Conifers’ wind-wrought woes renew calls for diverse urban forest in Spokane

One after another, clusters of towering coniferous trees in Comstock Park were unceremoniously swept to the ground, piling up like matchsticks in disarray.

One irony blown in by the brutal windstorm on Jan. 13 was that its arboreal damage was most acutely borne by the trees native to Spokane, those that are meant to thrive here and withstand the Inland Northwest climate.

But the recent gusts topped out at a near-record 71 miles per hour and followed a period of heavy rain and above-freezing January temperatures.

The “perfect storm” hit months after a record October snowfall that wreaked havoc on the city’s deciduous trees, which were still bearing foliage. In the not-too-distant past, a 2015 windstorm brought down hundreds of coniferous trees and caused power outages that lasted nearly a week.

As what were once freak occurrences become seemingly more routine, local leaders and environmentalists hope to prepare the city’s urban forest to withstand whatever climate cataclysms the future holds, while preserving the native species that make the city landscape unique.

This week, the city of Spokane’s Parks Department is still sifting through – and hoping to glean lessons from – the debris.

After an event like the Jan. 13 windstorm, Spokane Parks Department staff, many of whom were around for the 2015 storm, work on “how we can improve our understanding” of the factors at play, according to Garrett Jones, director of Parks and Recreation for the city of Spokane.

City staff and their partners at organizations like The Lands Council look at downed trees and assess not only the species, but its age, the condition of the soil it was in, and the structure of its root ball.

In Comstock Park, where more than dozens of trees fell and forced the park’s temporary closure, the bulk were coniferous, and it appears many were aging.

“We’re already working on a strategy of restoration of bringing in other varieties and also other ages of trees,” Jones said.

Although coniferous trees like the native ponderosa pine took a beating last week, Jones said they’ll continue to be a part of the city’s landscape.

“The ponderosa pine is our city tree and it has a lot of value,” Jones said. “We just want to make sure – any time we have an event whether it’s a storm event or it has a positive or negative impact – we are able to evaluate the lessons learned.”

Ted Hensold is a forester and member of the city’s sustainability action subcommittee, through which he’s part of a work group that’s considering drafting a tree planting plan for the city.

“I’m a real proponent of ponderosa pine,” Hensold said, but he added, “I can understand the concern about that because they are so big, and when they come down they leave such a big shadow of wreckage.”

Experts agree that a diverse urban forest is a healthy one.

“You don’t want a monoculture,” said Spokane City Council Member Lori Kinnear, who joked that she returned to college for a degree in horticulture “instead of getting a sports car for my 40th birthday midlife crisis.”

An urban forest that lacks diversity is susceptible to disease. If a sizable portion of trees are of the same age – as many in Comstock Park were – they can begin to weaken and fail simultaneously.

Though she’s not “a treehugger,” Kinnear spearheaded the adoption of the city’s new urban forestry ordinance in 2019. Among other goals, the ordinance aimed to increase the city’s tree canopy coverage and called for the creation of a new urban forestry plan every five years.

The immediate issue, she said, is not what will be planted in Spokane, but what’s already in the ground.

“The ponderosa pines are here. More importantly, how are we taking care of them?” Kinnear asked. “We should be taking care of what we have.”

Many people don’t prune their ponderosa pines, Kinnear argued, and some should be taken down because they’re sick. She recommended people have their trees assessed by a certified arborist.

“If it’s a hazardous tree, it should go … you don’t make that decision on your own,” Kinnear said.

To Hensold, it might be wise to retire ponderosa pines and similarly imposing conifers when they get to a certain height or age if they pose a risk to the surrounding area.

Water should be a consideration, Hensold noted, both for existing trees and whatever the city hopes to root in the ground in the coming years.

“Will we have the water to maintain an urban canopy that’s composed of non-native trees?” Hensold asked.

On the flip side, many in Spokane are of the belief that the plentiful water in irrigated areas deter deep root growth in ponderosa pines.

Hensold, whose career has mostly been spent in the wild forests of the Spokane Indian Reservation, said the ponderosa pines he’s seen topple in the wind usually snap. Last week, in Spokane, they simply uprooted at the base and fell over.

“I think that ponderosa pine may not be a great choice where you’re going to have turf that you’re watering all the time,” Hensold said.

The Parks Department has already made a concerted effort to better mimic native conditions, Jones noted. In part of Manito Park, areas difficult to irrigate and preserve turf have been returned to wilderness.

But it’s not just winds and snow that forest planners have to contend with. As the weather changes, they worry that insects, such as the pine engraver beetle, will more easily proliferate and damage trees.

They also have to contend with the unstoppable march of time. As trees get older, Hensold noted, many become shaded and lose their lower limbs.

“They’re just way more susceptible to wind,” Hensold said.

In some areas of the city, where the ponderosa pines are younger, the damage appeared less severe, Hensold added. But the South Hill “really got hit, and the South Hill has a lot more old trees.”

Despite their challenges, Jones said the city will not give up on ponderosa pines, Douglas firs and spruces.

Experts will help the Parks Department analyze how trees have been growing over time, the best ways to promote a solid root structure, and ameliorate other potential weaknesses, like exposure to wind, Jones said.

There are certainly “questions out there,” he said, and the “easy answer” might be to move away from conifers.

“That’s not the approach we’re going to take,” Jones said.