Sacramento’s status as “City of Trees,” whether celebrated by a water tower or not, is healthy – and so are the city’s trees.
Kevin Hocker, the city’s lead arborist, said Sacramento’s public trees are in great shape despite enduring five years of drought followed by flooding rains and powerful winds this winter that caused a spike in the number of trees his department was forced to cut down.
“We had a relatively low percentage of trees lost during the drought,” Hocker said.
Over the last decade, the city annually lost about 300 trees of its inventory of 100,000 in public parks and right-of-ways, Hocker said. That number jumped to about 500 trees lost over the last 12 months, a mortality rate of 0.5 percent. By comparison, 2 percent of trees are lost annually in a healthy forest environment, Hocker said. A formal count of annual tree mortality will be given to the Sacramento City Council in the fall.
A recent Massachusetts Institute of Technology study bolsters Sacramento’s longstanding City of Trees nickname.
The study used Google Street View images to look at what percentage of streets in 20 selected cities around the world are covered by a tree canopy. Of the 20 cities examined, it found that Sacramento (23.6 percent) trailed Cambridge, Mass. (25.3), Vancouver (25.9) , Sydney (25.9) and Singapore (29.3). Sacramento’s tree canopy exceeded those of Seattle (20.0), Boston (18.2), Los Angeles (15.2), Miami (19.4), New York (13.5) and Paris (8.8), the study found.
Hocker said he read the study methodology and found it to be credible. He was struck by one major takeaway.
“This MIT study shows that we are not neck and neck with Paris. Paris isn’t even in our league,” Hocker said. For decades, Sacramentans have compared our tree canopy to Paris’.
But while there is reason for pride in Sacramento’s urban forest, there are looming questions and a new threat.
Neither the city’s monitoring efforts, nor the MIT study, look at trees on private property, away from roadways. Private trees represent 80 percent of all trees within city limits, Hocker said. He said at present they can’t say much about the health or species of those trees.
The city is reviewing bids to produce a new Urban Forest Master Plan. The process will collect existing studies and create new ones to better understand and support the health of the city’s trees. It will also delve into the city’s tree regulations.
Those regulations will be tested if a new pest menacing trees in Southern California makes its way to Sacramento.
U.S. Forest Service researchers estimate that the polyphagous shot hole borer beetle could kill 27 million trees in Los Angeles, Orange, Riverside and San Bernardino counties, 38 percent of the 71 million trees in that region. The beetle bores tiny holes into the tree, infecting it with a fungus. The beetles have attacked a wide variety of hosts, including oak, sycamore and sweet gum trees.
The beetle has not been spotted locally, but Hocker said they are monitoring what’s happening in Southern California. He said drastic action – like clearing whole neighborhoods – might be needed to stop the aggressive and hard-to-kill pest, if it makes its way here.
Greg McPherson, a supervisory research forester with the U.S. Forest Service, said swift action is needed to prevent massive tree loss.
“We can lose in a matter of years what has taken generations to create,” he warned listeners of KPBS radio in San Diego.
In response to the city’s move to replace the “City of Trees” slogan on Freeport water tower with “American’s Farm-to-Fork Capital,” 3,700 people have signed a change.org petition in protest. The city’s Visit Sacramento tourist arm orchestrated the move in March.
“City Of Trees” isn’t a brand, it’s who we are … it’s home,” writes petition author Kelan Johnson. “Let’s Bring Back Our City of Trees!”