Archive for the 'Trees' Category

Mar 25 2017

Face In A Twig

Published by under Trees

A face in a twig, Schenley Park, 23 March 2017 (photo by Kate St. John)

A face in a twig, Schenley Park, 23 March 2017 (photo by Kate St. John)

After more than a week of cold weather, the buds were not bursting in Schenley Park last Thursday as I walked around taking pictures of Spring.

Instead, I found this unopened bud that looks like a devil’s face.

It’s the bud of a black locust (Robinia pseudoacacia) a very common tree in southwestern Pennsylvania that tolerates pollution and thrives in the poor soil of old fields, disturbed woodlots and roadsides.

Though black locusts have devilish looking buds and twisted branches, they’re good trees to have around because they enrich the soil through nitrogen fixation.

Their roots have a symbiotic relationship with the Rhizobium bacteria. Rhizobium enters the root hairs, the plant makes tumor-like growths to surround it, then the bacteria takes in nitrogen and converts it into a form that fertilizes the plant.  Strange but true.

Look for these devilish twigs soon.  When the buds open they won’t look like faces anymore.

 

(photos by Kate St. John)

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Feb 25 2017

A Bad Month For Maple Syrup

Published by under Phenology,Trees

Maple trees with sugar pails (photo from Wikimedia Commons)

Maple trees with sugar pails (photo from Wikimedia Commons)

There’s snow in this picture but there hasn’t been snow in Pennsylvania’s Laurel Highlands for half of this month.

March is supposed to be the best month for tapping sugar maples to collect sap for maple syrup.  The sap runs best with daytime temperatures above freezing and nights below freezing.  When the nights don’t freeze the sap stops running and the season is over.

This year Somerset County’s maple season was hampered by bursts of extremely warm weather in January and summer-like temperatures this month.  The thermometer hasn’t dipped below freezing since February 17 and some days have been more than 20oF above normal.  Maple sugaring stopped before it should have reached its best.

This trend isn’t unique to southwestern Pennsylvania.  The maple syrup industry tracks what’s happening to maple farmers from Virginia to Maine. Since 1970 they’ve noticed that the seasons have become shorter and the sap is less sweet so it takes more sap to make the same amount of syrup.

No matter where you stand on climate change the people whose livelihoods depend on cold winters (maple sugar farmers and ski operators) can tell you this:  Whacky climate ruins their business.

Read more here in a 2014 article from the Allegheny Front.

 

(*) Today the weather is yo-yoing again.  Meyersdale, PA will dip below freezing tonight (25 Feb) for two nights, then run up again to a 48oF low on Tuesday 28 Feb.

(photo from Wikimedia Commons. Click on the image to see the original.)

UPDATE on 7 March 2017: Here’s more on this year’s maple sugar season from the Allegheny Front, WESA-FM.

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Feb 19 2017

The Walking Palm

Published by under Trees

Roots of the walking palm, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

Roots of the walking palm, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

Here’s a tree whose roots are taller than a man and are said to “walk” 20 meters a year(*).  Really?

The walking palm (Socratea exorrhiza) is native to Central and South America where its narrow trunk grows 50-80 feet tall with stilt roots up to eight feet high. The walking palms at Wilson Botanical Gardens, Costa Rica were so tall that I couldn’t get their tops in the viewfinder.

Walking palm trees, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

Walking palm trees, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

The tree’s claim to fame, repeated by local guides and the BBC, is that it can “walk” more than 65 feet a year by throwing out new roots to one side, leaning toward the new roots and abandoning those on the trailing edge.

But this is not true.

Reality Check:  20 meters per year is 65.6 feet, the height of 6 story building.  At 5.5 feet per month it’s a distance that’s easy to see and hard to ignore. You would notice that the plant is not where you left it!

Scientists have measured over and over and the walking palm never walks.  But they are puzzled why it has enormous stilt roots.  It occurred to me that an old theory about the roots may have spawned the walking legend.

In 1980, John Bodley and Foley C. Benson proposed that the tree has stilts so it can recover when downed by another tree, as shown in the diagram below.

How the stilt roots of Socratea exhorriza allow it to right itself (Bodley, John; Foley C. Benson (March 1980) via Wikimedia Commons)

1980: How the stilt roots of Socratea exhorriza allow it to right itself (from a paper by John Bodley & Foley C. Benson, March 1980, via Wikimedia Commons)

Tree #4 took root from the crown that hit the ground.  Its distance from the old root system is the height of the old tree. The trees average 65 feet tall.  Hmmmm!

Other fallen trees can sprout roots, too, and later studies disputed Bodley & Benson’s theory, yet none have solved the underlying mystery.  Why does Socratea exorrhiza have such long stilts? No one knows for sure.

Meanwhile, at Wilson Botanical Gardens the walking palms stay rooted where the Wilsons planted them.  Otherwise they’d be half a mile away by now.

 

(*) Meters or centimeters? See the comments here!

(photos by Kate St. John. Diagram from Wikimedia Commons; click on the image to see the original)

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Jan 26 2017

Faster Than Expected

Emerald Ash Borer galleries in bark (photo by April Claus)

Emerald Ash Borer galleries in bark (photo by April Claus)

On Throw Back Thursday:

Back in January 2010 when I first learned about emerald ash borer, I thought we’d see a slow decline of ash trees in the Pittsburgh area.

Not so!  The bugs wiped out the ashes much faster than expected.  Within five years Schenley Park’s ash trees were dead except for the few treated with pesticides.

What did things look like as the invasion began?  Here’s a look back seven years.

Doomed

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Nov 19 2016

Burls

Published by under Trees

Burl on black locust trunk (photo by Kate St. John)

Burl on black locust trunk (photo by Kate St. John)

November’s a good month to get reacquainted with trees. After the leaves are gone unusual features stand out.  That’s how I noticed these burls.

Burls are dense growths of deformed-grain wood and failed buds found on tree trunks or roots.  They’re a tree’s stress reaction to virus, fungus, bacteria or injury.

The wood in burls is sometimes beautiful but very dense and hard to work with.  Some species create particularly beautiful burl wood.  My hunch is that these two do not.

Above, a black locust.  Below, a white oak.

Burl on white oak (photo by Kate St. John)

Burl on white oak (photo by Kate St. John)

Take time this month to look at trees.

 

(photos by Kate St. John)

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Sep 11 2016

Unusual Trees

Published by under Travel,Trees

Tree trunk bowed and bare (photo by Kate St. John)

Tree trunk, bowed and bare (photo by Kate St. John)

Last week I found some odd trees in Acadia National Park.

Above, a dead tree is bowed over in a perfect C, probably knocked over in its youth by wind, ice or another tree.

Below, the swirls on this cedar look like drapery.

Pattern of growth on cedar trunk (photo by Kate St. John)

Swirled pattern of growth on cedar trunk (photo by Kate St. John)

 

Evergreens usually lose their lower branches as they grow but the branches on this tree grew stout and curled up.  I can’t even imagine what caused this.

Odd branching on a pine, Mount Desert Island, Maine (photo by Kate St. John)

Odd branches, Mount Desert Island, Maine (photo by Kate St. John)

 

(photos by Kate St. John)

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Jul 27 2016

Alien On The Loose

Asian longhorned beetle animation linked from USDA website

Asian longhorned beetle animation linked from USDA website.

Eeeeewww!  It’s an alien!

I’m not kidding.  This bug is an alien invader from China that hitchhikes as larvae in wooden packing material.  When it gets here it eats trees … lots of them!  If it shows up in your neighborhood it has to be eradicated.  Otherwise your town is doomed.

The Asian longhorned beetle (Anoplophora glabripennis (Motschulsky, 1853)), or ALB, is a very large wood-eating beetle native to China and the Korean peninsula.  Its white-spotted black body is an inch long with antennae 1.5 to 2 times longer than its body.  The antennae are unique, banded black and white.

Because it arrives in infected wood, ALB’s first location in North America is a warehouse. From there it spreads unpredictably, depending on the shipment.  It’s been found in suburbs and cities in New York, New Jersey, Massachusetts, Illinois, Ohio and Ontario.  Click here for the map as of July 2015.

When the beetle gets loose it’s not picky.  Its eats maples, elms, birches, willows, poplars, ashes, hackberries, horsechestnuts, London planetrees … just about anything … but it takes 3-4 years to notice it.  The adults are active late spring until fall so July is a good time of year to see its damage or the bug itself.

And this bug is noticeable. Big and showy, even its larvae (at left) are huge.

Larva and adut Asian longhorned beetle (photos by Joe Boggs, Ohio State University, Bugwood.org)

Larva and adult Asian longhorned beetle (photos by Joe Boggs, Ohio State University, Bugwood.org)

If you don’t see the bug you may see its evidence.

This unusual leaf damage is a hallmark of ALB. They eat the ribs of leaves, not the papery part.

Leaf damage from Asian longhorned beetle (photo byPennsylvania Department of Conservation and Natural Resources - Forestry , Bugwood.org)

Leaf damage from Asian longhorned beetle (photo by PA DCNR, Forestry at Bugwood.org)

Its entrance and exit holes are unique, too.

The female excavates a niche in the bark and lays her eggs in the hole.  Each roughly chewed egg niche is half the size of a dime.

Two egg niches drilled by Asian longhorned beetles (photo by Joe Boggs, Ohio State University, Bugwood.org)

Two egg niches drilled by Asian longhorned beetles (photo by Joe Boggs, Ohio State University, Bugwood.org)

To get out of the tree, the beetle chews a perfect-circle hole as big as a pencil!

Asian longhorned beetle exit holes (photos by Leslie J. Mehrhoff, University of Connecticut and Joe Boggs, Ohio State University, Bugwood.org)

Asian longhorned beetle exit holes (photos by Leslie J. Mehrhoff, University of Connecticut and Joe Boggs, Ohio State University, Bugwood.org)

We can stop ALB if he’s confined to cities but if he gets loose in our forests all bets are off.

So if you see an Asian longhorned beetle or its damage, report it.  There are some look alikes, but USDA wants us to be better safe than sorry.  Call them at 1-866-702-9938 or click here for details.

Report this invader!  Don’t let him take hold!

Adult Asian longhorned beetle in someone's hand (photo by Michael Bohne, Bugwood.org)

Adult Asian longhorned beetle in hand (photo by Michael Bohne, Bugwood.org)

 

Read more about Asian longhorned beetles at USDA’s beetlebusters.info website.

(beetle animation linked from USDA’s website, photos from Bugwood.org)

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Jul 12 2016

Gone But Not Forgotten

Cicada damage on an oak tree (photo by Kate St. John)

Cicada damage on an oak tree (photo by Kate St. John)

After weeks of roaring in late May and June, the 17-year periodical cicadas (Magicicadas, Brood V) are gone but not forgotten.

During the mating frenzy the females used their ovipositors to slit the bark near the ends of twigs and deposit up to 600 eggs per slit. Weeks later the adults are dead but they’ve left their mark on the trees.  The slits killed the leafy branch tips.

Everywhere you go in cicada country the trees are green inside and brown at the tips.  (This is called “flagging.”)

Cicada damage on an oak tree (photo by Kate St. John)

Cicada damage on an oak tree (photo by Kate St. John)

The trees look as if someone has sprayed defoliant on this year’s new growth.  Fortunately that’s not the case!

Cicada damage on an oak tree (photo by Kate St. John)

Cicada damage on an oak tree (photo by Kate St. John)

The trees will be fine.  They have plenty of time to recover before Brood V reappears in 2033.

If you lived through the cicada invasion this summer, you won’t soon forget their roar.

If you missed them, your next big chance near Pittsburgh will be Brood VIII in 2019.

 

(photos by Kate St. John)

4 responses so far

Apr 16 2016

Buds Bursting

Horse chestnut bud bursting, 13 April 2016 (photo by Kate St. John)

Horse chestnut bud bursting, 13 April 2016 (photo by Kate St. John)

Last week’s cold weather was deadly for flowering trees but good for those still in bud.

A hard freeze on April 5 —  23 o F — wiped out the early-blooming trees in Schenley Park.  Most of the eastern redbuds had already flowered so Schenley’s redbud display this year is anemic.

On the other hand, buds that were closed 10 days ago are in good shape now.  On Wednesday I found a horse chestnut bud about to burst (above) and one with leaves and flower stack already emerged (below).

Horse chestnut leaves and flowers stack emerged from bud, 13 April 2016 (photo by Kate St. John)

Horse chestnut leaves and flowers stack emerged from bud, 13 April 2016 (photo by Kate St. John)

 

Even the hickories are getting into the act.

Mockernut hickory bud opening, Schenley Park, 13 April 2016 (photo by Kate St. John)

Mockernut hickory bud opening, Schenley Park, 13 April 2016 (photo by Kate St. John)

 

Check out your neighborhood for emerging leaves and flowers. Buds are opening fast in this weekend’s warm weather.

 

(photos by Kate St. John)

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Apr 13 2016

Pittsburgh’s Redbud Project

Published by under Books & Events,Trees

Redbud blooming (photo by Dianne Machesney)

Redbud blooming (photo by Dianne Machesney)

Imagine that Pittsburgh was as beautiful in the spring as Washington, D.C. during the Cherry Blossom Festival.

That’s the vision that local landscape architect Frank Dawson had when he proposed planting eastern redbud trees along Pittsburgh’s riverfronts.

This spring the dream is starting to come true.

Thanks to a grant from Colcom Foundation, the Western Pennsylvania Conservancy is launching the Pittsburgh Redbud Project.  From now through Spring 2017 they’ll plant 1,200 eastern redbud and other native trees in Downtown Pittsburgh and along the city’s riverfronts.  Everyone who helps through May 12 will get a free seedling. (They’re giving away 1,500 of them!)

Eastern redbuds (Cercis canadensis) are understory trees in the Pea family that bloom in early spring.  Native from southern Pennsylvania to eastern Texas, they’re cultivated for their beauty because their rose-pink flowers open on bare branches before the leaves.

Come to the Redbud Project’s Launch Event on Tuesday, April 19 at 10:00am at the Three Rivers Heritage Trail near the Mister Rogers statue.  Students and volunteers will plant 60 trees along the riverfront.  Attendees get a free redbud seedling.  (Click here for more information, here to RSVP.)

Here’s a planting along River Avenue to give you an idea of the beautiful results.

Redbud trees along River Road, Pittsburgh, April 2016 (photo courtesy Western PA Conservancy)

Redbud trees along River Avenue, Pittsburgh, April 2016 (photo courtesy Western PA Conservancy)

More events and volunteer opportunities are coming in the weeks ahead. Click here for a list.  Get a free tree!

Soon our Downtown and riverfronts will be transformed.

 

(photos: redbud flowers’ closeup by Dianne Machesney. Row of redbud trees on River Avenue, courtesy Western Pennsylvania Conservancy)

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