Archive for the 'Trees' Category

Aug 23 2015

The Tuliptrees Respond

Published by under Trees

Tuliptree responds to anthracnose by growing new leaves, August 2015 (photo by Kate St. John)

Tuliptree responds to anthracnose by growing new leaves, August 2015 (photo by Kate St. John)

In June’s wet weather, Pittsburgh’s tuliptrees were attacked by anthracnose, a fungus that turned most of their leaves brown.  Click here to see.

July and August were very dry so the fungus died.

The tuliptrees responded.  They’ve grown new leaves!  It doesn’t matter that August is so close to autumn.  They need leaves to make food.

Photosynthesis is restored.

 

p.s.  The first time I saw trees grow new leaves in the fall was after Hurricane Bob stripped the leaves from the trees on Cape Cod on August 19, 1991.  It was very odd to see spring-like trees on the Cape in early October.

(photo by Kate St. John)

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Aug 05 2015

Smells Like Vanilla

Published by under Travel,Trees

Ponderosa pine: a look at the bark (photo by Donna Memon)

Ponderosa pine bark — photo by Donna Memon

Did you know you can recognize this tree by the smell of its bark?

After the Southwest Wings Festival I visited with Donna and Razzak Memon in Tuscon, Arizona.  On Monday Donna and I went birding on top of Mount Lemmon, one of the few mountains named for a woman (Sara Plummer Lemmon).

The summit is 9,159 feet above sea level and 6,770 feet above Tucson so the air is thinner and cooler, a welcome change from the valley’s heat.  That day it was 72oF on the mountain, 104oF in the valley.  Because of the thin mountain air we learned something about this tree.  

Donna and I were heading downhill when a group of hikers paused near the tree to catch their breath and I overheard one of them say it smelled like vanilla.  On our way back up the thin air hit me at the same spot so I paused and sniffed the bark.  Yes, the bark smells like vanilla.

The Ponderosa pine (on Mount Lemmon*) is one of the few trees you can identify this way.  When the tree is young the bark is black, but when it reaches 100-120 years old it sheds the black and shows a yellow bark that smells like vanilla or butterscotch or baking cookies, depending your point of view.

The unusual bark is also a fire shield.  According to this NPR report, when fire hits the tree it flash-boils the sap and blows the bark off the tree, but the tree doesn’t burn.

Ponderosa pine on Mt Lemmon, Arizona (photo by Donna Memon)

Ponderosa pine on Mt Lemmon, Arizona (photo by Donna Memon)

In the top photo you can see some snags at left that died in a fire on the mountain.

But not this one.  Its vanilla-scented bark protects it.

 

p.s.  Here we are at the top of the mountain.  You can see Tucson in the valley below.

Kate St. John and Donna Memon at Mount Lemmon, AZ (photo by Razzak Memon)

Kate St. John and Donna Memon at Mount Lemmon, AZ (photo by Razzak Memon)

(tree photos by Donna Memon; Kate & Donna photo by Razzak Memon; information about Ponderosas from this 2009 NPR article)

(*) In the comments below Nickie explains that in California Jeffrey pines smell like vanilla but Ponderosas do not. However the Jeffrey pine doesn’t grow in Arizona. In Arizona the Ponderosa (and/or the Arizona species/ subspecies) does.

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May 12 2015

Color Coded For Bees

Published by under Schenley Park,Trees

Horse Chestnut flowers, Schenley Park (photo by Kate St. John)

A close look at horse chestnut flowers (photo by Kate St. John)

This week the horse chestnut trees are in full bloom in Schenley Park.

Common horse chestnuts (Aesculus hippocastanum) are native to southeastern Europe but are planted widely in the U.S. for their beauty and shade.  Their flowers are dramatic in 10″ tall clusters and their large leaves with seven leaflets provide lots of shade.
Horse Chestnut tower of flowers, Schenley Park (photo by Kate St. John)

Up close, the ornate white flowers have spots in either yellow or pinkish-red.  There’s a purpose behind the beauty.

When the flower is unfertilized the spot inside is yellow.  After pollination the spot turns reddish to tell the bees, “Don’t waste your time on me.”

The flowers are color coded for the bees.

 

(photos by Kate St. John)

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Mar 18 2015

Listening To The Secret Sounds Of Trees

Woman listening with headphones (photo from Wikimedia Commons)

In early May when the trees leaf out we’ll once again hear the soothing sound of rustling leaves.  Did you know trees make sounds we cannot hear?

Last year an article by Sarah Zhang in Gizmodo caught my attention.  Eavesdropping On The Secret Sounds Of Trees describes the art and science of a Swiss research team who’s recording the internal sounds of trees.

The project, fittingly called trees, attaches sensitive microphones to trunks, branches and even leaves, then records the sounds and analyzes them in light of simultaneous environmental factors such as drought.  Click here and scroll down to hear the clicks, pops, hisses and taps made by a Scots pine (Pinus sylvestris).

Closer to home our trees are getting ready for spring, the sap is running, and it’s maple sugaring time in North America.

Maple sugar bucket hanging on a tree (photo from Wikimedia Commons)

And so I wonder …

If we had those special microphones could we heard the sap rising in the maples?  Or is it so loud that we can hear it by putting our ears to the trees?

I’ll have to see.

 

(photos from Wikimedia Commons. Click on the images to see the originals)

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Jan 10 2015

Take A Look Outdoors

Published by under Beyond Bounds,Trees

Cone of a Japanese larch (photo from Wikimedia Commons)

Feeling cooped up by winter weather?  Tired of staring at four walls?

Put on your hat and coat and take a walk outside.  Even though it’s cold, nature has beauty on display.

Take a look outdoors. … Then you can reward yourself with hot chocolate.

 

(photo of a Japanese larch cone at John J. Tyler Arboretum in Media, Pennsylvania. Click on the image to see this Featured Picture on Wikimedia Commons.)

6 responses so far

Dec 03 2014

The Link Between Hemlocks And Birds

Published by under Trees

Eastern hemlocks shading Tom's Run, Cook Forest State Park (photo by Nicholas Tonelli via Wikimedia Commons)

As I mentioned two weeks ago, a Pennsylvania hemlock project needs volunteers to report hemlock woolly adelgid in the Allegheny High Plateau so that the trees can be protected against this deadly pest.

Many of us want to help because we love the hemlock’s beauty, but for some birds the trees are more than beautiful, they’re essential.

At the project kickoff seminar Dale Luthringer told us about hemlocks and their link to birds.

Eastern hemlocks are the most shade tolerant tree in the U.S. and can thrive in pure stands or in damp areas of deciduous forests.  Wherever hemlocks grow their dense evergreen canopy creates a cool, shady habitat that’s used by 90 species of birds.

Studies have shown that six species depend so much on hemlocks that they decline when the woolly adelgid kills the trees.  Here are the six who go missing:

Black-throated green warbler (photo by Steve Gosser)

(1) Black-throated green warblers are obligate to hemlock stands. They experience a 93% decline when the trees die off. (photo by Steve Gosser)

Blackburnian warbler (photo by Chuck Tague)

(2) Blackburnian warblers like all hemlocks but prefer old growth stands. They’re found 40 times more often among old growth hemlocks than younger trees. (photo by Chuck Tague)

Ovenbird with nesting material, May 2014 (photo by Marcy Cunkelman)

(3) Ovenbird populations go down when hemlocks die (photo by Marcy Cunkelman)

and… (4) hermit thrushes, (5) blue headed vireos and (6) Acadian flycatchers decline where the woolly adelgid takes its toll.

 

With hemlocks covering 19 million acres in the eastern U.S., we’ll lose a lot of habitat — and birds — if we do nothing to combat the hemlock woolly adelgid.

Read more here on how you can help the Allegheny High Plateau adelgid project. (See where on this map — from Cooks Forest northward to NY).

 

(photos:
Eastern hemlocks shading Tom’s Run in Cook Forest by Nicholas Tonelli, via Wikimedia Commons, Creative Commons license. Click on the image to see the original.
Black-throated green warbler by Steve Gosser
Blackburnian warbler by Chuck Tague
Ovenbird by Marcy Cunkelman
)

p.s. Magnolia warblers are also affected. They’re 45 times more likely to be found in old growth hemlock forests than in stands of younger trees.

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Nov 19 2014

Start Looking Now

Hemlock woolly adelgid at Jacobsburg (photo by Nicholas A, Tonelli via Wikimedia Commons)

Yesterday I mentioned hemlock woolly adelgid, a really bad invasive insect that’s killing our eastern hemlock forests.  It devastated the southern Appalachians (click here to see, here to read) and has moved north into south, central and eastern Pennsylvania.  Has it conquered the Allegheny High Plateau?  Now’s the best time to find out.

Hemlock woolly adelgids (Adelges tsugae) have no North American predators and a very unusual lifestyle.  Originally from Japan, they kill eastern hemlocks in 4-20 years by locking onto the underside of their branches and sucking the lifeblood out of them.

The adults are female, immobile and practically microscopic.  Twice a year they reproduce asexually, laying up to 300 eggs a year in woolly white egg sacs that protect their young.  The larvae, present in April and July, are the only mobile phase and so tiny that they spread easily on the wind or hitchhike unseen on birds, animals and humans.
Hemlock wooly adelgid adults (photo by Ashley Lamb, Virginia Polytechnic Institute and State University, Bugwood.org)

Harsh winters used to protect Pennsylvania’s hemlocks but the climate is warming.  Our worst fears were realized when they were found in Cook Forest in March 2013.  Last winter’s Polar Vortex reduced that infection 90-100% but the bugs are poised to take off again. Unfortunately the only biological control, a tiny beetle, is even less winter-hardy than the pest so the only way to save our hemlocks right now is by treating individual trees with pesticide. (*)

What trees should be treated?  The Nature Conservancy, the U.S. Forest Service and DCNR have teamed up to survey the area from Cook Forest to New York’s Allegany State Park (click on this map to see a larger version).

Priority hemlock conservation areas on the Allegheny High Plateau (map from The Nature Conservancy and US Forest Service)

It’s a big area and they need your help.  Don’t worry, it’s easy.

In the winter hemlock woolly adelgid egg sacs are large and visible (see top photo).  If you’re in this region — even for a quick hike or birding trip — take a moment to notice the underside of hemlock branches.  Birders, you may accidentally find this while looking at a bird.

Report infections by calling or emailing the location to one of the folks on this list of contacts.  (Contact any of them and they’ll forward the information if necessary).

Do you need more information before you begin?  Contact Sarah Johnson at The Nature Conservancy, sejohnson@tnc.org, 717-232-6001 Ext 231.

Start looking now.

 

(photo credits:
top photo, wool sacs: Nicholas Tonelli via Wikimedia Commons
middle photo, adults: Ashley Lamb, Virginia Polytechnic Institute and State University, Bugwood.org
map: courtesy The Nature Conservancy and U.S. Forest Service. Click on the map to see a larger version.
)

 

(*) Note: Work is underway to breed winter-hardy biological controls.  It just takes time.

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Jun 04 2014

What Made This Tree Fall Over?

Published by under Quiz,Schenley Park,Trees

Black cherry tree toppled at Schenley Park, 30 May 2014 (photo by Kate St. John)

When I see a tree snapped in half like this I have to ask: What made this tree fall over?

I did some detective work but I don’t know the answer yet.  Maybe you can help.  Here are the clues:

  • The tree is a black cherry (Prunus serotina)
  • It was alive when it fell.  It grew leaves this spring so the structural weakness wasn’t evident until the tree broke.
  • This is the only broken tree at this location in Schenley Park.  Even if a strong wind snapped the trunk it wasn’t strong enough to damage other trees.
  • The trunk is not hollow inside the break though there are air gaps between the light outer wood and dark inner core.
  • There’s a white flaky substance inside the trunk that coats the light wood layers.  Is it a fungus?
  • Did the white stuff weaken the trunk?  Is it responsible for the break?

The trunk isn’t hollow, but…
Black cherry break, 30 May 2014 (photo by Kate St. John)

Here’s a close look at the white flaky fungus.  It reminds me of the white correction tape I use on paper.
White flaky fungus. What is it? (photo by Kate St. John)

Do any of you know what this is?  Is it the reason the tree fell over?

Leave a comment with your answer.

Thanks!

(photos by Kate St. John)

UPDATE on June 5 with the ANSWER!   It’s a species of Armillaria or honey fungus.  (See Maureen Hobma’s comment below.)   Well, I feel a little dumb.  I wrote about Armillaria on 16 January 2014 because I was fascinated that it’s the largest living organism.  I even included a photo of the white sheets inside the heartwood but, having never seen the white sheets before, I did not remember them.  Until now I had only seen the black rope-y strands and the honey mushrooms so that’s all I knew of Armillaria.  The white sheets are the newer growth, the mycelium, and can be bio-luminescent!   I learn something new every day.

10 responses so far

May 03 2014

Leaf Out!

Published by under Schenley Park,Trees

Tulip tree leaves unfurling, 28 April 2014 (photo by Kate St. John)

Very soon southwestern Pennsylvania will reach the moment when most of the trees have leaves.  This usually happens around May 5.

Leaf out seems a bit delayed this year but it’s making progress.  On Monday (April 28) I found a tulip tree unfurling its leaves one by one.  By Thursday the same branch looked like this:

Tulip tree leaf-out, 1 May 2014 (photo by Kate St. John)

There’s probably another leaf inside that big bud, and then there will be a flower.

When will “Most of the Trees Have Leaves?”

For Schenley Park, I’ll let you know.

 

(photos by Kate St. John)

Later:  “Full Leaf” was late this year.  It didn’t happen until May 13 in Schenley Park.

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Apr 30 2014

April Showers Bring…

Published by under Phenology,Plants,Trees

Great chickweed (photo by Kate St. John)

While it feels like it’s been raining forever, last weekend’s weather was sunny and so were the flowers. Here’s a selection I found at Raccoon Creek Wildflower Reserve and Friendship Hill National Historic Site on Saturday and Sunday.

Above, a very close look at Great Chickweed (Stellaria pubera), also called Star Chickweed.  The flower is only 1/2″ across and it has only five petals but they’re so deeply cleft that they look like ten.

Below, inch-long Virginia bluebells (Mertensia virginica) in bloom at Raccoon Wildflower Reserve.  I love how they change color as they open.

Virginia Bluebells (photo by Kate St. John)

 

Toad Trillium or Toadshade (Trillium sessile) is rarely seen from this angle because the plant is only four inches tall.  (I got muddy taking this picture.)  The dark, closed petals look boring from above but graceful from the side.  Perhaps they open like this so the pollen can disperse more easily.  It’s dusting the leaf at front left.
Sessile trillium (photo by Kate St. John)

 

Today’s April showers will bring May flowers. It’s hard to believe that May begins tomorrow.

 

(photos by Kate St. John)

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