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May 2017
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Save The Elms Program (STEP) Update
By Jason Sullivan-Halpern, Volunteer Specialist
May 7, 2017
It was a cool yet sunny morning
as our team of volunteer Citizen Scientists for SacTree's Save The Elms Program (STEP)
met at Curtis Park for our first Saturday morning “walkabout” with certified
arborist Dan Pskowski this year. Everyone was wearing their stylish STEP
t-shirts and ready to learn more about American and English elm trees,
identifying the symptoms of Dutch elm disease (DED), and using Greenprint
Maps to report the elm trees with symptoms of the disease. Dan has been an
arborist for 30+ years and spent many of them working with the City of
Sacramento’s Urban Forestry Department, SacTree’s partner on this important
project, to quell the spread of this unwelcome pest across our city, so he
knows more about DED than almost anyone. Given that two of our beloved, mature
public elms near the Sierra 2 Center, a few blocks away, were just confirmed as
having DED and removed by the City, our location and timing couldn’t have been
more perfect.
Dan got us started by telling us a little more about his personal experience
with DED, how it spreads, what its symptoms are, and what’s being done around
the city to stop it’s spreading. He then walked us through his process for
monitoring the elms for DED step-by-step: thoroughly examining the tree from
top to bottom walking around its drip line, looking for yellow wilted leaves
that seem to be localized to certain branches or spreading up the base of the
tree, and eliminating any other issues that may cause similar symptoms – such
as squirrel damage. Squirrels apparently love the elms’ bark, and they chew around the branch until all the tree’s water-conducting vessels (which are
close to the surface) are eventually eaten, causing the leaves to start turning
yellow and die. You can typically follow the branch – with binoculars, if it’s
too high – until you find evidence of the squirrels’ destruction. When the leaves
die due to DED, you won’t see the same damage.
As we walked North through the park, we monitored all the
American and English elms we saw using Greenprint Maps. The binoculars
SacTree provided for our STEP Citizen Scientists this year helped a lot! Having
more eyes on each of our elms helped too. Luckily, we didn’t see any symptoms
of DED on any of those trees. We did, however, see lots of terrific
examples of Asian elms that are DED-resistant though, like the Zelkovas
available from our Sacramento Shade
program, along the way.
As soon as we rounded the corner onto 5th Avenue,
we saw a suspicious-looking elm. Dan and our team immediately walked over to
investigate. While inspecting the tree, we found wilted leaves on one of the
lower branches but not the others, and with no evident cause – a prime
example of how DED looks when it first begins to spread up the tree. Our STEP
Citizen Scientists took photographs of the tree’s symptoms using their mobile
phones and uploaded them to Greenprint Maps right away, marking the tree as
“Monitored for DED (with symptoms)” in the application. The elm’s City Tree ID
Number was referenced in order to alert the City of Sacramento’s Urban Forestry
Department that this particular elm might have DED and it should be tested as soon as
possible. If the City confirms the tree has DED, they can either remove the
infected area or remove the tree entirely to stop the disease from spreading. Early detection of the disease, if confirmed, means there’s a better chance that something can be done to save the
three elms directly beside this one too.
We can’t thank Dan enough for sharing his time and expertise
with all of us. Our STEP Citizen Scientists felt more confident than ever in
their mission to save Sacramento’s elms from DED and are looking forward to
“adopting” and monitoring their own public elms soon. There are likely more elms with DED that need to be discovered! The faster we can find them, the more we can
enjoy our elms’ environmental, social, economic, and psychological benefits for
years to come.
Do you want to get involved in STEP this year? Check out
our next
training for STEP Citizen Scientists on Saturday, May 20 at Breathe
California of Sacramento’s office downtown to get started. Our next walkabout
with Dan is scheduled for the morning of Saturday, June 3. We hope you can join
us!