The biggest problems Inland Northwest family foresters will deal with in 2025 will all come down to how much rain and snow they get over the winter, a University of Idaho expert says.

“Drought or drought stress of any kind tends to exacerbate any insect or disease issues,” said Chris Schnepf, UI forestry professor and extension educator. “It was a fairly dry summer. We got a little more moisture this fall, so things are looking a little better than they were, but we had a period the last half of the summer through early fall where it was just really dry and the rivers were really low.”

Most insects and diseases are familiar problems, Schnepf said.

Root diseases are “huge,” because forests have more Douglas fir and grand fir today than they did historically.

“You don’t get past that until you change species composition,” Schnepf said.

The species that tend to resist root diseases, such as larch and pine, need more light to successfully regenerate than Douglas fir and grand fir do, he said.

Fire risk is the same, “probably a little bit worse,” Schnepf said.

The fire season is about a month longer than it used to be, he said.

“You’ve got a longer fire season, more climate extremes and there’s still a boatload of fuel out there,” he said.

He used the expression “global climate weirding.”

“You get a month longer growing season, and all of a sudden that starts to shuffle the deck on some of our insect and disease issues,” he said.

Insects, in particular, are highly sensitive to temperature.

The pine engraver beetle, one of the major bark beetle species, famous for breeding in ponderosa pine and lodgepole pine slash, normally has two generations per year in North Idaho.

In recent years, the region has seen three generations, Schnepf said.

“If that becomes the new normal, that changes our management recommendations, to account for that third wave,” he said.

Cydia moths have been killing the tops of sapling larch trees in some plantations, which is “particularly concerning” for foresters battling root disease, as larch is the “No. 1 most tolerant tree of root diseases.”

They were previously found only in Montana, not Idaho, Schnepf said.

“That’s one of the things I’m watching for — insects and diseases behaving differently because of changes in temperature and a longer growing season.”

His biggest recommendations are to have the right tree species for a site, and reduce the stand density.

Family foresters are getting the message, but a reduced market for small-diameter trees presents a challenge.

A mill closed in Plummer, Idaho, over the summer.

“That’s always concerning, because (with) thinning of small trees, you’re not going to make much money with that, which is OK, because the value isn’t the money you get from the mill for bringing in those small trees; it’s the health and growth of your remaining forest,” Schnepf said. “But if there’s not even any market for that, all of a sudden those formerly commercial thinnings become non-commercial. Finding a way to pay for getting all that work done is no small thing.”

Forest Health workshop

Registration is due Dec. 6 for UI Extension’s annual Forest Health program in Coeur d’Alene.

The event is 8:30 a.m. to 4:15 p.m. Dec. 13 at North Idaho College.

The program is eligible for 6 Idaho pesticide license re-certification credits, 6 Idaho Pro-Logger continuing education credits, and five Society of American Foresters continuing forestry education credits.

The program can accommodate up to 100 people. A $26 registration fee covers handouts and refreshments. Registration forms are also available at local University of Idaho Extension Offices.