 (photo by Kate St. John)Tulip tree flower, 4 May 2017 (photo by Kate St. John)
Still beautiful and intricate even when not magnified.
For more information on the mosaic image see the description of the image here. It is so technical that I need a glossary to figure out what it means.
Oak tree in bloom with dangling pollen flowers (photo by Kate St. John)
25 April 2023
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.
Yale Climate Connections reports “In Anderegg’s research on pollen in North America, he saw pollen seasons starting about 20 days earlier than they did in the 1990s” and pollen concentrations increased by 21%. The higher temperatures and carbon dioxide in today’s atmosphere make plants more productive and allergies worse.
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.
Bluets, Knob Hill Community Park, 14 April 2023 (photo by Kate St. John)
15 April 2023
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.
Spring beauty, Knob Hill Community Park, 14 April 2023 (photo by Kate St. John)
In Frick Park on Thursday this box elder (Acer negundo) was blooming and leafing out at the same time.
Box elder flowers and leafout, Frick Park, 13 April 2023 (photo by Kate St. John)
But many native trees still looked bare, such as the oaks on this hillside.
Progress of leafout at Frick Park, 13 April 2023 (photo by Kate St. John)
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.
p.s. This weekend the downy serviceberries are blooming (white) and the Callery pears are growing leaves (white+green) so it’s no longer possible to pinpoint the invasive species.
A redbud branch in full bloom, Frick Park, 12 April 2023 (photo by Kate St. John)
13 April 2023
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.
Seven years ago today I wrote about the Pittsburgh Redbud Project as I was about to participate in the launch event on 19 April 2016. We gathered for tree planting on the North Shore near the Mister Rogers statue and learned why our assignment — digging holes! — was so important for a tree this size.
Pittsburgh Redbud Project: Volunteers watch how it’s done, Pittsburgh’s North Shore, 19 April 2016 (photo by Kate St. John)
The trees have now been in place for seven years and they are beautiful. This stand near the Frick Environmental Education Center drew attention yesterday even though they were still in bud.
Redbuds drawing attention at Frick Park, 12 April 2023 (photo by Kate St. John)
With temperatures in the low 80s this weekend will be the perfect time to see redbuds at their best.
.JPG){kind=link}
.jpg){kind=link}